Marine Drugs

11 pages, 1934 KiB

Open AccessArticle

New Marine Fungal Deoxy-14,15-Dehydroisoaustamide Resensitizes Prostate Cancer Cells to Enzalutamide

by Sergey A. Dyshlovoy, Olesya I. Zhuravleva, Jessica Hauschild, Tobias Busenbender, Dmitry N. Pelageev, Anton N. Yurchenko, Yuliya V. Khudyakova, Alexandr S. Antonov, Markus Graefen, Carsten Bokemeyer and Gunhild von Amsberg

Mar. Drugs 2023, 21(1), 54; https://doi.org/10.3390/md21010054 - 14 Jan 2023

Cited by 1 | Viewed by 2939

Abstract

Marine fungi serve as a valuable source for new bioactive molecules bearing various biological activities. In this study, we report on the isolation of a new indole diketopiperazine alkaloid deoxy-14,15-dehydroisoaustamide (1) from the marine-derived fungus Penicillium dimorphosporum KMM 4689 associated with [...] Read more.

Marine fungi serve as a valuable source for new bioactive molecules bearing various biological activities. In this study, we report on the isolation of a new indole diketopiperazine alkaloid deoxy-14,15-dehydroisoaustamide (1) from the marine-derived fungus Penicillium dimorphosporum KMM 4689 associated with a soft coral. The structure of this metabolite, including its absolute configuration, was determined by HR-MS, 1D and 2D NMR as well as CD data. Compound 1 is a very first deoxyisoaustamide alkaloid possessing two double bonds in the proline ring. The isolated compound was noncytotoxic to a panel of human normal and cancer cell lines up to 100 µM. At the same time, compound 1 resensitized prostate cancer 22Rv1 cells to androgen receptor (AR) blocker enzalutamide. The mechanism of this phenomenon was identified as specific drug-induced degradation of androgen receptor transcription variant V7 (AR-V7), which also resulted in general suppression of AR signaling. Our data suggest that the isolated alkaloid is a promising candidate for combinational therapy of castration resistant prostate cancer, including drug-resistant subtypes. Full article

(This article belongs to the Collection Marine Compounds and Cancer)

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15 pages, 2993 KiB

Open AccessArticle

Limited Metabolomic Overlap between Commensal Bacteria and Marine Sponge Holobionts Revealed by Large Scale Culturing and Mass Spectrometry-Based Metabolomics: An Undergraduate Laboratory Pedagogical Effort at Georgia Tech

by Jessica M. Deutsch, Madison O. Green, Priyanka Akavaram, Ashleigh C. Davis, Sarth S. Diskalkar, Isabelle A. Du Plessis, Hannah A. Fallon, Emma M. Grason, Emma G. Kauf, Zoe M. Kim, Jeffrey R. Miller II, Abby L. Neal, Tatiana Riera, Sofie-Ellen Stroeva, Jollin Tran, Vivi Tran, Azucena Velgara Coronado, Vanessa Velgara Coronado, Benjamin T. Wall, Chung mo Yang, Ipsita Mohanty, Nadine H. Abrahamse, Christopher J. Freeman, Cole G. Easson, Cara L. Fiore, Alison E. Onstine, Naima Djeddar, Shweta Biliya, Anton V. Bryksin, Neha Garg and Vinayak Agarwal Show full author list Hide full author list

Mar. Drugs 2023, 21(1), 53; https://doi.org/10.3390/md21010053 - 14 Jan 2023

Cited by 2 | Viewed by 3311

Abstract

Sponges are the richest source of bioactive organic small molecules, referred to as natural products, in the marine environment. It is well established that laboratory culturing-resistant symbiotic bacteria residing within the eukaryotic sponge host matrix often synthesize the natural products that are detected [...] Read more.

Sponges are the richest source of bioactive organic small molecules, referred to as natural products, in the marine environment. It is well established that laboratory culturing-resistant symbiotic bacteria residing within the eukaryotic sponge host matrix often synthesize the natural products that are detected in the sponge tissue extracts. However, the contributions of the culturing-amenable commensal bacteria that are also associated with the sponge host to the overall metabolome of the sponge holobiont are not well defined. In this study, we cultured a large library of bacteria from three marine sponges commonly found in the Florida Keys. Metabolomes of isolated bacterial strains and that of the sponge holobiont were compared using mass spectrometry to reveal minimal metabolomic overlap between commensal bacteria and the sponge hosts. We also find that the phylogenetic overlap between cultured commensal bacteria and that of the sponge microbiome is minimal. Despite these observations, the commensal bacteria were found to be a rich resource for novel natural product discovery. Mass spectrometry-based metabolomics provided structural insights into these cryptic natural products. Pedagogic innovation in the form of laboratory curricula development is described which provided undergraduate students with hands-on instruction in microbiology and natural product discovery using metabolomic data mining strategies. Full article

(This article belongs to the Special Issue Marine Metabolomics 2023)

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17 pages, 5015 KiB

Open AccessArticle

Echinochrome Prevents Sulfide Catabolism-Associated Chronic Heart Failure after Myocardial Infarction in Mice

by Xiaokang Tang, Akiyuki Nishimura, Kohei Ariyoshi, Kazuhiro Nishiyama, Yuri Kato, Elena A. Vasileva, Natalia P. Mishchenko, Sergey A. Fedoreyev, Valentin A. Stonik, Hyoung-Kyu Kim, Jin Han, Yasunari Kanda, Keitaro Umezawa, Yasuteru Urano, Takaaki Akaike and Motohiro Nishida

Mar. Drugs 2023, 21(1), 52; https://doi.org/10.3390/md21010052 - 12 Jan 2023

Cited by 6 | Viewed by 2873

Abstract

Abnormal sulfide catabolism, especially the accumulation of hydrogen sulfide (H₂S) during hypoxic or inflammatory stresses, is a major cause of redox imbalance-associated cardiac dysfunction. Polyhydroxynaphtoquinone echinochrome A (Ech-A), a natural pigment of marine origin found in the shells and needles of [...] Read more.

Abnormal sulfide catabolism, especially the accumulation of hydrogen sulfide (H₂S) during hypoxic or inflammatory stresses, is a major cause of redox imbalance-associated cardiac dysfunction. Polyhydroxynaphtoquinone echinochrome A (Ech-A), a natural pigment of marine origin found in the shells and needles of many species of sea urchins, is a potent antioxidant and inhibits acute myocardial ferroptosis after ischemia/reperfusion, but the chronic effect of Ech-A on heart failure is unknown. Reactive sulfur species (RSS), which include catenated sulfur atoms, have been revealed as true biomolecules with high redox reactivity required for intracellular energy metabolism and signal transduction. Here, we report that continuous intraperitoneal administration of Ech-A (2.0 mg/kg/day) prevents RSS catabolism-associated chronic heart failure after myocardial infarction (MI) in mice. Ech-A prevented left ventricular (LV) systolic dysfunction and structural remodeling after MI. Fluorescence imaging revealed that intracellular RSS level was reduced after MI, while H₂S/HS⁻ level was increased in LV myocardium, which was attenuated by Ech-A. This result indicates that Ech-A suppresses RSS catabolism to H₂S/HS⁻ in LV myocardium after MI. In addition, Ech-A reduced oxidative stress formation by MI. Ech-A suppressed RSS catabolism caused by hypoxia in neonatal rat cardiomyocytes and human iPS cell-derived cardiomyocytes. Ech-A also suppressed RSS catabolism caused by lipopolysaccharide stimulation in macrophages. Thus, Ech-A has the potential to improve chronic heart failure after MI, in part by preventing sulfide catabolism. Full article

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13 pages, 3832 KiB

Open AccessArticle

Halorotetin A: A Novel Terpenoid Compound Isolated from Ascidian Halocynthia rotetzi Exhibits the Inhibition Activity on Tumor Cell Proliferation

by Jianhui Li, Shanhao Han, Yuting Zhu and Bo Dong

Mar. Drugs 2023, 21(1), 51; https://doi.org/10.3390/md21010051 - 12 Jan 2023

Cited by 3 | Viewed by 2253

Abstract

Halocynthia roretzi, the edible ascidian, has been demonstrated to be an important source of bioactive natural metabolites. Here, we reported a novel terpenoid compound named Halorotetin A that was isolated from tunic ethanol extract of H. roretzi by silica gel column chromatography, [...] Read more.

Halocynthia roretzi, the edible ascidian, has been demonstrated to be an important source of bioactive natural metabolites. Here, we reported a novel terpenoid compound named Halorotetin A that was isolated from tunic ethanol extract of H. roretzi by silica gel column chromatography, preparative layer chromatography (PLC), and semipreparative-HPLC. ¹H and ¹³C NMRs, ¹H-¹H COSY, HSQC, HMBC, NOESY, and HRESIMS profiles revealed that Halorotetin A was a novel terpenoid compound with antitumor potentials. We therefore treated the culture cells with Halorotetin A and found that it significantly inhibited the proliferation of a series of tumor cells by exerting cytotoxicity, especially for the liver carcinoma cell line (HepG-2 cells). Further studies revealed that Halorotetin A affected the expression of several genes associated with the development of hepatocellular carcinoma (HCC), including oncogenes (c-myc and c-met) and HCC suppressor genes (TP53 and KEAP1). In addition, we compared the cytotoxicities of Halorotetin A and doxorubicin on HepG-2 cells. To our surprise, the cytotoxicities of Halorotetin A and doxorubicin on HepG-2 cells were similar at the same concentration and Halorotetin A did not significantly reduce the viability of the normal cells. Thus, our study identified a novel compound that significantly inhibited the proliferation of tumor cells, which provided the basis for the discovery of leading compounds for antitumor drugs. Full article

(This article belongs to the Special Issue Marine Drugs in Cell Signaling Pathways)

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26 pages, 2681 KiB

Open AccessEditor’s ChoiceReview

Secondary Metabolites from Marine-Derived Bacteria with Antibiotic and Antibiofilm Activities against Drug-Resistant Pathogens

by Joko Tri Wibowo, Asep Bayu, Widya Dwi Aryati, Carla Fernandes, Arry Yanuar, Anake Kijjoa and Masteria Yunovilsa Putra

Mar. Drugs 2023, 21(1), 50; https://doi.org/10.3390/md21010050 - 12 Jan 2023

Cited by 8 | Viewed by 3975

Abstract

The search for new antibiotics against drug-resistant microbes has been expanded to marine bacteria. Marine bacteria have been proven to be a prolific source of a myriad of novel compounds with potential biological activities. Therefore, this review highlights novel and bioactive compounds from [...] Read more.

The search for new antibiotics against drug-resistant microbes has been expanded to marine bacteria. Marine bacteria have been proven to be a prolific source of a myriad of novel compounds with potential biological activities. Therefore, this review highlights novel and bioactive compounds from marine bacteria reported during the period of January 2016 to December 2021. Published articles containing novel marine bacterial secondary metabolites that are active against drug-resistant pathogens were collected. Previously described compounds (prior to January 2016) are not included in this review. Unreported compounds during this period that exhibited activity against pathogenic microbes were discussed and compared in order to find the cue of the structure–bioactivity relationship. The results showed that Streptomyces are the most studied bacteria with undescribed bioactive compounds, followed by other genera in the Actinobacteria. We have categorized the structures of the compounds in the present review into four groups, based on their biosynthetic origins, as polyketide derivatives, amino acid derivatives, terpenoids, as well as compounds with mixed origin. These compounds were active against one or more drug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant Enterococci (VRE), multidrug-resistant Mycobacterium tuberculosis (MDR-TB), and amphotericin B-resistant Candida albicans. In addition, some of the compounds also showed activity against biofilm formation of the test bacteria. Some previously undescribed compounds, isolated from marine-derived bacteria during this period, could have a good potential as lead compounds for the development of drug candidates to overcome multidrug-resistant pathogens. Full article

(This article belongs to the Special Issue Pharmaceutical, Nutraceutical, Cosmeceutical and Biotechnological Potentials of Southeast Asian Marine Resources)

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15 pages, 3060 KiB

Open AccessArticle

Characterisation of Bioactive Peptides from Red Alga Gracilariopsis chorda

by Martin Alain Mune Mune, Yoshikatsu Miyabe, Takeshi Shimizu, Wataru Matsui, Yuya Kumagai and Hideki Kishimura

Mar. Drugs 2023, 21(1), 49; https://doi.org/10.3390/md21010049 - 11 Jan 2023

Cited by 6 | Viewed by 2077

Abstract

In this study, we studied the bioactive peptides produced by thermolysin hydrolysis of a water-soluble protein (WSP) from the red alga Gracilariopsis chorda, whose major components are phycobiliproteins and Ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCo). The results showed that WSP hydrolysate exhibited significantly higher ACE [...] Read more.

In this study, we studied the bioactive peptides produced by thermolysin hydrolysis of a water-soluble protein (WSP) from the red alga Gracilariopsis chorda, whose major components are phycobiliproteins and Ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCo). The results showed that WSP hydrolysate exhibited significantly higher ACE inhibitory activity (92% inhibition) compared to DPP-IV inhibitory activity and DPPH scavenging activity. The phycobiliproteins and RuBisCo of G. chorda contain a high proportion of hydrophobic (31.0–46.5%) and aromatic (5.1–46.5%) amino acid residues, which was considered suitable for the formation of peptides with strong ACE inhibitory activity. Therefore, we searched for peptides with strong ACE inhibitory activity and identified two novel peptides (IDHY and LVVER). Then, their interaction with human ACE was evaluated by molecular docking, and IDHY was found to be a promising inhibitor. In silico analysis was then performed on the structural factors affecting ACE inhibitory peptide release, using the predicted 3D structures of phycobiliproteins and RuBisCo. The results showed that most of the ACE inhibitory peptides are located in the highly solvent accessible α-helix. Therefore, it was suggested that G. chorda is a good source of bioactive peptides, especially ACE-inhibitory peptides. Full article

(This article belongs to the Special Issue Marine Bioactive Peptides—Structure, Function, and Application)

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18 pages, 1812 KiB

Open AccessArticle

Characterization and Cytotoxic Activity of Microwave-Assisted Extracted Crude Fucoidans from Different Brown Seaweeds

by Ahmed Zayed, Doris Finkelmeier, Thomas Hahn, Lisa Rebers, Anusriha Shanmugam, Anke Burger-Kentischer and Roland Ulber

Mar. Drugs 2023, 21(1), 48; https://doi.org/10.3390/md21010048 - 11 Jan 2023

Cited by 6 | Viewed by 2068

Abstract

Microwave-assisted extraction (MAE) is recognized as a green method for extraction of natural products. The current research aimed to explore the MAE for fucoidans extraction from different brown seaweeds, including Fucus vesiculosus, F. spiralis, and Laminaria saccharina. Following several solvent-extraction [...] Read more.

Microwave-assisted extraction (MAE) is recognized as a green method for extraction of natural products. The current research aimed to explore the MAE for fucoidans extraction from different brown seaweeds, including Fucus vesiculosus, F. spiralis, and Laminaria saccharina. Following several solvent-extraction pre-treatment steps and MAE optimization, the algal biomasses were extracted in a ratio of 1:25 in 0.1 M HCl containing 2 M CaCl₂ for 1.0 min. The results showed that L. saccharina’s extract was different from the others, regarding the highest sugar content reached 0.47 mg glucose equivalent/mg extract being confirmed by monosaccharide composition analysis and the lowest fucoidan content and sulfation degree at 0.09 mg/mg extract and 0.13, respectively. Moreover, these findings were confirmed by tentative structural elucidation based on Fourier-transform infrared spectrometry which also showed a different spectrum. However, the MAE enhanced melanoidins formation in products, which was confirmed by the intense band at 1420 cm⁻¹. Interestingly, the results of monomeric composition showed that fucoidan extract by MAE from F. vesiculosus belonged to sulfated galactofucans which are known for their potential bioactivities. Furthermore, the cytotoxic activity of the four fucoidans in concentrations ranging from 4.9 µg/mL to 2500 µg/mL was investigated and correlated with the chemical characterization showing that F. vesiculosus_MAE fucoidan was the most potent and safest. The current research revealed the chemical heterogeneity of fucoidans regarding taxonomical class and used greener extraction method of fucoidans toward the achievement of the UN sustainability goals. Full article

(This article belongs to the Special Issue Researches in High-Value Algal Products: From Extraction to Application)

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14 pages, 2570 KiB

Open AccessArticle

Two-Step Enzymolysis of Antarctic Krill for Simultaneous Preparation of Value-Added Oil and Enzymolysate

by Xin-Nan Teng, Shu-Chang Wang, Liaqat Zeb, Yue-Sheng Dong and Zhi-Long Xiu

Mar. Drugs 2023, 21(1), 47; https://doi.org/10.3390/md21010047 - 11 Jan 2023

Cited by 2 | Viewed by 1766

Abstract

Antarctic krill is a crucial marine resource containing plenty of high-valued nutrients. However, krill oil as a single product has been developed by the current solvent extraction with high cost. From the perspective of comprehensive utilization of Antarctic krill, this study proposed a [...] Read more.

Antarctic krill is a crucial marine resource containing plenty of high-valued nutrients. However, krill oil as a single product has been developed by the current solvent extraction with high cost. From the perspective of comprehensive utilization of Antarctic krill, this study proposed a novel two-step enzymolysis-assisted extraction in attempt to produce value-added oil and enzymolysate simultaneously. After two-step chitinase/protease hydrolysis, the lipid yield increased from 2.09% to 4.18%, reaching 112% of Soxhlet extraction. The method greatly improved the yields of main components while reducing the impurity content without further refining. After optimization, the oil contained 246.05 mg/g of phospholipid, 80.96 mg/g of free eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and 0.82 mg/g of astaxanthin. The by-product enzymolysate was abundant in water-soluble proteins (34.35 mg/g), oligopeptides (13.92 mg/g), amino acids (34.24 mg/g), and carbohydrates (5.79 mg/g), which was a good source of functional nutrients. In addition, both oil and enzymolysate showed high antioxidant capacity. This novel method could simultaneously provide oil and enzymolysate amounting for 58.61% of dried krill. Full article

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13 pages, 2272 KiB

Open AccessArticle

Identification of Anhydrodebromoaplysiatoxin as a Dichotomic Autophagy Inhibitor

by Limin Feng, Chung-Kuang Lu, Jiajun Wu, Leo Lai Chan and Jianbo Yue

Mar. Drugs 2023, 21(1), 46; https://doi.org/10.3390/md21010046 - 10 Jan 2023

Cited by 2 | Viewed by 1595

Abstract

Dysfunctional autophagy is associated with various human diseases, e.g., cancer. The discovery of small molecules modulating autophagy with therapeutic potential could be significant. To this end, we screened the ability of a series of metabolites isolated from marine microorganisms to modulate autophagy. Anhydrodebromoaplysiatoxin [...] Read more.

Dysfunctional autophagy is associated with various human diseases, e.g., cancer. The discovery of small molecules modulating autophagy with therapeutic potential could be significant. To this end, we screened the ability of a series of metabolites isolated from marine microorganisms to modulate autophagy. Anhydrodebromoaplysiatoxin (ADAT), a metabolite yielded by the marine red algae Gracilaria coronopifolia, inhibited autophagosome-lysosome fusion in mammalian cells, thereby inducing the accumulation of autophagosomes. Treatment of cells with ADAT alkalinized lysosomal pH. Interestingly, ADAT also activated the mTOR/p70S6K/FoxO3a signaling pathway, likely leading to the inhibition of autophagy induction. ADAT had little effect on apoptosis. Our results suggest that ADAT is a dichotomic autophagy inhibitor that inhibits both late-stage (autophagosome-lysosome fusion) and early-stage (autophagy induction) autophagy. Full article

(This article belongs to the Special Issue Bioactive Products from Marine Cyanobacteria and Their Potential Therapeutic Applications 2022)

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19 pages, 3968 KiB

Open AccessArticle

Probiotic Potential of the Marine Isolate Enterococcus faecium EA9 and In Vivo Evaluation of Its Antisepsis Action in Rats

by Eman H. Zaghloul, Hatem M. Abuohashish, Amany S. El Sharkawy, Eman M. Abbas, Mohammed M. Ahmed and Salim S. Al-Rejaie

Mar. Drugs 2023, 21(1), 45; https://doi.org/10.3390/md21010045 - 07 Jan 2023

Cited by 4 | Viewed by 2120

Abstract

This study aims to obtain a novel probiotic strain adapted to marine habitats and to assess its antisepsis properties using a cecal ligation and puncture (CLP) model in rodents. The marine Enterococcus faecium EA9 was isolated from marine shrimp samples and evaluated for [...] Read more.

This study aims to obtain a novel probiotic strain adapted to marine habitats and to assess its antisepsis properties using a cecal ligation and puncture (CLP) model in rodents. The marine Enterococcus faecium EA9 was isolated from marine shrimp samples and evaluated for probiotic potential after phenotypical and molecular identification. In septic animals, hepatic and renal tissues were histologically and biochemically evaluated for inflammation and oxidative stress following the probiotic treatment. Moreover, gene expressions of multiple signaling cascades were determined using RT-PCR. EA9 was identified and genotyped as Enterococcus faecium with a 99.88% identity. EA9 did not exhibit any signs of hemolysis and survived at low pH and elevated concentrations of bile salts. Moreover, EA9 isolate had antibacterial activity against different pathogenic bacteria and could thrive in 6.5% NaCl. Septic animals treated with EA9 had improved liver and kidney functions, lower inflammatory and lipid peroxidation biomarkers, and enhanced antioxidant enzymes. The CLP-induced necrotic histological changes and altered gene expressions of IL-10, IL-1β, INF-γ, COX-2, SOD-1, SOD-2, HO-1, AKT, mTOR, iNOS, and STAT-3 were abolished by the EA9 probiotic in septic animals. The isolate Enterococcus faecium EA9 represents a promising marine probiotic. The in vivo antisepsis testing of EA9 highlighted its potential and effective therapeutic approach. Full article

(This article belongs to the Special Issue Marine Bioactive Compounds against Oxidative Stress and Inflammation)

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21 pages, 6435 KiB

Open AccessArticle

Paralytic Shellfish Toxins in the Gastropod Concholepas concholepas: Variability, Toxin Profiles and Mechanisms for Toxicity Reduction

by Miriam Seguel, Carlos Molinet, Manuel Díaz, Gonzalo Álvarez, Carlos García, Andrés Marín, María Olga Millanao and Patricio A. Díaz

Mar. Drugs 2023, 21(1), 44; https://doi.org/10.3390/md21010044 - 06 Jan 2023

Viewed by 2473

Abstract

Harmful algal blooms of toxin-producing microalgae are recurrent in southern Chile. Paralytic shellfish poisoning (PSP) outbreaks pose the main threat to public health and the fishing industry in the Patagonian fjords. This study aims to increase understanding of the individual and spatial variability [...] Read more.

Harmful algal blooms of toxin-producing microalgae are recurrent in southern Chile. Paralytic shellfish poisoning (PSP) outbreaks pose the main threat to public health and the fishing industry in the Patagonian fjords. This study aims to increase understanding of the individual and spatial variability of PSP toxicity in the foot of Concholepas concholepas, Chile’s most valuable commercial benthic invertebrate species, extracted from the Guaitecas Archipelago in Chilean Patagonia. The objective is to determine the effect of pigment removal and freezing during the detoxification process. A total of 150 specimens (≥90 mm length) were collected from this area. The live specimens were transferred to a processing plant, where they were measured and gutted, the foot was divided into two equal parts, and pigment was manually removed from one of these parts. The PSP toxicity of each foot (edible tissue) was determined by mouse bioassay (MBA) and high-performance liquid chromatography with fluorescence detection and postcolumn oxidation (HPLC-FLD PCOX). The individual toxicity per loco, as the species is known locally, varied from <30 to 146 μg STX diHCL eq 100 g⁻¹ (CV = 43.83%) and from 5.96 to 216.3 μg STX diHCL eq 100 g⁻¹ (CV = 34.63%), using MBA and HPLC, respectively. A generalized linear model showed a negative relation between individual weight and toxicity. The toxicological profile showed a dominance of STX (>95%), neoSTX and GTX2. The removal of pigment produced a reduction in PSP toxicity of up to 90% and could represent a good detoxification tool moving forward. The freezing process in the muscle with pigment did not produce a clear pattern. There is a significant reduction (p < 0.05) of PSP toxicity via PCOX but not MBA. Furthermore, the study discusses possible management and commercialization implications of the findings regarding small-scale fisheries. Full article

(This article belongs to the Special Issue Novel Methods for Marine Toxins Detection and Quantification 2.0)

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25 pages, 2967 KiB

Open AccessReview

Application of Marine Natural Products against Alzheimer’s Disease: Past, Present and Future

by Di Hu, Yating Jin, Xiangqi Hou, Yinlong Zhu, Danting Chen, Jingjing Tai, Qianqian Chen, Cui Shi, Jing Ye, Mengxu Wu, Hong Zhang and Yanbin Lu

Mar. Drugs 2023, 21(1), 43; https://doi.org/10.3390/md21010043 - 05 Jan 2023

Cited by 8 | Viewed by 4968

Abstract

Alzheimer’s disease (AD), a neurodegenerative disease, is one of the most intractable illnesses which affects the elderly. Clinically manifested as various impairments in memory, language, cognition, visuospatial skills, executive function, etc., the symptoms gradually aggravated over time. The drugs currently used clinically can [...] Read more.

Alzheimer’s disease (AD), a neurodegenerative disease, is one of the most intractable illnesses which affects the elderly. Clinically manifested as various impairments in memory, language, cognition, visuospatial skills, executive function, etc., the symptoms gradually aggravated over time. The drugs currently used clinically can slow down the deterioration of AD and relieve symptoms but cannot completely cure them. The drugs are mainly acetylcholinesterase inhibitors (AChEI) and non-competitive N-methyl-D-aspartate receptor (NDMAR) antagonists. The pathogenesis of AD is inconclusive, but it is often associated with the expression of beta-amyloid. Abnormal deposition of amyloid and hyperphosphorylation of tau protein in the brain have been key targets for past, current, and future drug development for the disease. At present, researchers are paying more and more attention to excavate natural compounds which can be effective against Alzheimer’s disease and other neurodegenerative pathologies. Marine natural products have been demonstrated to be the most prospective candidates of these compounds, and some have presented significant neuroprotection functions. Consequently, we intend to describe the potential effect of bioactive compounds derived from marine organisms, including polysaccharides, carotenoids, polyphenols, sterols and alkaloids as drug candidates, to further discover novel and efficacious drug compounds which are effective against AD. Full article

(This article belongs to the Special Issue Anti-Alzheimer Agents from Marine Sources)

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14 pages, 1276 KiB

Open AccessArticle

The Polysaccharidic Nature of the Skeleton of Marennine as Determined by NMR Spectroscopy

by Ilhem Zebiri, Boris Jacquette, Nellie Francezon, Mickaël Herbaut, Amina Latigui, Sullivan Bricaud, Réjean Tremblay, Pamela Pasetto, Jean-Luc Mouget and Jens Dittmer

Mar. Drugs 2023, 21(1), 42; https://doi.org/10.3390/md21010042 - 04 Jan 2023

Cited by 5 | Viewed by 1641

Abstract

The water-soluble blue–green pigment marennine, produced and partly excreted by the diatom Haslea ostrearia, and known for a long time for its role in the greening of oysters, was isolated from the culture medium, purified, and analyzed by Nuclear Magnetic Resonance (NMR) [...] Read more.

The water-soluble blue–green pigment marennine, produced and partly excreted by the diatom Haslea ostrearia, and known for a long time for its role in the greening of oysters, was isolated from the culture medium, purified, and analyzed by Nuclear Magnetic Resonance (NMR) in order to gain insight into its chemical structure. The spectra show mainly carbohydrates of a complex composition, apparently highly branched, and with a mass in the order of 10 kDa. There are, in addition, some signals of aliphatic and, much weaker, aromatic groups that present aglycons. The latter might be responsible for the color. These carbohydrates are always associated with the blue–green color and cannot be separated from it by most treatments; they are interpreted as constituting the frame of the pigment. NMR after hydrolysis identifies the most abundant monosaccharides in marennine as galactose, xylose, mannose, rhamnose, and fucose. Full article

(This article belongs to the Special Issue Marine Pigments)

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11 pages, 1080 KiB

Open AccessArticle

Type-I Hemins and Free Porphyrins from a Western Australian Sponge Isabela sp.

by Samuele Sala, Stephen A. Moggach, Gareth L. Nealon, Jane Fromont, Oliver Gomez, Daniel Vuong, Ernest Lacey and Gavin R. Flematti

Mar. Drugs 2023, 21(1), 41; https://doi.org/10.3390/md21010041 - 03 Jan 2023

Cited by 3 | Viewed by 2088

Abstract

Two novel free porphyrins, isabellins A and B, as well as the known compounds corallistin D and deuteroporphyrin IX were isolated from a marine sponge Isabela sp. LC-MS analysis of the crude extract revealed that the natural products were present both as free [...] Read more.

Two novel free porphyrins, isabellins A and B, as well as the known compounds corallistin D and deuteroporphyrin IX were isolated from a marine sponge Isabela sp. LC-MS analysis of the crude extract revealed that the natural products were present both as free porphyrins and iron(III) coordinated hemins, designated isabellihemin A, isabellihemin B, corallistihemin D and deuterohemin IX, respectively. Structures were determined via high-resolution mass spectrometry, UV-Vis spectroscopy and extensive NOESY NMR spectroscopic experiments. The type-I alkyl substitution pattern of isabellin A and isabellihemin A was assigned unambiguously by single crystal X-ray diffraction. Biological evaluation of the metabolites revealed potent cytotoxicity for isabellin A against the NS-1 murine myeloma cell line. Full article

(This article belongs to the Special Issue Marine Natural Products as Anticancer Agents 2.0)

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15 pages, 3656 KiB

Open AccessReview

A Concise Review on the Potential Applications of Rugulopteryx okamurae Macroalgae

by Ligia Barcellos, Christopher K. Pham, Gui Menezes, Raúl Bettencourt, Nieta Rocha, Miguel Carvalho and Helena P. Felgueiras

Mar. Drugs 2023, 21(1), 40; https://doi.org/10.3390/md21010040 - 03 Jan 2023

Cited by 8 | Viewed by 3328

Abstract

The brown macroalgae of the species Rugulopteryx okamurae has reached European waters and the Strait of Gibraltar as an invasive species. The proliferation and colonization of the species in subtidal and intertidal zones of these regions imposes significant threats to local ecosystems and [...] Read more.

The brown macroalgae of the species Rugulopteryx okamurae has reached European waters and the Strait of Gibraltar as an invasive species. The proliferation and colonization of the species in subtidal and intertidal zones of these regions imposes significant threats to local ecosystems and additionally represents a significant socioeconomic burden related to the large amounts of biomass accumulated as waste. As a way to minimize the effects caused by the accumulation of algae biomass, investigations have been made to employ this biomass as a raw material in value-added products or technologies. The present review explores the potential uses of R. okamurae, focusing on its impact for biogas production, composting, bioplastic and pharmaceutical purposes, with potential anti-inflammatory, antibacterial and

α

-glucosity inhibitory activities being highlighted. Overall, this species appears to present many attributes, with remarkable potential for uses in several fields of research and in various industries. Full article

(This article belongs to the Special Issue High-Value Products from Seaweeds: Medical, Cosmetic, and Biotechnological Applications)

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19 pages, 2110 KiB

Open AccessArticle

N-3 PUFA Deficiency Aggravates Streptozotocin-Induced Pancreatic Injury in Mice but Dietary Supplementation with DHA/EPA Protects the Pancreas via Suppressing Inflammation, Oxidative Stress and Apoptosis

by Hong-Yu Zou, Hui-Juan Zhang, Ying-Cai Zhao, Xiao-Yue Li, Yu-Ming Wang, Tian-Tian Zhang and Chang-Hu Xue

Mar. Drugs 2023, 21(1), 39; https://doi.org/10.3390/md21010039 - 01 Jan 2023

Cited by 6 | Viewed by 2025

Abstract

It has been reported that dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) exert therapeutic potential for the preservation of functional β-cell mass. However, the effect of dietary n-3 PUFA deficiency on pancreatic injury and whether the supplementation of n-3 PUFA could prevent the [...] Read more.

It has been reported that dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) exert therapeutic potential for the preservation of functional β-cell mass. However, the effect of dietary n-3 PUFA deficiency on pancreatic injury and whether the supplementation of n-3 PUFA could prevent the development of pancreatic injury are still not clear. In the present study, an n-3 PUFA deficiency mouse model was established by feeding them with n-3 PUFA deficiency diets for 30 days. Results showed that n-3 PUFA deficiency aggravated streptozotocin (STZ)-induced pancreas injury by reducing the insulin level by 18.21% and the HOMA β-cell indices by 31.13% and the area of islet by 52.58% compared with the STZ group. Moreover, pre-intervention with DHA and EPA for 15 days could alleviate STZ-induced pancreas damage by increasing the insulin level by 55.26% and 44.33%, the HOMA β-cell indices by 118.81% and 157.26% and reversed the area of islet by 196.75% and 205.57% compared to the n-3 Def group, and the effects were significant compared to γ-linolenic acid (GLA) and alpha-linolenic acid (ALA) treatment. The possible underlying mechanisms indicated that EPA and DHA significantly reduced the ration of n-6 PUFA to n-3 PUFA and then inhibited oxidative stress, inflammation and islet β-cell apoptosis levels in pancreas tissue. The results might provide insights into the prevention and alleviation of pancreas injury by dietary intervention with PUFAs and provide a theoretical basis for their application in functional foods. Full article

(This article belongs to the Special Issue Marine Fish Oils as Functional Foods)

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14 pages, 917 KiB

Open AccessReview

Effect of the Marine Polyketide Plocabulin on Tumor Progression

by Eleonora Turrini, Francesca Maffei and Carmela Fimognari

Mar. Drugs 2023, 21(1), 38; https://doi.org/10.3390/md21010038 - 31 Dec 2022

Cited by 2 | Viewed by 1660

Abstract

Marine sponges represent one of the richest sources of natural marine compounds with anticancer potential. Plocabulin (PM060184), a polyketide originally isolated from the sponge Lithoplocamia lithistoides, elicits its main anticancer properties binding tubulin, which still represents one of the most important targets [...] Read more.

Marine sponges represent one of the richest sources of natural marine compounds with anticancer potential. Plocabulin (PM060184), a polyketide originally isolated from the sponge Lithoplocamia lithistoides, elicits its main anticancer properties binding tubulin, which still represents one of the most important targets for anticancer drugs. Plocabulin showed potent antitumor activity, in both in vitro and in vivo models of different types of cancers, mediated not only by its antitubulin activity, but also by its ability to block endothelial cell migration and invasion. The objective of this review is to offer a description of plocabulin’s mechanisms of action, with special emphasis on the antiangiogenic signals and the latest progress on its development as an anticancer agent. Full article

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23 pages, 6346 KiB

Open AccessReview

Recent Advances in Biologically Active Coumarins from Marine Sources: Synthesis and Evaluation

by Laura Fernández-Peña, Maria João Matos and Enol López

Mar. Drugs 2023, 21(1), 37; https://doi.org/10.3390/md21010037 - 31 Dec 2022

Cited by 7 | Viewed by 2411

Abstract

Coumarin and its derivatives have significantly attracted the attention of medicinal chemists and chemical biologists due to their huge range of biological, and in particular, pharmacological properties. Interesting families of coumarins have been found from marine sources, which has accelerated the drug discovery [...] Read more.

Coumarin and its derivatives have significantly attracted the attention of medicinal chemists and chemical biologists due to their huge range of biological, and in particular, pharmacological properties. Interesting families of coumarins have been found from marine sources, which has accelerated the drug discovery process by inspiring innovation or even by the identification of analogues with remarkable biological properties. The purpose of this review is to showcase the most interesting marine-derived coumarins from a medicinal chemistry point of view, as well as the novel and useful synthetic routes described to date to achieve these chemical structures. The references that compose this overview were collected from PubMed, Mendeley and SciFinder. Full article

(This article belongs to the Special Issue Heterocyclic Compounds from Marine Organisms 2.0)

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21 pages, 3394 KiB

Open AccessArticle

FTIR Characterization of Sulfated Polysaccharides Obtained from Macrocystis integrifolia Algae and Verification of Their Antiangiogenic and Immunomodulatory Potency In Vitro and In Vivo

by Marilú Roxana Soto-Vásquez, Paúl Alan Arkin Alvarado-García, Fadia S. Youssef, Mohamed L. Ashour, Hanin A. Bogari and Sameh S. Elhady

Mar. Drugs 2023, 21(1), 36; https://doi.org/10.3390/md21010036 - 31 Dec 2022

Cited by 3 | Viewed by 2764

Abstract

The aim of this study was to evaluate the antiangiogenic and immunomodulatory potential of sulfated polysaccharides from the marine algae Macrocystis integrifolia characterized by FTIR. The cytotoxicity of sulfated polysaccharides was evaluated using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay. Antiangiogenic activity was evaluated [...] Read more.

The aim of this study was to evaluate the antiangiogenic and immunomodulatory potential of sulfated polysaccharides from the marine algae Macrocystis integrifolia characterized by FTIR. The cytotoxicity of sulfated polysaccharides was evaluated using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay. Antiangiogenic activity was evaluated using the chicken chorioallantoic membrane (CAM) assay. Immunomodulatory activity was determined on macrophage functionality and allergic response. The results showed that sulfated polysaccharides significantly decreased angiogenesis in chicken chorioallantoic membranes (p < 0.05). Likewise, they inhibited in vivo chemotaxis and in vitro phagocytosis, the transcription process of genes that code the enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and nitric oxide synthase-2 (NOS-2) and the nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), showing immunomodulatory properties on the allergic response, as well as an in vivo inhibitory effect in the ovalbumin-induced inflammatory allergy model (OVA) and inhibited lymphocyte proliferation specific to the OVA antigen in immunized mice. Finally, these compounds inhibited the histamine-induced skin reaction in rats, the production of immunoglobulin E (IgE) in mice, and the passive response to skin anaphylaxis in rats. Therefore, the results of this research showed the potential of these compounds to be a promising source for the development of antiangiogenic and immunomodulatory drugs. Full article

(This article belongs to the Special Issue Bioactive Polysaccharides from Seaweeds)

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19 pages, 2321 KiB

Open AccessArticle

Bio-Guided Optimization of Cystoseira abies-marina Cosmeceuticals Extraction by Advanced Technologies

by Gonçalo P. Rosa, Andreia F. Peixoto, Maria Carmo Barreto, Ana M. L. Seca and Diana C. G. A. Pinto

Mar. Drugs 2023, 21(1), 35; https://doi.org/10.3390/md21010035 - 31 Dec 2022

Cited by 2 | Viewed by 1651

Abstract

Cystoseira abies-marina (reclassified as Gongolaria abies-marina) is a brown seaweed species rich in meroterpenoids, presenting interesting antioxidant, antitumor, and anti-inflammatory activities. However, there is still a lot to uncover regarding the bioactive potential of this species, as evidenced by the lack of [...] Read more.

Cystoseira abies-marina (reclassified as Gongolaria abies-marina) is a brown seaweed species rich in meroterpenoids, presenting interesting antioxidant, antitumor, and anti-inflammatory activities. However, there is still a lot to uncover regarding the bioactive potential of this species, as evidenced by the lack of records of antiaging activities from Cystoseira abies-marina, making this macroalga an excellent candidate for studies of its cosmeceutical potential. Ultrasound-(UAE) and microwave-assisted extraction (MAE) are advanced sustainable technologies that are very efficient in enhancing bioactive compound extraction. Applying these extraction techniques to a new biological matrix often calls for optimizing the parameters toward the best extraction yield. Since Cystoseira abies-marina is a new matrix for both UAE and MAE techniques, the present work proposes the optimization of the extraction process, using a novel approach: instead of only focusing on increasing the yield, the goal of this work is to determine the parameters for UAE and MAE that lead to extracts with better antiaging activities. For this bio-guided approach, several Cystoseira abies-marina extracts were prepared by UAE and MAE under varying conditions of solvent, time, and algae/solvent ratios. Their antiaging activities were then determined, and all the results combined to unveil the conditions yielding extracts with higher cosmeceutical potential. Using statistical tools, it was found that, for UAE, the best conditions were ethyl acetate, 15 min, and a ratio of 1:4, which led to an extract with high yield, and causing the strong inhibition of tyrosinase and elastase. In turn, ethanol, 10 min, and a ratio of 1:4 were the best conditions for MAE, leading to the extract with the best antioxidant activity. The results show that the proposed bio-guided approach was effective in obtaining extracts with high cosmeceutical potential, unveiling the possibility of modulating an extract’s activity by changing the extraction method. Full article

(This article belongs to the Special Issue Green Extraction and Fermentation Processes for Obtaining Marine Bioactive Products)

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28 pages, 6086 KiB

Open AccessEditor’s ChoiceArticle

Marine Sponge and Octocoral-Associated Bacteria Show Versatile Secondary Metabolite Biosynthesis Potential and Antimicrobial Activities against Human Pathogens

by João F. Almeida, Matilde Marques, Vanessa Oliveira, Conceição Egas, Dalila Mil-Homens, Romeu Viana, Daniel F. R. Cleary, Yusheng M. Huang, Arsénio M. Fialho, Miguel C. Teixeira, Newton C. M. Gomes, Rodrigo Costa and Tina Keller-Costa

Mar. Drugs 2023, 21(1), 34; https://doi.org/10.3390/md21010034 - 30 Dec 2022

Cited by 5 | Viewed by 4319

Abstract

Marine microbiomes are prolific sources of bioactive natural products of potential pharmaceutical value. This study inspected two culture collections comprising 919 host-associated marine bacteria belonging to 55 genera and several thus-far unclassified lineages to identify isolates with potentially rich secondary metabolism and antimicrobial [...] Read more.

Marine microbiomes are prolific sources of bioactive natural products of potential pharmaceutical value. This study inspected two culture collections comprising 919 host-associated marine bacteria belonging to 55 genera and several thus-far unclassified lineages to identify isolates with potentially rich secondary metabolism and antimicrobial activities. Seventy representative isolates had their genomes mined for secondary metabolite biosynthetic gene clusters (SM-BGCs) and were screened for antimicrobial activities against four pathogenic bacteria and five pathogenic Candida strains. In total, 466 SM-BGCs were identified, with antimicrobial peptide- and polyketide synthase-related SM-BGCs being frequently detected. Only 38 SM-BGCs had similarities greater than 70% to SM-BGCs encoding known compounds, highlighting the potential biosynthetic novelty encoded by these genomes. Cross-streak assays showed that 33 of the 70 genome-sequenced isolates were active against at least one Candida species, while 44 isolates showed activity against at least one bacterial pathogen. Taxon-specific differences in antimicrobial activity among isolates suggested distinct molecules involved in antagonism against bacterial versus Candida pathogens. The here reported culture collections and genome-sequenced isolates constitute a valuable resource of understudied marine bacteria displaying antimicrobial activities and potential for the biosynthesis of novel secondary metabolites, holding promise for a future sustainable production of marine drug leads. Full article

(This article belongs to the Special Issue Reef Ecology and Marine Drug Discovery)

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18 pages, 3108 KiB

Open AccessArticle

Effect of Phlorotannins from Brown Algae Costaria costata on α-N-Acetylgalactosaminidase Produced by Duodenal Adenocarcinoma and Melanoma Cells

by Irina Bakunina, Tatiana Imbs, Galina Likhatskaya, Valeria Grigorchuk, Anastasya Zueva, Olesya Malyarenko and Svetlana Ermakova

Mar. Drugs 2023, 21(1), 33; https://doi.org/10.3390/md21010033 - 30 Dec 2022

Cited by 2 | Viewed by 1445

Abstract

The inhibitor of human α-N-acetylgalactosaminidase (α-NaGalase) was isolated from a water–ethanol extract of the brown algae Costaria costata. Currently, tumor α-NaGalase is considered to be a therapeutic target in the treatment of cancer. According to NMR spectroscopy and mass spectrometric analysis, it [...] Read more.

The inhibitor of human α-N-acetylgalactosaminidase (α-NaGalase) was isolated from a water–ethanol extract of the brown algae Costaria costata. Currently, tumor α-NaGalase is considered to be a therapeutic target in the treatment of cancer. According to NMR spectroscopy and mass spectrometric analysis, it is a high-molecular-weight fraction of phlorethols with a degree of polymerization (DP) equaling 11–23 phloroglucinols (CcPh). It was shown that CcPh is a direct inhibitor of α-NaGalases isolated from HuTu 80 and SK-MEL-28 cells (IC₅₀ 0.14 ± 0.008 and 0.12 ± 0.004 mg/mL, respectively) and reduces the activity of this enzyme in HuTu 80 and SK-MEL-28 cells up to 50% at concentrations of 15.2 ± 9.5 and 5.7 ± 1.6 μg/mL, respectively. Molecular docking of the putative DP-15 oligophlorethol (P15OPh) and heptaphlorethol (PHPh) with human α-NaGalase (PDB ID 4DO4) showed that this compound forms a complex and interacts directly with the Asp 156 and Asp 217 catalytic residues of the enzyme in question. Thus, brown algae phlorethol CcPh is an effective marine-based natural inhibitor of the α-NaGalase of cancer cells and, therefore, has high therapeutic potential. Full article

(This article belongs to the Special Issue Enzyme Inhibitors from Marine Resources)

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11 pages, 2105 KiB

Open AccessArticle

New Chlorinated Metabolites and Antiproliferative Polyketone from the Mangrove Sediments-Derived Fungus Mollisia sp. SCSIO41409

by Jian Cai, Xueni Wang, Xia Gan, Qian Zhou, Xiaowei Luo, Bin Yang, Yonghong Liu, Disna Ratnasekera and Xuefeng Zhou

Mar. Drugs 2023, 21(1), 32; https://doi.org/10.3390/md21010032 - 30 Dec 2022

Cited by 9 | Viewed by 2021

Abstract

Two new chlorinated metabolites, 8-chlorine-5-hydroxy-2,3-dimethyl-7-methoxychromone (1) and 3,4-dichloro-1H-pyrrole-2,5-dione (3), and eight known compounds (2 and 4–9) were isolated from the mangrove sediments-derived fungus Mollisia sp. SCSIO41409. Their structures were elucidated by physicochemical properties [...] Read more.

Two new chlorinated metabolites, 8-chlorine-5-hydroxy-2,3-dimethyl-7-methoxychromone (1) and 3,4-dichloro-1H-pyrrole-2,5-dione (3), and eight known compounds (2 and 4–9) were isolated from the mangrove sediments-derived fungus Mollisia sp. SCSIO41409. Their structures were elucidated by physicochemical properties and extensive spectroscopic analysis. The absolute configuration of stemphone C (4) was established for the first time by the X-ray crystallographic analysis. Compounds 3 and 4 showed different intensity of antimicrobial activities against several pathogenic fungi and bacteria, and antiproliferative activities against two human prostate cancer cell lines (IC₅₀ values 2.77 to 9.60 μM). Further, stemphone C (4) showed a reducing PC-3 cell colony formation, inducing apoptosis and blocking the cell cycle at S-phase in a dose-dependent manner; thus, it could be considered as a potential antiproliferative agent and a promising anti-prostate cancer lead compound. Full article

(This article belongs to the Special Issue Bio-Active Products from Mangrove Ecosystems)

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14 pages, 6073 KiB

Open AccessArticle

Description and Genomic Characterization of Oceaniferula flavus sp. nov., a Novel Potential Polysaccharide-Degrading Candidate of the Difficult-to-Cultivate Phylum Verrucomicrobiota Isolated from Seaweed

by Meng-Qi Ye, Chuan-Bo Jin, Xin-Jiang Liu, Xin-Yun Tan, Yu-Qi Ye and Zong-Jun Du

Mar. Drugs 2023, 21(1), 31; https://doi.org/10.3390/md21010031 - 29 Dec 2022

Cited by 1 | Viewed by 1818

Abstract

A novel strain, isolate 5K15^T, which belongs to difficult-to-cultivate phylum Verrucomicrobiota, was recovered from kelp collected from Li Island, Rongcheng, China. The genome sequence of the strain (genome size 3.95 Mbp) showed the presence of four putative biosynthetic gene clusters [...] Read more.

A novel strain, isolate 5K15^T, which belongs to difficult-to-cultivate phylum Verrucomicrobiota, was recovered from kelp collected from Li Island, Rongcheng, China. The genome sequence of the strain (genome size 3.95 Mbp) showed the presence of four putative biosynthetic gene clusters (BGCs), namely, two terpene biosynthetic gene clusters, one aryl polyene biosynthetic cluster, and one type III PKS cluster. Genomic analysis revealed 79 sulfatase-encoded genes, 24 sulfatase-like hydrolase/transferase-encoded genes, and 25 arylsulfatase-encoded genes, which indicated the great potential of 5K15^T to degrade sulfated polysaccharides. Comparative analysis of 16S rRNA gene sequence showed that the novel strain was most closely related to Oceaniferula marina N1E253^T (96.4%). On the basis of evidence from a polyphasic study, it is proposed that the strain 5K15^T (= KCTC 82748^T = MCCC 1H00442^T = SDUM 810003^T) be classified as Oceaniferula flavus sp. nov. The strain has the ability of carbohydrate transport and metabolism. This ability allows it to survive in carbohydrate-rich materials such as kelp. It has the potential to be used in the marine drug industry using seaweed. Full article

(This article belongs to the Special Issue Genomic Studies on Marine Extreme Microbes)

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19 pages, 3125 KiB

Open AccessReview

The Soft Coral Sarcophyton trocheliophorum: A Warehouse of Terpenoids with Structural and Pharmacological Diversity

by Qi-Bin Yang, Qihao Wu, Jun-Kun Chen and Lin-Fu Liang

Mar. Drugs 2023, 21(1), 30; https://doi.org/10.3390/md21010030 - 29 Dec 2022

Cited by 2 | Viewed by 1881

Abstract

The soft coral Sarcophyton trocheliophorum, which was frequently encountered on Indo-Pacific and Red Sea coral reefs, furnished a wealth of secondary metabolites. Notably, terpenoids dominated the chemical profile of this species. In this review, we summarized the discovery of 156 terpenoids from [...] Read more.

The soft coral Sarcophyton trocheliophorum, which was frequently encountered on Indo-Pacific and Red Sea coral reefs, furnished a wealth of secondary metabolites. Notably, terpenoids dominated the chemical profile of this species. In this review, we summarized the discovery of 156 terpenoids from the soft coral S. trocheliophorum specimens in different geographical areas. The structures comprised 13 terpenoidal classes with various functionalities. We covered the era from the first report of S. trocheliophorum-derived metabolites in 1976 up to October 2022. The biological effects of these chemical compositions on a vast array of potential pharmacological activities such as protein tyrosine phosphatase 1B (PTP1B) inhibitory, neuroprotective, cytotoxic, anti-inflammatory, antibacterial, antivirus, and immunomodulatory activities were also presented. This review also revealed an immense demand to explore the terpene biosynthetic gene clusters of this species besides the chemo- and bio-investigations. Full article

(This article belongs to the Special Issue Reef Ecology and Marine Drug Discovery)

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18 pages, 2873 KiB

Open AccessArticle

Diversity of Bacterial Secondary Metabolite Biosynthetic Gene Clusters in Three Vietnamese Sponges

by Ton That Huu Dat, Georg Steinert, Nguyen Thi Kim Cuc, Pham Viet Cuong, Hauke Smidt and Detmer Sipkema

Mar. Drugs 2023, 21(1), 29; https://doi.org/10.3390/md21010029 - 29 Dec 2022

Cited by 1 | Viewed by 2713

Abstract

Recent reviews have reinforced sponge-associated bacteria as a valuable source of structurally diverse secondary metabolites with potent biological properties, which makes these microbial communities promising sources of new drug candidates. However, the overall diversity of secondary metabolite biosynthetic potential present in bacteria is [...] Read more.

Recent reviews have reinforced sponge-associated bacteria as a valuable source of structurally diverse secondary metabolites with potent biological properties, which makes these microbial communities promising sources of new drug candidates. However, the overall diversity of secondary metabolite biosynthetic potential present in bacteria is difficult to access due to the fact that the majority of bacteria are not readily cultured in the laboratory. Thus, use of cultivation-independent approaches may allow accessing “silent” and “cryptic” secondary metabolite biosynthetic gene clusters present in bacteria that cannot yet be cultured. In the present study, we investigated the diversity of secondary metabolite biosynthetic gene clusters (BGCs) in metagenomes of bacterial communities associated with three sponge species: Clathria reinwardti, Rhabdastrella globostellata, and Spheciospongia sp. The results reveal that the three metagenomes contain a high number of predicted BGCs, ranging from 282 to 463 BGCs per metagenome. The types of BGCs were diverse and represented 12 different cluster types. Clusters predicted to encode fatty acid synthases and polyketide synthases (PKS) were the most dominant BGC types, followed by clusters encoding synthesis of terpenes and bacteriocins. Based on BGC sequence similarity analysis, 363 gene cluster families (GCFs) were identified. Interestingly, no GCFs were assigned to pathways responsible for the production of known compounds, implying that the clusters detected might be responsible for production of several novel compounds. The KS gene sequences from PKS clusters were used to predict the taxonomic origin of the clusters involved. The KS sequences were related to 12 bacterial phyla with Actinobacteria, Proteobacteria, and Firmicutes as the most predominant. At the genus level, the KSs were most related to those found in the genera Mycolicibacterium, Mycobacterium, Burkholderia, and Streptomyces. Phylogenetic analysis of KS sequences resulted in detection of two known ‘sponge-specific’ BGCs, i.e., SupA and SwfA, as well as a new ‘sponge-specific’ cluster related to fatty acid synthesis in the phylum Candidatus Poribacteria and composed only by KS sequences of the three sponge-associated bacterial communities assessed here. Full article

(This article belongs to the Special Issue Genetic Approach and Data Mining in Discovery of Marine Natural Products)

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24 pages, 1874 KiB

Open AccessReview

A Review on a Hidden Gem: Phycoerythrin from Blue-Green Algae

by Hui Teng Tan, Fatimah Md. Yusoff, Yam Sim Khaw, Nur Amirah Izyan Noor Mazli, Muhammad Farhan Nazarudin, Noor Azmi Shaharuddin, Tomoyo Katayama and Siti Aqlima Ahmad

Mar. Drugs 2023, 21(1), 28; https://doi.org/10.3390/md21010028 - 29 Dec 2022

Cited by 6 | Viewed by 2992

Abstract

Phycoerythrin (PE) is a pink/red-colored pigment found in rhodophytes, cryptophytes, and blue-green algae (cyanobacteria). The interest in PE is emerging from its role in delivering health benefits. Unfortunately, the current cyanobacterial-PE (C-PE) knowledge is still in the infant stage. It is essential to [...] Read more.

Phycoerythrin (PE) is a pink/red-colored pigment found in rhodophytes, cryptophytes, and blue-green algae (cyanobacteria). The interest in PE is emerging from its role in delivering health benefits. Unfortunately, the current cyanobacterial-PE (C-PE) knowledge is still in the infant stage. It is essential to acquire a more comprehensive understanding of C-PE. This study aimed to review the C-PE structure, up and downstream processes of C-PE, application of C-PE, and strategies to enhance its stability and market value. In addition, this study also presented a strengths, weaknesses, opportunities, and threats (SWOT) analysis on C-PE. Cyanobacteria appeared to be the more promising PE producers compared to rhodophytes, cryptophytes, and macroalgae. Green/blue light is preferred to accumulate higher PE content in cyanobacteria. Currently, the prominent C-PE extraction method is repeated freezing–thawing. A combination of precipitation and chromatography approaches is proposed to obtain greater purity of C-PE. C-PE has been widely exploited in various fields, such as nutraceuticals, pharmaceuticals, therapeutics, cosmetics, biotechnology, food, and feed, owing to its bioactivities and fluorescent properties. This review provides insight into the state-of-art nature of C-PE and advances a step further in commercializing this prospective pigment. Full article

(This article belongs to the Special Issue Researches in High-Value Algal Products: From Extraction to Application)

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11 pages, 1864 KiB

Open AccessArticle

Two New Alkaloids and a New Butenolide Derivative from the Beibu Gulf Sponge-Derived Fungus Penicillium sp. SCSIO 41413

by Yuxiu Ye, Jiaqi Liang, Jianglian She, Xiuping Lin, Junfeng Wang, Yonghong Liu, Dehua Yang, Yanhui Tan, Xiaowei Luo and Xuefeng Zhou

Mar. Drugs 2023, 21(1), 27; https://doi.org/10.3390/md21010027 - 29 Dec 2022

Cited by 6 | Viewed by 2151

Abstract

Marine sponge-derived fungi have been proven to be a prolific source of bioactive natural products. Two new alkaloids, polonimides E (1) and D (2), and a new butenolide derivative, eutypoid F (11), were isolated from the Beibu [...] Read more.

Marine sponge-derived fungi have been proven to be a prolific source of bioactive natural products. Two new alkaloids, polonimides E (1) and D (2), and a new butenolide derivative, eutypoid F (11), were isolated from the Beibu Gulf sponge-derived fungus, Penicillium sp. SCSIO 41413, together with thirteen known compounds (3–10, 12–16). Their structures were determined by detailed NMR, MS spectroscopic analyses, and electronic circular dichroism (ECD) analyses. Butenolide derivatives 11 and 12 exhibited inhibitory effect against the enzyme PI3K with IC₅₀ values of 1.7 μM and 9.8 μM, respectively. The molecular docking was also performed to understand the inhibitory activity, while 11 and 12 showed obvious protein/ligand-binding effects to the PI3K protein. Moreover, 4 and 15 displayed obvious inhibitory activity against LPS-induced NF-κB activation in RAW264.7 cells at 10 µM. Full article

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4 pages, 204 KiB

Open AccessEditorial

News and Updates from 2022 on Antioxidant and Anti-Inflammatory Properties of Marine Products

by Marzia Vasarri and Donatella Degl’Innocenti

Mar. Drugs 2023, 21(1), 26; https://doi.org/10.3390/md21010026 - 29 Dec 2022

Cited by 1 | Viewed by 1607

Abstract

Inflammation and oxidative stress are often the common denominators of most modern chronic diseases and disorders, resulting in serious problems for health care systems [...] Full article

(This article belongs to the Special Issue Marine Anti-inflammatory and Antioxidant Agents 2.0)

14 pages, 3228 KiB

Open AccessArticle

Therapeutic Potency of Ovothiol A on Ethanol-Induced Gastric Ulcers in Wistar Rats

by Amira Tarek Salaheldin, Mohamed Refaat Shehata, Hader I. Sakr, Tarek Atia and Ayman Saber Mohamed

Mar. Drugs 2023, 21(1), 25; https://doi.org/10.3390/md21010025 - 28 Dec 2022

Cited by 4 | Viewed by 1853

Abstract

Peptic ulcer is a widespread disease, with a lifetime frequency of 5–10% among the general population and an annual incidence of 0.1–0.3%. Ovothiol A is naturally produced from sea urchin eggs with special antioxidant activity. Gastric ulcers were induced in rats by a [...] Read more.

Peptic ulcer is a widespread disease, with a lifetime frequency of 5–10% among the general population and an annual incidence of 0.1–0.3%. Ovothiol A is naturally produced from sea urchin eggs with special antioxidant activity. Gastric ulcers were induced in rats by a single ethanol dose (5 mL/kg). The rats were divided into control, ulcer, and ulcer with 250 and 500 mg/kg ovothiol A doses. Molecular docking studies were used to examine the interactions between ovothiol A and the H+/K+ ATPase active site residues. Ovothiol A led to a significant decline (p < 0.05) in gastric juice volume, ulcer index, MDA, IL-6, and cytochrome c, while levels of gastric juice pH, GSH, CAT, GST, SOD, and NO increased. Histopathological investigation of stomach sections revealed architecture preservation of the gastric mucosa after ovothiol A administration. The anti-ulcerogenic activity of ovothiol A includes scavenging free radicals, inhibition of inflammation, regulation of apoptosis, and stabilization of fibroblast growth factors to promote gastric ulcers healing. Full article

(This article belongs to the Topic Antioxidant Activity of Natural Products)

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