Next Issue
Volume 16, June
Previous Issue
Volume 16, April
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
9.6
5.4
Journals
Marine Drugs
Volume 16
Issue 5
share announcement

Mar. Drugs, Volume 16, Issue 5 (May 2018) – 38 articles

Cover Story (view full-size image): The purpose of this study is to change the paradigm based on the harvest/extraction approach and replace it with remote trapping of marine invertebrate molecules. This ecofriendly and sustainable approach aimed to exploit the animals in their natural habitat and to highlight the interdependence between the animal and its neighbors and between the animal and its symbionts. Our results demonstrate that when maintaining Crambe crambe and Anemonia sulcate in an aquarium and trapping the compounds released in the water, we succeeded in isolating and identifying toxic compounds to Anemonia, released by Crambe. Thus, This publication provide the proof of concept of a technology named Somartex® for (Self Operating MARine Trapping EXtractor) which was patented and built in order to transfer the concept from closed aquarium systems to open marine ecosystems. View this paper.
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
21 pages, 1830 KiB  
Review
Molecular Targets of Active Anticancer Compounds Derived from Marine Sources
by Xiaoping Song, Ying Xiong, Xin Qi, Wei Tang, Jiajia Dai, Qianqun Gu and Jing Li
Mar. Drugs 2018, 16(5), 175; https://doi.org/10.3390/md16050175 - 22 May 2018
Cited by 25 | Viewed by 5078
Abstract
Over the past decades, a number of novel compounds, which are produced in the marine environment, have been found to exhibit the anticancer effects. This review focuses on molecular targets of marine-derived anticancer candidates in clinical and preclinical studies. They are kinases, transcription [...] Read more.
Over the past decades, a number of novel compounds, which are produced in the marine environment, have been found to exhibit the anticancer effects. This review focuses on molecular targets of marine-derived anticancer candidates in clinical and preclinical studies. They are kinases, transcription factors, histone deacetylase, the ubiquitin-proteasome system, and so on. Specific emphasis of this review paper is to provide information on the optimization of new target compounds for future research and development of anticancer drugs, based on the identification of structures of these target molecules and parallel compounds. Full article
(This article belongs to the Special Issue Marine Drugs Interact with Functional Proteins)
►▼ Show Figures

Figure 1

14 pages, 2837 KiB  
Article
Bioactive Pyridone Alkaloids from a Deep-Sea-Derived Fungus Arthrinium sp. UJNMF0008
by Jie Bao, Huijuan Zhai, Kongkai Zhu, Jin-Hai Yu, Yuying Zhang, Yinyin Wang, Cheng-Shi Jiang, Xiaoyong Zhang, Yun Zhang and Hua Zhang
Mar. Drugs 2018, 16(5), 174; https://doi.org/10.3390/md16050174 - 22 May 2018
Cited by 52 | Viewed by 5235
Abstract
Eight new 4-hydroxy-2-pyridone alkaloids arthpyrones D–K (1–8), along with two known analogues apiosporamide (9) and arthpyrone B (10), were isolated from a deep-sea-derived fungus Arthrinium sp. UJNMF0008. The structures of the isolated compounds were elucidated [...] Read more.
Eight new 4-hydroxy-2-pyridone alkaloids arthpyrones D–K (1–8), along with two known analogues apiosporamide (9) and arthpyrone B (10), were isolated from a deep-sea-derived fungus Arthrinium sp. UJNMF0008. The structures of the isolated compounds were elucidated on the basis of spectroscopic methods with that of 1 being established by chemical transformation and X-ray diffraction analysis. Compounds 1 and 2 bore an ester functionality linking the pyridone and decalin moieties first reported in this class of metabolites, while 3 and 4 incorporated a rare natural hexa- or tetrahydrobenzofuro[3,2-c]pyridin-3(2H)-one motif. Compounds 3–6 and 9 exhibited moderate to significant antibacterial activity against Mycobacterium smegmatis and Staphylococcus aureus with IC50 values ranging from 1.66–42.8 μM, while 9 displayed cytotoxicity against two human osteosarcoma cell lines (U2OS and MG63) with IC50 values of 19.3 and 11.7 μM, respectively. Full article
►▼ Show Figures

Graphical abstract

9 pages, 2420 KiB  
Article
Mono- and Dimeric Naphthalenones from the Marine-Derived Fungus Leptosphaerulina chartarum 3608
by Panpan Zhang, Chunxiu Jia, Jiajia Lang, Jing Li, Guangyuan Luo, Senhua Chen, Sujun Yan and Lan Liu
Mar. Drugs 2018, 16(5), 173; https://doi.org/10.3390/md16050173 - 21 May 2018
Cited by 13 | Viewed by 3603
Abstract
Five new naphthalenones, two enantiomers (−)-1 and (+)-1 leptothalenone A, (−)-4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one ((−)-2), (4S, 10R, 4’S)-leptotha-lenone B (5), (4R, 10S, 4’S)-leptothalenone B (6 [...] Read more.
Five new naphthalenones, two enantiomers (−)-1 and (+)-1 leptothalenone A, (−)-4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one ((−)-2), (4S, 10R, 4’S)-leptotha-lenone B (5), (4R, 10S, 4’S)-leptothalenone B (6), and a new isocoumarine, 6-hydroxy-5,8-dimethoxy-3-methyl-1H-isochromen-1-one (4), along with two known compounds (+)-4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one ((+)-2) and (+)-10-norparvulenone (3) were isolated from the marine-derived fungus Leptosphaerulina chartarum 3608. The structures of new compounds were elucidated by HR-ESIMS, NMR, and ECD analysis. All compounds were evaluated for cytotoxicity and anti-inflammatory activity. Compound 6 showed moderate anti-inflammatory activity by inhibiting the production of nitric oxide (NO) in lipopolysaccharide-stimulated RAW264.7 cells, with an IC50 value of 44.5 μM. Full article
►▼ Show Figures

Graphical abstract

15 pages, 5823 KiB  
Article
Anti-Tumorigenic and Anti-Metastatic Activity of the Sponge-Derived Marine Drugs Aeroplysinin-1 and Isofistularin-3 against Pheochromocytoma In Vitro
by Nicole Bechmann, Hermann Ehrlich, Graeme Eisenhofer, Andre Ehrlich, Stephan Meschke, Christian G. Ziegler and Stefan R. Bornstein
Mar. Drugs 2018, 16(5), 172; https://doi.org/10.3390/md16050172 - 20 May 2018
Cited by 40 | Viewed by 5130
Abstract
Over 10% of pheochromocytoma and paraganglioma (PPGL) patients have malignant disease at their first presentation in the clinic. Development of malignancy and the underlying molecular pathways in PPGLs are poorly understood and efficient treatment strategies are missing. Marine sponges provide a natural source [...] Read more.
Over 10% of pheochromocytoma and paraganglioma (PPGL) patients have malignant disease at their first presentation in the clinic. Development of malignancy and the underlying molecular pathways in PPGLs are poorly understood and efficient treatment strategies are missing. Marine sponges provide a natural source of promising anti-tumorigenic and anti-metastatic agents. We evaluate the anti-tumorigenic and anti-metastatic potential of Aeroplysinin-1 and Isofistularin-3, two secondary metabolites isolated from the marine sponge Aplysina aerophoba, on pheochromocytoma cells. Aeroplysinin-1 diminished the number of proliferating cells and reduced spheroid growth significantly. Beside these anti-tumorigenic activity, Aeroplysinin-1 decreased the migration ability of the cells significantly (p = 0.01), whereas, the invasion capacity was not affected. Aeroplysinin-1 diminished the high adhesion capacity of the MTT cells to collagen (p < 0.001) and, furthermore, reduced the ability to form spheroids significantly. Western Blot and qRT-PCR analysis showed a downregulation of integrin β1 that might explain the lower adhesion and migration capacity after Aeroplysinin-1 treatment. Isofistularin-3 showed only a negligible influence on proliferative and pro-metastatic cell properties. These in vitro investigations show promise for the application of the sponge-derived marine drug, Aeroplysinin-1 as anti-tumorigenic and anti-metastatic agent against PPGLs for the first time. Full article
(This article belongs to the Collection Marine Compounds and Cancer)
►▼ Show Figures

Graphical abstract

14 pages, 1674 KiB  
Article
Isolation and Composition Analysis of Bioactive Glycosaminoglycans from Whelk
by Chrow Khurshid and David Alexander Pye
Mar. Drugs 2018, 16(5), 171; https://doi.org/10.3390/md16050171 - 18 May 2018
Cited by 9 | Viewed by 4171
Abstract
Glycosaminoglycans (GAGs) are found covalently attached to proteins, which create conjugates known as proteoglycans. GAGs have remarkable biological activity as co-receptors for a variety of growth factors, cytokines, and chemokines. The present study identifies the key compositional differences between the GAGs isolated from [...] Read more.
Glycosaminoglycans (GAGs) are found covalently attached to proteins, which create conjugates known as proteoglycans. GAGs have remarkable biological activity as co-receptors for a variety of growth factors, cytokines, and chemokines. The present study identifies the key compositional differences between the GAGs isolated from whelk and mammalian GAGs. This polysaccharide represents a new, previously undescribed GAG with cytotoxic activity on cancer cells. Disaccharides were obtained by sample digestion with heparinases I, II, and III and chondroitinase ABC. The resistant oligosaccharides from whelk GAGs treated with heparinase I, II, and III and chondroitinase ABC were retained by the filter due to their larger size. Disaccharide analysis was performed using Glycan Reduction Isotope Labeling (GRIL LCQ-MS). The amounts of filter-retained fragments, as assessed by monosaccharides analysis, suggested that a proportion of the whelk GAG chains remained resistant to the enzymes used in the disaccharide analysis. Thus, the proportions of individual disaccharide produced in this analysis may not truly represent the overall proportions of disaccharide types within the intact whelk GAGs chain. However, they do serve as important descriptors for the classification and make-up of the anti-cancer GAGs chains. Furthermore, these data represent clear evidence of the compositional differences between whelk GAGs and commercial mammalian GAGs. Full article
►▼ Show Figures

Figure 1

14 pages, 3233 KiB  
Article
Glycosaminoglycans from a Sea Snake (Lapemis curtus): Extraction, Structural Characterization and Antioxidant Activity
by Mingyue Bai, Wenwei Han, Xia Zhao, Qingchi Wang, Yanyun Gao and Shiming Deng
Mar. Drugs 2018, 16(5), 170; https://doi.org/10.3390/md16050170 - 18 May 2018
Cited by 18 | Viewed by 4519
Abstract
Sea snakes have wide application prospects in medicine, health food and other fields. Several novel polysaccharides were successfully obtained from the skin and the meat of a sea snake (Lapemis curtus). The structures of polysaccharides LSP3 and LMP3, which were extracted [...] Read more.
Sea snakes have wide application prospects in medicine, health food and other fields. Several novel polysaccharides were successfully obtained from the skin and the meat of a sea snake (Lapemis curtus). The structures of polysaccharides LSP3 and LMP3, which were extracted and purified from Lapemis curtus, were determined to be new and highly heterogenic glycosaminoglycans (GAGs) by means of FT-IR, ESI-MS/MS and NMR. LSP3 is a hybrid dermatan sulfate (DS) and composed of 48% 4-sulfated disaccharides (Di4S), 42% 6-sulfated disaccharides (Di6S) and 5% disulfated disaccharides (Di2,6S), while LMP3 is a hybrid chondroitin sulfate (CS) and composed of 70% Di4S, 20% Di6S, and 8% Di2,6S. More importantly, LSP3 and LMP3 showed a strong scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, iron (Fe2+) chelating activity and total antioxidant capacity in vitro, especially LSP3, with high contents of uronic acid and sulfate, which possessed a higher scavenging ability of DPPH radicals than other fractions. These data suggested that the sea snake polysaccharides could be promising candidates for natural antioxidant ingredients. Full article
(This article belongs to the Collection Marine Polysaccharides)
►▼ Show Figures

Graphical abstract

15 pages, 2941 KiB  
Article
Characteristics of the Copper,Zinc Superoxide Dismutase of a Hadal Sea Cucumber (Paelopatides sp.) from the Mariana Trench
by Yanan Li, Xue Kong, Jiawei Chen, Helu Liu and Haibin Zhang
Mar. Drugs 2018, 16(5), 169; https://doi.org/10.3390/md16050169 - 18 May 2018
Cited by 21 | Viewed by 4230
Abstract
Superoxide dismutases (SODs) are among the most important antioxidant enzymes and show great potential in preventing adverse effects during therapeutic trials. In the present study, cloning, expression, and characterization of a novel Cu,Zn superoxide dismutase (Ps-Cu,Zn-SOD) from a hadal sea cucumber (Paelopatides [...] Read more.
Superoxide dismutases (SODs) are among the most important antioxidant enzymes and show great potential in preventing adverse effects during therapeutic trials. In the present study, cloning, expression, and characterization of a novel Cu,Zn superoxide dismutase (Ps-Cu,Zn-SOD) from a hadal sea cucumber (Paelopatides sp.) were reported. Phylogenetic analysis showed that Ps-Cu,Zn-SOD belonged to a class of intracellular SOD. Its Km and Vmax were 0.0258 ± 0.0048 mM and 925.1816 ± 28.0430 units/mg, respectively. The low Km value of this enzyme represents a high substrate affinity and can adapt to the low metabolic rate of deep sea organisms. The enzyme functioned from 0 °C to 80 °C with an optimal temperature of 40 °C. Moreover, the enzyme activity was maintained up to 87.12% at 5 °C. The enzyme was active at pH 4 to 12 with an optimal pH of 8.5. Furthermore, Ps-Cu,Zn-SOD tolerated high concentration of urea and GuHCl, resisted hydrolysis by proteases, and maintained stability at high pressure. All these features demonstrated that the deep sea Ps-Cu,Zn-SOD is a potential candidate for application to the biopharmaceutical field. Full article
►▼ Show Figures

Figure 1

9 pages, 1240 KiB  
Communication
Precursor-Directed Generation of Indolocarbazoles with Topoisomerase IIα Inhibitory Activity
by Cong Wang, Adeep Monger, Liping Wang, Peng Fu, Pawinee Piyachaturawat, Arthit Chairoungdua and Weiming Zhu
Mar. Drugs 2018, 16(5), 168; https://doi.org/10.3390/md16050168 - 17 May 2018
Cited by 14 | Viewed by 4523
Abstract
One new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3′-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-l-tryptophan. Their structures [...] Read more.
One new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3′-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-l-tryptophan. Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 potently induced apoptosis of gastric cancer cells by inhibiting topoisomerase IIα enzyme activity and reducing the expression of antiapoptosis protein level. Compound 3 displayed moderate cytotoxicity against the A549 and MCF-7 cell lines with IC50 values of 1.2 ± 0.05 μM, 1.6 ± 0.09 μM, respectively. Full article
►▼ Show Figures

Graphical abstract

15 pages, 1969 KiB  
Article
Dietary Polysaccharide from Enteromorpha Clathrata Modulates Gut Microbiota and Promotes the Growth of Akkermansia muciniphila, Bifidobacterium spp. and Lactobacillus spp.
by Qingsen Shang, Ya Wang, Lin Pan, Qingfeng Niu, Chao Li, Hao Jiang, Chao Cai, Jiejie Hao, Guoyun Li and Guangli Yu
Mar. Drugs 2018, 16(5), 167; https://doi.org/10.3390/md16050167 - 17 May 2018
Cited by 55 | Viewed by 6851
Abstract
Recently, accumulating evidence has suggested that Enteromorpha clathrata polysaccharide (ECP) could contribute to the treatment of diseases. However, as a promising candidate for marine drug development, although ECP has been extensively studied, less consideration has been given to exploring its effect on gut [...] Read more.
Recently, accumulating evidence has suggested that Enteromorpha clathrata polysaccharide (ECP) could contribute to the treatment of diseases. However, as a promising candidate for marine drug development, although ECP has been extensively studied, less consideration has been given to exploring its effect on gut microbiota. In this light, given the critical role of gut microbiota in health and disease, we investigated here the effect of ECP on gut microbiota using 16S rRNA high-throughput sequencing. As revealed by bioinformatic analyses, ECP considerably changed the structure of the gut microbiota and significantly promoted the growth of probiotic bacteria in C57BL/6J mice. However, interestingly, ECP exerted different effects on male and female microbiota. In females, ECP increased the abundances of Bifidobacterium spp. and Akkermansia muciniphila, a next-generation probiotic bacterium, whereas in males, ECP increased the population of Lactobacillus spp. Moreover, by shaping a more balanced structure of the microbiota, ECP remarkably reduced the antigen load from the gut in females. Altogether, our study demonstrates for the first time a prebiotic effect of ECP on gut microbiota and forms the basis for the development of ECP as a novel gut microbiota modulator for health promotion and disease management. Full article
(This article belongs to the Collection Marine Polysaccharides)
►▼ Show Figures

Figure 1

15 pages, 12771 KiB  
Article
Anticancer Activity of Euplotin C, Isolated from the Marine Ciliate Euplotes crassus, Against Human Melanoma Cells
by Sara Carpi, Beatrice Polini, Giulio Poli, Gabriela Alcantara Barata, Stefano Fogli, Antonella Romanini, Tiziano Tuccinardi, Graziano Guella, Francesco Paolo Frontini, Paola Nieri and Graziano Di Giuseppe
Mar. Drugs 2018, 16(5), 166; https://doi.org/10.3390/md16050166 - 16 May 2018
Cited by 21 | Viewed by 4303
Abstract
Cutaneous melanoma is the most serious type of skin cancer, so new cytotoxic weapons against novel targets in melanoma are of great interest. Euplotin C (EC), a cytotoxic secondary metabolite of the marine ciliate Euplotes crassus, was evaluated in the present study [...] Read more.
Cutaneous melanoma is the most serious type of skin cancer, so new cytotoxic weapons against novel targets in melanoma are of great interest. Euplotin C (EC), a cytotoxic secondary metabolite of the marine ciliate Euplotes crassus, was evaluated in the present study on human cutaneous melanoma cells to explore its anti-melanoma activity and to gain more insight into its mechanism of action. EC exerted a marked cytotoxic effect against three different human melanoma cell lines (A375, 501Mel and MeWo) with a potency about 30-fold higher than that observed in non-cancer cells (HDFa cells). A pro-apoptotic activity and a decrease in melanoma cell migration by EC were also observed. At the molecular level, the inhibition of the Erk and Akt pathways, which control many aspects of melanoma aggressiveness, was shown. EC cytotoxicity was antagonized by dantrolene, a ryanodine receptor (RyR) antagonist, in a concentration-dependent manner. A role of RyR as a direct target of EC was also suggested by molecular modelling studies. In conclusion, our data provide the first evidence of the anti-melanoma activity of EC, suggesting it may be a promising new scaffold for the development of selective activators of RyR to be used for the treatment of melanoma and other cancer types. Full article
(This article belongs to the Special Issue Terpenoids from Marine Organisms)
►▼ Show Figures

Figure 1

17 pages, 5379 KiB  
Review
Marine Microalgae with Anti-Cancer Properties
by Kevin A. Martínez Andrade, Chiara Lauritano, Giovanna Romano and Adrianna Ianora
Mar. Drugs 2018, 16(5), 165; https://doi.org/10.3390/md16050165 - 15 May 2018
Cited by 187 | Viewed by 15967
Abstract
Cancer is the leading cause of death globally and finding new therapeutic agents for cancer treatment remains a major challenge in the pursuit for a cure. This paper presents an overview on microalgae with anti-cancer activities. Microalgae are eukaryotic unicellular plants that contribute [...] Read more.
Cancer is the leading cause of death globally and finding new therapeutic agents for cancer treatment remains a major challenge in the pursuit for a cure. This paper presents an overview on microalgae with anti-cancer activities. Microalgae are eukaryotic unicellular plants that contribute up to 40% of global primary productivity. They are excellent sources of pigments, lipids, carotenoids, omega-3 fatty acids, polysaccharides, vitamins and other fine chemicals, and there is an increasing demand for their use as nutraceuticals and food supplements. Some microalgae are also reported as having anti-cancer activity. In this review, we report the microalgal species that have shown anti-cancer properties, the cancer cell lines affected by algae and the concentrations of compounds/extracts tested to induce arrest of cell growth. We also report the mediums used for growing microalgae that showed anti-cancer activity and compare the bioactivity of these microalgae with marine anticancer drugs already on the market and in phase III clinical trials. Finally, we discuss why some microalgae can be promising sources of anti-cancer compounds for future development. Full article
(This article belongs to the Collection Marine Compounds and Cancer)
►▼ Show Figures

Figure 1

12 pages, 1148 KiB  
Article
Structure of the Exopolysaccharide Secreted by a Marine Strain Vibrio alginolyticus
by Sophie Drouillard, Isabelle Jeacomine, Laurine Buon, Claire Boisset, Anthony Courtois, Bertrand Thollas, Pierre-Yves Morvan, Romuald Vallée and William Helbert
Mar. Drugs 2018, 16(5), 164; https://doi.org/10.3390/md16050164 - 15 May 2018
Cited by 13 | Viewed by 4388
Abstract
Vibrio alginolyticus (CNCM I-4151) secretes an exopolysaccharide whose carbohydrate backbone is decorated with amino acids, likely conferring its properties that are appreciated in cosmetics. Here, the secreted polysaccharide of another strain of V. alginolyticus (CNCM I-5034) was characterized by chromatography and one- and [...] Read more.
Vibrio alginolyticus (CNCM I-4151) secretes an exopolysaccharide whose carbohydrate backbone is decorated with amino acids, likely conferring its properties that are appreciated in cosmetics. Here, the secreted polysaccharide of another strain of V. alginolyticus (CNCM I-5034) was characterized by chromatography and one- and two-dimensional NMR spectroscopy experiments. The structure was resolved and shows that the carbohydrate backbone is made of four residues: D-galactose (Gal), D-galacturonic acid (GalA) D-N-acetylglucosamine (GlcNAc) and D-glucuronic acid (GlcA), forming a tetrasaccharide repetition unit [→4)-β-d-GlcA-(1→3)-α-d-Gal-(1→3)-α-d-GalA-(1→3)-β-GlcNAc(1→]. GlcA is derivatized with a lactate group giving ‘nosturonic acid’, and GalA is decorated with the amino acid alanine. Full article
(This article belongs to the Special Issue Marine Oligosaccharides and Polysaccharides)
►▼ Show Figures

Figure 1

19 pages, 2427 KiB  
Article
Characterization of Rhamnolipids Produced by an Arctic Marine Bacterium from the Pseudomonas fluorescence Group
by Venke Kristoffersen, Teppo Rämä, Johan Isaksson, Jeanette Hammer Andersen, William H. Gerwick and Espen Hansen
Mar. Drugs 2018, 16(5), 163; https://doi.org/10.3390/md16050163 - 14 May 2018
Cited by 28 | Viewed by 6046
Abstract
The marine environment is a rich source of biodiversity, including microorganisms that have proven to be prolific producers of bioactive secondary metabolites. Arctic seas are less explored than warmer, more accessible areas, providing a promising starting point to search for novel bioactive compounds. [...] Read more.
The marine environment is a rich source of biodiversity, including microorganisms that have proven to be prolific producers of bioactive secondary metabolites. Arctic seas are less explored than warmer, more accessible areas, providing a promising starting point to search for novel bioactive compounds. In the present work, an Arctic marine Pseudomonas sp. belonging to the Pseudomonas (P.) fluorescence group was cultivated in four different media in an attempt to activate biosynthetic pathways leading to the production of antibacterial and anticancer compounds. Culture extracts were pre-fractionated and screened for antibacterial and anticancer activities. One fraction from three of the four growth conditions showed inhibitory activity towards bacteria and cancer cells. The active fractions were dereplicated using molecular networking based on MS/MS fragmentation data, indicating the presence of a cluster of related rhamnolipids. Six compounds were isolated using HPLC and mass-guided fractionation, and by interpreting data from NMR and high-resolution MS/MS analysis; the structures of the compounds were determined to be five mono-rhamnolipids and the lipid moiety of one of the rhamnolipids. Molecular networking proved to be a valuable tool for dereplication of these related compounds, and for the first time, five mono-rhamnolipids from a bacterium within the P. fluorescence group were characterized, including one new mono-rhamnolipid. Full article
(This article belongs to the Special Issue Chilling Allelochemicals: Natural Products and Bioactivities from Polar and Sub-Polar Latitudes)
►▼ Show Figures

Figure 1

33 pages, 7060 KiB  
Review
Ascidian Toxins with Potential for Drug Development
by Dianne J. Watters
Mar. Drugs 2018, 16(5), 162; https://doi.org/10.3390/md16050162 - 13 May 2018
Cited by 45 | Viewed by 7401
Abstract
Ascidians (tunicates) are invertebrate chordates, and prolific producers of a wide variety of biologically active secondary metabolites from cyclic peptides to aromatic alkaloids. Several of these compounds have properties which make them candidates for potential new drugs to treat diseases such as cancer. [...] Read more.
Ascidians (tunicates) are invertebrate chordates, and prolific producers of a wide variety of biologically active secondary metabolites from cyclic peptides to aromatic alkaloids. Several of these compounds have properties which make them candidates for potential new drugs to treat diseases such as cancer. Many of these natural products are not produced by the ascidians themselves, rather by their associated symbionts. This review will focus mainly on the mechanism of action of important classes of cytotoxic molecules isolated from ascidians. These toxins affect DNA transcription, protein translation, drug efflux pumps, signaling pathways and the cytoskeleton. Two ascidian compounds have already found applications in the treatment of cancer and others are being investigated for their potential in cancer, neurodegenerative and other diseases. Full article
(This article belongs to the Special Issue Marine Invertebrate Toxins)
►▼ Show Figures

Figure 1

19 pages, 3338 KiB  
Article
Preparation, Physicochemical and Antioxidant Properties of Acid- and Pepsin-Soluble Collagens from the Swim Bladders of Miiuy Croaker (Miichthys miiuy)
by Wen-Hao Zhao, Chang-Feng Chi, Yu-Qin Zhao and Bin Wang
Mar. Drugs 2018, 16(5), 161; https://doi.org/10.3390/md16050161 - 12 May 2018
Cited by 71 | Viewed by 5311
Abstract
Collagen is one of the most useful biomaterials and widely applied in functional food and cosmetics. However, some consumers have paid close attention to the safety of mammalian collagens because of the outbreaks of bovine spongiform encephalopathy (BSE), foot-and-mouth disease (FMD), and other [...] Read more.
Collagen is one of the most useful biomaterials and widely applied in functional food and cosmetics. However, some consumers have paid close attention to the safety of mammalian collagens because of the outbreaks of bovine spongiform encephalopathy (BSE), foot-and-mouth disease (FMD), and other prion diseases. Therefore, there is a strong demand for developing alternative sources of collagen, with one promising source being from the process by-products of commercial fisheries. In this report, acid-soluble collagen (ASC-SB) and pepsin-soluble collagen (PSC-SB) from swim bladders of miiuy croaker (Miichthys miiuy) were isolated with yields of 1.33 ± 0.11% and 8.37 ± 0.24% of dry swim bladder weight. Glycine was the major amino acid present, with a content of 320.5 (ASC-SB) and 333.6 residues/1000 residues (PSC-SB). ASC-SB and PSC-SB had much lower denaturation temperatures compared to mammalian collagen, a consequence of low imino acid contents (196.7 and 199.5 residues/1000 residues for ASC-SB and PSC-SB, respectively). The data of amino acid composition, SDS-PAGE pattern, UV and FTIR spectra confirmed that ASC-SB and PSC-SB were mainly composed of type I collagen. FTIR spectra data indicated there were more hydrogen bonding and intermolecular crosslinks in ASC-SB. These collagens showed high solubility in the acidic pH ranges and low NaCl concentrations (less than 2%). The Zeta potential values of ASC-SB and PSC-SB were 6.74 and 6.85, respectively. ASC-SB and PSC-SB presented irregular, dense, sheet-like films linked by random-coiled filaments under scanning electron microscopy. In addition, ASC-SB and PSC-SB could scavenge DPPH radical, hydroxyl radical, superoxide anion radical, and ABTS radical in a dose-dependent manner. Overall, the results indicate that collagens from the swim bladders of miiuy croaker are a viable substitute for mammalian collagen, with potential functional food and cosmeceutical applications. Full article
(This article belongs to the Special Issue Marine Health Compounds: From Extraction to Food and Pharmaceutical Application)
►▼ Show Figures

Figure 1

15 pages, 10580 KiB  
Review
Investigation of the Anti-Prostate Cancer Properties of Marine-Derived Compounds
by Meiqi Fan, Amit Kumar Nath, Yujiao Tang, Young-Jin Choi, Trishna Debnath, Eun-Ju Choi and Eun-Kyung Kim
Mar. Drugs 2018, 16(5), 160; https://doi.org/10.3390/md16050160 - 12 May 2018
Cited by 32 | Viewed by 6351
Abstract
This review focuses on marine compounds with anti-prostate cancer properties. Marine species are unique and have great potential for the discovery of anticancer drugs. Marine sources are taxonomically diverse and include bacteria, cyanobacteria, fungi, algae, and mangroves. Marine-derived compounds, including nucleotides, amides, quinones, [...] Read more.
This review focuses on marine compounds with anti-prostate cancer properties. Marine species are unique and have great potential for the discovery of anticancer drugs. Marine sources are taxonomically diverse and include bacteria, cyanobacteria, fungi, algae, and mangroves. Marine-derived compounds, including nucleotides, amides, quinones, polyethers, and peptides are biologically active compounds isolated from marine organisms such as sponges, ascidians, gorgonians, soft corals, and bryozoans, including those mentioned above. Several compound classes such as macrolides and alkaloids include drugs with anti-cancer mechanisms, such as antioxidants, anti-angiogenics, antiproliferatives, and apoptosis-inducing drugs. Despite the diversity of marine species, most marine-derived bioactive compounds have not yet been evaluated. Our objective is to explore marine compounds to identify new treatment strategies for prostate cancer. This review discusses chemically and pharmacologically diverse marine natural compounds and their sources in the context of prostate cancer drug treatment. Full article
(This article belongs to the Collection Marine Compounds and Cancer)
25 pages, 10926 KiB  
Review
Diterpenes from the Marine Algae of the Genus Dictyota
by Jiayun Chen, Hong Li, Zishuo Zhao, Xue Xia, Bo Li, Jinrong Zhang and Xiaojun Yan
Mar. Drugs 2018, 16(5), 159; https://doi.org/10.3390/md16050159 - 11 May 2018
Cited by 57 | Viewed by 6844
Abstract
Species of the brown algae of the genus Dictyota are rich sources of bioactive secondary metabolites with diverse structural features. Excellent progress has been made in the discovery of diterpenes possessing broad chemical defensive activities from this genus. Most of these diterpenes exhibit [...] Read more.
Species of the brown algae of the genus Dictyota are rich sources of bioactive secondary metabolites with diverse structural features. Excellent progress has been made in the discovery of diterpenes possessing broad chemical defensive activities from this genus. Most of these diterpenes exhibit significant biological activities, such as antiviral, cytotoxic and chemical defensive activities. In the present review, we summarized diterpenes isolated from the brown algae of the genus. Full article
(This article belongs to the Special Issue Seaweeds and Their Biological Actions)
►▼ Show Figures

Figure 1

16 pages, 2726 KiB  
Article
High-Level Expression of a Thermally Stable Alginate Lyase Using Pichia pastoris, Characterization and Application in Producing Brown Alginate Oligosaccharide
by Haifeng Li, Shuling Wang, Yunyi Zhang and Liehuan Chen
Mar. Drugs 2018, 16(5), 158; https://doi.org/10.3390/md16050158 - 11 May 2018
Cited by 36 | Viewed by 4458
Abstract
An alginate lyase encoding gene sagl from Flavobacterium sp. H63 was codon optimized and recombinantly expressed at high level in P.pastoris through high cell-density fermentation. The highest yield of recombinant enzyme of sagl (rSAGL) in yeast culture supernatant reached 226.4 μg/mL (915.5 U/mL). [...] Read more.
An alginate lyase encoding gene sagl from Flavobacterium sp. H63 was codon optimized and recombinantly expressed at high level in P.pastoris through high cell-density fermentation. The highest yield of recombinant enzyme of sagl (rSAGL) in yeast culture supernatant reached 226.4 μg/mL (915.5 U/mL). This was the highest yield record of recombinant expression of alginate lyase so far. The rSAGL was confirmed as a partially glycosylated protein through EndoH digestion. The optimal reaction temperature and pH of this enzyme were 45 °C and 7.5; 80 mM K+ ions could improve the catalytic activity of the enzyme by 244% at most. rSAGL was a thermal stable enzyme with T5015 of 57–58 °C and T5030 of 53–54 °C. Its thermal stability was better than any known alginate lyase. In 100 mM phosphate buffer of pH 6.0, rSAGL could retain 98.8% of the initial activity after incubation at 50 °C for 2 h. Furthermore, it could retain 61.6% of the initial activity after 48 h. The specific activity of the purified rSAGL produced by P. pastoris attained 4044 U/mg protein, which was the second highest record of alginate lyase so far. When the crude enzyme of the rSAGL was directly used in transformation of sodium alginate with 40 g/L, 97.2% of the substrate was transformed to di, tri, tetra brown alginate oligosaccharide after 32 h of incubation at 50 °C, and the final concentration of reducing sugar in mixture reached 9.51 g/L. This is the first report of high-level expression of thermally stable alginate lyase using P. pastoris system. Full article
►▼ Show Figures

Figure 1

21 pages, 11626 KiB  
Article
The Maxi-K (BK) Channel Antagonist Penitrem A as a Novel Breast Cancer-Targeted Therapeutic
by Amira A. Goda, Abu Bakar Siddique, Mohamed Mohyeldin, Nehad M. Ayoub and Khalid A. El Sayed
Mar. Drugs 2018, 16(5), 157; https://doi.org/10.3390/md16050157 - 11 May 2018
Cited by 23 | Viewed by 6799
Abstract
Breast cancer (BC) is a heterogeneous disease with different molecular subtypes. The high conductance calcium-activated potassium channels (BK, Maxi-K channels) play an important role in the survival of some BC phenotypes, via membrane hyperpolarization and regulation of cell cycle. BK channels have been [...] Read more.
Breast cancer (BC) is a heterogeneous disease with different molecular subtypes. The high conductance calcium-activated potassium channels (BK, Maxi-K channels) play an important role in the survival of some BC phenotypes, via membrane hyperpolarization and regulation of cell cycle. BK channels have been implicated in BC cell proliferation and invasion. Penitrems are indole diterpene alkaloids produced by various terrestrial and marine Penicillium species. Penitrem A (1) is a selective BK channel antagonist with reported antiproliferative and anti-invasive activities against multiple malignancies, including BC. This study reports the high expression of BK channel in different BC subtypes. In silico BK channel binding affinity correlates with the antiproliferative activities of selected penitrem analogs. 1 showed the best binding fitting at multiple BK channel crystal structures, targeting the calcium-sensing aspartic acid moieties at the calcium bowel and calcium binding sites. Further, 1 reduced the levels of BK channel expression and increased expression of TNF-α in different BC cell types. Penitrem A (1) induced G1 cell cycle arrest of BC cells, and induced upregulation of the arrest protein p27. Combination treatment of 1 with targeted anti-HER drugs resulted in synergistic antiproliferative activity, which was associated with reduced EGFR and HER2 receptor activation, as well as reduced active forms of AKT and STAT3. Collectively, the BK channel antagonists represented by penitrem A can be novel sensitizing, chemotherapeutics synergizing, and therapeutic agents for targeted BC therapy. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine-Derived Aspergillus, Penicillium, Talaromyces and Trichoderma Species)
►▼ Show Figures

Graphical abstract

14 pages, 890 KiB  
Article
Pressurized Liquid Extraction (PLE) as an Innovative Green Technology for the Effective Enrichment of Galician Algae Extracts with High Quality Fatty Acids and Antimicrobial and Antioxidant Properties
by Paz Otero, Somaris E. Quintana, Guillermo Reglero, Tiziana Fornari and Mónica R. García-Risco
Mar. Drugs 2018, 16(5), 156; https://doi.org/10.3390/md16050156 - 10 May 2018
Cited by 65 | Viewed by 7088
Abstract
Marine organisms are potentially prolific sources of high qualify fatty acids that represent useful leads in the development of new nutraceutical agents. In this work, we investigated the lipid composition of six algae species from the Northwest of Spain (Ulva intestinalis, [...] Read more.
Marine organisms are potentially prolific sources of high qualify fatty acids that represent useful leads in the development of new nutraceutical agents. In this work, we investigated the lipid composition of six algae species from the Northwest of Spain (Ulva intestinalis, Ulva lactuca, Fucus vesiculosus, Dictyota dichotoma, Cystoseira baccata and Himanthalia elongata) and compared the antioxidant and antibacterial activity of ethanolic extracts obtained by pressurized liquid extraction (PLE). Furthermore, Fucus vesiculosus (F. vesiculosus) PLE using five solvents of different polarities (hexane, ethyl acetate, acetone, ethanol and ethanol:water 50:50) at three temperatures (80 °C, 120 °C and 160 °C) was investigated. F. vesiculosus ethanolic PLE extract presents considerably higher capacity of inhibiting 50% of DPPH (1,1-diphenyl-2-picryl hydrazyl) (IC50 = 7.17 μg/mL) in comparison with the rest of macroalgae studied. Moreover, the potential antimicrobial activity tested on E. coli and S. aureus shows that F. vesiculosus extract produced the best inhibition (IC50 was 2.24 mg/mL (E. coli) and 1.27 mg/mL (S. aureus)). Furthermore, regarding the different solvents and temperatures used to investigate F. vesiculosus PLE, results showed that this technique using ethyl acetate is a selective method to enrich long chain fatty acids (oleic acid, arachidonic acid and eicosapentaenoic acid) with ω-6/ω-3 ratios close to 2.7. Full article
(This article belongs to the Special Issue Screening of Bioactive Compounds from Marine Sources)
►▼ Show Figures

Figure 1

14 pages, 1692 KiB  
Article
The Effect of Fucoidan from the Brown Alga Fucus evanescence on the Activity of α-N-Acetylgalactosaminidase of Human Colon Carcinoma Cells
by Irina Bakunina, Oksana Chadova, Olesya Malyarenko and Svetlana Ermakova
Mar. Drugs 2018, 16(5), 155; https://doi.org/10.3390/md16050155 - 10 May 2018
Cited by 9 | Viewed by 6154
Abstract
α-N-acetylgalactosaminidase (EC 3.2.1.49) (alpha-NaGalase) catalyzes the hydrolysis of N-acetamido-2-deoxy-α-d-galactoside residues from non-reducing ends of various complex carbohydrates and glycoconjugates. It is known that human cancer cells express an alpha-NaGalase, which accumulates in the blood plasma of patients. The [...] Read more.
α-N-acetylgalactosaminidase (EC 3.2.1.49) (alpha-NaGalase) catalyzes the hydrolysis of N-acetamido-2-deoxy-α-d-galactoside residues from non-reducing ends of various complex carbohydrates and glycoconjugates. It is known that human cancer cells express an alpha-NaGalase, which accumulates in the blood plasma of patients. The enzyme deglycosylates the Gc protein-derived macrophage activating factor (GcMAF) and inhibits macrophage activity acting as an immunosuppressor. The high specific activity 0.033 ± 0.002 μmol mg−1 min−1 of the enzyme was found in human colon carcinoma cells DLD-1. The alpha-NaGalase of DLD-1 cells was isolated and biochemical characterized. The enzyme exhibits maximum activity at pH 5.2 and temperature 55 °C. The Km is 2.15 mM, Vmax–0.021 μmol min−1 mL−1, kcat–1.55 min−1 and kcat/Km–0.72 min−1 mM−1 at 37 °C, pH 5.2. The effects of fucoidan from the brown alga Fucus evanescence on the activity of alpha-NaGalase in human colon carcinoma DLD-1 cells and on the biosynthesis of this enzyme were investigated. It was shown that fucoidan did not inhibit free alpha-NaGalase, however, it reduced the expression of the enzyme in the DLD-1 cells at IC50 73 ± 4 μg mL−1. Full article
(This article belongs to the Special Issue Seaweeds and Their Biological Actions)
►▼ Show Figures

Figure 1

19 pages, 2173 KiB  
Article
Metabolite Profiling of the Microalgal Diatom Chaetoceros Calcitrans and Correlation with Antioxidant and Nitric Oxide Inhibitory Activities via 1H NMR-Based Metabolomics
by Awanis Azizan, Muhammad Safwan Ahamad Bustamam, M. Maulidiani, Khozirah Shaari, Intan Safinar Ismail, Norio Nagao and Faridah Abas
Mar. Drugs 2018, 16(5), 154; https://doi.org/10.3390/md16050154 - 07 May 2018
Cited by 46 | Viewed by 7944
Abstract
Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely 1H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data [...] Read more.
Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely 1H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data analysis, using principal component analysis (PCA), resolved the five types of extracts made by solvents ranging from polar to non-polar into five different clusters. Collectively, with various extraction solvents, 11 amino acids, cholesterol, 6 fatty acids, 2 sugars, 1 osmolyte, 6 carotenoids and 2 chlorophyll pigments were identified. The fatty acids and both carotenoid pigments as well as chlorophyll, were observed in the extracts made from medium polar (acetone, chloroform) and non-polar (hexane) solvents. It is suggested that the compounds were the characteristic markers that influenced the separation between the clusters. Based on partial least square (PLS) analysis, fucoxanthin, astaxanthin, violaxanthin, zeaxanthin, canthaxanthin, and lutein displayed strong correlation to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and nitric oxide (NO) inhibitory activity. This metabolomics study showed that solvent extractions are one of the main bottlenecks for the maximum recovery of bioactive microalgal compounds and could be a better source of natural antioxidants due to a high value of metabolites. Full article
(This article belongs to the Collection Bioactive Compounds from Marine Plankton)
►▼ Show Figures

Figure 1

15 pages, 4001 KiB  
Article
Determination of the μ-Conotoxin PIIIA Specificity Against Voltage-Gated Sodium Channels from Binding Energy Calculations
by Fangling Chen, Wenxin Huang, Tao Jiang and Rilei Yu
Mar. Drugs 2018, 16(5), 153; https://doi.org/10.3390/md16050153 - 07 May 2018
Cited by 12 | Viewed by 4356
Abstract
Voltage-gated sodium (NaV) channels generate and propagate action potentials in excitable cells, and several NaV subtypes have become important targets for pain management. The μ-conotoxins inhibit subtypes of the NaV with varied specificity but often lack of specificity to [...] Read more.
Voltage-gated sodium (NaV) channels generate and propagate action potentials in excitable cells, and several NaV subtypes have become important targets for pain management. The μ-conotoxins inhibit subtypes of the NaV with varied specificity but often lack of specificity to interested subtypes. Engineering the selectivity of the μ-conotoxins presents considerable complexity and challenge, as it involves the optimization of their binding affinities to multiple highly conserved NaV subtypes. In this study, a model of NaV1.4 bound with μ-conotoxin PIIIA complex was constructed using homology modeling, docking, molecular dynamic simulations and binding energy calculations. The accuracy of this model was confirmed based on the experimental mutagenesis data. The complex models of PIIIA bound with varied subtypes of NaV1.x (x = 1, 2, 3, 5, 6, 7, 8, or 9) were built using NaV1.4/PIIIA complex as a template, and refined using molecular dynamic simulations. The binding affinities of PIIIA to varied subtypes of NaV1.x (x = 1 to 9) were calculated using the Molecular Mechanics Generalized Born/Surface Area (MMGB/SA) and umbrella sampling, and were compared with the experimental values. The binding affinities calculated using MMGB/SA and umbrella sampling are correlated with the experimental values, with the former and the latter giving correlation coefficient of 0.41 (R2) and 0.68 (R2), respectively. Binding energy decomposition suggests that conserved and nonconserved residues among varied NaV subtypes have a synergistic effect on the selectivity of PIIIA. Full article
►▼ Show Figures

Graphical abstract

11 pages, 2622 KiB  
Article
Innovative Approach to Sustainable Marine Invertebrate Chemistry and a Scale-Up Technology for Open Marine Ecosystems
by Pinelopi Vlachou, Géraldine Le Goff, Carolina Alonso, Pedro A. Álvarez, Jean-François Gallard, Nikolas Fokialakis and Jamal Ouazzani
Mar. Drugs 2018, 16(5), 152; https://doi.org/10.3390/md16050152 - 06 May 2018
Cited by 13 | Viewed by 6301
Abstract
Isolation of marine compounds from living invertebrates represents a major challenge for sustainable and environmentally friendly exploitation of marine bio-resources. To develop innovative technology to trap invertebrate compounds in the open sea, the proof of concept of a system combining external continuous circulation [...] Read more.
Isolation of marine compounds from living invertebrates represents a major challenge for sustainable and environmentally friendly exploitation of marine bio-resources. To develop innovative technology to trap invertebrate compounds in the open sea, the proof of concept of a system combining external continuous circulation of water with XAD-amberlite solid-phase extraction was validated in an aquarium. In this work, we reported the elicitation of guanidine alkaloid production of Crambe crambe in the presence of Anemonia sulcata, both collected from the Mediterranean Sea. Besides the previously reported crambescidin 359 (1), and crambescidin acid (2), three new compounds were isolated; one carboxylated analog of 1 named crambescidin 401 (3), and two analogs of crambescin B, crambescin B 281 (4) and crambescin B 253 (5). Based on these results, a technology named Somartex® for “Self Operating MARine Trapping Extractor” was patented and built to transfer the concept from closed aquarium systems to open marine ecosystems. Full article
(This article belongs to the Special Issue Isolation and Structure Elucidation of Marine Secondary Metabolites)
►▼ Show Figures

Graphical abstract

13 pages, 3887 KiB  
Article
Conjugation of Inulin Improves Anti-Biofilm Activity of Chitosan
by Guiqiang Zhang, Jing Liu, Ruilian Li, Siming Jiao, Cui Feng, Zhuo A. Wang and Yuguang Du
Mar. Drugs 2018, 16(5), 151; https://doi.org/10.3390/md16050151 - 04 May 2018
Cited by 18 | Viewed by 4348
Abstract
Bacteria biofilm helps bacteria prevent phagocytosis during infection and increase resistance to antibiotics. Staphylococcus aureus is a Gram-positive pathogenic bacterium and is tightly associated with biofilm-related infections, which have led to great threat to human health. Chitosan, the only cationic polysaccharide in nature, [...] Read more.
Bacteria biofilm helps bacteria prevent phagocytosis during infection and increase resistance to antibiotics. Staphylococcus aureus is a Gram-positive pathogenic bacterium and is tightly associated with biofilm-related infections, which have led to great threat to human health. Chitosan, the only cationic polysaccharide in nature, has been demonstrated to have antimicrobial and anti-biofilm activities, which, however, require a relative high dosage of chitosan. Moreover, poor water solubility further restricts its applications on anti-infection therapy. Inulins are a group of polysaccharides produced by many types of plants, and are widely used in processed foods. Compared to chitosan, inulin is very soluble in water and possesses a mild antibacterial activity against certain pathogenic bacteria. In order to develop an effective strategy to treat biofilm-related infections, we introduce a method by covalent conjugation of inulin to chitosan. The physicochemical characterization of the inulin–chitosan conjugate was assayed, and the anti-biofilm activity was evaluated against S. aureus biofilm. The results indicated that, as compared to chitosan, this novel polysaccharide–polysaccharide conjugate significantly enhanced activities against S. aureus either in a biofilm or planktonic state. Of note, the conjugate also showed a broad spectrum anti-biofilm activity on different bacteria strains and low cellular toxicity to mammalian cells. These results suggested that chitosan conjugation of inulin was a viable strategy for treatment against biofilm-related infections. This finding may further spread the application of natural polysaccharides on treatments of infectious disease. Full article
►▼ Show Figures

Figure 1

10 pages, 1776 KiB  
Communication
Two New Terpenoids from Talaromyces purpurogenus
by Wenjing Wang, Xiao Wan, Junjun Liu, Jianping Wang, Hucheng Zhu, Chunmei Chen and Yonghui Zhang
Mar. Drugs 2018, 16(5), 150; https://doi.org/10.3390/md16050150 - 02 May 2018
Cited by 34 | Viewed by 5486
Abstract
A new sesquiterpenoid 9,10-diolhinokiic acid (1) and a new diterpenoid roussoellol C (2), together with 4 known compounds, were isolated from the extracts of laboratory cultures of marine-derived fungus Talaromyces purpurogenus. 9,10-diolhinokiic acid is the first thujopsene-type sesquiterpenoid [...] Read more.
A new sesquiterpenoid 9,10-diolhinokiic acid (1) and a new diterpenoid roussoellol C (2), together with 4 known compounds, were isolated from the extracts of laboratory cultures of marine-derived fungus Talaromyces purpurogenus. 9,10-diolhinokiic acid is the first thujopsene-type sesquiterpenoid containing a 9,10-diol moiety, and roussoellol C possesses a novel tetracyclic fusicoccane framework with an unexpected hydroxyl at C-4. These new structures were confirmed by spectroscopic data, chemical method, NMR data calculations and electronic circular dichroism (ECD) calculations. The selected compounds were evaluated for cytotoxicities against five human cancer cell lines, including SW480, HL-60, A549, MCF-7, and SMMC-7721 and the IC50 values of compound 2 against MCF-7 and 3 against HL-60 cells were 6.5 and 7.9 μM, respectively. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine-Derived Aspergillus, Penicillium, Talaromyces and Trichoderma Species)
►▼ Show Figures

Graphical abstract

12 pages, 673 KiB  
Article
Water-Soluble Fish Protein Intake Led to Lower Serum and Liver Cholesterol Concentrations in Obese Zucker fa/fa Rats
by Aslaug Drotningsvik, Linn Anja Vikøren, Svein Are Mjøs, Åge Oterhals, Daniela Pampanin, Ola Flesland and Oddrun Anita Gudbrandsen
Mar. Drugs 2018, 16(5), 149; https://doi.org/10.3390/md16050149 - 01 May 2018
Cited by 17 | Viewed by 4612
Abstract
Proteins from different fish species and different raw materials such as fish fillets and by-products have shown promising cardioprotective effects in rodents and humans, including effects on cholesterol metabolism. Blue whiting is used mainly to produce fish meal for the feed industry and [...] Read more.
Proteins from different fish species and different raw materials such as fish fillets and by-products have shown promising cardioprotective effects in rodents and humans, including effects on cholesterol metabolism. Blue whiting is used mainly to produce fish meal for the feed industry and during this production, a water-soluble protein fraction, containing small peptides that are easily absorbed and may hold bioactive properties, is isolated. The effects of water-soluble fish protein on cholesterol metabolism were investigated in twelve male obese Zucker fa/fa rats. Rats were fed diets with water-soluble protein from blue whiting (BWW) as 1/3 of the total protein and the remaining 2/3 as casein (BWW group) or with casein as the sole protein source (control group). After 5 weeks intervention, the BWW group had lower serum total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol concentrations and lower cholesteryl ester concentration compared to controls. Hepatic concentrations of cholesterol, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and LDL receptors were also lower in the BWW group. The groups had a similar concentration of serum total bile acids and similar fecal excretions of cholesterol and bile acids. To conclude, the BWW diet led to lower concentrations of serum and liver cholesterol in obese Zucker fa/fa rats, probably due to lower hepatic cholesterol synthesis. Full article
(This article belongs to the Collection Marine Drugs in the Management of Metabolic Diseases)
►▼ Show Figures

Figure 1

14 pages, 2722 KiB  
Article
Frondanol, a Nutraceutical Extract from Cucumaria frondosa, Attenuates Colonic Inflammation in a DSS-Induced Colitis Model in Mice
by Sandeep B. Subramanya, Sanjana Chandran, Saeeda Almarzooqi, Vishnu Raj, Aisha Salem Al Zahmi, Radeya Ahmed Al Katheeri, Samira Ali Al Zadjali, Peter D. Collin and Thomas E. Adrian
Mar. Drugs 2018, 16(5), 148; https://doi.org/10.3390/md16050148 - 30 Apr 2018
Cited by 14 | Viewed by 6316
Abstract
Frondanol is a nutraceutical lipid extract of the intestine of the edible Atlantic sea cucumber, Cucumaria frondosa, with potent anti-inflammatory effects. In the current study, we investigated Frondanol as a putative anti-inflammatory compound in an experimental model of colonic inflammation. C57BL/6J male black [...] Read more.
Frondanol is a nutraceutical lipid extract of the intestine of the edible Atlantic sea cucumber, Cucumaria frondosa, with potent anti-inflammatory effects. In the current study, we investigated Frondanol as a putative anti-inflammatory compound in an experimental model of colonic inflammation. C57BL/6J male black mice (C57BL/6J) were given 3% dextran sodium sulfate (DSS) in drinking water for 7 days to induce colitis. The colitis group received oral Frondanol (100 mg/kg body weight/per day by gavage) and were compared with a control group and the DSS group. Disease activity index (DAI) and colon histology were scored for macroscopic and microscopic changes. Colonic tissue length, myeloperoxidase (MPO) concentration, neutrophil and macrophage marker mRNA, pro-inflammatory cytokine proteins, and their respective mRNAs were measured using ELISA and real-time RT-PCR. The tissue content of leukotriene B4 (LTB4) was also measured using ELISA. Frondanol significantly decreased the DAI and reduced the inflammation-associated changes in colon length as well as macroscopic and microscopic architecture of the colon. Changes in tissue MPO concentrations, neutrophil and macrophage mRNA expression (F4/80 and MIP-2), and pro-inflammatory cytokine content (IL-1β, IL-6 and TNF-α) both at the protein and mRNA level were significantly reduced by Frondanol. The increase in content of the pro-inflammatory mediator leukotriene B4 (LTB4) induced by DSS was also significantly inhibited by Frondanol. It was thus found that Frondanol supplementation attenuates colon inflammation through its potent anti-inflammatory activity. Full article
(This article belongs to the Special Issue Marine Anti-inflammatory Agents)
►▼ Show Figures

Figure 1

12 pages, 1230 KiB  
Review
Natural Product Potential of the Genus Nocardiopsis
by Alyaa Hatem Ibrahim, Samar Yehia Desoukey, Mostafa A. Fouad, Mohamed Salah Kamel, Tobias A. M. Gulder and Usama Ramadan Abdelmohsen
Mar. Drugs 2018, 16(5), 147; https://doi.org/10.3390/md16050147 - 29 Apr 2018
Cited by 43 | Viewed by 6488
Abstract
Actinomycetes are a relevant source of novel bioactive compounds. One of the pharmaceutically and biotechnologically important genera that attract natural products research is the genus Nocardiopsis, mainly for its ability to produce a wide variety of secondary metabolites accounting for its wide range [...] Read more.
Actinomycetes are a relevant source of novel bioactive compounds. One of the pharmaceutically and biotechnologically important genera that attract natural products research is the genus Nocardiopsis, mainly for its ability to produce a wide variety of secondary metabolites accounting for its wide range of biological activities. This review covers the literature from January 2015 until February 2018 making a complete survey of all the compounds that were isolated from the genus Nocardiopsis, their biological activities, and natural sources, whenever applicable. Full article
(This article belongs to the Special Issue Bioprospecting of Marine Microorganisms)
►▼ Show Figures

Figure 1

16 pages, 3621 KiB  
Article
Bioactive Bromotyrosine-Derived Alkaloids from the Polynesian Sponge Suberea ianthelliformis
by Amr El-Demerdash, Céline Moriou, Jordan Toullec, Marc Besson, Stéphanie Soulet, Nelly Schmitt, Sylvain Petek, David Lecchini, Cécile Debitus and Ali Al-Mourabit
Mar. Drugs 2018, 16(5), 146; https://doi.org/10.3390/md16050146 - 27 Apr 2018
Cited by 19 | Viewed by 5996
Abstract
Herein, we describe the isolation and spectroscopic identification of eight new tetrabrominated tyrosine alkaloids 2–9 from the Polynesian sponge Suberea ianthelliformis, along with known major compound psammaplysene D (1), N,N-dimethyldibromotyramine, 5-hydroxy xanthenuric acid, and xanthenuric [...] Read more.
Herein, we describe the isolation and spectroscopic identification of eight new tetrabrominated tyrosine alkaloids 2–9 from the Polynesian sponge Suberea ianthelliformis, along with known major compound psammaplysene D (1), N,N-dimethyldibromotyramine, 5-hydroxy xanthenuric acid, and xanthenuric acid. Cytotoxicity and acetylcholinesterase inhibition activities were evaluated for some of the isolated metabolites. They exhibited moderate antiproliferative activity against KB cancer cell lines, but psammaplysene D (1) displayed substantial cytotoxicity as well as acetylcholinesterase inhibition with IC50 values of 0.7 μM and 1.3 μM, respectively. Full article
(This article belongs to the Collection TASCMAR)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-38
Previous Issue
Next Issue
Back to TopTop