Editorial

6 pages, 223 KiB

Open AccessEditorial

Secondary Metabolites from Fungi—In Honor of Prof. Dr. Ji-Kai Liu’s 60th Birthday

by Tao Feng and Frank Surup

J. Fungi 2022, 8(12), 1271; https://doi.org/10.3390/jof8121271 - 01 Dec 2022

Viewed by 1134

It is our pleasure and privilege to serve as Guest Editors for this Special Issue of the Journal of Fungi in honor of Professor Ji-Kai Liu’s 60th birthday [...] Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

Research

Jump to: Editorial, Review

14 pages, 2617 KiB

Open AccessArticle

Antiproliferative and Cytotoxic Cytochalasins from Sparticola triseptata Inhibit Actin Polymerization and Aggregation

by Katherine Yasmin M. Garcia, Mark Tristan J. Quimque, Christopher Lambert, Katharina Schmidt, Gian Primahana, Theresia E. B. Stradal, Andreas Ratzenböck, Hans-Martin Dahse, Chayanard Phukhamsakda, Marc Stadler, Frank Surup and Allan Patrick G. Macabeo

J. Fungi 2022, 8(6), 560; https://doi.org/10.3390/jof8060560 - 25 May 2022

Cited by 5 | Viewed by 2585

Abstract

Laying the groundwork on preliminary structure–activity relationship study relating to the disruptive activity of cytochalasan derivatives on mammalian cell actin cytoskeleton, we furthered our study on the cytochalasans of the Dothideomycetes fungus, Sparticola triseptata. A new cytochalasan analog triseptatin (1), [...] Read more.

Laying the groundwork on preliminary structure–activity relationship study relating to the disruptive activity of cytochalasan derivatives on mammalian cell actin cytoskeleton, we furthered our study on the cytochalasans of the Dothideomycetes fungus, Sparticola triseptata. A new cytochalasan analog triseptatin (1), along with the previously described cytochalasans deoxaphomin B (2) and cytochalasin B (3), and polyketide derivatives cis-4-hydroxy-6-deoxyscytalone (4) and 6-hydroxymellein (5) were isolated from the rice culture of S. triseptata. The structure of 1 was elucidated through NMR spectroscopic analysis and high-resolution mass spectrometry (HR-ESI-MS). The relative and absolute configurations were established through analysis of NOESY spectroscopic data and later correlated with experimental electronic circular dichroism and time-dependent density functional theory (ECD–TDDFT) computational analysis. Compounds 1 and 2 showed cytotoxic activities against seven mammalian cell lines (L929, KB3.1, MCF-7, A549, PC-3, SKOV-3, and A431) and antiproliferative effects against the myeloid leukemia K-562 cancer cell line. Both 1 and 2 were shown to possess properties inhibiting the F-actin network, prompting further hypotheses that should to be tested in the future to enable a well-resolved concept of the structural implications determining the bioactivity of the cytochalasin backbone against F-actin. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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10 pages, 1464 KiB

Open AccessArticle

Cytochalasans from the Endophytic Fungus Phomopsis sp. shj2 and Their Antimigratory Activities

by Bing-Chao Yan, Wei-Guang Wang, Ling-Mei Kong, Jian-Wei Tang, Xue Du, Yan Li and Pema-Tenzin Puno

J. Fungi 2022, 8(5), 543; https://doi.org/10.3390/jof8050543 - 23 May 2022

Cited by 3 | Viewed by 1746

Abstract

Cytochalasans from the endophytic fungi featured structure diversity. Our previous study has disclosed that cytochalasans from the endophytic fungus Phomopsis sp. shj2 exhibited an antimigratory effect. Further chemical investigation on Phomopsis sp. shj2 has led to the discovery of seven new cytochalasans ( [...] Read more.

Cytochalasans from the endophytic fungi featured structure diversity. Our previous study has disclosed that cytochalasans from the endophytic fungus Phomopsis sp. shj2 exhibited an antimigratory effect. Further chemical investigation on Phomopsis sp. shj2 has led to the discovery of seven new cytochalasans (1–7), together with four known ones. Their structures were elucidated through extensive spectroscopic data interpretation and single-crystal X-ray diffraction analysis. Compounds 1–3 and 8–11 exhibited antimigratory effects against MDA-MB-231 in vitro with IC₅₀ values in the range of 1.01−10.42 μM. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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15 pages, 2174 KiB

Open AccessArticle

Sorbicillinoid Derivatives with the Radical Scavenging Activities from the Marine-Derived Fungus Acremonium chrysogenum C10

by Chengbao Duan, Shiyuan Wang, Ruiyun Huo, Erwei Li, Min Wang, Jinwei Ren, Yuanyuan Pan, Ling Liu and Gang Liu

J. Fungi 2022, 8(5), 530; https://doi.org/10.3390/jof8050530 - 20 May 2022

Cited by 8 | Viewed by 1980

Abstract

Sorbicillinoids are a class of structurally diverse hexaketide metabolites with good biological activities. To explore new structural sorbicillinoids and their bioactivities, the marine-derived fungus Acremonium chrysogenum C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A–C (1–3), along with five [...] Read more.

Sorbicillinoids are a class of structurally diverse hexaketide metabolites with good biological activities. To explore new structural sorbicillinoids and their bioactivities, the marine-derived fungus Acremonium chrysogenum C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A–C (1–3), along with five known ones, trichotetronine (4), trichodimerol (5), demethyltrichodimerol (6), trichopyrone (7) and oxosorbicillinol (8), were isolated. The structures of new sorbicillinoids were elucidated by analysis of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS). The absolute configurations of compounds 1–3 were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Compound 3 exhibited a strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the IC₅₀ value ranging from 11.53 ± 1.53 to 60.29 ± 6.28 μM in 24 h. Additionally, compounds 2 and 3 showed moderate activities against Staphylococcus aureus and Cryptococcus neoformans, with IC₅₀ values of 86.93 ± 1.72 and 69.06 ± 10.50 μM, respectively. The boundary of sorbicillinoid biosynthetic gene cluster in A. chrysogenum was confirmed by transcriptional analysis, and the biosynthetic pathway of compounds 1–8 was also proposed. In summary, our results indicated that A. chrysogenum is an important reservoir of sorbicillinoid derivatives, and compound 3 has the potential for new natural agents in DPPH radical scavenging. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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17 pages, 3557 KiB

Open AccessArticle

Gram-Level Production of Balanol through Regulatory Pathway and Medium Optimization in Herb Fungus Tolypocladium ophioglossoides

by Rui-Qi Li, Xiang Liu, Min Zhang, Wei-Qun Xu, Yong-Quan Li and Xin-Ai Chen

J. Fungi 2022, 8(5), 510; https://doi.org/10.3390/jof8050510 - 16 May 2022

Cited by 1 | Viewed by 1686

Abstract

As a potential protein kinase C inhibitor, the fungus metabolite balanol has become more attractive in recent decades. In our previous work, we revealed its biosynthetic pathway through overexpression of the cluster-situated regulator gene blnR in Chinese herb fungus Tolypocladium ophioglossoides. However, [...] Read more.

As a potential protein kinase C inhibitor, the fungus metabolite balanol has become more attractive in recent decades. In our previous work, we revealed its biosynthetic pathway through overexpression of the cluster-situated regulator gene blnR in Chinese herb fungus Tolypocladium ophioglossoides. However, information on the regulation of blnR is still largely unknown. In this study, we further investigated the regulation of balanol biosynthesis by BlnR through the analysis of affinity binding using EMSA and RNA-seq analysis. The results showed that BlnR positively regulates balanol biosynthesis through binding to all promoters of bln gene members, including its own promoter. Microscopic observation revealed blnR overexpression also affected spore development and hypha growth. Furthermore, RNA-seq analysis suggested that BlnR can regulate other genes outside of the balanol biosynthetic gene cluster, including those involved in conidiospore development. Finally, balanol production was further improved to 2187.39 mg/L using the optimized medium through statistical optimization based on response surface methodology. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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17 pages, 4446 KiB

Open AccessArticle

[20(22)E]-Lanostane Triterpenes from the Fungus Ganoderma australe

by Lin Zhou, Li-Li Guo, Masahiko Isaka, Zheng-Hui Li and He-Ping Chen

J. Fungi 2022, 8(5), 503; https://doi.org/10.3390/jof8050503 - 12 May 2022

Cited by 3 | Viewed by 2197

Abstract

Twelve new lanostane triterpenoids (1–5, 7–13) were isolated from the fruiting bodies of the fungus Ganoderma australe. The structures of the new compounds were elucidated by extensive 1D and 2D NMR, and HRESIMS spectroscopic analysis. [...] Read more.

Twelve new lanostane triterpenoids (1–5, 7–13) were isolated from the fruiting bodies of the fungus Ganoderma australe. The structures of the new compounds were elucidated by extensive 1D and 2D NMR, and HRESIMS spectroscopic analysis. All the triterpenes are featured by 20(22)E configurations which are uncommon in the Ganoderma triterpene family. The absolute configuration of the C-25 of compounds 1, 2, and 6 were determined by the phenylglycine methyl ester (PGME) method. A postulated biosynthetic pathway for compound 1 was discussed. This study opens new insights into the secondary metabolites of the chemically underinvestigated fungus G. australe. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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Graphical abstract

10 pages, 2281 KiB

Open AccessArticle

Four New Highly Oxygenated Eremophilane Sesquiterpenes from an Endophytic Fungus Boeremia exigua Isolated from Fritillaria hupehensis

by Hong-Lian Ai, Xiao Lv, Ke Ye, Meng-Xi Wang, Rong Huang, Bao-Bao Shi and Zheng-Hui Li

J. Fungi 2022, 8(5), 492; https://doi.org/10.3390/jof8050492 - 08 May 2022

Cited by 3 | Viewed by 2020

Abstract

Four new eremophilane-type sesquiterpenes, boeremialanes A–D (1–4) were obtained from solid substrate cultures of Boeremia exigua (Didymellaceae), an endophytic fungus isolated from Fritillaria hupehensis (Liliaceae). Boeremialanes A–C (1–3) are highly oxygenated eremophilanes with a benzoate [...] Read more.

Four new eremophilane-type sesquiterpenes, boeremialanes A–D (1–4) were obtained from solid substrate cultures of Boeremia exigua (Didymellaceae), an endophytic fungus isolated from Fritillaria hupehensis (Liliaceae). Boeremialanes A–C (1–3) are highly oxygenated eremophilanes with a benzoate unit attached at the C-13 position and are rarely found in nature. Their structures and absolute configurations were determined by extensive spectroscopic methods, electronic circular dichroism (ECD), and nuclear magnetic resonance (NMR) calculations with DP4+ analysis. Boeremialane D (4) potently inhibited nitric oxide production in lipopolysaccharide-treated RAW264.7 macrophages with an IC₅₀ of 8.62 μM and was more potent than the positive control, pyrrolidinedithiocarbamate (IC₅₀ = 23.1 μM). Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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17 pages, 2505 KiB

Open AccessArticle

New Antibacterial Chloro-Containing Polyketides from the Alga-Derived Fungus Asteromyces cruciatus KMM 4696

by Olesya I. Zhuravleva, Galina K. Oleinikova, Alexandr S. Antonov, Natalia N. Kirichuk, Dmitry N. Pelageev, Anton B. Rasin, Alexander S. Menshov, Roman S. Popov, Natalya Yu. Kim, Ekaterina A. Chingizova, Artur R. Chingizov, Olga O. Volchkova, Gunhild von Amsberg, Sergey A. Dyshlovoy, Ekaterina A. Yurchenko, Irina V. Guzhova and Anton N. Yurchenko

J. Fungi 2022, 8(5), 454; https://doi.org/10.3390/jof8050454 - 27 Apr 2022

Cited by 7 | Viewed by 2197

Abstract

Six new polyketides acrucipentyns A–F (1–6) were isolated from the alga-derived fungus Asteromyces cruciatus KMM 4696. Their structures were established based on spectroscopic methods. The absolute configurations of acrucipentyn A was assigned by the modified Mosher’s method and ROESY [...] Read more.

Six new polyketides acrucipentyns A–F (1–6) were isolated from the alga-derived fungus Asteromyces cruciatus KMM 4696. Their structures were established based on spectroscopic methods. The absolute configurations of acrucipentyn A was assigned by the modified Mosher’s method and ROESY data analysis. Acrucipentyns A–E were identified to be the very first examples of chlorine-containing asperpentyn-like compounds. The cytotoxic and antimicrobial activities of the isolated compounds were examined. Acrucipentyns A–F were found as antimicrobial agents, which inhibited sortase A enzyme activity, bacterial growth and biofilm formation of Staphylococcus aureus and decreased LDH release from human keratinocytes HaCaT in S. aureus skin infection in an in vitro model. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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29 pages, 11728 KiB

Open AccessArticle

Exploring the Activity of Fungal Phenalenone Derivatives as Potential CK2 Inhibitors Using Computational Methods

by Sabrin R. M. Ibrahim, Alaa A. Bagalagel, Reem M. Diri, Ahmad O. Noor, Hussain T. Bakhsh, Yosra A. Muhammad, Gamal A. Mohamed and Abdelsattar M. Omar

J. Fungi 2022, 8(5), 443; https://doi.org/10.3390/jof8050443 - 24 Apr 2022

Cited by 7 | Viewed by 2310

Abstract

Cancer represents one of the most prevalent causes of global death. CK2 (casein kinase 2) activation boosted cancer proliferation and progression. Therefore, CK2 inhibition can have a crucial role in prohibiting cancer progression and enhancing apoptosis. Fungi have gained vast interest as a [...] Read more.

Cancer represents one of the most prevalent causes of global death. CK2 (casein kinase 2) activation boosted cancer proliferation and progression. Therefore, CK2 inhibition can have a crucial role in prohibiting cancer progression and enhancing apoptosis. Fungi have gained vast interest as a wealthy pool of anticancer metabolites that could particularly target various cancer progression-linked signaling pathways. Phenalenones are a unique class of secondary metabolites that possess diverse bioactivities. In the current work, the CK2 inhibitory capacity of 33 fungal phenalenones was explored using computational studies. After evaluating the usefulness of the compounds as enzyme inhibitors by ADMET prediction, the compounds were prepared for molecular docking in the CK2-α1 crystal structure (PDB: 7BU4). Molecular dynamic simulation was performed on the top two scoring compounds to evaluate their binding affinity and protein stability through a simulated physiological environment. Compound 19 had a superior binding affinity to the co-crystallized ligand (Y49). The improved affinity can be attributed to the fact that the aliphatic chain makes additional contact with Asp120 in a pocket distant from the active site. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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13 pages, 2067 KiB

Open AccessArticle

Heterologous Expression of Secondary Metabolite Genes in Trichoderma reesei for Waste Valorization

by Mary L. Shenouda, Maria Ambilika, Elizabeth Skellam and Russell J. Cox

J. Fungi 2022, 8(4), 355; https://doi.org/10.3390/jof8040355 - 30 Mar 2022

Cited by 9 | Viewed by 3401

Abstract

Trichoderma reesei (Hypocrea jecorina) was developed as a microbial cell factory for the heterologous expression of fungal secondary metabolites. This was achieved by inactivation of sorbicillinoid biosynthesis and construction of vectors for the rapid cloning and expression of heterologous fungal biosynthetic [...] Read more.

Trichoderma reesei (Hypocrea jecorina) was developed as a microbial cell factory for the heterologous expression of fungal secondary metabolites. This was achieved by inactivation of sorbicillinoid biosynthesis and construction of vectors for the rapid cloning and expression of heterologous fungal biosynthetic genes. Two types of megasynth(et)ases were used to test the strain and vectors, namely a non-reducing polyketide synthase (nr-PKS, aspks1) from Acremonium strictum and a hybrid highly-reducing PKS non-ribosomal peptide synthetase (hr-PKS-NRPS, tenS + tenC) from Beauveria bassiana. The resulting engineered T. reesei strains were able to produce the expected natural products 3-methylorcinaldehyde and pretenellin A on waste materials including potato, orange, banana and kiwi peels and barley straw. Developing T. reesei as a heterologous host for secondary metabolite production represents a new method for waste valorization by the direct conversion of waste biomass into secondary metabolites. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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17 pages, 4854 KiB

Open AccessArticle

Anti-Adipogenic Lanostane-Type Triterpenoids from the Edible and Medicinal Mushroom Ganoderma applanatum

by Xing-Rong Peng, Qian Wang, Hai-Guo Su, Lin Zhou, Wen-Yong Xiong and Ming-Hua Qiu

J. Fungi 2022, 8(4), 331; https://doi.org/10.3390/jof8040331 - 22 Mar 2022

Cited by 10 | Viewed by 2400

Abstract

Our previous research has shown that lanostane triterpenoids from Ganoderma applanatum exhibit significant anti-adipogenesis effects. In order to obtain more structurally diverse lanostane triterpenoids to establish a structure–activity relationship, we continued the study of lanostane triterpenoids from the fruiting bodies of G. applanatum [...] Read more.

Our previous research has shown that lanostane triterpenoids from Ganoderma applanatum exhibit significant anti-adipogenesis effects. In order to obtain more structurally diverse lanostane triterpenoids to establish a structure–activity relationship, we continued the study of lanostane triterpenoids from the fruiting bodies of G. applanatum, and forty highly oxygenated lanostane-type triterpenoinds (1–40), including sixteen new compounds (1–16), were isolated. Their structures were elucidated using NMR spectra, X-ray crystallographic analysis, and Mosher’s method. In addition, some of their parts were evaluated to determine their anti-adipogenesis activities in the 3T3-L1 cell model. The results showed that compounds 16, 22, 28, and 32 exhibited stronger anti-adipogenesis effects than the positive control (LiCl, 20 mM) at the concentration of 20 μM. Compounds 15 and 20 could significantly reduce the lipid accumulation during the differentiation process of 3T3-L1 cells, comparable to the untreated group. Their IC₅₀ values were 6.42 and 5.39 μM, respectively. The combined results of our previous and present studies allow us to establish a structure-activity relationship of lanostane triterpenoids, indicating that the A-seco-23→26 lactone skeleton could play a key role in anti-adipogenesis activity. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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16 pages, 3313 KiB

Open AccessArticle

Polyketide Derivatives from the Endophytic Fungus Phaeosphaeria sp. LF5 Isolated from Huperzia serrata and Their Acetylcholinesterase Inhibitory Activities

by Yiwen Xiao, Weizhong Liang, Zhibin Zhang, Ya Wang, Shanshan Zhang, Jiantao Liu, Jun Chang, Changjiu Ji and Du Zhu

J. Fungi 2022, 8(3), 232; https://doi.org/10.3390/jof8030232 - 26 Feb 2022

Cited by 8 | Viewed by 2488

Abstract

The secondary metabolites of Phaeosphaeria sp. LF5, an endophytic fungus with acetylcholinesterase (AChE) inhibitory activity isolated from Huperzia serrata, were investigated. Their structures and absolute configurations were elucidated by means of extensive spectroscopic data, including one- and two-dimensional nuclear magnetic resonance (NMR), [...] Read more.

The secondary metabolites of Phaeosphaeria sp. LF5, an endophytic fungus with acetylcholinesterase (AChE) inhibitory activity isolated from Huperzia serrata, were investigated. Their structures and absolute configurations were elucidated by means of extensive spectroscopic data, including one- and two-dimensional nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) analyses, and calculations of electronic circular dichroism (ECD). A chemical study on the solid-cultured fungus LF5 resulted in 11 polyketide derivatives, which included three previously undescribed derivatives: aspilactonol I (4), 2-(1-hydroxyethyl)-6-methylisonicotinic acid (7), and 6,8-dihydroxy-3-(1′R, 2′R-dihydroxypropyl)-isocoumarin (9), and two new natural-source-derived aspilactonols (G, H) (2, 3). Moreover, the absolute configuration of de-O-methyldiaporthin (11) was identified for the first time. Compounds 4 and 11 exhibited inhibitory activity against AChE with half maximal inhibitory concentration (IC₅₀) values of 6.26 and 21.18 µM, respectively. Aspilactonol I (4) is the first reported furanone AChE inhibitor (AChEI). The results indicated that Phaeosphaeria is a good source of polyketide derivatives. This study identified intriguing lead compounds for further research and development of new AChEIs. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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16 pages, 3185 KiB

Open AccessArticle

Exploring Verrucosidin Derivatives with Glucose-Uptake-Stimulatory Activity from Penicillium cellarum Using MS/MS-Based Molecular Networking

by Junjie Han, Baosong Chen, Rui Zhang, Jinjin Zhang, Huanqin Dai, Tao Wang, Jingzu Sun, Guoliang Zhu, Wei Li, Erwei Li, Xueting Liu, Wenbing Yin and Hongwei Liu

J. Fungi 2022, 8(2), 143; https://doi.org/10.3390/jof8020143 - 30 Jan 2022

Cited by 4 | Viewed by 2770

Abstract

Under the guidance of LC-MS/MS-based molecular networking, seven new verrucosidin derivatives, penicicellarusins A-G (3–9), were isolated together with three known analogues from the fungus Penicillium cellarum. The structures of the new compounds were determined by a combination of [...] Read more.

Under the guidance of LC-MS/MS-based molecular networking, seven new verrucosidin derivatives, penicicellarusins A-G (3–9), were isolated together with three known analogues from the fungus Penicillium cellarum. The structures of the new compounds were determined by a combination of NMR, mass and electronic circular dichroism spectral data analysis. The absolute configuration of penicyrone A (10) was corrected based on X-ray diffraction analyses. Bioactivity screening indicated that compounds 1, 2, and 4 showed much stronger promising hypoglycemic activity than the positive drug (rosiglitazone) in the range of 25–100 μM, which represents a potential new class of hypoglycemic agents. Preliminary structure-activity relationship analysis indicates that the formation of epoxy ring on C₆-C₇ in the structures is important for the glucose uptake-stimulating activity. The gene cluster for the biosynthesis of 1–12 is identified by sequencing the genome of P. cellarum and similarity analysis with the gene cluster of verrucosidins in P. polonicum. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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17 pages, 3612 KiB

Open AccessArticle

Sesquiterpenoids and Xanthones from the Kiwifruit-Associated Fungus Bipolaris sp. and Their Anti-Pathogenic Microorganism Activity

by Jun-Jie Yu, Ying-Xue Jin, Shan-Shan Huang and Juan He

J. Fungi 2022, 8(1), 9; https://doi.org/10.3390/jof8010009 - 23 Dec 2021

Cited by 10 | Viewed by 2536

Abstract

Nine previously undescribed sesquiterpenoids, bipolarisorokins A–I (1–9); two new xanthones, bipolarithones A and B (10 and 11); two novel sativene-xanthone adducts, bipolarithones C and D (12 and 13); as well as five known compounds ( [...] Read more.

Nine previously undescribed sesquiterpenoids, bipolarisorokins A–I (1–9); two new xanthones, bipolarithones A and B (10 and 11); two novel sativene-xanthone adducts, bipolarithones C and D (12 and 13); as well as five known compounds (14–18) were characterized from the kiwifruit-associated fungus Bipolaris sp. Their structures were elucidated by extensive spectroscopic methods, electronic circular dichroism (ECD), ¹³C NMR calculations, DP4+ probability analyses, and single crystal X-ray diffractions. Many compounds exhibited anti-pathogenic microorganism activity against the bacterium Pseudomonas syringae pv. actinidiae and four pathogenic microorganisms. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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18 pages, 2943 KiB

Open AccessEditor’s ChoiceArticle

Engineering Aspergillus oryzae for the Heterologous Expression of a Bacterial Modular Polyketide Synthase

by Jin Feng, Maurice Hauser, Russell J. Cox and Elizabeth Skellam

J. Fungi 2021, 7(12), 1085; https://doi.org/10.3390/jof7121085 - 17 Dec 2021

Cited by 5 | Viewed by 3969

Abstract

Microbial natural products have had phenomenal success in drug discovery and development yet form distinct classes based on the origin of their native producer. Methods that enable metabolic engineers to combine the most useful features of the different classes of natural products may [...] Read more.

Microbial natural products have had phenomenal success in drug discovery and development yet form distinct classes based on the origin of their native producer. Methods that enable metabolic engineers to combine the most useful features of the different classes of natural products may lead to molecules with enhanced biological activities. In this study, we modified the metabolism of the fungus Aspergillus oryzae to enable the synthesis of triketide lactone (TKL), the product of the modular polyketide synthase DEBS1-TE engineered from bacteria. We established (2S)-methylmalonyl-CoA biosynthesis via introducing a propionyl-CoA carboxylase complex (PCC); reassembled the 11.2 kb DEBS1-TE coding region from synthetic codon-optimized gene fragments using yeast recombination; introduced bacterial phosphopantetheinyltransferase SePptII; investigated propionyl-CoA synthesis and degradation pathways; and developed improved delivery of exogenous propionate. Depending on the conditions used titers of TKL ranged from <0.01–7.4 mg/L. In conclusion, we have demonstrated that A. oryzae can be used as an alternative host for the synthesis of polyketides from bacteria, even those that require toxic or non-native substrates. Our metabolically engineered A. oryzae may offer advantages over current heterologous platforms for producing valuable and complex natural products. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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20 pages, 2242 KiB

Open AccessArticle

Immunosuppressive Sesquiterpenoids from the Edible Mushroom Craterellus odoratus

by Quan Dai, Fa-Lei Zhang, Zheng-Hui Li, Juan He and Tao Feng

J. Fungi 2021, 7(12), 1052; https://doi.org/10.3390/jof7121052 - 08 Dec 2021

Cited by 8 | Viewed by 2374

Abstract

The aim of this work was to comprehensively understand the chemical constituents of the edible mushroom Craterellus ordoratus and their bioactivity. A chemical investigation on this mushroom led to the isolation of 23 sesquiterpenoids including eighteen previously undescribed bergamotane sesquiterpenes, craterodoratins A–R ( [...] Read more.

The aim of this work was to comprehensively understand the chemical constituents of the edible mushroom Craterellus ordoratus and their bioactivity. A chemical investigation on this mushroom led to the isolation of 23 sesquiterpenoids including eighteen previously undescribed bergamotane sesquiterpenes, craterodoratins A–R (1–18), and one new victoxinine derivative, craterodoratin S (19). The new structures were elucidated by detailed interpretation of spectrometric data, theoretical nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD) calculations, and single-crystal X-ray crystallographic analysis. Compounds 1 and 2 possess a ring-rearranged carbon skeleton. Compounds 3, 10, 12–15, 19, 20 and 23 exhibit potent inhibitory activity against the lipopolysaccharide (LPS)-induced proliferation of B lymphocyte cells with the IC₅₀ values ranging from 0.67 to 22.68 μM. Compounds 17 and 20 inhibit the concanavalin A (ConA)-induced proliferation of T lymphocyte cell with IC₅₀ values of 31.50 and 0.98 μM, respectively. It is suggested that C. ordoratus is a good source for bergamotane sesquiterpenoids, and their immunosuppressive activity was reported for the first time. This research is conducive to the further development and utilization of C. ordoratus. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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11 pages, 2409 KiB

Open AccessArticle

Trichoderma reesei Contains a Biosynthetic Gene Cluster That Encodes the Antifungal Agent Ilicicolin H

by Mary L. Shenouda, Maria Ambilika and Russell J. Cox

J. Fungi 2021, 7(12), 1034; https://doi.org/10.3390/jof7121034 - 01 Dec 2021

Cited by 5 | Viewed by 3106

Abstract

The trili biosynthetic gene cluster (BGC) from the well-studied organism Trichoderma reesei was studied by heterologous expression in the fungal host Aspergillus oryzae. Coexpression of triliA and triliB produces two new acyl tetramic acids. Addition of the ring-expanding cytochrome P450 encoded by [...] Read more.

The trili biosynthetic gene cluster (BGC) from the well-studied organism Trichoderma reesei was studied by heterologous expression in the fungal host Aspergillus oryzae. Coexpression of triliA and triliB produces two new acyl tetramic acids. Addition of the ring-expanding cytochrome P450 encoded by triliC then yields a known pyridone intermediate to ilicicolin H and a new chain-truncated shunt metabolite. Finally, addition of the intramolecular Diels-Alderase encoded by triliD affords a mixture of 8-epi ilicicolin H and ilicicolin H itself, showing that the T. reesei trili BGC encodes biosynthesis of this potent antifungal agent. Unexpected A. oryzae shunt pathways are responsible for the production of the new compounds, emphasising the role of fungal hosts in catalysing diversification reactions. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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Review

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36 pages, 20701 KiB

Open AccessReview

Sulfur-Containing Compounds from Endophytic Fungi: Sources, Structures and Bioactivities

by Yaqin Fan, Zhiheng Ma, Yan Zhang, Yufei Wang, Yousong Ding, Cong Wang and Shugeng Cao

J. Fungi 2022, 8(6), 628; https://doi.org/10.3390/jof8060628 - 13 Jun 2022

Cited by 3 | Viewed by 2412

Abstract

Endophytic fungi have attracted increasing attention as an under-explored source for the discovery and development of structurally and functionally diverse secondary metabolites. These microorganisms colonize their hosts, primarily plants, and demonstrate diverse ecological distribution. Among endophytic fungal natural products, sulfur-containing compounds feature one [...] Read more.

Endophytic fungi have attracted increasing attention as an under-explored source for the discovery and development of structurally and functionally diverse secondary metabolites. These microorganisms colonize their hosts, primarily plants, and demonstrate diverse ecological distribution. Among endophytic fungal natural products, sulfur-containing compounds feature one or more sulfur atoms and possess a range of bioactivities, e.g., cytotoxicity and antimicrobial activities. These natural products mainly belong to the classes of polyketides, nonribosomal peptides, terpenoids, and hybrids. Here, we reviewed the fungal producers, plant sources, chemical structures, and bioactivities of 143 new sulfur-containing compounds that were reported from 1985 to March 2022. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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16 pages, 20550 KiB

Open AccessReview

Biosynthesis of Fungal Natural Products Involving Two Separate Pathway Crosstalk

by Guangzhi Dai, Qiyao Shen, Youming Zhang and Xiaoying Bian

J. Fungi 2022, 8(3), 320; https://doi.org/10.3390/jof8030320 - 21 Mar 2022

Cited by 6 | Viewed by 3969

Abstract

Fungal natural products (NPs) usually possess complicated structures, exhibit satisfactory bioactivities, and are an outstanding source of drug leads, such as the cholesterol-lowering drug lovastatin and the immunosuppressive drug mycophenolic acid. The fungal NPs biosynthetic genes are always arranged within one single biosynthetic [...] Read more.

Fungal natural products (NPs) usually possess complicated structures, exhibit satisfactory bioactivities, and are an outstanding source of drug leads, such as the cholesterol-lowering drug lovastatin and the immunosuppressive drug mycophenolic acid. The fungal NPs biosynthetic genes are always arranged within one single biosynthetic gene cluster (BGC). However, a rare but fascinating phenomenon that a crosstalk between two separate BGCs is indispensable to some fungal dimeric NPs biosynthesis has attracted increasing attention. The hybridization of two separate BGCs not only increases the structural complexity and chemical diversity of fungal NPs, but also expands the scope of bioactivities. More importantly, the underlying mechanism for this hybridization process is poorly understood and needs further exploration, especially the determination of BGCs for each building block construction and the identification of enzyme(s) catalyzing the two biosynthetic precursors coupling processes such as Diels–Alder cycloaddition and Michael addition. In this review, we summarized the fungal NPs produced by functional crosstalk of two discrete BGCs, and highlighted their biosynthetic processes, which might shed new light on genome mining for fungal NPs with unprecedented frameworks, and provide valuable insights into the investigation of mysterious biosynthetic mechanisms of fungal dimeric NPs which are constructed by collaboration of two separate BGCs. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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32 pages, 11060 KiB

Open AccessReview

Diterpenes Specially Produced by Fungi: Structures, Biological Activities, and Biosynthesis (2010–2020)

by Fa-Lei Zhang and Tao Feng

J. Fungi 2022, 8(3), 244; https://doi.org/10.3390/jof8030244 - 28 Feb 2022

Cited by 13 | Viewed by 3799

Abstract

Fungi have traditionally been a very rewarding source of biologically active natural products, while diterpenoids from fungi, such as the cyathane-type diterpenoids from Cyathus and Hericium sp., the fusicoccane-type diterpenoids from Fusicoccum and Alternaria sp., the guanacastane-type diterpenoids from Coprinus and Cercospora sp., [...] Read more.

Fungi have traditionally been a very rewarding source of biologically active natural products, while diterpenoids from fungi, such as the cyathane-type diterpenoids from Cyathus and Hericium sp., the fusicoccane-type diterpenoids from Fusicoccum and Alternaria sp., the guanacastane-type diterpenoids from Coprinus and Cercospora sp., and the harziene-type diterpenoids from Trichoderma sp., often represent unique carbon skeletons as well as diverse biological functions. The abundances of novel skeletons, biological activities, and biosynthetic pathways present new opportunities for drug discovery, genome mining, and enzymology. In addition, diterpenoids peculiar to fungi also reveal the possibility of differing biological evolution, although they have similar biosynthetic pathways. In this review, we provide an overview about the structures, biological activities, evolution, organic synthesis, and biosynthesis of diterpenoids that have been specially produced by fungi from 2010 to 2020. We hope this review provides timely illumination and beneficial guidance for future research works of scholars who are interested in this area. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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45 pages, 7866 KiB

Open AccessReview

Endophytic Fungi: An Effective Alternative Source of Plant-Derived Bioactive Compounds for Pharmacological Studies

by Juan Wen, Samuel Kumi Okyere, Shu Wang, Jianchen Wang, Lei Xie, Yinan Ran and Yanchun Hu

J. Fungi 2022, 8(2), 205; https://doi.org/10.3390/jof8020205 - 20 Feb 2022

Cited by 68 | Viewed by 5475

Abstract

Plant-associated fungi (endophytic fungi) are a biodiversity-rich group of microorganisms that are normally found asymptomatically within plant tissues or in the intercellular spaces. Endophytic fungi promote the growth of host plants by directly producing secondary metabolites, which enhances the plant’s resistance to biotic [...] Read more.

Plant-associated fungi (endophytic fungi) are a biodiversity-rich group of microorganisms that are normally found asymptomatically within plant tissues or in the intercellular spaces. Endophytic fungi promote the growth of host plants by directly producing secondary metabolites, which enhances the plant’s resistance to biotic and abiotic stresses. Additionally, they are capable of biosynthesizing medically important “phytochemicals” that were initially thought to be produced only by the host plant. In this review, we summarized some compounds from endophyte fungi with novel structures and diverse biological activities published between 2011 and 2021, with a focus on the origin of endophytic fungi, the structural and biological activity of the compounds they produce, and special attention paid to the exploration of pharmacological activities and mechanisms of action of certain compounds. This review revealed that endophytic fungi had high potential to be harnessed as an alternative source of secondary metabolites for pharmacological studies. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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18 pages, 1781 KiB

Open AccessReview

Recent Advances in Sorbicillinoids from Fungi and Their Bioactivities (Covering 2016–2021)

by Xuwen Hou, Xuping Zhang, Mengyao Xue, Zhitong Zhao, Huizhen Zhang, Dan Xu, Daowan Lai and Ligang Zhou

J. Fungi 2022, 8(1), 62; https://doi.org/10.3390/jof8010062 - 07 Jan 2022

Cited by 22 | Viewed by 2582

Abstract

Sorbicillinoids are a family of hexaketide metabolites with a characteristic sorbyl side chain residue. Sixty-nine sorbicillinoids from fungi, newly identified from 2016 to 2021, are summarized in this review, including their structures and bioactivities. They are classified into monomeric, dimeric, trimeric, and hybrid [...] Read more.

Sorbicillinoids are a family of hexaketide metabolites with a characteristic sorbyl side chain residue. Sixty-nine sorbicillinoids from fungi, newly identified from 2016 to 2021, are summarized in this review, including their structures and bioactivities. They are classified into monomeric, dimeric, trimeric, and hybrid sorbicillinoids according to their basic structural features, with the main groups comprising both monomeric and dimeric sorbicillinoids. Some of the identified sorbicillinoids have special structures such as ustilobisorbicillinol A, and sorbicillasins A and B. The majority of sorbicillinoids have been reported from fungi genera such as Acremonium, Penicillium, Trichoderma, and Ustilaginoidea, with some sorbicillinoids exhibiting cytotoxic, antimicrobial, anti-inflammatory, phytotoxic, and α-glucosidase inhibitory activities. In recent years, marine-derived, extremophilic, plant endophytic, and phytopathogenic fungi have emerged as important resources for diverse sorbicillinoids with unique skeletons. The recently revealed biological activities of sorbicillinoids discovered before 2016 are also described in this review. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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48 pages, 9714 KiB

Open AccessReview

Sesquiterpenoids Specially Produced by Fungi: Structures, Biological Activities, Chemical and Biosynthesis (2015–2020)

by Quan Dai, Fa-Lei Zhang and Tao Feng

J. Fungi 2021, 7(12), 1026; https://doi.org/10.3390/jof7121026 - 30 Nov 2021

Cited by 21 | Viewed by 3834

Abstract

Fungi are widely distributed in the terrestrial environment, freshwater, and marine habitat. Only approximately 100,000 of these have been classified although there are about 5.1 million characteristic fungi all over the world. These eukaryotic microbes produce specialized metabolites and participate in a variety [...] Read more.

Fungi are widely distributed in the terrestrial environment, freshwater, and marine habitat. Only approximately 100,000 of these have been classified although there are about 5.1 million characteristic fungi all over the world. These eukaryotic microbes produce specialized metabolites and participate in a variety of ecological functions, such as quorum detection, chemical defense, allelopathy, and maintenance of symbiosis. Fungi therefore remain an important resource for the screening and discovery of biologically active natural products. Sesquiterpenoids are arguably the richest natural products from plants and micro-organisms. The rearrangement of the 15 high-ductility carbons gave rise to a large number of different skeletons. At the same time, abundant structural variations lead to a diversification of biological activity. This review examines the isolation, structural determination, bioactivities, and synthesis of sesquiterpenoids that were specially produced by fungi over the past five years (2015–2020). Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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