Six new ergosterols from the marine-derived fungus Rhizopus sp

Discovery of Prenyltransferase-Guided Hydroxyphenylacetic Acid Derivatives from Marine Fungus Penicillium sp. W21C371

Traditional isolation methods often lead to the rediscovery of known natural products. In contrast, genome mining strategies are considered effective for the continual discovery of new natural products. In this study, we discovered a unique prenyltransferase (PT) through genome mining, capable of catalyzing the transfer of a prenyl group to an aromatic nucleus to form C-C or C-O bonds. A pair of new hydroxyphenylacetic acid derivative enantiomers with prenyl units, (±)-peniprenydiol A (1), along with 16 known compounds (2-17), were isolated from a marine fungus, Penicillium sp. W21C371. The separation of 1 using chiral HPLC led to the isolation of the enantiomers 1a and 1b. Their structures were established on the basis of extensive spectroscopic analysis, including 1D, 2D NMR and HRESIMS. The absolute configurations of the new compounds were determined by a modified Mosher method. A plausible biosynthetic pathway for 1 was deduced, facilitated by PT catalysis. In the in vitro assay, 2 and 3 showed promising inhibitory activity against Escherichia coli β-glucuronidase (EcGUS), with IC50 values of 44.60 ± 0.84 μM and 21.60 ± 0.76 μM, respectively, compared to the positive control, D-saccharic acid 1,4-lactone hydrate (DSL). This study demonstrates the advantages of genome mining in the rational acquisition of new natural products.

Minor ergosteroids and a 19-nor labdane-type diterpenoid with anti-inflammatory effects from Ganoderma lucidum

A chemical investigation on the fruiting bodies of Ganoderma lucidum led to the isolation and identification of five undescribed ergosteroids including two des-D-steroids (3 and 4) and one rare 6/6/7/5-fused carbon skeletal ergosterol (5) along with one 19-nor labdane-type diterpenoid (6). Their structures including their absolute configurations, were assigned by spectroscopic methods, ECD calculations, and X-ray diffraction analysis. In addition, the anti-inflammatory activities of all the isolates were evaluated. The results indicated that compound 1 can significantly down-regulate the protein expression of iNOS and COX-2 at 20 μM in LPS- stimulated RAW264.7 cells.

Cytotoxic Compounds from Marine Fungi: Sources, Structures, and Bioactivity

Marine fungi, such as species from the Penicillium and Aspergillus genera, are prolific producers of a diversity of natural products with cytotoxic properties. These fungi have been successfully isolated and identified from various marine sources, including sponges, coral, algae, mangroves, sediment, and seawater. The cytotoxic compounds derived from marine fungi can be categorized into five distinct classes: polyketides, peptides, terpenoids and sterols, hybrids, and other miscellaneous compounds. Notably, the pre-eminent group among these compounds comprises polyketides, accounting for 307 out of 642 identified compounds. Particularly, within this collection, 23 out of the 642 compounds exhibit remarkable cytotoxic potency, with IC50 values measured at the nanomolar (nM) or nanogram per milliliter (ng/mL) levels. This review elucidates the originating fungal strains, the sources of isolation, chemical structures, and the noteworthy antitumor activity of the 642 novel natural products isolated from marine fungi. The scope of this review encompasses the period from 1991 to 2023.

Anti-Inflammatory Ergosteroid Derivatives from the Coral-Associated Fungi Penicillium oxalicum HL-44

To obtain the optimal fermentation condition for more abundant secondary metabolites, Potato Dextrose Agar (PDA) medium was chosen for the scale-up fermentation of the fungus Penicillium oxalicum HL-44 associated with the soft coral Sinularia gaweli. The EtOAc extract of the fungi HL-44 was subjected to repeated column chromatography (CC) on silica gel and Sephadex LH-20 and semipreparative RP-HPLC to afford a new ergostane-type sterol ester (1) together with fifteen derivatives (2-16). Their structures were determined with spectroscopic analyses and comparisons with reported data. The anti-inflammatory activity of the tested isolates was assessed by evaluating the expression of pro-inflammatory factors Tnfα and Ifnb1 in Raw264.7 cells stimulated with LPS or DMXAA. Compounds 2, 9, and 14 exhibited significant inhibition of Ifnb1 expression, while compounds 2, 4, and 5 showed strong inhibition of Tnfα expression in LPS-stimulated cells. In DMXAA-stimulated cells, compounds 1, 5, and 7 effectively suppressed Ifnb1 expression, whereas compounds 7, 8, and 11 demonstrated the most potent inhibition of Tnfα expression. These findings suggest that the tested compounds may exert their anti-inflammatory effects by modulating the cGAS-STING pathway. This study provides valuable insight into the chemical diversity of ergosteroid derivatives and their potential as anti-inflammatory agents.

Isolation, identification, and antibacterial evaluation of endophytic fungi from Gannan navel orange

Gannan navel orange is a famous brand in China but the isolation of its endophytic fungi was rarely reported. In this study, a total of 54 strains of endophytic fungi were successfully isolated from the pulp, peel, twig, and leaf of Gannan navel orange; they were successfully identified to belong to 17 species of 12 genera. All these strains were fermented using potato-dextrose agar (PDA) medium, and their secondary metabolites were then extracted with ethyl acetate (EtOAc). The antibacterial assays of Escherichia coli (E. coli), methicillin-resistant Staphylococcus aureus (MRSA), and Xanthomonas citri subsp. citri (Xcc) were also performed for the EtOAc extracts of these strains. As a result, the extracts of both Geotrichum sp. (gc-1-127-30) and Diaporthe biconispora (gc-1-128-79) demonstrated significant antibacterial activities against Xcc, and the MIC value for the extract of Colletotrichum gloeosporioides against MRSA was low to 62.5 μg/mL. Moreover, the chemical components of the extracts of Colletotrichum sp., Diaporthe biconispora, and Annulohypoxylon atroroseum were primarily investigated, and they successfully led to the isolation of 24 compounds involving a new botryane sesquiterpene. Among the isolated products, compound 2 showed significant inhibitory activities toward SA, MRSA, E. coli, and Xcc with MIC values of 12.5, 3.1, 125, and 12.5 μg/mL, respectively. This study revealed that the endophytic fungi of Gannan navel orange showed high potency to produce secondary metabolites with significant antibacterial effects.

Anti-Inflammatory Polyketide Derivatives from the Sponge-Derived Fungus Pestalotiopsis sp. SWMU-WZ04-2

Five undescribed polyketide derivatives, pestaloketides A-E (1-5), along with eleven known analogues (6-16), were isolated from the sponge-derived fungus Pestalotiopsis sp. Their structures, including absolute configurations, were elucidated by analyses of NMR spectroscopic HRESIMS data and electronic circular dichroism (ECD) calculations. Compounds 5, 6, 9, and 14 exhibited weak cytotoxicities against four human cancer cell lines, with IC50 values ranging from 22.1 to 100 μM. Pestaloketide A (1) is an unusual polyketide, featuring a rare 5/10/5-fused ring system. Pestaloketides A (1) and B (2) exhibited moderately inhibited LPS-induced NO production activity, with IC50 values of 23.6 and 14.5 μM, respectively, without cytotoxicity observed. Preliminary bioactivity evaluations and molecular docking analysis indicated that pestaloketides A (1) and B (2) had the potential to be developed into anti-inflammatory activity drug leads.

Pathogenicity and Metabolites of Purpureocillium lavendulum YMF1.00683 against Meloidogyne incognita

Purpureocillium lavendulum is a biological control agent with several registered products that can parasitize the eggs and larvae of various pathogenic nematodes. In this study, the pathogenicity and secondary metabolites of the fungus P. lavendulum YMF1.00683 were investigated. The strain YMF1.00683 had infection efficiency against the plant root-knot nematode Meloidogyne incognita. The strain’s process of infecting nematodes was observed under a microscope. Moreover, seven metabolites, including a new sterol (1), were isolated and identified from cultures of YMF1.0068 in Sabouraud’s dextrose agar. A bioassay showed that 5-methoxymethyl-1H-pyrrole-2-carboxaldehyde (7) is toxic to M. incognita and affects the egg hatching. It caused 98.23% mortality in M. incognita and could inhibit 80.78% of the hatching eggs at 400 μg/mL over a period of 96 h. Furthermore, 5-methoxymethyl-1H-pyrrole-2-carboxaldehyde (7) showed a strong avoidance effect at 40 ppm, and its chemotactic index value was −0.37. The results indicate that P. lavendulum could produce active metabolites against M. incognita.

Triterpenoids and meroterpenoids from the edible Ganoderma resinaceum and their potential anti-inflammatory, antioxidant and anti-apoptosis activities

Ganoderma resinaceum, as a traditional edible mushroom, has been widely reported to improve neurodegenerative diseases characterized by oxidative stress and inflammation. In this study, five new terpenoids, including four lanostane triterpenoids, named ganoresinoid A-D (1-4) and one meroterpenoid, named ganoresinoid E (5), along with 27 known compounds (6-32), were isolated from the fruiting bodies of edible mushroom G. resinaceum. These structures were identified by NMR, HRESIMS data analysis. All metabolites were evaluated for anti-inflammatory, antioxidative and anti-apoptosis activities. Among them, ganoresinoid A showed notably restrained nitric oxide (NO), IL-1β, IL-6 and TNF-α levels in LPS-activated BV-2 microglial cells via suppressing TLR-4/ NF-κB and MAPK signaling pathway. Simultaneously, ganoresinoid A remarkably alleviated LPS-induced apoptosis by means of the decrease of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). In addition, ganoresinoid A demonstrated antioxidant effects in H₂O₂-induced SH-SY5Y cells by activating the Akt/GSK-3β/Nrf2 signaling pathway. Taken together, these results may provide a stronger theoretical basis for ganoresinoid A from G. resinaceum as nutrition intervention to alleviate neurodegenerative diseases.

A New Fusicoccane-Type Norditerpene and a New Indone from the Marine-Derived Fungus Aspergillus aculeatinus WHUF0198

A new norditerpene named aculeaterpene A (1) and a new indone named aculeaindone A (2), along with eight known compounds 3-10 were isolated from the culture extract of Aspergillus aculeatinus WHUF0198. The structural characterization of compounds 1 and 2 were performed by spectroscopic analysis, including 1D and 2D NMR and HR-ESI-MS experiments, whereas the absolute configurations were determined by comparing their experimental or calculated ECD spectra. Compound 1 was the first report of fusicoccane-based norditerpene, in which the C-20 was degraded and tured into a hydroxy group.

Anticancer Drug Discovery from Microbial Sources: The Unique Mangrove Streptomycetes

Worldwide cancer incidence and mortality have always been a concern to the community. The cancer mortality rate has generally declined over the years; however, there is still an increased mortality rate in poorer countries that receives considerable attention from healthcare professionals. This suggested the importance of the prompt detection, effective treatment, and prevention strategies. The genus Streptomyces has been documented as a prolific producer of biologically active secondary metabolites. Streptomycetes from mangrove environments attract researchers' attention due to their ability to synthesize diverse, interesting bioactive metabolites. The present review highlights research on mangrove-derived streptomycetes and the production of anticancer-related compounds from these microorganisms. Research studies conducted between 2008 and 2019, specifically mentioning the isolation of streptomycetes from mangrove areas and described the successful purification of compound(s) or generation of crude extracts with cytotoxic activity against human cancer cell lines, were compiled in this review. It is anticipated that there will be an increase in prospects for mangrove-derived streptomycetes as one of the natural resources for the isolation of chemotherapeutic agents.

Chemical constituents and their cytotoxicities from mushroom Tricholoma imbricatum

Two undescribed triterpenes, tricholimbrins A and B, three undescribed steroids, tricholimbrins C‒E, one undescribed 4-chromanone derivative, along with 27 known compounds were isolated from fruiting bodies of the mushroom Tricholoma imbricatum. Tricholimbrins A and B are two polycyclic triterpenoids with a carbon degradation, while tricholimbrin C is a ring-rearranged steroid containing an aromatic moiety that might be derived from an ergosterol. Isocyathisterol, 3β,15α-dihydroxyl-(22E,24R)-ergosta-5,8(14),22-trien-7-one, demethylincisterol A₃, and volemolide showed cytotoxicities to six human cancer cell lines. 3β-Hydroxyl-(22E,24R)-ergosta-5,8,22-trien-7,15-dione and 3β-hydroxyl-(22E,24R)-ergosta-5,8,22-trien-7-one showed preferable cytotoxicities against HL-60 while chaxine C and volemolide showed preferable cytotoxicities against A-549, with IC₅₀ values less than 10 μM.

One new α,β-unsaturated 7-ketone sterol from the mangrove-derived fungus Phomopsis sp.MGF222

A new α,β-unsaturated 7-ketone sterol, 5β,6β-epoxy-3β, 15α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-7-one (1), along with five known sterone derivatives, 5β,6β-epoxy-3β,7α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (2), 5β,6β-epoxy-3β,7α,9α-trihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (3), 3β,9α,15α-trihydroxy-(22E,24R)-10(5→4)-abeo-ergosta-6,8(14),22-trien-5-one (4), 3,15-dihydroxyl-(22E,24R)-ergosta-5,8(14),22-trien-7-one (5) and (22E,24R)-ergosta-4,6,8(14),22-tetraen-3,15-dione (6) were isolated from the mangrove-derived fungus Phomopsis sp. MGF222. Their structures were established on the basis of extensive spectroscopic data and comparison with the data of literature. Compound 2 showed weak antibacterial activity against Micrococcus tenuis with the MIC value of 28.2 (±0.52) μM. Compound 5 exhibited moderate antibacterial activity against Staphylococcus aureus with the MIC value of 14.6 (±0.47) μM.

Secondary Metabolites from Marine-Derived Fungi from China

Marine-derived fungi play an important role in the search for structurally unique secondary metabolites, some of which show promising pharmacological activities that make them useful leads for drug discovery. Marine natural product research in China in general has made enormous progress in the last two decades as described in this chapter on fungal metabolites. This contribution covers 613 new natural products reported from 2001 to 2017 from marine-derived fungi obtained from algae, sponges, corals, and other marine organisms from Chinese waters. The genera Aspergillus (170 new natural products, 28%) and Penicillium (70 new natural products, 11%) were the main fungal producers of new natural products during the time period covered, whereas sponges (184 new natural products, 30%) were the most abundant source of new natural products, followed by corals (154 new natural products, 25%) and algae (130 new natural products, 21%). Close to 40% of all natural products covered in this contribution displayed various bioactivities. The major bioactivities reported were cytotoxicity against different cancer cell lines, antimicrobial (mainly antibacterial) activity, and antiviral activity, which accounted for 13%, 9%, and 3% of all natural products reported. In terms of structural classes, polyketides (188 new natural products, 31%) play a dominant role, and if prenylated polyketides and nitrogen-containing polyketides (included in meroterpenes and alkaloids in this contribution) are taken into account, their total number even exceeds 50%. Nitrogen-containing compounds including peptides (65 new natural products, 10%) and alkaloids (103 new natural products, 17%) are the second largest group.

Macroalgae Derived Fungi Have High Abilities to Degrade Algal Polymers

Marine fungi associated with macroalgae are an ecologically important group that have a strong potential for industrial applications. In this study, twenty-two marine fungi isolated from the brown seaweed Fucus sp. were examined for their abilities to produce algal and plant biomass degrading enzymes. Growth of these isolates on brown and green algal biomass revealed a good growth, but no preference for any specific algae. Based on the analysis of enzymatic activities, macroalgae derived fungi were able to produce algae specific and (hemi-)cellulose degrading enzymes both on algal and plant biomass. However, the production of algae specific activities was lower than the production of cellulases and xylanases. These data revealed the presence of different enzymatic approaches for the degradation of algal biomass by macroalgae derived fungi. In addition, the results of the present study indicate our poor understanding of the enzymes involved in algal biomass degradation and the mechanisms of algal carbon source utilization by marine derived fungi.

C28 steroids from the fruiting bodies of Ganoderma resinaceum with potential anti-inflammatory activity

Eight undescribed ergostane-type steroids, (22E,24R)-ergosta-7,22-dien-3β,5α-diol- 6,5-olide, (22E,24R)-ergosta-7,9(11),22-trien-3β,5β,6β-triol, (22E,24R)-6β-methoxy ergosta-7,9(11),22-trien-3β,5α,14β-triol, (22E,24R)-9α,15α-dihydroxyergosta-4,6,8 (14),22-tetraen-3-one, (22E,24R)-ergosta-5,8,22-trien-3β,11α-dihydroxyl-7-one, (22E,24R)-ergosta-4,7,22-trien-3β,9α,14β-trihydroxyl-6-one, (22E,24R)-ergosta-7,22- dien-3β,9α,14β-trihydroxyl-6-one, and (22E,24R)-6β-methoxyergosta-7,22-dien-3β, 5α,9α,14β-tetraol, and twenty-one known analogues were isolated from the fruiting bodies of Ganoderma resinaceum Boud. Their chemical structures were determined on the basis of comprehensive spectroscopic analysis and X-ray crystal diffraction, as well as empirical pyridine-induced deshielding effects. Furthermore, selected compounds were evaluated for their inhibitory effects on macrophage activation using an inhibition of nitric oxide production assay. Finally, (22E,24R)-ergosta-5,8,22- trien-3β,11α-dihydroxyl-7-one, (22E,24R)-ergosta-4,7,22-trien-3β,9α,14β-tri hydroxyl-6-one, (22E,24R)-6β-methoxyergosta-7,22-dien-3β,5α,9α,14β-tetraol, (22E,24R)-ergosta-6,9,22-trien-3β,5α,8α-triol,ergost-6,22-dien-3β,5α,8α-triol, 5α,6α-epoxy-(22E,24R)-ergosta-8,22-diene-3β,7α-diol, 5α,6α-epoxy-(22E,24R)- ergosta-8(14),22-diene-3β,7α-diol, 5α,6α-epoxy-(22E,24R)-ergosta-8(14),22-diene-3β, 7β-diol, and 22E-7α-methoxy-5α,6α-epoxyergosta-8(14),22-dien-3β-ol showed inhibitory effects on NO production with IC₅₀ values ranging from 3.24 ± 0.02 to 35.19 ± 0.41 μM compared with L-NMMA (IC₅₀ 49.86 ± 2.13 μM), indicating that they have potential anti-inflammatory activity.

Steroids from Marine-Derived Fungi: Evaluation of Antiproliferative and Antimicrobial Activities of Eburicol

The most common sterol in fungi is ergosterol, which has frequently been investigated in human pathogenic fungal strains. This sterol, and others isolated from fungal strains, has also demonstrated cytotoxicity against cancer cell lines and antimicrobial activities. Marine fungi can produce high amounts of bioactive compounds. So, a screening was performed to study sterol composition using GC/MS in 19 marine fungal strains and ergosterol was always the major one. One strain, Clonostachys rosea MMS1090, was selected due to its high amount of eburicol and a one strain many compounds approach was performed on seven culture media to optimize its production. After purification and structural identification by NMR, eburicol was assessed against four cancer cell lines, MCF-7, MDA-MB-231, NSCLC-N6-L16 and A549, and seven human pathogenic bacteria Staphylococcus aureus, Bacillus sp., Bacillus cereus, Listeria ivanovii, Escherichia coli, Citrobacter freundii and Salmonella spp. The most significant activity was cytotoxicity against MCF-7 cells (2 µM). This is the first report of such an accumulation of eburicol in the marine fungal strain C. rosea confirming its potential in the production of bioactive lipids.

Anti-Vibrio Indole-Diterpenoids and C-25 Epimeric Steroids From the Marine-Derived Fungus Penicillium janthinellum

A systematic chemical exploration of the marine-derived fungus Penicillium janthinellum led to the isolation of four indole-diterpenoid derivatives (1–4), including new penijanthines C and D (1 and 2), and a pair of new steroidal epimers, penijanthoids A and B (5 and 6). The calculated ECD spectra and Snatzke's method for the new compound 1 were carried out to determine its absolute configuration. The absolute configuration of 3 was established by X-ray diffraction and calculated ECD methods for the first time. DP4plus approach was used to elucidate the absolute configurations of the C-25 epimeric steroids 5 and 6. 25-Epimeric 5 and 6 represent the first examples of steroids forming a five-membered lactone between C-23 and C-27 from marine fungi. Compounds 1, 2, 5, and 6 displayed significant anti-Vibrio activity (Minimum inhibitory concentration, MIC values ranging from 3.1 to 50.0 μM) against three pathogenic Vibrio spp.

Three new highly oxygenated sterols and one new dihydroisocoumarin from the marine sponge-derived fungus Cladosporium sp. SCSIO41007

Three new highly oxygenated sterols (1-3) and a new dihydroisocoumarin (7) together with six known compounds were isolated from the extracts of the culture of a sponge-derived fungus Cladosporium sp. SCSIO41007. The structures of all new compounds (1-3, 7) were determined by the extensive spectroscopic analysis including NMR, MS, IR, and UV. Their absolute configurations were determined by X-ray single-crystal and CD data analysis. Compound 2 exhibited weak inhibitory activity against H3N2 with the IC₅₀ value of 16.2 μM.

Secondary metabolites of endophytic Xylaria species with potential applications in medicine and agriculture

Fungal endophytes are important sources of bioactive secondary metabolites. The genus Xylaria Hill (ex Schrank, 1789, Xylariaceae) comprises various endophytic species associated to both vascular and non vascular plants. The secondary metabolites produced by Xylaria species include a variety of volatile and non-volatile compounds. Examples of the former are sesquiterpenoids, esters, and alcohols, among others; and of the latter we find terpenoids, cytochalasins, mellein, alkaloids, polyketides, and aromatic compounds. Some of these metabolites have shown potential activity as herbicides, fungicides, and insecticides; others possess antibacterial, antimalarial, and antifungal activities, or α-glucosidase inhibitory activity. Thus metabolites from Xylaria are promising compounds for applications in agriculture for plague control as biopesticides, and biocontrol agents; and in medicine, for example as drugs for the treatment of infectious and non-infectious diseases. This review seeks to show the great value of the secondary metabolites of Xylaria, particularly in the agriculture and medicine fields.

Six new ergostane-type steroids from king trumpet mushroom (Pleurotus eryngii) and their inhibitory effects on nitric oxide production

Six new ergostane-type steroids; (22E)-3β,5α,6α,11-tetrahydroxy-9(11)-seco-ergosta-7,22-dien-9-one (1), (22E)-8,14-epoxyergosta-6,22-diene-3β,5α,9α-triol (2), (22E)-4α,5α-epoxyergosta-7,22-diene-3β,6β-diol (3), (22E)-3β,4β,5α-trihydroxyergosta-7,22-dien-6-one (4), (22E)-ergosta-7,22-diene-3β,5β,6α-triol (5), and (22E)-6β-methoxyergosta-7,22-diene-3β,5α-diol 3-O-β-d-glucopyranoside (6) were isolated from the fruiting bodies of king trumpet mushroom (Pleurotus eryngii), along with fourteen known compounds (7-20). All isolated compounds were evaluated for their inhibitory effects on macrophage activation using a nitric oxide production inhibition assay.

Metabolites of the Endophytic Fungus Penicillium sp. FJ-1 of Acanthus ilicifolius

Two new compounds, named as (2 R,3 S)-pinobanksin-3-cinnamate (1), and 15α-hydroxy-(22 E,24 R)-ergosta-3,5,8(14),22-tetraen-7-one (2), were isolated from the endophytic fungus Penicillium sp. FJ-1 of Acanthus ilicifolius Linn. Their structures were elucidated on the basis of spectroscopic analysis. Additionally, compound 1 exhibited potent neuroprotective effects on corticosterone-damaged PC12 cells, and compound 2 showed potent cytotoxicity on glioma cell lines.

Peroxy natural products

This review covers the structures and biological activities of peroxy natural products from a wide variety of terrestrial fungi, higher plants, and marine organisms. Syntheses that confirm or revise structures or stereochemistries have also been included, and 406 references are cited.

Chemical Constituents from an Endophytic Fungus Chaetomium Globosum Z1

A new ergosterol, 15β-hydroxyl-(22 E,24 R)-ergosta-3,5,8,22-tetraen-one (1), along with three known ergosterols, two known cytochalasins, and two known azapholines were isolated from Chaetomium globosum Z1. The structures of these compounds were elucidated on the basis of spectroscopic methods (HR-ESI-MS, 1D NMR, and 2D NMR). Compound 6 showed significant cytotoxic activity against A-549 and MG-63 cell lines with IC50 values of 6.96 and 1.73 μg/mL, respectively.

Six novel steroids from culture of basidiomycete Polyporus ellisii

Investigation of the culture of basidiomycete Polyporus ellisii led to the isolation of a novel compound 3β,9α,15α-trihydroxy-(22E,24R)-10(5→4)-abeo-ergosta-6,8(14),22-trien-5-one (1) with a new 5/7/6/5 ring system of ergosterol skeleton. In addition, five new steroids, 5β,6β-epoxy-3β,7α,9α-trihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (2), 5β,6β-epoxy-3β,7α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (3), 5α,6α-epoxy-3β,9α,15α-trihydroxy-(22E,24R)-ergosta-8(14),22-dien-7-one (4), 15α-acetoxy-(22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (5), 15β-methoxy-(22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (6), along with four known ergosterols (7–10), were obtained. All structures were elucidated based on 1D and 2D NMR spectral data. New compounds were evaluated for cytotoxicity against five human cancer cell lines, only compound 4 was found to exhibit a favorable cytotoxicity profile toward all tested tumor cell lines.

Three new cytochalasins from the marine-derived fungus Spicaria elegans KLA03 by supplementing the cultures with L- and D-tryptophan

Three new cytochalasins Z(21) -Z(23) (1-3, resp.), together with five analogs, 4-8, were isolated from Spicaria elegans KLA03 by the OSMAC (one strain-many compounds) approach with adding L- and D-tryptophan during its cultivation. The structures of new cytochalasins were elucidated on the basis of comprehensive 1D- and 2D-NMR and HR-ESI-MS analyses. Cytochalasins Z(21) and Z(22) (1 and 2, resp.), and compound 5 showed cytotoxic activities against A-549 cell lines with IC(50) values of 8.2, 20.0, and 3.1 μM, respectively.

Terpenes from marine-derived fungi

Terpenes from marine-derived fungi show a pronounced degree of structural diversity, and due to their interesting biological and pharmacological properties many of them have aroused interest from synthetic chemists and the pharmaceutical industry alike. The aim of this paper is to give an overview of the structural diversity of terpenes from marine-derived fungi, highlighting individual examples of chemical structures and placing them in a context of other terpenes of fungal origin. Wherever possible, information regarding the biological activity is presented.

Synthesis of the marine pyrroloiminoquinone alkaloids, discorhabdins

Many natural products with biologically interesting structures have been isolated from marine animals and plants such as sponges, corals, worms, etc. Some of them are discorhabdin alkaloids. The discorhabdin alkaloids (discorhabdin A-X), isolated from marine sponges, have a unique structure with azacarbocyclic spirocyclohexanone and pyrroloiminoquinone units. Due to their prominent potent antitumor activity, discorhabdins have attracted considerable attention. Many studies have been reported toward the synthesis of discorhabdins. We have accomplished the first total synthesis of discorhabdin A (1), having the strongest activity in vitro among discorhabdins in 2003. In 2009, we have also accomplished the first total synthesis of prianosin B (2), having the 16,17-dehydropyrroloiminoquinone moiety, by a novel dehydrogenation reaction with a catalytic amount of NaN(3). These synthetic studies, as well as syntheses of the discorhabdins by various chemists to-date, are reviewed here.

Structural determination of aspericins A-C, new furan and pyran derivates from the marine-derived fungus Rhizopus sp. 2-PDA-61, by 1D and 2D NMR spectroscopy

Three new furan and pyran derivatives named aspericins A-C (1-3), as well as a known asperic acid (4), have been isolated from the marine-derived fungus Rhizopus sp. 2-PDA-61. The complete (1)H and (13)C NMR assignments for the new compounds were carried out using (1)H, (13)C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1-3 were evaluated for their cytotoxic activities on P388, A549, HL-60, and BEL-7420 cell lines by the MTT and SRB methods.

Evaluation of antiproliferative activities and action mechanisms of extracts from two species of Ganoderma on tumor cell lines

The antiproliferative activities on tumoral cells, namely, human breast cancer (MCF-7 and MDA-MB-231), hepatoma (HepG2) and myeloid leukemia (HL-60), of ethanolic extracts from two species of Ganoderma, G. lucidum and G. sinense, were investigated. Though both extracts had certain antiproliferative activities, their chemical characteristics, including nucleosides, triterpenoids and sterols, were significantly different. Their effects on MDA-MB-231 cells were further studied using apoptotic detection and cell cycle analyses. As a result, both had apoptosis induction through the alternation of mitochondrial transmembrane depolarization, though no triterpenoids were detected in ethanolic extract of G. sinense. Furthermore, the two extracts from G. lucidum and G. sinense could arrest cell cycle at different phases. This study showed that ethanol extracts of both G. lucidum and G. sinense have antitumoral proliferation effect through both apoptosis pathway and cell cycle arrest effect, and some other compounds such as sterols and/or nucleosides may contribute to their activity besides triterpenoids.

Advances in marine microbial symbionts in the china sea and related pharmaceutical metabolites

Marine animals and plants such as sponges, sea squirts, corals, worms and algae host diverse and abundant symbiotic microorganisms. Marine microbial symbionts are possible the true producers or take part in the biosynthesis of some bioactive marine natural products isolated from the marine organism hosts. Investigation of the pharmaceutical metabolites may reveal the biosynthesis mechanisms of related natural products and solve the current problem of supply limitation in marine drug development. This paper reviews the advances in diversity revelation, biological activity and related pharmaceutical metabolites, and functional genes of marine microbial symbionts from the China Sea.

Steroids from an Australian sponge Psammoclema sp

Investigation of an extract of the Australian marine sponge Psammoclema sp. for dynamin I inhibitory activity led to the isolation of four new trihydroxysterols (1-4) related to aragusterol G. These compounds were largely identified by 1D and 2D NMR spectroscopic methods. While 1 was found to be inactive in the dynamin bioassay, bioassays did reveal that compounds 1-4 inhibited the growth of colorectal, breast, ovarian, and prostate cancer cell lines (GI(50) 5-27 microM). The additional insight that these new compounds give to previous SAR studies is discussed briefly.