Citrinin derivatives from the marine-derived fungus Penicillium citrinum

Three new citrinin derivatives, penicitrinols C, D, and E (1-3), along with two known compounds, citrinin (4) and decarboxydihydrocitrinone (5), were isolated from Penicillium citrinum. Their structures were determined by spectroscopic methods and X-ray diffraction analysis. Compounds 1 and 3 demonstrated weak cytotoxicity against the HL-60 cell line.     

Three new aspochalasin derivatives from the marine-derived fungus Spicaria elegans

<正>Three new aspochalsins(R-T)(1-3) were isolated from the marine-derived fungus Spicaria elegans.Their structures were elucidated on the basis of comprehensive spectral analysis including 1D and 2D NMR techniques,and HR-ESI-MS.     

New virescenosides from the marine-derived fungus Acremonium striatisporum

Five new diterpene glycosides, virescenosides Z4-Z8 (1-5) have been isolated from a marine strain of Acremonium striatisporum KMM 4401 associated with the holothurian Eupentacta fraudatrix. Their structures were determined by HRESI-MS and 1D and 2D NMR. Virescenosides Z4-Z8 contain rare altruronic acid 4C1 and 1C4 conformations as their carbohydrate components. Virescenosides Z5 and Z7 exhibit an unusual 16-chloro, 15-hydroxyethylgroup as their side chains.     

New metabolites from the marine-derived fungus Aspergillus fumigatus

A new alkaloid, fumiquinazoline K (1), and a new nordammarane triterpenoid (2), together with three known diketopiperazines (3-5) and tryptoquivaline F (6) have been isolated from a marine strain of Aspergillus fumigatus KMM 4 631 associated with the soft coral Sinularia sp. Their structures were determined by HR-MS and 1D and 2D NMR. Compounds 3-5 exhibit weak cytotoxicity against cytoplasm non-specific esterase in Ehrlich carcinoma cells. Compound 3 also induces early apoptosis of the same cells in a non-toxic range of concentrations.     

Cytotoxic sterols from marine-derived fungus Pennicillium sp

A new sterol, ergosta-8(14), 22-diene-3,5,6,7-tetraol(3beta, 5alpha, 6beta, 7alpha, 22E) (1), together with four known sterols ergosta-8(9), 22-diene-3,5,6,7-tetraol (3beta, 5alpha, 6beta, 7alpha, 22E) (2), 5alpha,8alpha-epidioxy-24(S)-methylcholesta-6,22-diene-3beta-ol (3), 5alpha,8alpha-epidioxy-24(S)-methylcholesta-6,9(11), 22-triene-3beta-ol (4), 3beta,5alpha,9alpha-trihydroxyergosta-7,22-diene-6-one (5) was isolated from marine fungus Pennicillium sp. Their structures were determined based on chemical analysis and spectral methods (IR, 1D and 2D NMR, HR-FAB-MS). Compounds 1-5 were evaluated for cytotoxicity against human liver cancer cell (Hep G), and most of them exhibited potent activity. Compound 1 display the highest potency with IC50 values 10.4 microg mL-1.     

Antimicrobial activity and molecular docking studies of a novel anthraquinone from a marine-derived fungus Aspergillus versicolor

A novel anthraquinone, 2-(dimethoxymethyl)-1-hydroxyanthracene-9,10-dione (1), together with nine known compounds (2–10), were isolated from the fermentation of Aspergillus versicolor derived from deep sea sediment. Their structures were established through spectroscopic methods. Compound 1 exhibited strong inhibitory activities against MRSA ATCC 43300 and MRSA CGMCC 1.12409 (with MIC values of 3.9 and 7.8 μg/mL respectively) and moderate activities against tested strains of Vibrio (with MIC values ranging from 15.6 to 62.5 μg/mL). Compound 1 was subjected to molecular docking studies for inhibition of topoisomerase IV and AmpC β-lactamase enzymes indicating its usefulness as antimicrobial agent.     

8'-Hydroxyzearalanone and 2'-hydroxyzearalanol: resorcyclic acid lactone derivatives from the marine-derived fungus Penicillium sp

Two new 14-membered resorcyclic acid lactone derivatives, 8'-hydroxyzearalanone (1) and 2'-hydroxyzearalanol (2), and four known zearalanone derivatives (3-6) were isolated from the marine-derived fungus Penicillium sp. The structures of compounds 1-6 were elucidated by spectroscopic methods.     

A new alkaloid from the marine-derived fungus Hypocrea virens

A new alkaloid, 2-methylimidazo[1,5-b]isoquinoline-1,3,5(2H)-trione, was isolated from the EtOAc extract of the marine-derived fungus Hypocrea virens. Its structure was confirmed by spectroscopic methods (1D and 2D NMR, MS).     

Prenylated indole alkaloids from the marine-derived fungus Paecilomyces variotii

Two new prenylated indole alkaloids, namely, dihydrocarneamide A (1) and iso-notoamide B (2), were isolated from the marine-derived endophytic fungus Paecilomyces variotii EN-291. The structures of these metabolites were determined based on comprehensive spectral analysis, together with chiral HPLC analysis of the acidic hydrolysates. Unlike other prenylated indole alkaloids such as asperparalines, notoamides, and versicolamides, compounds 1 and 2 are the rare examples of C-5 prenylation, forming the fused dimethyldihydropyran ring at C-5 and C-6 of the indole ring. The cytotoxic activity of the isolated compounds was evaluated.     

Myrothenones A and B, cyclopentenone derivatives with tyrosinase inhibitory activity from the marine-derived fungus Myrothecium sp

New 3-amino-5-ethenylcyclopentenones, myrothenones A (4) and B (5), were isolated together with known 6-n-pentyl-alpha-pyrone (1), trichodenone A (2), and cyclonerodiol (3) from the marine algicolous fungus of genus of Myrothecium. The structure and absolute stereochemistry of the new compounds were established by spectral interpretation and X-ray analysis. Compounds 1 and 4 exhibited a tyrosinase inhibitory activity with IC(50) value of 0.8 and 6.6 muM, respectively, which are more active than kojic acid (IC(50), 7.7 muM) currently being used as a functional personal-care compound.     

Three xanthones from a marine-derived mangrove endophytic fungus

Three xanthones were produced from the marine-derived endophytic fungus isolate 1850 from a leaf of Kandelia candel from an estuarine mangrove in Hong Kong. Their structures were elucidated as sterigmatocystin (1), dihydrosterigmatocystin (2), and secosterigmatocystin (3) by analysis of spectroscopic data. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 111–113, March–April, 2007.     

Cytosporin-related compounds from the marine-derived fungus Eutypella scoparia

Chemical investigation of the culture broth of the fungus Eutypella scoparia ICB-OBX, isolated from the marine pulmonate mollusc Onchidium sp., led to the finding of novel compounds 1 and 2, structurally related to angiotensin II binding inhibitors cytosporins, along with unrelated known nitrogen metabolites (compounds 3-5). The structure and the relative stereochemistry of the novel metabolites were assigned mainly by a detailed analysis of two-dimensional NMR techniques whereas the absolute stereochemistry was proposed by modified Mosher's method. Compound 2 contains an unusual cyclic carbonate functionality that is rare among natural products.     

A new polyketide,penicillolide from the marine-derived fungus Penicillium sacculum

A new polyketide, penicillolide (1) was isolated from the fermentation broth of the marine-derived fungus Penicillium sacculum GT-308. Compound 1 is a polyketide with a unique carbon skeleton. The structure of this compound was established via extensive spectroscopic analyses including 1D-, 2D-NMR, and HRESI-MS.     

Trichodermatides A-D, novel polyketides from the marine-derived fungus Trichoderma reesei

Four new polyketide derivatives, Trichodermatides A-D (1-4) were isolated from the marine-derived fungus Trichoderma reesei. Trichodermatide A (1) is an unprecedented example of a polyketide with a ketal-containing pentacyclic skeleton. The chemical structures and absolute configurations of compounds 1-4 were elucidated by extensive spectroscopic methods, especially 2D NMR and CD spectral analysis, and supported by their proposed biosynthesis pathway. The cytotoxicity of 1-4 was evaluated against A375-S2 human melanoma cell line.     

Bioactive metabolites from a marine-derived strain of the fungus Neosartorya fischeri

Two new compounds named fischeacid and fischexanthone, together with eight known compounds, were obtained from the culture of a marine-derived fungus Neosartorya fischeri strain 1008F?. The structures of the new compounds were elucidated based on the spectroscopic data. Bioassays indicated that AGI-B4 and 3,4-dihydroxybenzoic acid showed potent inhibitory effect on the replication of tobacco mosaic virus, and AGI-B4 also possessed an inhibition of the cell proliferation of human gastric cancer cell line SGC-7901 and hepatic cancer cells BEL-7404.     

Absolute stereochemistry of citrinadins a and B from marine-derived fungus

[Structure: see text]. Citrinadin A (2) is a pentacyclic indolinone alkaloid isolated from the cultured broth of a fungus, Penicillium citrinum, which was separated from a marine red alga. The absolute stereochemistry of the pentacyclic core in 2 and its new congener, citrinadin B (1), was elucidated by analysis of the ROESY spectrum for the chlorohydrin derivative (3) of 1 as well as comparison of the electronic circular dichroism (ECD) spectra for 1 and 2 with those of known spirooxiindole alkaloids. On the other hand, the absolute configuration at C-21 bearing an epoxide ring was assigned as S by comparison of the vibrational circular dichroism (VCD) spectra of 1 with those of model compounds 2S- and 2R-2,3-epoxy-3,3-dimethyl-1-phenylpropan-1-one (4a and 4b, respectively).     

New cytotoxic 14-membered macrolides from marine-derived fungus Aspergillus ostianus

Three new 14-membered macrolides, named aspergillides A, B, and C (1, 5, and 7), were isolated from marine-derived fungus Aspergillus ostianus strain 01F313, cultured in a medium composed of bromine-modified artificial seawater. The structures of the new compounds were determined by analyses of 1D and 2D NMR spectra. Their absolute configurations were elucidated by the modified Mosher's method and chemical conversions. The new compounds showed cytotoxic activity against mouse lymphocytic leukemia cells (L1210).     

Secondary metabolites from Antarctic marine-derived fungus Penicillium crustosum HDN153086

A new polyene compound (1) and a new diketopiperazine (2), as well as three known compounds (3–5), were isolated from the Antarctic marine-derived fungus Penicillium crustosum HDN153086. The structures of 1–5 were deduced based on MS, NMR and TD-DFT calculations of specific ECD spectra. These compounds were evaluated for their cytotoxic activities against K562 cell line and only compound 2 exhibited cytotoxicity against K562 cell, with IC₅₀ value of 12.7 μM.