Communiols E-H: new polyketide metabolites from the coprophilous fungus Podospora communis

Communiols E-H (1-4), four new polyketide-derived natural products containing furanocyclopentane, furanocyclopentene, cyclopentene, or gamma-lactone moieties, have been isolated from two geographically distinct isolates of the coprophilous fungus Podospora communis. The structures of these compounds were determined by analysis of NMR and MS data.     

Pseudodestruxins A and B: new cyclic depsipeptides from the coprophilous fungus Nigrosabulum globosum

Pseudodestruxins A (1) and B (2), two new cyclic peptides, have been isolated from cultures of the coprophilous fungus Nigrosabulum globosum. The structure of pseudodestruxin A (1) was elucidated using 2D NMR techniques and confirmed by single-crystal X-ray diffraction analysis. The structure of 2 was assigned by comparing its NMR and FABMS data with those of compound 1. The known compounds ascochlorin and 5-chlorocollectorin B were also isolated from N. globosum. Although 1 and 2 display antibacterial effects, ascochlorin was found to be responsible for the antifungal activity of the crude extract.     

Sporovexins A-C and a new preussomerin analog: antibacterial and antifungal metabolites from the coprophilous fungus Sporormiella vexans

Sporovexins A-C (1-3) and 3'-O-desmethyl-1-epipreussomerin C (4) have been isolated from liquid cultures of the coprophilous fungus Sporormiella vexans (JS 306). The structures of these new metabolites were elucidated on the basis of MS and NMR analysis. Compounds 1 and 4 show antifungal activity against competitor fungi, as well as antibacterial effects.     

Phytotoxic compounds from the new coprophilous fungus guanomyces polythrix

Bioactivity-directed fractionation of the fermentation broth and mycelium of the coprophilous fungus Guanomyces polythrix led to the isolation of several phytotoxic compounds, including five new naphthopyranone derivatives (1-5). In addition, rubrofusarin B, emodin, citrinin, and 4-hydroxybenzoic acid methyl ester were obtained. The structures of the new compounds were established by spectral and chiroptical methods. The isolates caused significant inhibition of radicle growth of two weed seedlings (Amaranthus hypochondriacus and Echinochloa crusgalli) and interacted with both spinach and bovine brain calmodulins.     

Bombardolides: new antifungal and antibacterial gamma-lactones from the coprophilous fungus Bombardioidea anartia.

Chemical studies of organic extracts from cultures of the coprophilous fungus Bombardioidea anartia have led to the discovery of bombardolides A--D (1--4), a series of new antifungal and antibacterial metabolites. Three of these metabolites (1--3) were obtained as inseparable pairs of geometric isomers. A new 3-substituted phenol (5) and the known compound asterriquinone B4 were also encountered. The structures of compounds 1--5 were determined by analysis of NMR and MS data.     

New bioactive diterpene polyesters from Euphorbia decipiens

A reinvestigation with a modified extraction procedure of Euphorbia decipiens resulted in the isolation and structure elucidation of three new myrsinane-type diterpene esters (1-3). The structures of compounds 1-3 were elucidated by spectroscopic data interpretation. Compound 1 showed inhibitory activity against prolyl endopeptidase (PEP), whereas compound 2 exhibited DNA-damaging activity in a mutant yeast bioassay.     

Pestalazines and pestalamides, bioactive metabolites from the plant pathogenic fungus Pestalotiopsis theae

Pestalazines A (1) and B (2), two new diketopiperazine heterodimers, and pestalamides A-C (3-5), three new amides, have been isolated from cultures of the plant pathogenic fungus Pestalotiopsis theae. The structures of these compounds were elucidated mainly by NMR spectroscopy. The absolute configurations of 1 and 2 were determined using Marfey's method on their acid hydrolysates and by comparison of their CD spectra with that of a model compound. Compounds 1, 3, and 6 displayed inhibitory effects on HIV-1 replication in C8166 cells. Compound 3 also showed potent antifungal activity against Aspergillus fumigatus.     

Decaspirones F-I, bioactive secondary metabolites from the saprophytic fungus Helicoma viridis

Decaspirones F-H (1-3), three new spirobisnaphthalene derivatives, and one new non-spirobisnaphthalene, decaspirone I (4), have been isolated from cultures of an isolate of the saprophytic fungus Helicoma viridis. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The absolute configuration of decaspirone F (1) was established by X-ray crystallographic analysis of its mono-bromobenzoate derivative. In standard disk assays, compounds 1-4 showed modest activity against Pseudomonas aeruginosa (multiple antibiotic-resistant strain, ATCC 27853), and decaspirone G (2) also displayed activity against Lactococcus lacti (PCM 2379).     

Pestalotheols A-D, bioactive metabolites from the plant endophytic fungus Pestalotiopsis theae

Pestalotheols A-D ( 1- 4 ), four new metabolites, have been isolated from cultures of an isolate of the plant endophytic fungus Pestalotiopsis theae. The structures of these compounds were determined by NMR spectroscopy, and 1 is further confirmed by X-ray crystallography. The absolute configurations of compounds 1 and 3 were assigned by application of the modified Mosher method. Pestalotheol C ( 3) displayed an inhibitory effect on HIV-1 LAI replication in C8166 cells with an EC 50 value of 16.1 microM.     

Massarinolins A-C: new bioactive sesquiterpenoids from the aquatic fungus massarina tunicata

Massarinolins A-C (1-3), three new bioactive sesquiterpenoids possessing rare ring systems, have been isolated from liquid cultures of the aquatic fungus Massarina tunicata Shearer & Fallah. The structures were determined primarily by analysis of NMR data. Metabolites 1-3 are the first compounds to be reported from any member of the genus Massarina.     

New bioactive metabolites from a freshwater isolate of the fungus Kirschsteiniothelia sp.

The new cytotoxic naphthoquinone dimer kirschsteinin [5], two new chlorinated diphenyl ethers 8 and 9, three known naphthoquinone derivatives 1, 2, and 7, a monoacetyl derivative of 2, and the (-)-enantiomer of O-methylasparvenone [4], have been isolated from a previously undescribed species of Kirschsteiniothelia. The structures of these compounds were assigned primarily by nmr studies and by spectral comparisons.     

Helicascolides A and B: new lactones from the marine fungus Helicascus kanaloanus

Two new isomeric delta-lactones 2 and 3 have been isolated from the marine fungus Helicascus kanaloanus (ATCC 18591). The structures and relative configurations of these compounds were assigned primarily by nmr studies, and absolute configurations are proposed based on cd data.     

New bioactive rosigenin analogues and aromatic polyketide metabolites from the freshwater aquatic fungus Massarina tunicata

Four new rosigenin analogues (massarigenins A-D; 1-4) and two new aromatic polyketide-derived secondary metabolites (massarinins A and B; 6, 7) and have been isolated from the freshwater aquatic fungus Massarina tunicata. The structures of these compounds were determined primarily by analysis of NMR data, and that of compound 1 was verified by X-ray crystallography. The known compound 4-(2-hydroxybutynoxy)benzoic acid (11) was also obtained, and its absolute stereochemistry was assigned. Several of these metabolites showed antibiotic activity against Gram-positive bacteria.     

Annularins A-H: new polyketide metabolites from the freshwater aquatic fungus Annulatascus triseptatus

Eight new polyketide metabolites, annularins A-H (1-8), along with the known compound (-)-(S)-p-hydroxyphenyllactic acid, were isolated from the organic extracts of the freshwater fungus Annulatascus triseptatus. Compounds 1-6 are 3,4,5-trisubstituted alpha-pyrones, and the fused bicyclic pyrone-furanone system in annularin F (6) has not been reported previously among natural products. Compounds 7 and 8 are 3,4-disubstituted alpha,beta-unsaturated gamma-lactones. Annularins A (1), B (2), C (3), and F (6) exhibited antibacterial activity.     

Tenellic acids A-D: new bioactive diphenyl ether derivatives from the aquatic fungus Dendrospora tenella

Tenellic acids A-D (1-4) were isolated from cultures of the freshwater fungus Dendrospora tenella. The structures of these new diphenyl ether derivatives were determined primarily by analysis of NMR data. Compounds 1-4 display antimicrobial activity against Gram-positive bacteria.     

Pseudotrienic acids A and B, two bioactive metabolites from Pseudomonas sp. MF381-IODS

Bioassay-guided fractionation of the liquid culture broth of Pseudomonas sp. MF381-IODS yielded two new antimicrobial substances, identified as (2E,4E,6E)-9-[((2S,3R)-3-hydroxy-4-{[(3E,5E,7RS)-7-hydroxy-4-methylhexadeca-3,5-dienoyl]amino}-2-methylbutanoyl)amino]nona-2,4,6-trienoic acid and the tetradeca equivalent, named pseudotrienic acids A (1) and B (2), respectively. The compounds are prone to lactone formation, and their structures suggest them to be derived from ring opening of a macrolide. Pseudotrienic acids A and B inhibited growth of Staphylococcus aureus (MIC 70 microg/mL) and Pseudomonas syringae pv. syringae (MIC 70 microg/mL). Two known antimicrobial compounds, the polyketide 2,3-deepoxy-2,3-didehydrorhizoxin (3) and the tryptophan-derived pyrrolnitrin (4), were also identified.     

Auranticins A and B: two new depsidones from a mangrove isolate of the fungus Preussia aurantiaca

Auranticins A and B, two new antimicrobial depsidones, have been obtained from a mangrove isolate of the fungus Preussia aurantiaca. The structures were determined through analysis of selective INEPT, decoupling, COSY, and NOESY experiments.     

Mode of action of epoxyphomalins A and B and characterization of related metabolites from the marine-derived fungus Paraconiothyrium sp

Epoxyphomalins A (1) and B (2) are highly potent cytotoxic fungal metabolites. During the course of purifying larger quantities of 1 and 2 from Paraconiothyrium sp. fermentation extracts, three new epoxyphomalins (3-5) were isolated and characterized, showing modifications to the oxidation pattern of the cyclohexene moiety or of C-9 of the decalin system. IC(50) values for cytotoxicity against a panel of 36 human tumor cell lines were determined for all new compounds. Compound 4 was found to be cytotoxic particularly toward prostate PC3M (IC(50) = 0.72 μM) and bladder BXF 1218 L (IC(50) = 1.43 μM) cancer cell lines. In addition, inhibition of chymotrypsin-, caspase-, and trypsin-like activity of purified 20S proteasomes was determined for epoxyphomalins A (1) and B (2). The results indicate that compounds 1 and 2 exert their cytotoxic effect through potent inhibition of the 20S proteasome.     

Sculezonones A and B, two metabolites possessing a phenalenone skeleton from a marine-derived fungus Penicillium species

Two new metabolites possessing a phenalenone skeleton, sculezonones A (1) and B (2), were isolated from cultured broth of the fungus Penicillium sp., which was separated from the Okinawan marine bivalve Mytilus coruscus, and the structures were elucidated by spectroscopic data.     

Modiolides A and B,two new 10-membered macrolides from a marine-derived fungus

Two new 10-membered macrolides, modiolides A (1) and B (2), and a new linear pentaketide, modiolin (3), were isolated from the cultured broth of a fungus Paraphaeosphaeria sp. (N-119), which was separated from a marine horse mussel, and the structures were elucidated by spectroscopic data.