Novel triterpene sulfates from Fusarium compactum using a rhinovirus 3C protease inhibitor screen

Two novel triterpene sulfates have been isolated from Fusarium compactum by bioactivity-directed fractionation using an assay which measures the inhibition of proteolytic activity of rhinovirus 3C protease on a fluorogenic peptide substrate. The compounds were purified by countercurrent and reverse phase chromatographies. NMR, MS, UV and IR studies revealed two triterpene sulfates, uncommon metabolites of terrestrial fungi.

Dibefurin, a novel fungal metabolite inhibiting calcineurin phosphatase activity

The novel calcineurin inhibitor, dibefurin, has been isolated from the fungal culture AB 1650I-759. The isolation was bioactivity-directed fractionation using an assay which measures the phosphatase activity of calcineurin. The compound was purified by countercurrent, reverse phase and gel filtration chromatographies. Several studies, including crystallographic, NMR and MS, revealed that dibefurin is a novel dimeric compound of a unique structural type.

Calbistrins, novel antifungal agents produced by Penicillium restrictum. II. Isolation and elucidation of structure

The novel antifungal agents, calbistrins A, B, C and D have been isolated from a strain of Penicillium restrictum (AB 1875C-28). The four congeners were separated by bioactivity directed fractionation using countercurrent chromatography and preparative-HPLC. NMR studies revealed that the calbistrins each contain a carboxylic acid conjugated tetraene attached through an aliphatic ester linkage to a hexahydronaphthalene system.

Dunaimycins, a new complex of spiroketal 24-membered macrolides with immunosuppressive activity. II. Isolation and elucidation of structures

A novel complex of antifungal and immunosuppressant compounds has been isolated from the fermentation broth and mycelia of two strains of Streptomyces diastatochromogenes. The structures of eight related components were determined employing 1D and 2D homonuclear and the heteronuclear NMR spectroscopy and mass spectrometry. These structures represent the first reported spiroketal 24-membered macrolide natural products related to the common 26-membered oligomycins.

Altromycins, novel pluramycin-like antibiotics. II. Isolation and elucidation of structure

A novel complex of Gram-positive antibiotics was produced from the fermentation of an actinomycete culture AB 1246E-26. The antibiotics were recovered from the whole fermentation broth by extraction with organic solvent and isolated using counter-current chromatography. UV and IR data place these compounds in the anthraquinone-derived class of antibiotics. Mass spectral and NMR data indicate a new complex of compounds related to, but distinctly different from the pluramycin type antibiotics.

Tirandalydigin, a novel tetramic acid of the tirandamycin-streptolydigin type. II. Isolation and structural characterization

Tirandalydigin a structurally unique hybrid of the tirandamycin-streptolydigin families of tetramic acid antibiotics has been isolated from the fermentation beers of Streptomyces sp. AB-1006A-9. The structure of this anti-anaerobic antibiotic has been characterized based upon NMR, UV and mass spectrometric data.

Arizonins, a new complex of antibiotics related to kalafungin. II. Isolation and characterization

A new complex of anti-Gram-positive antibiotics was produced by the fermentation of Actinoplanes arizonaensis sp. nov. The antibiotics were recovered from the fermentation broth with Amberlite XAD-7 resin and from the mycelium by acetone lysis. UV, IR, MS and NMR spectral studies characterized these compounds as kalafungin-type antibiotics. They differ from other known members by an unusual oxidation pattern on the aromatic ring. They vary from one another by the degree and position of O-methylation on the aromatic ring and in the aliphatic portion of the molecules. The structure of one component was confirmed by X-ray diffraction analysis.

Spenolimycin, a new spectinomycin-type antibiotic. II. Isolation and structure determination

A new water-soluble, basic antibiotic has been isolated from the fermentation beers of Streptomyces gilvospiralis sp. nov. The structure of the antibiotic has been deduced from spectral studies and confirmed by chemical degradation to spectinomycin. This structure, 3'-O-methylspectinomycin-3',4'-enol ether has led to the name spenolimycin.