Two new 9,10-seco-cycloartanes from the seeds of Sphaerophysa salsula.

Two new 9,10-seco-cycloartanes, named sphaerophyside SC (1) and sphaerophyside SD (2), together with four known compounds (3-6), were obtained from the ethanol extract of the seeds of Sphaerophysa salsula. The structures of these compounds were elucidated on the basis of spectral and chemical evidences. Compounds 3-6 were isolated from the plant for the first time.

Scalarane metabolites of the nudibranch Glossodoris rufomarginata and Its dietary sponge from the South China Sea.

Chemical investigation of the nudibranch Glossodoris rufomarginata and its sponge prey provided additional evidence of the trophic relationship between Glossodoris nudibranchs and scalarane-containing sponges. Scalaradial (1) and its deacetyl derivative 2 were found to be the main components of the extract of the sponge, whereas a series of related scalaranes (3-7), probably derived from dietary scalaradial, were isolated from the mollusk. Two new scalarane sesterterpenes (5 and 6), exhibiting a keto functionalization at C-12, were characterized by spectroscopic methods and chemical correlations.

A new scalarane sesterterpenoid from the marine sponge Cacospongia mollior.

A new sesterterpene, 12-deacetoxyscalaradial [2a] has been isolated from the sponge Cacospongia mollior, together with the previously described scalaradial [2b] and furoscalarol [3]. The structure of the new compound, proposed by spectral data, was confirmed by X-ray diffraction analysis. Compound 2a is the first scalarane sesterterpenoid, without a substituent at C-12, to have been identified in nature. It shows high antifeedant activity and is hot to taste for the human tongue. Both 2a and 2b display cytotoxic activity.

[Steroid alkaloids from stems and leaves of Fritillaria ussuriensis Maxim].

Three crystalline chemical components were isolated from the stems and leaves of Fritillaria ussuriensis by column chromatographic technique. On the basis of the IR, MS and 1HNMR spectra, the structure has been identified as pingbeimine B, pingbeimine C and pingbeininoside.

[Structure of pingbeimine C].

A new C-nor-D-homosteroid alkaloid, C27H43O6N, mp 171.5-173 degrees C, named pingbeimine C, was isolated from the bulb of Fritillaria ussuriensis Maxim. On the basis of IR, MS, 1HNMR and 13CNMR spectroscopic data, particularly X-ray crystallographic analysis, structure IV has been assigned to this alkaloid.

New azasteroidal antifungal antibotics from Geotrichum flavo-brunneum. I. Discovery and fermentation studies.

Although Geotrichum species occur ubiquitously, antibiotic production by members of this genus has not previously been reported. The antibiotic complex designated A25822, consisting of one major and six minor structurally-related components active primarily against Candida and Trichophyton, represents a new family of naturally-occurring compounds. Approximately 90% of the antibiotic activity synthesized remained associated with the fungal cell mass, from which it was recovered by multiple methanolic extractions for quantitation. Antibiotic production was enhanced by tryptophan, iron, zinc, and high levels of dextrin.

New azasteroidal antifungal antibiotics from Geotrichum flavo-brunneum. II. Isolation and characterization.

A novel group of antibiotics, comprising microbiologically-active structurally-related factors A25822A, B, D, H, L, M and N, produced by culturing Geotrichum flavo-brunneum NRRL 3862 under submerged aerobic fermentation conditions was isolated by extraction. The individual factors were separated and purified by chromatography and crystallization. The major factor, A25822B, a 15-aza-24-methylene-D-homocholestadiene is a white crystalline compound, C25H45NO. The antibiotics are highly active against fungi and marginally active against bacteria.