Joseph D. Korshalla

Spiroxins, DNA cleaving antitumor antibiotics from a marine-derived fungus

The spiroxins (1–5) were purified from the culture extract of a marine-derived fungus. Their unique bisnaphthospiroketal structures were established by NMR spectroscopy. In addition to cytotoxicity, these compounds showed antibiotic activity and were active in a mouse xenograft model against human ovarian carcinoma. The mechanism of action of these compounds was shown to be due, in part, to their effect on DNA.

Circulocins, new antibacterial lipopeptides from Bacillus circulans, J2154

Abstract A series of new lipopeptides, circulocins α–δ (1–4), was isolated from the fermentation broth of Bacillus circulans, J2154. These compounds exhibited potent antibiotic activity against the Gram-positive bacteria, including the piperacillin-resistant Streptococci and vancomycin-resistant Enterococci. Their structures were established using spectroscopic methods, and the absolute configurations were determined by amino acid analyses.