Jerzy Golik

The structure of brevetoxin C

Abstract The structure of brevetoxin C (BTX-C), a polyether marine toxin from Ptychodiscus brevis , has been elucidated by comparison of its spectral data with those of brevetoxin B (BTX-B).

Characterization of methyl glycosides at the pico- to nano-gram level

Abstract We describe a general method that permits characterization of 100-pg to 1-ng quantities of sugars. Thus, oligosaccharides are subjected to methanolysis, followed by per- p -bromobenzoylation or pernaphthoylation, and the methyl glycoside peresters are separated by high-pressure liquid chromatography. The method is also applicable to amino and acetamido sugars. If required, the separated sugar derivatives may be unequivocally identified by the characteristic quasi-M + peaks of bromobenzoates and extrema of exciton-split circular-dichroism (c.d.) curves. Furthermore, as the c.d. extrema of polybenzoates are predictable from extrema of component dibenzoate units, the c.d. data yield information on the unknown spatial disposition of -OH, -NH 2 and -NHAc groups of glycopyranoses. Application of the method is demonstrated with viridopentaose C, a pentasaccharide obtained from the antibiotic sporaviridin.

Esperamicin A1 (BMY28175) — A Novel Potent Antitumor Agent of the Diyne-ENE Class

Preclinical antitumor research at Bristol-Myers Squibb Company is concentrated on four major areas: programs for the discovery and development of novel chemotypes, analog research, novel drug delivery systems (e.g. monoclonal antibodies) and the exploitation of newer biotechnological approaches to cancer therapy. Historically, the discovery and development of novel chemotypes especially natural products or compounds synthesized based on natural product models has resulted in most of the important antitumor agents in current clinical use. While it is hoped that biotechnology will provide newer and less toxic treatment modalities in the future it is our belief that conventional chemotherapy will continue to have an important role.