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Biomedical subjects

W J Gensler

Publications and source records attributed to W J Gensler.

11 recordsLinked to original sources
PubMed1978

Structure-activity study of the inhibition of microtubule assembly in vitro by podophyllotoxin and its congeners.

This study investigates the inhibition of microtubule assembly in vitro by podophyllotoxin and its derivatives, which include in part the antitumor compounds 4'-demethylepipodophyllotoxin ethylidene beta-D-glucoside (VP-16-213) and 4'-demethylepipodophyllotoxin thenylidene beta-D-glucoside (VM-26); the cyclic ethers, cyclic sulfides, and cyclic sulfones of podophyllotoxin and deoxypodophyllotoxin; epipodophyllotoxin; picropodophyllotoxin; and several 4'-demethyl compounds. The inhibitory activity of these derivatives is sensitive to the configuration and size of substituents at position 4 in ring C and to steric features of substituents at position 12 in ring D. Decreasing activity correlates with the increasing size of the substituent at position 12, as indexed by their van der Waals radii. These results suggest that rings C and D of these drugs are involved in their interaction with the podophyllotoxin-binding site in tubulin.

Animals↗
PubMed1977

Structure of mycobacterial bis-cyclopropane mycolates by mass spectrometry.

Methyl mycolate from a human strain (Brévannes) of Mycobacterium tuberculosis has been converted to the corresponding methyl neromycolate, the monketo-meromycolate, and the meromycolic pyrrolidide. The fragmentation pattern of each of these materials has been determined, and with information from a synthetic meromycolate serving as a basis of comparison, has been analyzed to obtain reliable structural assignments.

Chemical Phenomena↗
PubMed1977

Nonenolizable podophyllotoxin derivatives.

To block epimerization and the resulting biological deactivation podophyllotoxin compounds, the lactone carbonyl group has been changed to methylene. Syntheses of several of these delactonized derivatives are described, all with modifications in the original lactone ring and some without the 4-hydroxyl group. Several biological assays show that most of the nonenolizable derivatives retain activity.

Animals↗