Bruce O. Linn

Rapid loss of ATP by tumor cells deprived of glucose: contrast to normal cells.

Abstract When starved of a carbon source, early passage normal cells (chick embryo fibroblasts, human skin fibroblasts and mouse splenic lymphocytes) are able to maintain their ATP content for 12 to 24 hours at levels essentially similar to those of cells fed glucose. In contrast, several malignant or transformed cell types (Py6, PyNil, Ehrlich acites tumor, P 388 , CHO in suspension) under the same conditions of cultivation suffer a dramatic lowering in their ATP levels within the first hour of starvation. This sharply different response to glucose starvation and the loss of viability that accompanies loss of ATP are the principal findings reported here.

4 -DEOXY-4 -AMINOAVERMECTINS WITH POTENT BROAD SPECTRUM ANTIPARASITIC ACTIVITIES

Abstract Reductive amination of 4″-oxo-5-O-tert-butyldimethylsilyl-avermectins with sodium cyanoborohydride and ammonium acetate gave an epimeric mixture of 4″-deoxy-4″-amino analogs with the epimeric, axial 4″-β-amino derivative as the major component. Acylation of the amino substituent gave highly active broad spectrum antiparasitic compounds, as determined in a sheep anthelmintic assay. 4″-Epi-acetylamino-4″-deoxyavermectin B 1 ( 12 ) was selected for further antiparasitic studies and is currently under development as a novel avermectin endectocide.