Synthesis and Anti-tubulin Activity of Ustiloxin D Derivatives.

Abstract
Ustiloxin D, produced by the rice plant pathogen Ustilaginoidea virens, exhibits potent anti-tubulin activity. In order to elucidate the effects of functional groups in ustiloxin D on its activity, several derivatives were synthesized and their anti-tubulin activities were estimated. The N, N-dimethylamino derivative and the 14-O-methyl derivative were inactive (IC50>50 μM). 20-Hydroxymethylated ustiloxin D showed decreased inhibitory activity compared with ustiloxin D.