A New Screening Method for Antimitotic Substances and Isolation of Glycolipids as Stimulators of Tubulin Polymerization from Okinawan Sponge Pseudoceratina sp.

A new screening method to detect antimitotic substances utilizing purified porcine brain microtubule proteins was developed. This method observes the inhibitory and stimulatory activities on microtubule polymerization and inhibitory activity on depolymerization in sequence. Two glycolipids, 1-O-beta-D-galactopyranosyl-2,3-di-O-acylglycerol and 1-O-tetrahydroxycyclopentyl-2-O-acyl-3-O-alkylglycerol were isolated from Okinawan marine sponge Pseudoceratina sp. by this screening method. These compounds stimulated the microtubule polymerization at 10 degrees C.