Effects of synthetic analogues of teleocidin, indolactam-V, on the differentiation of murine pre-adipose cells.

The ability of 4 steric isomers of indolactam-V, the synthetic analogues of the tumor promoter teleocidin, to affect the adipose conversion of ST-13 murine pre-adipose cells was investigated. The isomers share the common skeleton with teleocidin A and B, but unlike teleocidins, none of them possess the terepenoid chain in the molecule. We found that only one of the isomers, (-)-indolactam-V, was biologically active and produced up to 70% inhibition of adipose conversion, while the other 3 isomers were without effect. We propose that the biological activity of indolactam-V isomers as inhibitors of adipose conversion requires the indole- and 9-membered lactam-rings with proper chiral substituents, but does not require the terpenoid chain.