Louisianins A, B, C and D: Non-steroidal Growth Inhibitors of Testosterone-responsive SC 115 Cells

I. Taxonomy, Fermentation, Isolation and Biological Characteristics

Abstract

In the course of screening for non-steroidal growth inhibitors of testosterone-responsive Shionogi carcinoma 115 cells, louisianins A, B, C and D, were isolated from fermentation broth of Streptomyces sp. WK-4028. Louisianin A remarkably inhibited the growth of SC 115 cells in the presence of 10^-7M testosterone at an IC₅₀ value of 0.6μg/ml, whereas, no inhibition was observed on the other cell lines. Furthermore, inhibitory activity of testosterone 5α-reductase and antimicrobial activity have not been observed at a concentration of 50μg/ml and 1, 000μg/ml, respectively.