Anandins A and B, Two Rare Steroidal Alkaloids from a Marine Streptomyces anandii H41-59

Abstract

Anandins A (<b>1</b>) and B (<b>2</b>), two rare steroidal alkaloids, were isolated from the fermentative broth of a marine actinobacteria <i>Streptomyces anandii</i> H41-59. The gross structures of the two alkaloids were elucidated by spectroscopic methods including HR-ESI-MS, and NMR. Their absolute configurations were confirmed by single-crystal X-ray diffraction analysis and comparison of their experimental and calculated electronic circular dichroism spectra, respectively. Anandin A exhibited a moderate inhibitory effect against three human cancer cell lines MCF-7, SF-268, and NCI-H460 with IC₅₀ values of 7.5, 7.9, 7.8 μg/mL, respectively.