Naphthoquinone–Oxindole Alkaloids, Coprisidins A and B, from a Gut-Associated Bacterium in the Dung Beetle, <i>Copris tripartitus</i>

Abstract

Coprisidins A and B (1 and 2) were isolated from a gut-associated Streptomyces sp. in the dung beetle Copris tripartitus. Using a combination of spectroscopic techniques, the structures of the compounds were determined to be the first examples of natural naphthoquinone-oxindole alkaloids. Coprisidin A was found to inhibit the action of Na⁺/K⁺-ATPase, and coprisidin B showed activity for the induction of NAD(P)H:quinone oxidoreductase 1.