In vitro nephroprotective indolizidine alkaloids from marine-derived Streptomyces sp. KIB629

Three new indolizidine alkaloids, bohemindolizidines C–E (1–3), together with two known analogues bohemindolizidines A and B (4 and 5) were isolated from marine-derived Streptomyces sp. KIB629. Their structures were established by a comprehensive analysis of NMR, HRESIMS, ECD and X-ray crystallography. All isolates were evaluated for nephroprotective activity against cisplatin-induced cytotoxicity in human embryonic kidney 293 (HEK293) cells. Compounds 1 and 4 exhibited significant protective effects with EC50 values of 10.00 μM and 4.28 μM, respectively. These results indicate that bohemindolizidines are promising candidates as nephroprotective agents for patients undergoing cisplatin chemotherapy.