biostudies-literatureUnknown16(5)Wang COne new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3'-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-l-tryptophan. Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 potently induced apoptosis of gastric cancer cells by inhibiting topoisomerase II? enzyme activity and reducing the expression of antiapoptosis protein level. Compound 3 displayed moderate cytotoxicity against the A549 and MCF-7 cell lines with IC50 values of 1.2 ± 0.05 ?M, 1.6 ± 0.09 ?M, respectively.Marine drugshttps://www.ebi.ac.uk/biostudies/studies/S-EPMC5983299biostudies-literaturePrecursor-Directed Generation of Indolocarbazoles with Topoisomerase II? Inhibitory Activity.PMC5983299Wang CMonger AChairoungdua AZhu WFu PWang LPiyachaturawat PfalsePrecursor-Directed Generation of Indolocarbazoles with Topoisomerase II? Inhibitory Activity.One new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3'-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-l-tryptophan. Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 potently induced apoptosis of gastric cancer cells by inhibiting topoisomerase II? enzyme activity and reducing the expression of antiapoptosis protein level. Compound 3 displayed moderate cytotoxicity against the A549 and MCF-7 cell lines with IC50 values of 1.2 ± 0.05 ?M, 1.6 ± 0.09 ?M, respectively.2018-01-01T00:00:00Z2018 May2020-11-09T08:29:05Z2019-03-26T23:40:14ZS-EPMC59832992977279610.3390/md16050168