Antimicrobial and cytotoxic activities of indole alkaloids and other constituents from the stem barks of Sond (Apocynaceae).

Twenty indole alkaloids, among which two undescribed ones named rauvolfianoids A () and B (), were isolated from the stem barks of Sond along with eight other compounds from other biosynthetic pathways. The structures were elucidated by analysis of spectroscopic data, including 1 D and 2 D NMR; absolute configurations of and were determined by CD exciton chirality method. Compounds and were evaluated for antimicrobial and anticancer activities against three bacterial strains (, and ) and CRC-related opportunistic pathogens. showed moderate antibacterial activity against with the MIC value of 25 μg/ml, while exhibited weak selective activity against all tested pathogens. In addition, these alkaloids were characterized as weak apoptosis inducers in HCT116 human colon carcinoma cell line.