Two new bioactive iridoids from Rothmannia wittii

The first reported study of the isolation and identification of compounds from the bark and fruit of Rothmannia wittii yielded two new iridoids, 6β-hydroxy-10-O-acetylgenipin (1) and 10-O-acetylmacrophyllide (2) together with six known iridoids; 6β-hydroxygenipin (3), genipin (4), garjasmine (5), cerbinal (6), and mixture of β-gardiol (7) and α-gardiol (8); benzoic acid (9); vanillic acid (10); and stigmasterol (11). Their structures were elucidated by spectroscopic methods. Iridoid 1 showed antimycobacterial activity against Mycobacterium tuberculosis with a MIC value of 12.50μg/mL. Iridoid 2 showed cytotoxicity against the NCI-H187 cancer cell line with an IC50 value of 6.82μg/mL. In addition, 2 and 5 exhibited weak cytotoxic activity against KB and MCF-7 cell lines, while 4 was active against the NCI-H187 cancer cell line.