Antimycobacterial activity of bisbenzylisoquinoline alkaloids from Tiliacora triandra against multidrug-resistant isolates of Mycobacterium tuberculosis

Bisbenzylisoquinoline alkaloids, tiliacorinine (1), 2'-nortiliacorinine (2), and tiliacorine (3), isolated from the edible plant, Tiliacora triandra, as well as a synthetic derivative, 13'-bromo-tiliacorinine (4), were tested against 59 clinical isolates of multidrug-resistant Mycobacterium tuberculosis (MDR-MTB). The alkaloids 1-4 showed MIC values ranging from 0.7 to 6.2 μg/ml, but they exhibited the MIC value at 3.1 μg/ml against most MDR-MTB isolates. The present work suggests that bisbenzylisoquinoline alkaloids are potential new chemical scaffolds for antimycobacterial activity.