Modulation of multidrug resistance in tumor cells by taxinine derivatives

Among a series of taxinine (1) and its designed derivatives (2 33), two taxoids (29 and 33) increased cellular accumulation of vincristine in multidrug-resistant tumor cells more potently than verapamil, while the activities of eight taxoids (11, 14 16, 22, and 30 32) were comparable with that of verapamil. These results reveal that some taxinine derivatives are good modifiers of multidrug resistance in tumor cells.