maytansine 99% kanbei

An ansa macrolide isolated from the MAYTENUS genus of East African shrubs.
This novel ansa macrolide alkaloid occurs in a number of May tan us species. The structure given has been elucidated from chemical and spectroscopic data. In low doses (25-50 mcg/kg), maytansine prolonged the survival of mice bearing vincristine-sensitive P388 leukemia but not those bearing vincristine-resistant tumour lines. In vitro, it suppressed the growth of U21 0, LSl78Y and P388 leukemia cells with ED50of 2 X 10-9, 1.5 X 10-9and 6 X 10-10M respectively and elevated the mitotic index in L 121 0 cells. From labelling studies it was shown that the alkaloid inhibited DNA formation by P388 cells to a greater extent than RNA and protein synthesis. Maytensine did not inhibit RNA polymerase from Escherichia coli at levels as high as 1 X 10-4M.
ChEBI: An organic heterotetracyclic compound and 19-membered macrocyclic lactam antibiotic originally isolated from the Ethiopian shrub Maytenus serrata but also found in other Maytenus species. It exhibits cytotoxicity against many tumo r cell lines.