Hydroxylated Gedunin Derivatives from Cedrela sinensis
摘要:
Four new limonoids, 11 alpha-hydroxygedunin ( 1), 11 beta-hydroxygedunin (2), 7-deacetoxy-7 alpha,11 alpha-dihydroxygedunin ( 3), and 7-deacetoxy-7 alpha, 11 beta-dihydroxygedunin (4), were isolated from the cortex of Cedrela sinensis, together with three known compounds, gedunin ( 5), 7-deacetoxy-7 alpha-hydroxygedunin ( 6), and 11-oxogedunin ( 7). The structures of 1-4 were determined by a combination of 2D NMR experiments and chemical methods and by X-ray crystallography of 1 and 2.
When treated with (diethylamino)sulfurtrifluoride (DAST), 11α-hydroxygedunin gave 11β-fluorogedunin and 9,11-didehydrogedunin, whereas deacetylgedunin afforded two skeletal rearranged products 6 and 7, in which the Me-30 had shifted from position 8 to position 7. Of those products, 11β-fluorogedunin and 6 were shown to be more cytotoxic than gedunin on P-388 leukemia cells.