Structure determination by nmr of azadirachtin and related compounds from azadirachta indica a. Juss (Meliaceae)

Abstract

Two novel limonoids 3-deacetyl-3-cinnamoylazadirachtin (6) and 1-tigloyl-3-acetyl-11-methoxyazadirachtinin (8) have been isolated from Azadirachta indica extracts in addition to azadirachtin (4), 22,23-dihydro-23β-methoxyazadirachtin (5) and 3-tigloylazadirachtol (7). The assignment of the structures (5) - (8) and the reassignment of the azadirachtin structure as (4) was achieved on the basis of detailed 1H and 13C n.m.r. spectroscopic analyses. © 1987.