“…)-linked β-D -galactosyl and terminal rhamnosyl and α-L -arabinosyl residues was isolated from Azadirachta indica leaves (Saha et al 2010 ). Nimbolide [systematic name, (4α,5α,6α,7α,15β,17α)-7,15:21,23-diepoxy-6-hydroxy-4,8-dimethyl-1-oxo-18,24-dinor-11,12-secochola-2,13,20,22-tetraene-4,11-dicarboxylic acid gamma-lactone methyl ester] was isolated from neem leaves, and its isomer, isonimbolide [systematic name, (4α,5α,6α,7α,15α)-7,15:21,23-diepoxy-6-hydroxy-4,8-dimethyl-1-oxo-18,24-dinor-11,12-secochola-2,16,20,22-tetraene-4,11-dicarboxylic acid gamma-lactone methyl ester], was prepared from a novel rearrangement reaction of nimbolide using boron trifl uoride etherate and tetrabutylammonium bromide (Solomon et al 2005 ).…”