Anti-inflammatory 5-(11′ Z-heptadecenyl)- and 5-(8′ Z,11′ Z-heptadecadienyl)-resorcinols from mango ( Mangifera indica L.) peels

Bioassay-guided fractionation of mango ( Mangifera indica L.) peels extract revealed the 5-(11′ Z-heptadecenyl)-resorcinol ( 1) which showed potent in vitro anti-inflammatory activity in COX-1 and COX-2 inhibition assays. Bioassay directed extraction and purification of mango peels revealed the 5-(11′ Z-heptadecenyl)-resorcinol ( 1) and the known 5-(8′ Z,11′ Z-heptadecadienyl)-resorcinol ( 2) previously not described in Mangifera indica L. The structures of both compounds were determined by extensive 1D and 2D NMR studies and MS. Both compounds exhibited potent cyclooxygenase (COX)-1 and COX-2 inhibitory activity with IC 50 values ranging from 1.9 ( 2) to 3.5 μM ( 1) and from 3.5 ( 2) to 4.4 ( 1) μM, respectively, coming close to the IC 50 values of reference drugs. 5-Lipoxygenase (5-LOX) catalyzed leukotriene formation was only slightly inhibited. Structure–activity studies by referring to synthetic saturated homologues indicated that the degree of unsaturation in the alkyl chain plays a key role for COX inhibitory activity, whereas the influence of chain length was less significant.