Fruits of Mangifera indica L. (Anacardiaceae) as well as other parts of the plant have widely been used in traditional medicine. As a part of our continuing research project aimed at the discovery of bioactive compounds from food- and pharmaceutical processing by-products [SAFEWASTES (www.safewastes.info)], the anti-inflammatory activities of aqueous, hydroethanolic and lipophilic mango peel extracts have been examined by means of in vitro assays [1,2]. Bioassay-directed fractionation of the dichloromethane extract revealed the presence of the novel 5-(11Z-heptadecenyl)-resorcinol (1) and the known 5-(8Z,11Z-heptadecadienyl)-resorcinol (2) beside a series of recently described C15-, C17, and C19-substituted alk(en)ylresorcinols [3] in low abundance. The structures of the two isolates were elucidated by 1D and 2D NMR studies, MS and chemical methods. Both compounds exhibited potent COX-1 and COX-2 inhibitory activity with IC50 values given in table 1. Structure activity relation by referring to synthetic saturated homologues indicated that degree of unsaturation in the alkyl chain plays an important role for the inhibitory activity.
Table 1: IC50 values of compounds 1 and 2
|
Compound
|
IC50 COX-1 (µM)
|
IC50 COX-2 (µM)
|
|
1
|
3,54
|
4,42
|
|
2
|
1,93
|
3,52
|
Acknowledgements
: This work was funded by the Sixth Research Framework Program of the European Union (No. 513949).
References: [1] Fiebich, et al. (2005) Planta Med. 71: 12–19. [2] Adams, M. et al. (2004) Planta Med. 2004 70: 904–908. [3] Knödler, M. et al. (2007) Rapid Comm. Mass Spectrom. 6: 945–951.
