Study of volatile compounds of Pyrus mamorensis Trab. a characteristic plant of Mamora forest (north-western Morocco)

Abstract

Pyrus mamorensis Trab. commonly called “wild pear” was considered for long time as an endemic of the Mamora forest of Morocco (north-west). Although lack of protection and it is threatened with extinction in its range, this tree is of great interest due to its ecological and medicinal properties . This study focused on evaluation of volatiles in Pyrus mamorensis for its valorisation as a natural resource. So, the volatile compounds from different parts (leaves, stems, fruits, and flowers) were investigated after extraction by cold maceration in ethyl ether and analyzed by gas chromatography coupled to the mass spectrometry (GC - MS). Thirty one (31) compounds were identified and quantified including fifteen (15) terpenes, seven (7) alcans, two (2) aldehydes, four (4) esters and three (3) allyl alkoxybenzen derivatives. Estragol was the dominant component of the plant and that was only detected in leaves (83,09 %), while hexadecane (36,92 %) and allyl hexanoate (29,39 %) were mainly detected in the stems. The fruits showed relatively high levels (20,59 %) of benzyl butanoate, whereas in the flowers, limonene is the most abundant constituent (30,12 %). The analysis of the relative rates of different classes of volatile compounds, revealed the diversity of these compounds in P. mamorensis compared to two cultivars of edible species : P. communis L. et P. pyrifolia . The significant difference in composition in this case could be due to the wild character of P. mamorensis .