Abstract

Background: Rhus pentaphylla Desf. (Anacardiaceae) widely grown in Algeria, is an underutilized plant and remains poorly studied. To investigate for the first time, the chemical composition profile of essential oil and hydrosol extract; besides Total Phenolic (TPC), Flavonoid (TFC) and Condensed Tannins Contents (CTC) of fruits, leaves and roots, the fatty acid composition was assessed. The radical scavenging activity of R. pentaphylla extracts was then evaluated.

Methods: Essential oil and hydrosol extract were isolated respectively by hydrodistillation and liquidliquid- extraction from the aerial parts of R. pentaphylla. The antioxidant activity was evaluated using 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical and ferric reducing antioxidant power (FRAP). Chemical compositions of various extracts were investigated using Gas Chromatography (GC) and GC-Mass Spectrometry (GC-MS).

Results: The results of GC and GC-MS analysis revealed 83 components in essential oil and 75 components in hydrosol extract representing respectively 96.9% and 92.5% of the total extract composition. The main constituents were hexadecanoic acid (31.5%) followed by spathulenol (14.9%) in the oil while the higher amount present in the hydrosol extract was of spathulenol (14.2%). Otherwise, 13 and 18 fatty acids were identified in roots and fruits respectively. The highest levels of TPC and CTC were found in roots extracts while the highest quantity of TFC has been recorded in the leaves extract. Besides, hydrosol extract was able to scavenge DPPH and FRAP free radicals more efficiently than essential oil.

Conclusion: R. pentaphylla contains bioactive substances that could be used as a new promising source of antioxidant compounds in different applications.

Keywords: Essential oil, hydrosol, fatty acid, phenolic compounds, antioxidant activity, Rhus pentaphylla.