Allium roseum L. volatile compounds profile and antioxydant activity for chemotype discrimination – Case study of the wild plant of Sfax (Tunisia)

This study deals with the chemical composition and antioxidant activities of Allium roseum L. a chemotype growing wild in Tunisia, to evidence new bioactive natural compounds in its flower essential oil, and to investigate possible antioxidative methanolic leaves extract properties. This essential oil was extracted by hydrodistillation and analyzed by GC and GC/MS. The main compounds were butylated hydroxytoluene, eugenol, farnesol, dimethyl trisulfide, methyl 2-propenyl trisulfide, Z-9-octadecenoic acid and tricosane found at respectively 10.0%, 8.4%, 6.9%, 6.1%, 5.3%, 5.2% and 4.8%. Moreover, 1-oxa-4,6-diazacyclooctane-5-thione (3.9%) was isolated for the first time in the Tunisian A. roseum, especially in the country central area (Sfax City). The methanolic leaves extract had antioxidant activities, assessed by two complementary tests: the DPPH radical-scavenging and the reducing power essays, when compared with those of butylated hydroxy anisole and ascorbic acid. These antioxidant activities and the essential oil profile would be a fingerprint for chemotype discrimination.

► Allium roseum new bioactive components were evidenced by GC/MS analyses. ► Essential oil included butylatedhydroxytoluene, eugenol, farnesol, di and trisulfides (5–10%). ► The 1-oxa-4,6-diazacyclootane (3.9%) was isolated for the first time in A. roseum. ► The leaves methanolic extract exhibited strong antioxidant activity (DPPH and reducing power). ► Antioxidant activity and essential oil profile be fingerprint for chemotype discrimination.