Abstract
The aim of this research was to investigate the influence of time of extraction methods on yield and chemical composition of the essential oil from dark green parts of Allium ampeloprasum and examine their anti-diabetic activity. The essential oil of dark green parts of Egyptian A. ampeloprasum L. which are not edible, and with less flavor, have been isolated by hydro distillations (HD). The compositions of the essential oils were characterized by GC-MS. A total of 35 and 31 compounds were identified, constituting over (87.8 %, 8 h) and (36.4 %, 6 h) of oil composition of A. ampeloprasum L., respectively. Oxygenated monoterpenes were shown to be the main group of volatiles (HD after 8 h, 35.5%). The amount of total volatiles were found to be better in HD of A. ampeloprasum L. which isolated after 8 h. The anti-diabetic activity of the isolated essential oils from green parts of A. ampeloprasum L.was investigated.