Abstract:
Lipid paste was extracted with petroleum ether from Ginkgo biloba L. leaves. Fatty acids and their esters, wax etc. were separated from sterols by saponification,extraction and refrigeration. The yield of sterols was 0.03%-0.08% by molecular distillation and recrystallization. Chemical components of sterols from G. biloba leaves were analyzed by GC-MS. Seventeen compounds were separated in which eight sterols were identified, which amounted to 97.633% of total peak area. These are β-sitosterol(67.984%),ergosta-8-en-3β-ol(10.624%), stigmastan-3β-ol (10.065%),stigmasta-5,24-dien-3β-ol,(3β,24Z)(5.255%),stigmasta-4,22-dien-3β-ol(1.926%),ergosta-5,8,22-trien-3β-ol,(3β,22E)(0.618%),fucosterol(0.595%)and α-sitosterol(0.566%). Among ketones(1.066%) there were 13α-androsta-5,7-dien-3-one, 17,19-diacetoxy-4,4-dimethyl(0.336%),17α-acetoxypregnenolone(0.730%); Except β-sitosterol, all other sterols were first reported in G. biloba leaves.