Triterpene saponins and other constituents from Fatsia japonica

Abstract

Fatsia japonica Decne. (Araliaceae) is used in eastern folk medicine [1]. Various class of compounds such as triterpene saponins [2–5], squalene, fatty acids and their methyl esters [6], anthocynanins [7], and sterols [6] and their glycosides [8] have been isolated from this plant. Shade air-dried and powdered roots (16.3 kg) and mature fruits (425.0 g) of F. japonica were extracted with 95% ethanol. Dried EtOH extracts of roots (752.2 g) and fruits (58.9 g) were dissolved in water and fractionated with n-hexane, dichloromethane, and ethyl acetate. The dichloromethane- soluble fraction (139.0 g) of F. japonica root produced some precipitate, which was filtered to give two fractions, FRD-1 (precipitate) and FRD-2 (filtrate). FRD-1 on a silica gel column (CHCl 3 –MeOH 7:1) gave compound 1 (415 mg). On the other hand, fraction FRD-2 on a Sephadex LH-20 column (MeOH) gave four fractions, FRD-2-1 to FRD-2-4. Fraction FRD-2-2 (20 g) on a silica gel column (CHCl 3 –MeOH 20:1) gave 15 fractions, FRD-2-2-1 to FRD-2-2-15. Separate column chromatography of FRD-2-2-6, FRD-2-2-9, and FRD-2-2-10 on Sephadex LH-20 columns using acetone as an eluent yielded compounds 4 (90 mg), 3 (350 mg), and 7 (50 mg), respectively. The EtOAcsoluble fraction of F. japonica fruit (6 g) was chromatographed on a Sephadex LH-20 column using MeOH as eluent to give five fractions, FFE-I to FFE-V. Fraction FFE-I was further chromatographed on a silica gel column using CHCl 3 –MeOH (7:1, v/v) as eluent to yield nine fractions, FFE-I to FFE-IX. Separate preparative TLC of fractions FFE-I-II and FFE-I-VIII in CHCl 3 –MeOH (5:1, v/v) and fractions FFE-I-IV in a solvent system of CHCl 3 –MeOH–H 2 O (15:6:0.6, v/v/v) gave compounds 1 (40 mg), 5 (20 mg), and 2 (190 mg), respectively. The shade air-dried and powdered wood (4.7 kg) of F. japonica was extracted with acetone. The dried acetone extract of wood was dissolved in water and fractionated with n-hexane, dichloromethane, and ethyl acetate. The EtOAc-soluble fraction of F. japonica wood (2.12 g) on a Sephadex column (MeOH– EtOH, 1:1, v/v) gave four fractions. Fraction 3 (114.5 mg) was further purified on a silica column using benzene–MeOH (5:1, v/v) as eluent to give compound 6 (64.2 mg).