Misico R I, Gil R R, Oberti J C, Veleiro A S, Burton G
Departamento de Química Orgánica and IMBIV, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
J Nat Prod. 2000 Oct;63(10):1329-32. doi: 10.1021/np000022z.
Eight new withanolides were isolated from the aerial parts of Vassobia lorentzii and characterized by spectroscopic methods and with the aid of molecular modeling. The compounds were identified as (17S,20R,22R)-5beta,6beta:18,20-diepoxy-18-hydro xy-1-oxowitha-2,5, 24-trienolide (1); (17S,20R,22R)-18,20-epoxy-4beta, 18-dihydroxy-1-oxowitha-2,5,24-trienolide (2); (17S,18R,20R, 22R)-4beta-hydroxy-18,20-epoxy-18-methoxy-1-oxowitha-2,5, 24-trienolide (3); (17S,18S,20R,22R)-4beta-hydroxy-18, 20-epoxy-18-methoxy-1-oxowitha-2,5,24-trienolide (4); (17S,20R, 22R)-4beta-hydroxy-18,20-epoxy-1,18-dioxowitha-2,5,24-tri enolide (5); (17S,18R,20R,22R)-18,20-epoxy-18-methoxy-1,4-dioxowitha++ +-2,5, 24-trienolide (6); (17S,18S,20R,22R)-18,20-epoxy-18-methoxy-1, 4-dioxowitha-2,5,24-trienolide (7); and (17S,20R,22R)-5beta, 6beta-epoxy-4beta,18,20-trihydroxy-1-oxowitha-2,24-die nolide (8). Compounds 1 and 2 were obtained as epimeric mixtures at C-18.
从洛伦茨氏瓦斯比亚（Vassobia lorentzii）地上部分分离出8种新的维甾烷醇内酯，并通过光谱方法和借助分子模型对其进行了表征。这些化合物被鉴定为(17S,20R,22R)-5β,6β:18,20-二环氧-18-羟基-1-氧代维甾-2,5,24-三烯醇内酯(1)；(17S,20R,22R)-18,20-环氧-4β,18-二羟基-1-氧代维甾-2,5,24-三烯醇内酯(2)；(17S,18R,20R,22R)-4β-羟基-18,20-环氧-18-甲氧基-1-氧代维甾-2,5,24-三烯醇内酯(3)；(17S,18S,20R,22R)-4β-羟基-18,20-环氧-18-甲氧基-1-氧代维甾-2,5,24-三烯醇内酯(4)；(17S,20R,22R)-4β-羟基-18,20-环氧-1,18-二氧代维甾-2,5,24-三烯醇内酯(5)；(17S,18R,20R,22R)-18,20-环氧-18-甲氧基-1,4-二氧代维甾-2,5,24-三烯醇内酯(6)；(17S,18S,20R,22R)-18,20-环氧-18-甲氧基-1,4-二氧代维甾-2,5,24-三烯醇内酯(7)；以及(17S,20R,22R)-5β,6β-环氧-4β,18,20-三羟基-1-氧代维甾-2,24-二烯醇内酯(8)。化合物1和2是以C-18位的差向异构体混合物形式获得的。
