薤中抗凝和抗癌活性成分的结构鉴定

R9; 从百合科葱属植物薤(Allium chinense)鳞茎的抗凝和抗癌活性部位中,分离得到了6个化合物.经过化学方法和光谱分析(IR,EI-MS,1HNMR,13CNMR,1H-1H COSY,HMBC,HMQC和NOESY谱),鉴定它们的结构分别为(25R,S)-5α-spirostane-3β-ol 3-O-{β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside} (1),(25R,S)-5α-spirostane-3β-ol 3-O-{β-D-glucopyranosyl (1→2)-[β-D-glucopyranosyl-(1→3)](6-acetyl-β-D-glucopyranosyl)-(1→4)-β-D-galactopyranoside} (2),(25R,S)-5α-spirostane-2α,3β-diol 3-O-{β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside} (3),(25S)-24-O-β-D-glucopyranosyl-3β,24β-dihydroxy-5α-spirost-3-O-α-arabinopyranosyl-(1→6)-β-D-glucopyranoside (4),chinenoside II (5)及2,3,4,9-tetrahydro-1-methyl-1H-pyrido [3,4-b] indole-3-carboxylic acid (6).化合物4为一新的甾体皂甙,命名为chinenoside VI.化合物1～3为3对甾体皂甙差向异构体.其中,化合物2的25S型异构体为首次报道;25R型异构体和化合物6为首次从本种植物中分得.此外,通过NOESY谱还首次确定了化合物6的相对构型,并对其C和H信号进行了确切归属.