长穗桑中的α-葡萄糖苷酶抑制剂成分研究

Study on Chemical Constituents of α-Glucosidase Inhibitors from Morus wittiorum

目的研究长穗桑中具有α-葡萄糖苷酶抑制活性的化学成分。方法采用各种离子交换树脂对长穗桑水提取物进行分离纯化,通过NMR、MS等波谱分析手段鉴定化合物结构。结果从长穗桑水提取物中分离到11个化合物,其中7个多羟基生物碱类化合物,2个酰胺类化合物,1个氨基酸以及甜菜碱。分别鉴定为1-deoxynojirimycin（1）,fagomine（2）,3-epi-fago-mine（3）,1,4-dideoxy-1,4-imino-D-arabinitol（4）,2-O-α-D-galactopyranosyl-1-deoxynojirimycin（5）,4-O-β-D-glucopyranosyl-fago-mine（6）,1,4-dideoxy-1,4-imino-（2-O-β-D-glucopyranosyl）-D-arabinitol（7）,（2S）-citrullinamide（8）,grateloupinamide（9）,天冬氨酸（10）,甜菜碱（11）。化合物1~10分别进行了α-葡萄糖苷酶抑制活性筛选。结论化合物1~11均为首次从该植物中分离得到。4个多羟基生物碱（1,5~7）以及1个酰胺类化合物（9）有较强的α-葡萄糖苷酶抑制活性,其中化合物1的IC50为0.07μmol.L-1;化合物5的IC50为0.39μmol.L-1,与阳性对照阿卡波糖（acarbose,IC50=0.52μmol.L-1）相当;化合物6,7,9的IC50值在1~5μmol.L-1。

OBJECTIVE To investigate the inhibitory activity chemical constituents from Morus wittiorum on α-glucosidase.METHODS The isolation and purification of the water extract of M.wittiorum was performed by various ion-exchange resin.The structures of compounds were determined on the basis of spectral analysis such as NMR,MS etc.RESULTS Eleven compounds were obtained from the water extract of M.wittiorum including seven polyhydroxyalkalines,two acylamides,one amino acid and betaine.The isolates were elucidated as 1-deoxynojirimycin（1）,fagomine（2）,3-epi-fagomine（3）,1,4-dideoxy-1,4-imino-D-arabinitol（4）,2-O-α-D-galactopyranosyl-1-deoxynojirimycin（5）,4-O-β-D-glucopyranosyl-fagomine（6）,1,4-dideoxy-1,4-imino-（2-O-β-D-glucopyranosyl）-D-arabinitol（7）,（2S）-citrullinamide（8）,grateloupinamide（9）,asparagic acid（10） and betaine（11）.Compound 1-10 were evaluated for their inhibitory activity on α-glucosidase respectively.CONCLUSION Compound 1-11 were isolated from this plant for the first time,among which compounds 1,5-7 and 9 showed potent inhibition on α-glucosidase.Compound 1 exhibited IC50 as 0.07 μmol·L-1.The IC50 value of compound 5 was 0.39 μmol·L-1,which was comparable to the positive control acarbose（IC50=0.52 μmol·L-1）.The IC50 values of compounds 6,7 and 9 were within the range of 1-5 μmol·L-1.