The pentadecanolide was biosynthesized in cyclohexane from 15-hydroxypentadecanoic acid, which as prepared from 15-tetracosenoic acid in Malania Olcifera Chum oil using lipase as catalyst. The effect of lipase activit...The pentadecanolide was biosynthesized in cyclohexane from 15-hydroxypentadecanoic acid, which as prepared from 15-tetracosenoic acid in Malania Olcifera Chum oil using lipase as catalyst. The effect of lipase activity on the lactonization was investigated. Lipases from fiften strains (13 strains of Candida and 2 strains of Penicillium) showed different catalytic effects to the synthesis reactions. The lipases from strains of Penicillium sp. and 4 strains of Candida sp. have catalytic lactonization activity, and the conversion ratio of substrate reached 88% by using lipase Candida sp.GXU01.展开更多
文摘The pentadecanolide was biosynthesized in cyclohexane from 15-hydroxypentadecanoic acid, which as prepared from 15-tetracosenoic acid in Malania Olcifera Chum oil using lipase as catalyst. The effect of lipase activity on the lactonization was investigated. Lipases from fiften strains (13 strains of Candida and 2 strains of Penicillium) showed different catalytic effects to the synthesis reactions. The lipases from strains of Penicillium sp. and 4 strains of Candida sp. have catalytic lactonization activity, and the conversion ratio of substrate reached 88% by using lipase Candida sp.GXU01.
文摘目的:比较黄芩炒炭前后挥发性成分的含量变化,为阐明其炮制机制提供参考。方法:利用水蒸气蒸馏法提取黄芩中挥发油,利用GC-MS分析黄芩炮制品中挥发油成分的组成及含量变化,DB-5MS气相色谱柱(0.25 mm×30 m,0.25μm),载气为氦气,电子轰击电离源,离子源温度280℃,质谱接口温度280℃,电子能量70 e V。全离子扫描,质量扫描范围m/z 33~350,流速40 m L·min^(-1),分流比5∶1,采集延时2 min,图谱采集时间50.0 min。通过检索比对NIST-05标准质谱图谱库,鉴定样品挥发油中化学成分。结果:生黄芩、黄芩炭中挥发油提取量分别为1.3,0.8μL·g^(-1),GC-MS共鉴定了50种挥发油成分,其中生黄芩25种,黄芩炭31种。根据峰面积归一化法分析,鉴定的成分分别占生黄芩、黄芩炭饮片挥发油总量的100.00%,99.93%。结论:黄芩炒炭后挥发性成分含量有所降低,挥发性成分组成有所改变,但炒炭后挥发性成分尚存,可为阐释黄芩"炒炭存性"的炮制机制提供科学依据。
