Two new oplopane sesquiterpenes from Artemisia gmelinii Web. ex Stechm.

Two new oplopane sesquiterpenes, gmelinin A（1） and gmelinin B（2）, were isolated from Artemisia gmelinii Web. ex Stechm. Their structures were established by spectroscopic techniques（mainly 1D and2 D NMR） and application of the modified Mosher method.

Flavonoids from Artemisia gmelinii Web. ex Stechm.

Phytochemical investigation of Artemisia gmelinii Web. ex Stechm. led to the isolation of 11 known flavonoids. Their structures were identified as genkwanin（1）, hispidulin（2）, 3＇-hydroxy-genkwanin（3）, chrysoeriol（4）, apigenin（5）, 5,7,3＇,4＇-tetrahydroxy-6,5＇-dimethoxy-flavone（6）, kumatakenin（7）, quercetin（8）, patuletin（9）, quercetagetin-3,6,7-trimethylether（10） and 7,3＇,4＇-trihydroxy-3-methoxy-flavone（11） by spectroscopic methods. Ten compounds（2–11） were isolated from this title plant for the first time, and five compounds（3, 6, 7, 10 and 11） were isolated from genus Artemisia for the first time.

响应面法优化碱蒿黄酮提取工艺及其体外抗氧化作用

用响应面法优化野生碱蒿黄酮类化合物的提取条件,通过羟自由基、超氧阴离子自由基、总还原力及脂质抗氧化实验测定碱蒿黄酮的体外抗氧化作用,并与抗坏血酸的抗氧化能力进行比较。结果表明提取工艺最佳条件为:提取温度80℃、提取时间1.75h、液料比27.5:1(mL/g)、提取2次,该条件下黄酮提取率预测值3.002%,验证值2.996%。对碱蒿黄酮的抗氧化研究表明,碱蒿黄酮对超氧阴离子自由基的清除作用与抗坏血酸比相对较弱,但对清除羟自由基、抗脂质体过氧化及还原能力均表现出较好的效果,是一种天然有效的抗氧化剂。