中文摘要：

从新疆一枝蒿中分离得到了一枝蒿酮酸,通过HPLC检测了其纯度（99.7%）,色谱条件：VPODSC_（18）（150 mm×4.6mm,5μL）色谱柱,流动相为甲醇-0.5%磷酸溶液（V/V,45/55）,检测波长245 nm。并采用IR,~1H NMR,~（13）C NMR,ESI-MS进行了表征。应用XRD单晶衍射确定了其晶体结构,该晶体属于单斜晶系,P2/m空间群,实验化学式为C_（30）H_（40）O_6（为双分子聚合体）,实际化学式为C_（15）H_（20）O_3,晶胞参数：a=9.5295（7）nm,b=9.4821（6）nm,c=15.0469（10）,α=90°,β=98.361（2）°,γ=90°,V=1345.18（16）nm~3,Z=2,M_r=496.62,D_c=1.226 g/cm~3,F（000）=536,R_1=0.0561,ωR_2=0.1265。接着采用量子化学中的密度泛函理论（DFT）,在B3LYP/6-311G（d,p）基组下计算了该化合物的优化结构参数、电荷分布、分子总能量及前线轨道能量。算得的键长、键角数据和单晶衍射数据相符合。结果表明计算得到的分子几何优化结构可靠,所用的计算方法可靠。

英文摘要：

The rupestonic acid was isolated from the Artemisia rupestris L.The purity（99.7%） was detected by HPLC on VP ODS C_（18）（150 mm×4.6 mm,5μL） column.The mobile phase was methanol -0.5%phosphoric acid（V/V,45/55） and detection wavelength was 245 nm.It was confirmed by IR,~1H NMR,~（13）C NMR,ESI-MS and XRD.XRD showed that the rupestonic acid crystallizes with two independent molecules in the asymmetric unit and belongs to monoclinic space,group of P2/m,with a=9.5295（7） nm,b=9.4821（6） nm,c=15.0469（10）,α=90°,β= 98.361（2）°,γ=90°,V=1345.18（16） nm~3,Z=2,M_r=496.62,D_c=1.226 g/cm~3,F（000）=536,μ=0.08 mm~（-1） and the final deviation factor R_1=0.0561,ωR_2=0.1265.The optimized structure,charge distribution,molecular total energy,HOMO and LUMO energy were calculated by quantum chemical method at DFT-B3LYP/6-311G（d,p） basis.The result shows that the bond lengths and angles obtained by quantum chemical calculation were almost the same with those of the experiment,suggesting that the molecular geometry optimization of the structure was reliable,and the calulation method used was reliable.