中文摘要：

本文对尖叶假龙胆中雏菊叶龙胆酮进行提取分离,采用红外光谱、紫外可见光谱和单晶X射线衍射分析技术对该化合物结构进行了表征;然后,采用密度泛函理论（DFT）,在B3LYP/6-31G基组水平上,对化合物结构进行了量子化学计算,结果表明其理论表征数据与实验表征数据吻合良好。另外,研究了雏菊叶龙胆酮对金黄色葡萄球菌、大肠杆菌、沙门氏菌和绿脓杆菌的初步抗菌活性。

英文摘要：

Bellidifolin was isolated from Gentianella acuta, and characterized by IR, UV-vis spectra and X-ray diffraction analysis. It crystallizes in the triclinic lattice, space group P-1 with a = 7. 0602 （14）, b = 7. 5236 （15） A, c = 10.662 （2）A,a = 86.65 （3）°, 13 = 79.84 （ 3 ）°,γ= 84.96 （ 3 ）°, V = 554.77 （ 19 ）A3, Z = 2, Dc = 1. 642 g/cm3 and F （000） = 284. Geometrical structure of bellidifolin was optimized by density functional theory （DFI＇）using B3 LYP method with 6-31 g（ d, p）as the basis set. The vibrational frequencies were calculated by the DFT/6-31g（ d, p）method and the results are nearly consistent with the observed frequencies. And the elec- tronic absorption spectra were studied with the time-dependent density functional theory（TD-DFT） and the calculated results are in good agreement with the corresponding experimental data. In addition, the preliminary antibacterial activities of bellidifolin against Staphylococcus aureus, Eseherichia coli, Salmonella enterica and Pseudomonas aeruginosa were investigated.