尖萼紫珠枝叶中1个新的异海松烷型二萜

A new isopimarane-type diterpenoid from branches and leaves of Callicarpa loboapiculata

目的研究尖萼紫珠Callicarpa loboapiculata枝叶的二萜类化学成分及其体外抗炎活性。方法以脂多糖(lipopolysaccharide,LPS)诱导的小鼠巨噬细胞RAW264.7炎症模型,筛选不同极性溶剂萃取物的体外抗炎活性,采用多种色谱分离方法对二氯甲烷活性部位展开化学成分分离,运用核磁共振谱、高分辨质谱及电子圆二色散谱等技术鉴定化合物的结构,并测试其体外抗炎活性。结果从尖萼紫珠枝叶的乙醇提取物的二氯甲烷萃取物中共分离得到8个二萜类化合物,分别鉴定为(4R,7S,9R,13R)-7β-羟基-5(10)-8(14)-15-异海松三烯-18-酸(1)、异海松酸(2)、14α-羟基异海松酸(3)、7-羟基异海松酸(4)、大叶紫珠烯B(5)、7β-羟基异海松-8(14)-15-二烯-18-酸(6)、(+)-7-氧代-13-表-海松-14,15-二烯-18-酸(7)和3β-羟基-半日花-8(17),13E-二烯-15-酸(8)。结论化合物1为新化合物,命名为尖萼紫珠酸A;化合物1~8为首次从尖萼紫珠中分离得到,包括7个异海松烷型二萜和1个半日花烷型二萜。8个二萜类化合物能够不同程度地抑制脂多糖诱导的RAW264.7细胞株一氧化氮(NO)的产生。

Objective To study the diterpenoids constituents from branches and leaves of Callicarpa loboapiculata and their anti-inflammatory activity in vitro.Methods Lipopolysaccharide(LPS)induced mouse macrophage RAW264.7 was used to screen the in vitro anti-inflammatory activity of different polar solvent extracts from C.loboapiculata.Multiple chromatographic separation methods were used to separate and purify dichloromethane soluble fraction.Compounds structures were elucidated by nuclear magnetic resonance(NMR),high resolution electro spray ionization mass spectroscopy(HR-ESI-MS)and electronic circular dichroism(ECD)spectral analysis.The in vitro anti-inflammatory activities of all compounds were also evaluated.Results A total of eight diterpenoids were isolated from the dichloromethane soluble fraction of C.loboapiculata and were identified as(4R,7S,9R,13R)-7β-hydroxy-5(10)-8(14)-15-isopimaratrien-18-oic acid(1),isopimaric acid(2),14α-hydroxyisopimaric acid(3),7-hydroxyisopimaric acid(4),macrophypene B(5),7β-hydroxyisopimara-8(14)-15-dien-18-oic acid(6),(+)-7-oxo-13-epi-pimara-14,15-dien-18-oic acid(7),3β-hydroxy-labda-8(17),13E-dien-15-oic acid(8).Conclusion Compound 1 was a new compound named loboapiculatoid A,and compounds 1—8 were isolated from C.loboapiculata for the first time,including seven isopimarane-type diterpenoids and one labdane-type diterpenoid.Eight diterpenoids inhibited the production of nitric oxide(NO)in LPS-induced RAW264.7 to varying degrees.