为了研究腺梗豨莶草中6个二萜成分(对映海松烯型二萜:奇任醇、Hythiemoside B和豨莶精醇;对映贝壳杉烷型二萜:对映-17,18-二羟基-贝壳杉烷-19-羧酸、对映-16β,17-二羟基-贝壳杉烷-19-羧酸和对映-16α氢-贝壳杉烷-17,19-二羧酸)的含量,本试验建立了高效液相色谱法-蒸发光散射检测器(HPLC-ELSD)同时测定二萜类化合物含量.样品粉碎过筛加甲醇和乙酸乙酯回流提取,蒸发减压除去溶剂,甲醇溶解,0.45 μm滤膜滤过,取续滤液进行测定.色谱条件:色谱柱为Wa-ters Symmetry Shield? RP18 柱(250 mm × 4.6 mm,5 μm),流动相为 0.3%甲酸水溶液-乙腈(v/v),梯度洗脱,流速为 1.0 mL/min.蒸发光散射检测器漂移管温度为103℃,雾化气流速为3.0 L/min.应用该方法测定腺梗豨莶草样品不同部位中6个二萜类化合物的含量,同时比较叶、枝、茎中对映海松烯型二萜、对映贝壳杉型二萜和总二萜含量的差异.结果显示,6个二萜成分在其线性范围内线性关系良好(r ≥ 0.999 2);日内和日间精密度相对标准偏差(RSD)均小于3.5%;回收率介于96.5%-101.5%,RSD均小于2.3%;腺梗豨莶草不同部位(叶、枝、茎)的二萜类化合物含量差异较大.结果表明,本试验所建立的HPLC-ELSD方法简便、准确、重复性好,为腺梗豨莶草药材全面的质量评价和临床应用中最佳药用部位的选择提供了参考.
In order to study the contents of six diterpenoids(ent-pimarane:kirenol,hythiemoside B,and darutigenol;ent-kaurane:ent-17,18-dihydroxy-kauran-19-oic acid,ent-16β,17-dihydroxy-kauran-19-oic acid,and ent-16α-hydro-kauran-17,19-dioic acid)in Siegesbeckia pubescens Makino,this study established high performance liquid chromatography-evaporative light scattering detector(HPLC-ELSD)for simultaneous determination of diterpenoids.The samples were pulverized,sieved,and reflux-extracted with methanol and ethyl acetate.After removing the solvent by vacuum evaporation,the residue was dissolved in methanol,filtered through 0.45 μm membrane,and the filtrate was determined.Chromatographic conditions:Waters Symmetry Shield? RP18 column(250 mm ×4.6 mm,5 μm);mobile phase of 0.3%formic acid water solution-acetonitrile(v/v),gradient elution,flow rate of 1.0 mL/min.The ELSD drift tube temperature was set at 103℃,and the nebulizing gas flow rate was 3.0 L/min.This method was applied to determine the content of the six diterpenoids in different parts of Siegesbeckia pubescens Makino samples.Simultaneously,the differences in ent-pimarane,ent-kaurane,and total diterpenoids in leaves,branches,and stems were compared.The results showed that the six diterpenoids had good linearity within their linear range(r≥0.999 2),and the intra-day and inter-day precision relative standard deviations(RSD)were less than 3.5%.The recoveries ranged from 96.5%to 101.5%,with RSD less than 2.3%.The content of diterpenoids varied greatly in different parts of Siegesbeckia pubescens Makino(leaves,branches,stems).The results indicate that the established HPLC-ELSD is simple,accurate,and reproducible,providing a reference for comprehensive quality evaluation of Siegesbeckia pubescens Makino medicinal materials and the selection of the optimal medicinal parts for clinical application.