半制备型高速逆流色谱分离制备铁棒锤根中的一种咪唑生物碱

采用高速逆流色谱（HSCCC）技术从铁棒锤根氯仿提取物中分离制备了一种高纯度咪唑类生物碱1H-imidazole-2-carboxylic acid，butyl ester （ICABE）。采用高效液相色谱（HPLC）测定目标化合物在两相溶剂中的分配系数，优化HSCCC分离ICABE的溶剂体系，确定了以正己烷-氯仿-乙醇-水（10：1：13：2，v/v/v/v）为HSCCC的两相溶剂系统，以上相为固定相，下相为流动相，流动相流速为1.8 mL/min，主机转速850 r/min，检测波长为230 nm条件下进行分离制备，在350 min内从100 mg粗样品中一步分离得到7.5 mg ICABE，经HPLC检测其纯度达98%以上（峰面积归一化法），结构由UV、¹H-NMR和¹³C-NMR得以鉴定。该方法简便、快速，所得产物纯度高，适合于铁棒锤中ICABE的制备分离。

Isolation and preparation of an imidazole alkaloid from radix of Aconitum pendulum Busch by semi-preparative high-speed counter-current chromatography

Aconitum pendulum Busch is rich C₁₉ diterpenoid alkaloids, but there is no report of imidazole alkaloid in Aconitum pendulum Busch. In this study, an imidazole alkaloid named 1H-imidazole-2-carboxylic acid, butyl ester (ICABE) was successfully separated from Aconitum pendulum Busch with semi-preparative high-speed counter-current chromatography (HSCCC). The partition coefficient was measured by HPLC to select the solvent systems for ICABE separation by HSCCC. The separation was performed with a two-phase solvent system composed of n-hexane-chloroform-ethanol-water (10:1:13:2, v/v/v/v). The upper phase was used as the stationary phase and the lower phase as the mobile phase. It was operated at a flow rate of 1.8 mL/min. The apparatus was rotated at 850 r/min, and the detection wavelength was set at 230 nm. Under the selected conditions, a high efficiency separation of HSCCC was achieved, and 7.5 mg of ICABE was obtained from 100 mg of the crude sample of Aconitum pendulum in one-step separation within 350 min. The HPLC analysis showed that the purity of the compound was over 98%. The chemical structure was confirmed by UV, ¹H-NMR and ¹³C-NMR. The established method is simple, highly efficient and suitable for large scale separation of ICABE from radix of Aconitum pendulum Busch.