Abstract

The influence of conditions on the separation of betulin (BT), betulinic (BIA), and betulonic (BOA) acids by reversed-phase high-performance liquid chromatography (RP-HPLC) with isocratic elution was studied. It was shown that the order of peaks in chromatograms changed with varying the acetonitrile (ACN) content in the mobile phase, and a poor separation under certain conditions was observed. The highest peak resolution with minimal retention times was at a column temperature of 20 °C, flow rate of 0.25 ml/min, and 92.5% ACN in the mobile phase. The extracts from jujube (Ziziphus jujuba) dried fruit, chaga mushroom (Inonotus obliquus), and white birch bark (Betula pendula) were studied using the obtained conditions. For extracts from the first two sources, it was found that peaks of the compound studied interfered with unknown peaks. By varying the ACN content in the mobile phase with a small step from run to run and tracking the peaks, a baseline separation was achieved. The optimal % ACN in the mobile phase was 87 and 89 for the extracts from jujube and chaga mushroom, respectively. Jujube dried fruit was found to contain, in terms of dry weight of the jujube, 0.223 ± 0.008 mg/g of BIA and 0.044 ± 0.006 mg/g of BOA. Chaga mushroom studied contains 0.022 ± 0.004 mg/g of BT and 0.062 ± 0.009 mg/g of BIA. White birch bark contains 50.9 ± 0.7 mg/g of BT, 11.2 ± 0.3 mg/g of BIA, and 2.5 ± 0.3 mg/g of BOA.

摘要

研究了条件对采用等度洗脱的反相高效液相色谱 (RP-HPLC) 分离桦木醇 (BT)、桦木酸 (BIA) 和桦木酮酸 (BOA) 酸的影响。结果表明，随着流动相中乙腈（ACN）含量的变化，色谱峰的顺序发生变化，并且在某些条件下观察到分离效果较差。柱温为 20 °C、流速为 0.25 ml/min、流动相中乙腈含量为 92.5% 时，可获得最高的峰分辨率和最短的保留时间。枣 ( Ziziphus jujuba ) 干果、白桦茸 ( Inonotus obliquus ) 和白桦树皮 ( Betula pendula )的提取物）使用所获得的条件进行了研究。对于前两个来源的提取物，发现所研究化合物的峰干扰未知峰。通过每次运行一小步改变流动相中的乙腈含量并跟踪峰，实现了基线分离。对于红枣和白桦茸提取物，流动相中的最佳 ACN % 分别为 87 和 89。枣干果中以枣干重计含有0.223±0.008mg/g的BIA和0.044±0.006mg/g的BOA。研究的白桦茸含有 0.022 ± 0.004 毫克/克的 BT 和 0.062 ± 0.009 毫克/克的 BIA。白桦树皮含有 50.9 ± 0.7 mg/g 的 BT、11.2 ± 0.3 mg/g 的 BIA 和 2.5 ± 0.3 mg/g 的 BOA。