Kotani Akira, Kojima Satoshi, Hakamata Hideki, Jin Dongri, Kusu Fumiyo
Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
Chem Pharm Bull (Tokyo). 2005 Mar;53(3):319-22. doi: 10.1248/cpb.53.319.
A simple and sensitive method has been developed for determining honokiol and magnolol in fresh Magnolia obovata (M. obovata) by micro high-performance liquid chromatography with electrochemical detection (microHPLC-ECD). Chromatography was performed using a Capcell Pak C-18 UG 120 microbore octadecylsilica (ODS) column, methanol-water-phosphoric acid (65 : 35 : 0.5, v/v/v), as a mobile phase and applied potential at +0.8 V vs. Ag/AgCl. Peak heights were found linearly related to the amounts of honokiol and magnolol injected from 0.67 pg to 2.0 ng (r>0.999). The detection limits (S/N=3) were 0.13 pg, respectively. Honokiol and magnolol of 0.27 ng were detected with relative standard deviation (RSD) of 0.73 and 1.17% (n=5), respectively. Honokiol and magnolol in Magnolia Bark of the Japanese Pharmacopoeia were extracted with 70% methanol, diluted with a mobile phase, and injected into the microHPLC-ECD for determination. Recoveries of honokiol and magnolol in Magnolia Bark exceeded 98.7% with RSD, less than 0.93% (n=5). Determination of the distributions of honokiol and magnolol in bark, phloem, wood, leaf blades, and petioles of fresh M. obovata were made using weight samples of 40-238 mg. This method is useful to determine honokiol and magnolol in M. obovata, which is a candidate for crude magnolia bark for traditional Japanese herbal medicines.
已开发出一种简单且灵敏的方法，通过微高效液相色谱-电化学检测法（microHPLC-ECD）测定新鲜厚朴中的厚朴酚与和厚朴酚。使用Capcell Pak C-18 UG 120微径十八烷基硅胶（ODS）柱进行色谱分析，以甲醇-水-磷酸（65:35:0.5，v/v/v）作为流动相，并施加相对于Ag/AgCl为+0.8 V的电位。发现峰高与注入的厚朴酚和和厚朴酚量在0.67 pg至2.0 ng范围内呈线性关系（r>0.999）。检测限（S/N = 3）分别为0.13 pg。检测0.27 ng的厚朴酚与和厚朴酚时，相对标准偏差（RSD）分别为0.73%和1.17%（n = 5）。日本药典中的厚朴树皮中的厚朴酚与和厚朴酚用70%甲醇提取，用流动相稀释后，注入microHPLC-ECD进行测定。厚朴树皮中厚朴酚与和厚朴酚的回收率超过98.7%，RSD小于0.93%（n = 5）。使用40 - 238 mg的称重样品测定新鲜厚朴树皮、韧皮部、木材、叶片和叶柄中厚朴酚与和厚朴酚的分布。该方法对于测定厚朴中的厚朴酚与和厚朴酚很有用，厚朴是日本传统草药厚朴树皮的候选原料。
