抄録
Quantitative methods for determining magnolol, [6]-gingerol, and rosmarinic acid in Hangekobokuto Extract are specified in the Japanese Pharmacopoeia 17th edition (JP17). Standard substances of these measurement components are used in the quantitative methods, but it is difficult to ensure consistent quality of these standards.
In this study, therefore, we aimed to establish a quantitative method not requiring the use of standard target substances. For this purpose, we investigated an analytical method to simultaneously quantify magnolol, [6]-gingerol, and rosmarinic acid in Hangekobokuto Extract by using 4-hydroxybenzoic acid propyl ester as a standard, based on the mass absorption coefficient ratios, determined by dividing the absorbance ratio measured by HPLC by the mass ratio corrected for purity.
The results obtained with this method agreed with those determined using the quantitative methods specified by JP17 within a 3% tolerance. Thus, evaluation based on the ratio of mass absorption coefficients with respect to 4-hydroxybenzoic acid propyl ester as an alternative standard appears to be a useful method for the quantitation of magnolol, [6]-gingerol, and rosmarinic acid in Hangekobokuto Extract. A similar approach might also be applicable to other components of other extracts.
