Application of a quantitative 1 H-NMR ( 1 H-qNMR) method for the determination of geniposidic acid and acteoside in Plantaginis semen.

A quantitative 1 H-NMR method (1 H-qNMR) was developed to determine the concentration of acteoside and geniposidic acid in Plantaginis semen, which is an important crude drug for diuretic purposes. The purity of geniposidic acid and acteoside was determined by the ratio of the intensity of the H-3 signal at δ 7.51 ppm or the H-7″ signal at δ 7.58 ppm in methanol-d 4 to that of a hexamethyldisilane (HMD) signal at 0.04 ppm, respectively. The concentration of HMD was corrected with the International System of Units traceability using potassium hydrogen phthalate of certified reference material grade. The geniposidic acid content in two batches of Plantaginis semen as determined by 1 H-qNMR was found to be 0.84 and 1.00 %, and the acteoside content was determined to be 0.80 and 0.93 %. We demonstrated that this method is useful for the quantitative analysis of geniposidic acid and acteoside in Plantainis semen.