ANALYSIS OF GINSENG Ⅰ.THE EXTRACTION AND CORLORIMETRIC DETERMINATION OF GINSENG SAPOGENINS
Wang Muzou, Gao Fengying, Zhang Guande and Zhang Shurong (Department of Analytical Chemistry, Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing)
Ginseng, the root of Panax ginseng C. A. Meyer, is one of the most well known Chinese drugs. It has long been used as a tonic or a drug of longevity in Chinese traditional medicine.Recently, it has been found that ginsenosides, a series of saponins extracted from ginseng, are the characteristic and active principles that represent mainly the biological activities of ginseng. Therefore the estimation of ginsenosides can be used practically for the evaluation of ginseng. Based on Shibata's method, three sapogenins: panaxdiol, panaxtriol and oleanolic acid were isolated from ginseng. After a comparative study of the various colorimetric reagents, it has been found that perchloric acid-vanillin reagent give the best results. The optimum conditions are as follows: To the sapogenin samples are added 0.8 ml of perchloric acid and 0.2 ml of freshly prepared 5％ vanillin in acetic acid solution, and the mixture is warmed in a water bath at 70℃ for 15 minutes. After cooling, 5 ml of acetic acid is added and Well shaken. Then colorimetry is run at 560 nm. The standard curve is linear in the range of 10～70 μg of sapogenin, This colorimetric method is simple, sensitive and relatively precise.