Determination of Ganoderic acids in Triterpenoid Constituents of Ganoderma tsugae 

DENG-HAI CHEN* AND WILLIAM KUAN-DEE CHEN 

Biotechnology Research and Development Institute, Double Crane Group No. 3-8, Chingshui Village, Yenshui Township, Tainan County 737, Taiwan (R.O.C.)

(Received: May 17, 2002; Accepted: December 23, 2002)

ABSTRACT

   Ganoderma product has the highest sale volume in the health food market in Taiwan. The most widely-used raw material is the species of G. tsuage. Nine triterpenoids were isolated from the fruiting body of G. tsuage and their structures were identified, using 1H NMR and FT-IR, as ganoderic acid A (1), B (2), C (3), D (4), E (5), C5 (6), C6 (7), G (8) and ganoderenic acid D (9). A reverse-phase HPLC method was also established for the determination of these nine triterpenoids. Among these compounds, ganoderic acid E, C5, C6, G and ganoderenic acid D were analyzed for the first time by reverse-phase HPLC.

   The separation was carried out on a C18 reverse-phase column with a gradient elution of acetonitrile and 2% acetic acid (1/4 and 1/2, v/v) as mobile phase at a flow-rate of 0.8 mL/min and detection at 252 nm.

   Regression equation revealed the linear relationship (correlation coefficient: 0.9990~0.9999) between the peak-area ratios and concentrations of ganoderic acids. The recoveries of nine ganoderic acids were between 96.85~105.09%. The relative standard deviations of nine ganoderic acids range from 0.8~4.8% (intraday) and 0.7~5.1% (interday). The total contents of the nine ganoderic acids in eight Ganoderma samples were between 0.28~2.20%.

Key words: Ganoderma, Ganoderma tsugae, triterpenoid, ganoderic acid