Germacrone Curcuma

Hikino et al. [153] have investigated by enzymatic means the stereospecific epoxidation reactions of olefinic double bonds in the plant Curcuma zedoaria Roscoe. They studied the bioconversion of germacrone (207), a constituent of C. zedoaria, by microorganisms in the hope of obtaining stereoselective epoxidation as in the case of the plant. Cuminghamella blakesleeana yielded three major products (208 - 210) from germacrone, Fig. (42). 

Germacrone (118), (+) -germacrone-4,5-epoxide (119), and curdione (120) isolated from Curcuma aromatica, which has been used as crude drug, were incubated with A. niger. From compound 119 (700 mg), two naturally occurring metabolites, zedoarondiol (121) and isozedoarondiol (122), were obtained (Takahashi, 1994). Compound 119 was cultured in callus of Curcuma zedoaria and C. aromatica to give the same secondary metabolites 121, 122, and 124 (Sakui et al., 1988) (Figures 20.40 and 20.41). 

FIGURE 20.41 Biotransformation of germacrone (118) by Curcuma zedoaria and Curcuma aromatica cells. 

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