"Isolation and Purification of active principles from Curcuma amada"

Abstract

Extraction of Curcuma amada rhizome (800 gm) at room temperature by maceration with methanol yielded 85.8 gm (10.73% of dry weight) extract. The methanol extract of Curcuma amada showed significant antimicrobial activity at a concentration of 1mg/disc. The methanol extract of Curcuma amada was subjected to vacuum liquid chromatography (VLC) and five different fractions were collected using five different solvents; Fractions were- Fraction-1 (6.50 gm) eluted with 5000 ml n-hexane, Fraction-2 (14.2 gm) eluted 3000 ml Dichloromethane, Fraction-3 (7.60 gm) eluted with 5000 ml ethyl acetate, Fraction-4 (26.5 gm) eluted with 5000 ml acetone and Fraction-5 (23.4 gm) eluted with 5000 ml methanol. Fraction-1 of was separated by open column chromatography with silica gel and the fractions were collected by monitoring the Thin Layer Chromatography (TLC) which gave 60 fractions. Among them Fraction-1-31 yielded a colorless crystal, CADH-31 (554 mg). This compound was UV active and charring with MeOH and H2SO4 (9:1) gave dark brown color. Based on 1H-NMR analysis, structure of CADH-31 is proposed as shown below (Fig-i). To the best of our knowledge the proposed structure of CADH-31 is novel. 13CNMR, Mass spectroscopy, 1H-1H COSY, HMQC, HMBC and NOESY are required to confirm the proposed structure. Fraction-1-35 yielded another colorless crystal, CADH-35 (50mg). The Antioxidant test of this CADH-31 showed no free radical scavenging activity up to a concentration of 1mg/ml. The antimicrobial activity test of CADH-31 showed no antimicrobial activity up to a concentration of 100μg/disc. Then Fraction-2 was subjected to open Colum chromatography and 184 fractions were separated according to different color bands in the column and by monitoring the TLC. Further chemical separation and testing biological activities of these fractions are yet to be done.