Isolation and structural elucidation of the novel flavone glycoside from Feronia limonia L.

Abstract

Background

The aim of this study is to isolate and structurally elucidate the flavone glycoside: 5,4-dihydroxy–3-(3-methyl-but-2-enyl) 3,5,6-trimethoxy-flavone-7-O-β-d-glucopyranoside from Feronia limonia L.

Methods

The air dried, powdered and defatted material of F. limonia L. fruits were extracted with rectified spirit extract was concentrated under reduced pressure to get a brown viscous mass, which was successively partitioned with petroleum ether, benzene, chloroform, ethyl acetate, acetone and methanol respectively. The ethyl acetate soluble part was concentrated under reduced pressure to get a brown syrupy mass, which when examined by TLC on silica-gel G using chloroform:methanol:water (8:5:3) and iodine vapors as visualizing agent displayed two spots. As such it was subjected to column chromatography on silica-gel Emerk and eluted by with acetone:methanol in various proportions. On removal of the solvent of fraction (7:4), light yellow needles (RS-2) were separated out. RS-2 was found to be homogenous on TLC (MeOH:H₂O:ACOH, 4:6:1).

Results

RS-2 responded to all the following characteristic color reactions for flavonoids (Shibata test and reaction with 5% FeCl₃) and also responded positively to Molisch test of glycoside; spectral analysis of the sample clearly showed the characteristic peaks of flavone glycoside as depicted in (Graph 1, Graph 2, Graph 3, Graph 4).

Conclusion

On the basis of spectral data obtained, the compound was identified as 5,4-dihydroxy–3-(3-methyl-but-2-enyl) 3,5,6-trimethoxy-flavone-7-O-β-d-glucopyranoside. Survey of the literature clearly indicated that 5,4-dihydroxy–3-(3-methyl-but-2-enyl) 3,5,6-trimethoxy-flavone-7-O-β-d-glucopyranoside, this is the first report from the fruit pulp of F. limonia L. a novel compound.