The flavonoid composition of Melilotus officinalis (L.) Desr. (Fabaceae) growing in Georgia is studied. Air-dried leaves and flowers (2 kg) were extracted with 80 " ethanol. The alcohol was distilled. The aqueous extract was purified with CHCi 3. The flavonoids (7 g) were obtained by fractionation of the aqueous layer on a polyamide column. Two pure fiavonoids, 1 and 2, were isolated by known methods from this fraction.Compound 1: mp 187-189~ [ff.]D 20= -83.5 ~ (c 0.1, ethanoi-DMF, 99:1), MM 740 (spectrometrically). Acid produces 33% kaempferol, D-glactose, L-rhamnose. Alkali solution (0.5%) gives kaempferol-3-robinobioside with mp 221-222~ [~tlD -~~ = -17.3 ~ (c 0.345, ethanol water, 1:1) and L-rhamnose, The [3-glycosidases produce robinobiose and kaempferol-7rhamnoside with mp 227-229~ lo:]o 2~ = -128" (c 0.1, absolute ethanol) [2]. Compound 2: mp 200-205~ MM 870 (spectrometrically); ~,ax, EtOH, nm: 352, 270: + sodium acetate, 356, 275: + aluminum chloride 360, 272: + aluminum chloride/HCl. 360, 256; + sodium acetate/boric acid, 358, 272; + sodium ethoxide, 430. 278. Acid hydrolysis forms 26% kaempferol. The cartx~hydrate portion contains D-galactose. D-glucose, L-arabinose, and L-rhamnose.The physicochemical properties, IR and UV spectra, chromatographic behavior, and lack of melting-point depression when mixed with authentic samples identify 1 as robinin 11-31 and 2 as kaempl~rol-3-O-lgalacto-~-gluco-~-arabo-~-rhanmoside[, which have been isolated previously from Astragalusfalcatus Lam., A. galeg~formis L., and A. glycyphyllus DC. [4, 51.
