New Apigenin Triosides From The Seeds of Syzygium aromaticum

Syzygium aromaticum (L.) Merr. & Perry belongs to the family Myrtaceae. S. aromaticum buds (clove) are used in folk medicine as diuretic, odontalgic, stomachic, tonicardiac, aromatic condiment and condiment with carminative and stimulant properties [1]. Compounds isolated from S. aromaticum have been found to possess growth inhibitory activity against oral pathogens [2]. The aim of this work is the isolation and structural elucidation of flavonoid glycosides from the seeds of S. aromaticum. The crushed seeds were subjected to successive extraction using n-hexane, dichloromethane and ethanol (70%). The aqueous ethanol extract was subjected to cellulose column chromatography. The eluted polar fractions were further chromatographed on Sephadex LH-20 columns to give two new apigenin triglycosides, apigenin 6-C-[ β-D-xylopyranosyl-(1→2)- β-D- galactopyranoside]-7-O-D-glucopyranoside (1) and apigenin 6-C-[β-D-xylopyranosyl-(1→2)-D-galactopyranoside]-7-O- β-D-(6-O-p-oumarylglucopyranoside) (2). The structures of the new compounds were elucidated by chemical and spectral analysis including UV, FABMS, ¹H, ¹³C NMR, DEPT, HMQC, HMBC and NOESY.

References: 1. Boulos, L. (1983), Medicinal Plants of North Africa. Ref. Publications Inc., Michigan. 2. Cai, L. et al. (1996), J. Nat. Prod. 59: 987–990.