547.972Two new prenylated isoflavanones have been isolated from the roots of Glycyrrhiza glabra L. along with the known compounds cetoleic acid, β-sitosterol, stigmasterol, lanast-5,24-dien-3β-D-glucuronopyranoside, and glucuronic acid. The structures of the prenylated isoflavanones have been established as 8-isoprenyl-7,4′-dihydroxylicoisoflavanone (glabraisoflavanone A) and 7,3′-dihydroxy-8-isoprenyl-4′-cyclogeranioloxyisoflavanone (glabraisoflavanone B) on the basis of spectral data analyses and chemical reactions.Glycyrrhiza glabra L. (Fabaceae), commonly known in trade as liquorice, is a perennial herb distributed in subtropical and warm temperate regions of the world [1]. The roots are reported to have anti-inflammatory, demulcent, expectorant, and tonic properties and are prescribed to treat sore throat, bronchial catarrh, cough, gastric and duodenal ulcers, dyspepsia, allergic reactions, arthritis, rheumatism, tuberculosis, and liver toxicity [1, 2]. The important phytoconstituents isolated from the roots included glycyrrhizin, liquiritic acid, glabranins A and B, glycyrrhetol, glabrolide, formononetin, liquiritin, isoliquertin, and other phenolic compounds [3][4][5][6][7][8][9]. This present paper describes the isolation and characterization of the known compounds cetoleic acid (1), β-sitosterol (2), stigmasterol (3), lanast-5,24-dien-3β-D-glucuronopyranoside (6), glucuronic acid (7) and of two new prenylated isoflavanones (4, 5) from the roots of G. glabra of northern India.Compound 4, designated as glabraisoflavanone A, was obtained as a pale yellow crystalline product from chloroform eluates. Its UV λ max at 211, 294 nm and the presence of the O-CH 2 -CH-CO sequence in its 1 H and 13 C NMR spectra (Table 1) accounted for its isoflavanone structure. The presence of a bathochromic shift after addition of sodium acetate in the UV spectrum indicated a free hydroxyl group at C-7. It was assigned a molecular formula of C 25 H 28 O 4 (m/z 392.1652) from HREIMS. A set of three AMX patterns of double doublets in the 1 H NMR spectrum at δ 4.45 (J = 10.5, 7.5 Hz), 4.62 (J = 11.3, 5.2 Hz), and 3.91 (J = 5.2, 10.5 Hz) for the aliphatic proton signals and carbon signals at δ 70.83 (C-2), 51.12 (C-3), and 196.89 (C-4) were consistent with compound 4 being an isoflavanone derivative [10,11]. The 1 H and 13 C NMR spectra indicated the presence of one 3-methylbut-2-enyl, one hydroxyl, and dimethyl pyranosyl substituents on the isoflavanone skeleton.

No abstract