Structural features of a heteroxylan from Sophora subprostrata roots

An acidic heteroxylan, SSb2, was isolated from the alkaline extract of Soph ora subprostrata by DEAE-Sephadex A-25 and Sephacryl S-300 chromatography, with an M-r of 4.4 x 10(5) and a specific optical rotation of -49.2 degrees (c 0.5, H2O). Its structural features were elucidated by methylation analy sis, partial acid hydrolysis, periodate oxidation and C-13 NMR spectroscopy . The data obtained indicated that SSb2 has a backbone consisting of 1,4-li nked xylopyranosyl residues with branches at O-2 or O-3, composed of L-Ara( f)(1 --> 5)L-Ara(f)(1 --> , 4-O-Me-D-GlcA(1 --> or D-GlcA(1 --> . SSb-2 exh ibited an immunostimulating activity in vivo in pharmacological experiments . (C) 1998 Elsevier Science Ltd. All rights reserved.