Structural elucidation of a new arabinogalactan from the leaves of Nerium indicum

Dong, Q Fang, JN

Q. Dong et Jn. Fang, Structural elucidation of a new arabinogalactan from the leaves of Nerium indicum, CARBOHY RES, 332(1), 2001, pp. 109-114

14

INGLESE

Article

Agricultural Chemistry","Chemistry & Analysis","Organic Chemistry/Polymer Science

CARBOHYDRATE RESEARCH

0008-6215 → ACNP

332

1

2001

109 - 114

ISI

0008-6215(20010508)332:1<109:SEOANA>2.0.ZU;2-V

A polysaccharide fraction, NIB-2, was obtained from the 3% aqueous sodium c arbonate extract of Nerium indicum leaves using anion-exchange chromatograp hy and gel-permeation chromatography. It was found to be composed of rhamno se, arabinose, galactose, in the ratios of 1.0:10.4:4.4, along with 4% of g alacturonic acid. The results of methylation analysis, periodate oxidation, partial acid hydrolysis, pectinase treatment, and C-13 rind H-1 NMR spectr oscopy indicate that it is mainly an arabinogalactan having a backbone of 1 ,6-linked beta -Galp, with branches at O-3, consisting of terminal, 1,5-, a nd 1,3,5-linked arabinofuranosyl residues, and a small proportion of galact osyl residues at the termini. Rhamnose and galacturonic acid arose from a c ontaminating rhamnogalacturonan. (C) 2001 Elsevier Science Ltd. All rights reserved.