An active heparinoid obtained by sulphation of a galactomannan extracted from the endosperm of Senna macranthera seeds

A galactomannan was isolated from the endosperm of seeds of Senna macranthe ra. It contained mannose and galactose in a 3.0:1 ratio and consisted mainl y of a (1 -->4)-linked beta -D-Manp main-chain partially substituted at O-6 with alpha -D-Galp side-chains. Sulphation with SO3-pyridine gave a produc t with DS 0.40. According to C-13 NMR analysis, the OH-6 groups of galactop yranosyl and mannopyranosyl units were preferentially substituted. The prod uct had 45 IU/mg of anticoagulant activity, as shown by the in vitro activa ted partial thromboplastin time (APTT), compared with 183 IU/mg for a porci ne intestinal mucosa heparin. Two fractions of the sulphated derivative wer e obtained differing in their affinity to AT III in gel. Only that with a h igh affinity (DS 1.4) showed a strong anticoagulant activity, as measured b y APTT (321 IU/ mg) and Heptest. By analogy with heparin, the anticoagulant activity of the derivative could be expressed through binding of the polys accharide to AT III. (C) 2001 Elsevier Science Ltd. All rights reserved.