ALKALI-INDUCED OPTICAL-ROTATION CHANGES IN HEPARINS AND HEPARAN SULFATES, AND THEIR RELATION TO IDURONIC ACID-CONTAINING SEQUENCES

Under specific basic conditions, the glucosaminoglycans heparin and he paran sulfate, containing alpha-L-iduronic acid 2-O-sulfate, undergo s elective epoxidation between C-2 and C-3 of this residue, with formati on of a residue of 2,3-anhydro-alpha-L-guluronic acid. The epoxidation reaction was studied by means of C-13 NMR and optical rotation measur ements. The optical rotation values correlate well with the compositio n of the reaction products as determined by C-13 NMR, thus indicating that the heparin- or heparan-like character of both natural and semisy nthetic polysaccharides can be easily determined also through optical rotation measurements.