“…Another feature of the NMR spectra is the absence of the characteristic minor signals at 6 5.9 and 5.6 which would be due to the presence of a proportion of a,@-unsaturated acid produced by @-elimination in esterified heparin. 18 The characteristic signals in the 6 5.5-4.5 region for the nitrous acid-prepared material are due to end residues of anhydromannitol that are produced by deamination and subsequent depolymerization .18*23 Raman Spectra-The Raman spectra of the two preparations of low molecular weight heparin are shown in Figure 2A. The major peaks at 1040 and 1060 cm-1 are produced by the symmetric S-0 stretching of the N-and 0-sulfate residues, respectively.…”