*4.5. FTIR and NMR Analysis*

FTIR is extensively used for the structural characterization of polymers as it allows identification of the functional groups. 10 mg of the purified polysaccharide powder were mixed with KBr and cast into pellets. The FTIR readings were taken using a Thermo Scientific NicoletTM 6700 FTIR spectrometer, MA USA. For the NMR analysis, the dialyzed polysaccharide was lyophilized, and deuterium exchanged with D2O. The samples were then dissolved in D2O, and a minute amount of deuterated dimethyl sulfoxide was added as an internal standard. NMR spectra were obtained using a JEOL JNMECX400, NMR spectrometer, Japan at 33 k.

## *4.6. Evaluation of Molecular Weight Distribution*

The molecular weights of the purified fractions were analyzed using agarose gel electrophoresis following our previous method [1]. Briefly, the polysaccharide samples were electrophoresed in 1% agarose gels using a running bu ffer composed of Tris-Borate-EDTA (pH 8.3). The electrophoresis was carried out for 20 min at 100 V. The gel was stained with 0.02% o-Toluidine in 3% acetic acid with 0.5% Triton X-100 and destained with 3% acetic acid. Molecular weight markers used were, dextran sulfate (MW 50–500 kDa), chondroitin 6-sulfate (MW 60 kDa), Dextran sulfate (MW ≈ 50 kDa) and Dextran sulfate (MW ≈ 8 kDa).
