Ultrasound-Assisted Extraction and Characterization of Polysaccharide From Maryland Tobacco Leaves

Ultrasound-assisted extraction (UAE) of polysaccharide from Maryland tobacco leaves was studied by response surface methodology.Furthermore, the crude polysaccharide was purified and two components (Fr-I and Fr-II) were obtained.FT-IR spectral analysis of the purified polysaccharide revealed prominent characteristic groups.The monosaccharide composition analysis by gas chromatography-mass spectrometry (GC/MS) indicated the main composition between Fr-I and Fr-II was different.Furthermore, thermo gravimetric analysis (TGA) indicated the degradation temperature (Td) of the Fr-I (241 o C) was higher than those of Fr-II (216 o C).Detected by the pyrolysis gas chromatography-mass spectrometry (py-GC/MS), it was found that the main kinds of pyrolysis products from both Fr-I and Fr-II were similar.Finally, On the basis of hydroxyl and DPPH radical scavenging assay, Fr-II has stronger antioxidant activities than Fr-I.The thermal behavior and antioxidant activity might be attributed to the configuration of the chemical compositions.