Assessment of antiherpetic activity of nonsulfated and sulfated polysaccharides from Azadirachta indica

Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

“…Fragmentation of polysaccharide molecules, either by mild acid hydrolysis or enzyme hydrolyses into oligosaccharides, and the characterization of the purified fragments, is often employed to determine the sequence of monosaccharide residues [115,120]. The oligosaccharides generated are fractionated and purified by size exclusion chromatography [7,8,25,[121][122][123][124], HPAE-PAD chromatography, or other techniques. Precise structures of these purified oligosaccharides may be determined by sugar compositional analysis, glycosidic linkage composition, periodate oxidation, NMR, MALDI-TOF-MS or other methods [125][126][127].…”

“…As a specific aspect of polysaccharides comprising pronounced levels of bioactivity, the presence of sulfate groups in polysaccharides creates additional challenges in deducing their structure, since the position of sulfation and the degree of sulfation (DS) needs be additionally determined. Traditional methods for the determination of sulfate contents in polysaccharides include the HPLC analysis of sulphates [94], turbidometric barium chloride method [7,8,25,122,124] and IR spectrometry [7,8,25,[121][122][123][124]. The position of sulfate groups can be determined conventionally by comparison of methylation analysis results obtained for the polysaccharide sulfates with those for its desulfated derivatives [7,8,121,123,124,130].…”

“…Traditional methods for the determination of sulfate contents in polysaccharides include the HPLC analysis of sulphates [94], turbidometric barium chloride method [7,8,25,122,124] and IR spectrometry [7,8,25,[121][122][123][124]. The position of sulfate groups can be determined conventionally by comparison of methylation analysis results obtained for the polysaccharide sulfates with those for its desulfated derivatives [7,8,121,123,124,130]. Infrared spectroscopy (IR) spectroscopy, 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy may provide additional information on the position of sulfate groups [8,121,123,[137][138][139][140].…”

“…The position of sulfate groups can be determined conventionally by comparison of methylation analysis results obtained for the polysaccharide sulfates with those for its desulfated derivatives [7,8,121,123,124,130]. Infrared spectroscopy (IR) spectroscopy, 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy may provide additional information on the position of sulfate groups [8,121,123,[137][138][139][140].…”

“…Significant research endeavors are directed towards sulfation of polysaccharides [141,142] and both the advantages and limitations have been recognized dependent on the characteristics of the source materials [19]. A selection of typical reagents namely, oleum [7,8,123,143], chlorosulfonic acid [141,[144][145][146][147][148], sulfamic acid [149][150][151][152][153][154], piperidine-N-sulfonic acid [155][156][157] and SO 3pyridine [25,121,122,[158][159][160][161][162] used in these sulfation processes is highlighted in Figure 5. The benefits and drawbacks of the sulfation modification techniques are presented by Table 2.…”