Characterisation of polysaccharides from the fern Platycerium bifurcatum with expected biological activity

Abstract

Platycerium bifurcatum, a widely growing fern was collected and the phytochemical analysis of the powdered plant showed that polysaccharides were present in appreciable quantity. It was found that 4.0 % sodium hydroxide solution was required for optimum extraction and then precipitated using 99.0 % ethanol in an overall yield of 4.85 %. By appropriate phytochemical analysis of the polysaccharides, it was found to be of very high purity- approximately 90.0 %. The chromatography of the hydrolysed polysaccharide established presence of mainly D-galactose units, using the retardation factor values (R f values) of various sugars as primary standard and reference. The solubility profile indicates that the polysaccharide was insoluble in organic solvents, sparingly soluble in water and acids, and soluble in alkaline medium. The crystalline compound was found to melt at a temperature range of 165-171°C and decomposes at a temperature range of 185-200°c. Other parameters for complete characterisation were established for the extract. The extract was found to be free from foreign matter, and microorganisms and heavy metals found were of acceptable concentration.