Spectroscopic Characterization of Pachyman Sulfate and Its Binding Interaction with Azur A

Abstract

High-purity pachyman isolated from the sclerotium of Poria cocos was reacted with chlorosulfonic acid to obtain pachyman sulfate (PS). The FTIR spectrum indicated sulfation of glucoside hydroxyl. The NMR results indicated almost complete sulfation on C-6, C-2, and C-4 of glucoside. Interaction between azur A (AA) and PS with AA concentration from 2.745 Â 10 25 to 6.863 Â 10 25 M was investigated using spectrophotometry at 625 nm. It was found that AA was a promising spectroscopic probe for the detection of sulfated groups in the PS macromolecule. Self-interference of AA on AA -PS interaction caused an overestimation of the molar mass of PS. The molecular weight mass of 13,110 Da obtained with an improved method for PS used in the current work agreed well with the value of 10,233 Da calculated from HPLC results.

In Vitro Fermentation Characteristics of Fungal Polysaccharides Derived from Wolfiporia cocos and Their Effect on Human Fecal Microbiota

“…FL was defatted in 1:10 w/w of ethyl acetate for 2 h and acetone for another 2 h. The dried and defatted powder was soaked in 1:20 w/w of 1 M sodium hydroxide for at least 16 h at room temperature with continuous agitation. The supernatant of the alkali-soluble fraction was neutralized with hydrochloric acid to yield jelly-like precipitates, which were then washed 5 times using Milli-Q water [20]. The washed precipitates were dialyzed (Spectra/Por molecularporous membrane tubing of MWCO 6-8 kDa, d = 32 mm) against Milli-Q water until the conductivity of the water-soaking dialysis membranes was below 10 µS/cm, as measured using a conductivity/TDS meter.…”