Characteristic features of polysaccharide derived from fungi (Tremella fuciformis), which are believed to have medical attributes for longevity, were investigated from the viewpoint of water interaction properties. Phase transition behaviour of Tremella fuciformis polysaccharide (TFP) in the presence of water in a range from 0 to 2.5 (mass of water / mass of dry sample, g/g) was measured by differential scanning calorimetry in a temperature range from 123 to 281K. Four transitions, i.e., glass transition, cold crystallization, melting and endotherm at a temperature higher than melting were detected. Furthermore, bound water content of the TFP was evaluated from the enthalpy of melting. From these results were obtained that non-freezing water content of TFP is similar to that of hyaluronan and larger than those of ordinal water-soluble polysaccharides. It is suggested that the chemical structure of TFP with dense placement of the hydroxyl groups is attributed to the above characteristic water binding

Tremella fuciformis polysaccharide, bound water, glass transition, non-freezing water

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

[*]O[C@H]1[C@H](O)[C@@H](CO)O[C@H](O[C@@H]2[C@H](O[C@@H]3O[C@H](C(=O)O)[C@@H](O)[C@H](O)[C@H]3O)[C@@H](O[C@@H]3[C@H](O)[C@@H](O[C@@H]4[C@H](O[C@@H]5O[C@H](C(=O)O)[C@@H](O)[C@H](O)[C@H]5O)[C@@H](O[C@@H]5[C@H](O)[C@@H](O[C@@H]6[C@H](O[C@H]7O[C@H](C)[C@H](O)[C@H](O)[C@H]7O)[C@@H](O[C@@H]7[C@H](O)[C@@H]([*])O[C@H](CO)[C@H]7O)O[C@H](CO)[C@H]6O)O[C@H](CO)[C@H]5O)O[C@H](CO)[C@H]4O)O[C@H](CO)[C@H]3O)O[C@H](CO)[C@H]2O)[C@H]1O[C@@H]1OC[C@@H](O)[C@H](O)[C@H]1O[C@@H]1OC[C@@H](O)[C@H](O)[C@H]1O

1897.607 g/mol (C₇₀H₁₁₂R₂O₅₉, R = next and previous repeats, not counted in mol weight)

β-glucan particles (GP) are polymeric carbohydrates, mainly found as components of cell wall fungi, yeast, bacteria and also in cereals such as barley and oat, and have been recently shown to have application in macrophage-targeted drug delivery. The aim of this study was to prepare and characterize GP containing a large payload of Rifabutin (RB), an anti-tuberculosis drug effective against MDR-TB at lower MIC than Rifampicin. GP were prepared from yeast cells by acidic and alkaline extraction were either spray dried or lyophilized, prior to RB loading and alginate sealing. The FTIR and 13C-NMR spectra of the GP confirmed a β-(1→3) linked glucan structure, with a triple-helical conformation. The spray dried GP exhibited better characteristics in terms of uniformity, size range (2.9 to 6.1 µm) and more than 75 % particles were below 3.5 μm. The RP-HPLC analysis of spray dried GP revealed drug entrapment and drug loading up to 81.46 ± 4.9 % and ~40.5 ± 1.9 %, respectively, as compared to those dried by lyophilization. Electron microscopy showed nearly spherical and porous nature of GP, and the presence of drug 'nanoprecipitates' filling the pore spaces. The formulation showed adequate thermal stability for pharmaceutical application. The particles were readily phagocytosed by macrophage(s) within 5 min of exposure. Drug release occurred in a sustained manner via diffusion, as the release kinetics best fit for drug release was obtained using Higuchi's equation. Thus, the spray dried GP-based-formulation technology holds promise for enhanced targeted delivery of anti-TB drug(s) to macrophage within a therapeutic window for the clearance of intracellular bacteria.

phagocytosis, macrophage, glucan particles, rifabutin, spray drying, targeted drug delivery

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
	bDGlcp	105.62	87.19	78.74	76.47	70.17	63.07


1H NMR data:
missing...

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

[*]O[C@@H]1[C@@H](O)[C@H]([*])O[C@H](CO)[C@H]1O

162.141 g/mol (C₆H₁₀R₂O₅, R = next and previous repeats, not counted in mol weight)