Biosynthesis and characterization of deuterated chitosan in filamentous fungus and yeast

Deuterated chitosan was produced from the filamentous fungus Rhizopus oryzae, cultivated with deuterated glucose in H2O medium, without need for conventional chemical deacetylation. After extraction and purification, composition structure were determined by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), small-angle neutron scattering (SANS). 13C NMR experiments provided additional information about position of deuterons glucoseamine backbone. The spectra indicated that deuterium incorporation at non-exchangeable hydrogen positions aminoglucopyranosyl ring C3 – C5 least 60–80 %. However, C2 a much lower level (6%). Also, SANS showed very similar compared to non-deuterated counterpart. most abundant radii protiated fibers 54 Å 60 Å, respectively, but there is broader distribution fiber sample. highly deuterated, soluble fungal described here can be used as model material studying chitosan-enzyme complexes future studies. Because physical behavior mimicked shrimp shell chitosan, methods presented represent new approach producing high quality non-animal-derived aminopolysaccharide structure-function association biocomposite materials drug delivery, tissue engineering other bioactive chitosan-based composites.