Production of mucic acid from pectin-derived D-galacturonic acid: a review / 生物工程学报

Mucic acid is a hexaric acid that can be biosynthesized by oxidation of D-galacturonic acid, which is the main constituent of pectin. The structure and properties of mucic acid are similar to that of glucaric acid, and can be widely applied in the preparation of important platform compounds, polymers and macromolecular materials. Pectin is a cheap and abundant renewable biomass resource, thus developing a process enabling production of mucic acid from pectin would be of important economic value and environmental significance. This review summarized the structure and hydrolysis of pectin, the catabolism and regulation of D-galacturonic acid in microorganisms, and the strategy for mucic acid production based on engineering of corresponding pathways. The future application of mucic acid are prospected, and future directions for the preparation of mucic acid by biological method are also proposed.

Quality evaluation and discrimination of Polygonati Rhizoma from three origins based on polysaccharide composition and content / 中草药

Objective: To compare the composition and content of polysaccharides in Polygonati Rhizoma by qualitative and quantitative analysis combined with chemometrics, and provide the reference for the quality evaluation of Polygonati Rhizoma. Methods Fourier transform infrared spectroscopy (FTIR) and pre-column derivatization-HPLC (PMP-HPLC) were employed to reveal the differences of polysaccharide among the three species, and the content of total polysaccharide was determined by ultraviolet spectroscopy (UV). Results:The result indicated that the average spectra and the second derivative atlas in FTIR fingerprint of Polygonati Rhizoma was significantly different. The PCA, PLS-DA and HCA analysis provided a further refinement of the method to distinguish three species. Furthermore, the PMP-HPLC showed that the components of monosaccharide and polysaccharides of three species were different. The main common components of the 10 common peaks were identified, which were as follows: D-mannose, D-ribose, L-rhamnose, D-galacturonic acid, D-glucuronic acid, D-galactose, D-glucose, D-xylose, D-arabinose and L-fucose. The content of the total polysaccharide meeted the requirements of Chinese pharmacopoeia 2015 edition Conclusion:The study provided a new reference for quality evaluation of P. Rhizoma.