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Duan X.,Shandong University | Zhang D.,Shandong University | Nie L.,Shandong University | Zang H.,Shandong University | Zang H.,National Glycoengineering Research Center
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

Radix Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li and Radix S. miltrorrhiza belong to the same genus. S. miltiorrhiza var. alba has a unique effectiveness for thromboangiitis besides therapeutical efficay of S. miltrorrhiza. It exhibits antioxidant activity (AA), while its quality and efficacy also vary with geographic locations. Therefore, a rapid and nondestructive method based on Fourier transform near infrared spectroscopy (FT-NIRS) was developed for discrimination of geographical origin and evaluation of AA of S. miltiorrhiza var. alba. The discrimination of geographical origin was achieved by using discriminant analysis and the accuracy was 100%. Partial least squares (PLS) regression was employed to establish the model for evaluation of AA by NIRS. The spectral regions were selected by interval PLS (i-PLS) method. Different pre-treated methods were compared for the spectral pre-processing. The final optimal results of PLS model showed that correlation coefficients in the calibration set (Rc) and the prediction set (Rp), root mean square error of prediction (RMSEP) and residual prediction deviation (RPD) were 0.974, 0.950, 0.163 mg mL-1 and 2.66, respectively. The results demonstrated that NIRs combined with chemometric methods could be a rapid and nondestructive tool to discriminate geographical origin and evaluate AA of S. miltiorrhiza var. alba. The developed NIRS method might have a potential application to high-throughput screening of a great number of raw S. miltiorrhiza var. alba samples for AA. © 2013 Elsevier B.V. All rights reserved. Source


Zhang D.,Shandong University | Duan X.,Shandong University | Deng S.,Shandong University | Nie L.,Shandong University | And 2 more authors.
Journal of Separation Science | Year: 2015

Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li has wide prospects in clinical practice. A useful comprehensive method was developed for the quality evaluation of S. miltiorrhiza var. alba by three quantitative parameters: high-performance liquid chromatography fingerprint, ten-component contents, and antioxidant activity. The established method was validated for linearity, precision, repeatability, stability, and recovery. Principal components analysis and hierarchical clustering analysis were both used to evaluate the quality of the samples from different origins. The results showed that there were category discrepancies in quality of S. miltiorrhiza var. alba samples according to the three quantitative parameters. Multivariate linear regression was adopted to explore the relationship between components and antioxidant activity. Three constituents, namely, danshensu, rosmarinic acid, and salvianolic acid B, significantly correlated with antioxidant activity, and were successfully elucidated by the optimized multivariate linear regression model. The combined use of high-performance liquid chromatography fingerprint analysis, simultaneous multicomponent quantitative analysis, and antioxidant activity for the quality evaluation of S. miltiorrhiza var. alba is a reliable, comprehensive, and promising approach, which might provide a valuable reference for other herbal products in general to improve their quality control. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Xue M.,National Glycoengineering Research Center | Xue M.,State Key Laboratory of Microbial Technology | Guan W.,National Glycoengineering Research Center | Guan W.,State Key Laboratory of Microbial Technology | And 11 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2012

Nucleotide sugars are essential glycosyl donors for Leloir-type glycosyltransferases. The UDP-N-acetylgalactosamine pyrophosphorylase (UDP-GalNAc PP; AGX1) from Homo sapiens catalyzes the synthesis of UDP-N-acetylgalactosamine from N-acetylgalactosamine 1-phosphate and UTP. In this Letter, we systematically studied nucleotide substrate specificity of AGX1 during its uridyltransfer reaction, and described the capability of AGX1 to catalyze dUTP and dTTP to their corresponding nucleotide sugars for the first time. Furthermore, using such a eukaryotic enzyme, we synthesized dUDP-GalNAc and dTDP-GalNAc in multiple mg scale in vitro efficiently and rapidly. © 2012 Elsevier Ltd. All rights reserved. Source


Liu J.,State Key Laboratory of Microbial Technology | Liu J.,National Glycoengineering Research Center | Zou Y.,State Key Laboratory of Microbial Technology | Zou Y.,National Glycoengineering Research Center | And 14 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2013

Nucleotide sugars are activated forms of monosaccharides and key intermediates of carbohydrate metabolism in all organisms. The availability of structurally diverse nucleotide sugars is particularly important for the characterization of glycosyltransferases. Given that limited methods are available for preparation of nucleotide sugars, especially their useful non-natural derivatives, we introduced herein an efficient one-step three-enzyme catalytic system for the synthesis of nucleotide sugars from monosaccharides. In this study, a promiscuous UDP-sugar pyrophosphorylase (USP) from Arabidopsis thaliana (AtUSP) was used with a galactokinase from Streptococcus pneumoniae TIGR4 (SpGalK) and an inorganic pyrophosphatase (PPase) to effectively synthesize four UDP-sugars. AtUSP has better tolerance for C4-derivatives of Gal-1-P compared to UDP-glucose pyrophosphorylase from S. pneumoniae TIGR4 (SpGalU). Besides, the nucleotide substrate specificity and kinetic parameters of AtUSP were systematically studied. AtUSP exhibited considerable activity toward UTP, dUTP and dTTP, the yield of which was 87%, 85% and 84%, respectively. These results provide abundant information for better understanding of the relationship between substrate specificity and structural features of AtUSP. © 2013 Elsevier Ltd. All rights reserved. Source


Zhu B.-W.,CAS Dalian Institute of Chemical Physics | Zhu B.-W.,University of Chinese Academy of Sciences | Huang L.-S.-X.,CAS Dalian Institute of Chemical Physics | Huang L.-S.-X.,University of Chinese Academy of Sciences | And 5 more authors.
Biotechnology Letters | Year: 2014

An alginate lyase gene, algA, encoding a new poly β-d-mannuronate (polyM)-specific alginate lyase AlgA, was cloned from Pseudomonas sp. E03. The recombinant AlgA with (His)6-tag, consisting of 364 amino acids (40.4 kDa),was purified using Ni–NTA Sepharose. The purified lyase had maximal activity (222 EU/mg) at pH 8 and 30 °C and also maintained activity between pH 7–9 and below 45 °C. It exclusively and endolytically depolymerized polyM by β-elimination into oligosaccharides with degrees of polymerization (DP) of 2–5. Due to its high substrate specificity, AlgA could be a valuable tool for production of polyM oligosaccharides with low DP and for determining the fine structure of alginate. © 2014, Springer Science+Business Media Dordrecht. Source

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