Research Progress of Endophytic Bacterial Resources and Their Secondary Metabolites / 中国实验方剂学杂志

Endophytic bacteria exist in the host and do not cause obvious damage to the host，which is an important part of the host ecosystem. Endophytic bacteria are a kind of important microbial resources with diverse species and wide distribution. In the process of long-term coevolution between endophytic bacteria and host，many symbiotic relationships，such as antagonism and reciprocity，have been gradually formed，which can directly or indirectly regulate the growth and development of host，assist host to resist diseases and insect pests，environmental stress and other biological processes. Endophytic bacteria can produce a variety of secondary metabolites in the process of symbiosis with the host，which plays an important role in the development of new natural products. In recent years，endophytic bacteria and their secondary metabolites have been widely used in the research and development of new drugs，biological control and other fields. In this paper，the diversity，species identification and secondary metabolites of endophytic bacterial resources are reviewed，and the future development direction is discussed，hoping to provide reference for the further development and utilization of endophytic bacterial resources.

Study on polysaccharide content and monosaccharide composition of Polyporus umbellatus from different production areas / 中国中药杂志

In order to provide scientific basics for exploitation and sufficient application of Polyporus umbellatus resources and study the monosaccharide composition of P. umbellatus polysaccharides,the anthrone-sulfuric acid method was applied to compare polysaccharide content of P. umbellatus from 17 producing areas. The monosaccharides were derived by 1-phenyl-3-methyl-5-pyrazolone( PMP) and the derivatives were identified by UPLC-MS/MS and the content of each monosaccharide component was determined simultaneously. The results demonstrated that there was a certain difference in total polysaccharide content of P. umbellatus from different regions,and the content of total P. umbellatus polysaccharide from Shaanxi province and Sichuan province( 1. 15% and 1. 90%) was relatively higher than that of others areas. Polysaccharides from P. umbellatus was mainly composed of eight monosaccharides,including glucose,glucuronic acid,galactose,ribose,xylose,arabinose,mannose and fucose. The contents of glucose( 17. 65 mg·g-1) was higher than others. The ribose was the lowest( 0. 13 mg·g-1). In addition,fructose,rhamnose and galacturonic acid were also detected in some samples. Furthermore,the results of cluster analysis( CA) and principal component analysis( PCA) indicated that totally 17 batches of P. umbellatus polysaccharide could be classified into three clusters,samples collected from Wuchang in Heilongjiang province were clustered into one group separately. The study can provide a basis for rational utilization of P. umbellatus resources,and also implies the sequence of monosaccharide linking and pharmacological activity of P. umbellatus polysaccharides.

Analysis of monosaccharide composition of twelve polysaccharides by pre-column derivatization procedure UPLC-MS/MS / 中国中药杂志

This study is to establish a pre-column derivatization procedure with 1-phenyl-3-methyl-5-pyrazolone (PMP) UPLC-MS/MS method for the determination of the monosaccharide composition of 12 polysaccharides. At the same time, the monosaccharide components of polysaccharides in Armillaria gallica were analyzed. The separation was performed on a ACQUITY ZORBAX RRHD Eclipse Plus C₁₈ column(2.1 mm×100 mm, 1.8 μm),using 95% acetonitrile (A) and ammonium acetate-5% acetonitrile-water (B) as mobile phase with gradient elution. The target components were detected in multiple-reaction monitoring (MRM) mode by mass spectrometry with electrospray ionization (ESI) source operated in ionization mode. The results showed that based on the monosaccharides detection method established by UPLC-MS/MS, the linearity of the 12 monosaccharides components were linear in their linear range (R²>0.990), and the recovery rate were 92.30%-105.6%. 11 monosaccharides such as fructose, mannose, and glucose were detected in A. gallica samples. The method established in this experiment is robust, highly reproducible and accurate, and is suitable for the determination of monosaccharide components such as A. gallica.