Antimicrobial activity and comparative metabolomic analysis of Priestia megaterium strains derived from potato and dendrobium.

The growth of endophytic bacteria is influenced by the host plants and their secondary metabolites and activities. In this study, P. megaterium P-NA14 and P. megaterium D-HT207 were isolated from potato tuber and dendrobium stem respectively. They were both identified as Priestia megaterium. The antimicrobial activities and metabolites of both strains were explored. For antimicrobial activities, results showed that P. megaterium P-NA14 exhibited a stronger inhibition effect on the pathogen of dendrobium, while P. megaterium D-HT207 exhibited a stronger inhibition effect on the pathogen of potato. The supernatant of P. megaterium P-NA14 showed an inhibition effect only on Staphylococcus aureus, while the sediment of P. megaterium D-HT207 showed an inhibition effect only on Escherichia coli. For metabolomic analysis, the content of L-phenylalanine in P. megaterium P-NA14 was higher than that of P. megaterium D-HT207, and several key downstream metabolites of L-phenylalanine were associated with inhibition of S. aureus including tyrosine, capsaicin, etc. Therefore, we speculated that the different antimicrobial activities between P. megaterium P-NA14 and P. megaterium D-HT207 were possibly related to the content of L-phenylalanine and its metabolites. This study preliminarily explored why the same strains isolated from different hosts exhibit different activities from the perspective of metabolomics.

Identification and activity evaluation of Astragalus Radix from different germplasm resources based on specific oligosaccharide fragments.

Objective: Based on trifluoroacetic acid (TFA) hydrolysis, polyacrylamide gel electrophoresis (PAGE) and high performance thin layer chromatography (HPTLC) analysis, the carbohydrate responsible for immunomodulatory activity are used as quality indicators for Astragalus Radix (AR). Methods: In this study, 24 batches of AR from different germplasm resources were selected as the research object, and AR polysaccharides were extracted. PAGE and HPTLC methods were used to analyze the partial acid hydrolyzate of AR polysaccharides and obtain a series of saccharide fingerprints. The data were analyzed by principal component analysis to obtain the difference between AR from different germplasm resources. Results: The results showed that trisaccharide and tetrasaccharide could be used as differential fragments to distinguish AR of different cultivation methods; Disaccharides and trisaccharides can be used as differential fragments to distinguish different species of AR. The immunological activity analysis of the specific oligosaccharide fragment of AR showed that the specific oligosaccharide fragment of AR could promote the secretion of TNF-α, IL-1ß, IL-6, and NO in THP-1 cells in a concentration-dependent manner. Conclusion: Both PAGE and HPTLC methods can be used to evaluate AR from different germplasm resources. This study laid the foundation for the quality evaluation of AR medicinal herbs.

Potential quality evaluation approach for the absolute growth years' wild and transplanted Astragali Radix based on anti-heart failure efficacy.

The quality of Astragali Radix (AR) was closely related to the growth period. However, the current commodity grades of AR were only divided by diameter but not directly related to the growth period, which leads to the contradiction between the grade standard and the quality evaluation index. Therefore, solving this problem will be the key for the quality evaluation of AR. The present study established a potential quality evaluation approach for the absolute growth years' wild Astragali Radix (WAR) and transplanted Astragali Radix (TAR) based on the chemical components and anti-heart failure efficacy through adopting a bare-handed sections approach to rapidly identify the growth years of WAR. In this study, the absolute growth years of WAR were obtained by identifying the growth rings of 1-6 growth years root through the methods. The contents of flavonoids and saponins in 2-6 growth years' WAR were determined by HPLC-UV-ELSD. The contents of 12 chemical components and the anti-fatigue failure effects of WAR (4-year-old) and TAR were compared on rat models of heart failure induced by doxorubicin. Meanwhile, NMR-based untargeted metabolomics studies were performed to investigate the regulative effects of WAR and TAR. The result shows that the numbers of growth rings were consistent with the actual growth periods of AR. The HPLC-UV-ELSD determination indicated that the content of total flavonoids in WAR was significantly higher than that in TAR. Pharmacodynamics analysis revealed that the effects of WAR on cardiac function parameters (EF, FS and LVIDs), contents of serum CK and BNP were superior to those of TAR. 13 metabolites of heart were identified that had a higher rate of change in WAR group than TAR. Overall, a rapid identification method for the growth years of WAR was established, and the fact that WAR were significantly better than TAR in the heart failure rats was first proved in the paper. This study provided a scientific basis for establishing a novel commodity specification and grade of AR for clinical rational drug use.

[Research progress and secondary development ideas of Astragali Radix polysaccharides for injection].

Astragali Radix( AR) polysaccharide for injection( Guoyao Zhunzi Z20040086) is a traditional Chinese medicine for intravenous powder injection developed by Shanxi Academy of Traditional Chinese Medicine in early 1990 s by taking advantage of AR resources in Shanxi province. The effective parts of AR polysaccharides were obtained by advanced technology. The hemogram of patients with radiotherapy and chemotherapy showed alleviations in clinic. However,due to the technical bottleneck in separation of the complex polysaccharides mixture and the difficulties in accurate measurement of the polysaccharide structures,the pharmacodynamic mechanism of the drug remained unclear,and the side effect was hard to control. In recent years,the theoretical studies for polysaccharide receptors have indicated that when polysaccharides bound to protein receptors,only the oligosaccharide fragments of the polysaccharide molecule bound to the receptors,and one or more active sites of oligosaccharide fragments may existed in the polysaccharide molecule.Therefore,the active center of polysaccharides can be studied based on the level of oligosaccharides through degradation of the polysaccharides,which provided a new strategy for breaking through the bottleneck in polysaccharide structure determination. Therefore,this paper reviews the current status of studies for AR polysaccharides for injection,the polysaccharide receptors theory and successful cases,in order to propose the secondary development ideas of AR polysaccharides for injection. The study results will lay a material foundation for the development of new drugs of polysaccharides from traditional Chinese medicine,and provide a basis for the resolution of international difficulties in quality control of polysaccharide drugs and molecular models,so as to further study of glycobiology,and enrich the polysaccharide receptors theory.

Characteristics and dissemination of mosaic penicillin-binding protein 2-harboring multidrug-resistant Neisseria gonorrhoeae isolates with reduced cephalosporin susceptibility in northern Taiwan.

Among 254 Neisseria gonorrhoeae isolates from a sexually transmitted infection (STI) clinic in northern Taiwan, 69 isolates were found to contain the mosaic penA (MA) gene and were associated with elevated cefixime and ceftriaxone MICs. Most of these MA gene-harboring isolates were also resistant to penicillin (71.4%) and ciprofloxacin (100%) and were from men who have sex with men (MSM) or from bisexual men (81.2%). Three major sequence types (ST835, ST2180, and ST2253) constituted 55.7% of these isolates. The major sequence types harboring the mosaic penA gene may represent major sexual networks responsible for the emergence/introduction and the spread of the multidrug-resistant clones in Taiwan.