Evaluation of isolation and field effect of ginseng disease resistance and growth-promoting bacteria / 中国中药杂志

This study was aimed to isolate the strains with both disease resistance and growth-promoting, and clarify the field application effects of the strain for laying the further application foundation. The strains with good antagonistic effect were isolated from the 298 strains in Panax ginseng and the soil by plate confrontation method. The nitrogen fixation potential was verified by Ashby medium. The Salkowski method was used to determine the ability of producing IAA. Silicate medium screening and flame spectrophotometry was used to determine the ability of dissolving potassium. CAS method was applied to detect the ability of producing siderophores to determine its growth characteristics. The morphological, physiological and biochemical and 16S rRNA sequences were used to identify the species. The method of root irrigation was used to determine the effects of its disease control and growth-promoting on ginseng. A strain TY15 with broad spectrum of antimicrobial effect, nitrogen fixation, potassium-dissolving and the capacity of producing IAA and siderophores was obtained by screening. And the strain TY15 was identified as Pantoea agglomerans. The control effect of TY15 on the disease of ginseng in the field was 68.02%, which was equivalent to 68.94% of 30 billion per gram of beneficial microecological bacterium agent. The fresh weight of P. ginseng treated with TY15 strain was increased by 22.73% compared with the control group treated with water. And finally a strain TY15 with good application prospects was obtained.

Preparation and structural sequence analysis of heparan sulfate dodecasaccharide / 中国药学杂志

OBJECITVE: To prepare a heparan sulfate dodecasaccharide and analyze its structural sequence. METHODS: HS-derived oligosaccharide was prepared by heparinase II depolymerization. Size-uniform dodecasaccharide mixture was acquired by low pressure gel permeation chromatography on Bio-Gel P-10 column. The dodecasaccharides were further separated by strong anion-ex-change high-performance liquid chromatography (SAX-HPLC) to get a charge-uniform dodecasaccharide. The dodecasaccharide was completely hydrolyzed by heparinases I, II, and III, its disaccharides composition was analyzed by HPLC, and its structural sequence was confirmed by electrospray collision-induced dissociation mass spectrometry (ES-CID-MSn). RESULTS: One size- and charge-uniform pure dodecasaccharide was separated from HS enzymatic hydrolyzed mixture, and it was composed by δUA-GlcNAc (IV-A) and AUA-GlcNS (IV-S) with the relative ratio of 5-1. Based on the ES-CID-MSn analysis, its structural sequence was δUA-GlcNAc-GlcA-GlcNS-GlcA-GlcNAc-GlcA-GlcNAc- GlcA-GlcNAc-GlcA-GlcNAc. CONCLUSION: The dodecasaccharide was prepared from HS, its detailed structure is analyzed, and it will offer a basis for the structure-activity relationship study of HS oligosaccharide.