A New Saponin Transformed from Ginsenoside Rh1 by Bacillus subtilis

A novel saponin was isolated from the transformed products of ginsenoside Rh1 by Bacillus subtilis. It‘s structure was determined to be 3-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-20 (S)-protopanaxatriol on the basis of the spectral data.     

Indium-mediated Facile Synthesis of （6-Chloropyridine-3-yl）methyl Heterocyclic Thioether Derivatives in Aqueous Media

A series of substituted (6-chloropyridine-3-yl)methyl heterocyclic thioether derivatives were prepared by indium mediating in water. The preliminary biological tests showed that compound 3d exhibited good antiviral activity.     

Study of Tea Digitized Chromatographic Fingerprint Spectra Using Micellar Electrokinetic Chromatography

IntroductionTeaisthemostwidelyconsumedbeverageinpeople’slife .Theheightenedpopularityofthisbeveragethroughouttheworldinrecentyearsmaybedueinparttotheevidenceofarelationshipbetweenteaconsumptionandpreventionofcertainformsofhumandisease .Themaincomponentsofteaarepolyphenoliccompounds ,commonlyknownascatechins ,whichrepresentagroupofcom poundsbelongingtotheflavonoidfamily .Thesecom poundsarewidelydistributedinthetealeavesandconsti tuteupto 30 %ofthedryleafweight.1Muchinteresthasbeenfocusedoncat…     

Preparation of Co3O4 Nanofibers via an Electrospinning Technique

Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique.After calcination of the above precursor fibers,Co3O4 nanofibers with a diameter of 50-150 nm could be successfully obtained.The fibers were characterized by SEM,FT-IR,WAXD,respectively.     

Oxidation of Styrene with Molecular Oxygen in Supercritical CO2

The oxidation of styrene with molecular oxygen catalyzed by PdCl2 CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.     

A Novel Green Synthesis of Quinolines through Acid-catalyzed Friedlander Reaction in Ionic Liquids

Quinoline derivatives were efficiently prepared through acid-catalyzed Friedlander reaction in ionic liquid ([bmim] [BF4]). It is shown that the proposed method is operationally simple and environmentally benign in that the reaction media and the catalyst can be recovered and be reused effectively for at least four times.     

Extraction Kinetics of Rare Earth Elements with sec—Octyl—phenoxy Acetic Acid

ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｙｔｔｒｉｕｍｃａｎｂｅｕｓｅｄｉｎｍａｎｙｆｉｅｌｄｓ ,ｓｕｃｈａｓｍｅｔａｌｌｕｒｇｙ ,ｃｅｒａｍｉｃｓ ,ｌａｓｅｒｓａｎｄｅｌｅｃｔｒｏｎ ｉｃｓ ,ｅｓｐｅｃｉａｌｌｙｉｎｆｌｕｏｒｅｓｃｅｎｔｍａｔｅｒｉａｌｓｗｈｏｓｅｎｅｅｄｆｏｒｈｉｇｈｐｕｒｉｔｙｙｔｔｒｉｕｍｏｘｉｄｅｉｓｉｎｃｒｅａｓｉｎｇ .ＩｎＣｈｉｎａ ,ｔｈｅｒｅ ｓｏｕｒｃｅｏｆｙｔｔｒｉｕｍｉｓｒｉｃｈ ,ａｎｄｔｈｅｈｉｇｈｐｕｒｅｙｔｔｒｉｕｍｉｓｂｅ ｉｎｇｏ…     

Theoretical Study on the Isomerization Mechanism of Enol Ester from 2-Acyl-1, 3-cyclohexanediones

The present paper employed density function theory to investigate two reaction pathways for isomerization of enol ester proposed by Yang(path a) and the present authors(path a), respectively. The base catalytic effects of solvent triethylamine on these two reactions were also evaluated. It is demonstrated that path B is more preferable than path a due to low barrier height for the rate-determining step.     

烯烃歧化催化剂Bu~4N[Mo(CO)~5Cl]-RAlCl~2活性衰减原因的探讨

考察了影响Bu_4N[Mo(CO)_5Cl]-RAlCl_2烯烃歧化催化剂活性的一些因素和反应过程中的动力学行为,并着重讨论催化剂活性衰减的原因。催化剂失活主要是由于形成的金属卡宾活性物种分解所引起。最后分析了烯烃加入顺序对催化剂活性的影响。     

Synthesis of Optically Active β-Alkyl-α-methylene-γ-butyro- lactones from Enantioselective Biotransformation of Nitriles, an Unusual Inversion of Enantioselectivity

ＩｎｔｒｏｄｕｃｔｉｏｎＢｉｏｔｒａｎｓｆｏｒｍａｔｉｏｎｓｏｆｎｉｔｒｉｌｅｓ ,ｅｉｔｈｅｒｔｈｒｏｕｇｈａｎｉｔｒｉ ｌａｓｅ ｃａｔａｌｙｚｅｄｄｉｒｅｃｔｃｏｎｖｅｒｓｉｏｎｔｏｔｈｅｃａｒｂｏｘｙｌｉｃａｃｉｄｓｏｒｖｉａａｎｉｔｒｉｌｅｈｙｄｒａｔａｓｅ ｃａｔａｌｙｚｅｄｈｙｄｒａｔｉｏｎｔｏｔｈｅａｍｉｄｅｓｆｏｌｌｏｗｅｄｂｙｔｈｅｈｙｄｒｏｌｙｓｉｓｔｏｔｈｅａｃｉｄｓｍｅｄｉａｔｅｄｂｙａｎａｍｉｄａｓｅ ,ｈａｖｅｐｒｏｖｉｄｅｄａｕｓｅｆｕｌａｎｄｅｎｖｉｒｏｎｍｅｎｔａｌ…