Synthesis, Characterization and the Effect of Glucose-lowering of Guanidino Acid Oxovanadium（Ⅳ） Complexes

Two guanidino acid oxovanadium(Ⅳ) complexes have been synthesized. Preliminary tests in vivo have shown that the two title complexes all display lowering glucose activity in vivo to STZ-rats. The effect of glucose-lowering of guanidino acetic acid oxovanadium(Ⅳ) complex in vivo is higher than that of guanidino propanoic acid oxovanadium(Ⅳ) complex.     

Purification and partial characterization ofRhizomucor miehei lipase for ester synthesis

A commercialRhizomucor miehei lipase was purified by ammonium sulfate precipitation. Phenyl Sepharose 6 Fast Row hydrophobic interaction chromatography, and DEAE Sepharose Fast Flow anion-exchange chromatography. The recovery of lipase activity was 32% with a 42-fold purification. The molecular size of the purified enzyme was 31,600 Dalton and the pI 3.8. The enzyme was stable for at least 24 h within a pH range of 7.0-10.0, and 96.8% of the enzyme activity remained when kept at 30‡C for 24 h. Further, about 10–30% of the lipase activity was inhibited by K⁺, Li⁺, Ni⁺, Co²⁺, Zn²⁺, Mg²⁺, Sn²⁺, Cu²⁺, Ba²⁺, Ca²⁺, and Fe²⁺ ions and by SDS, but EDTA had no effect. Under the experimental conditions, the optimum temperature for the hydrolysis of olive oil was 50‡C (pH 8.0), and for the synthesis of 1-butyl oleate, 37‡C. It was concluded that hydrolytic activity of lipase alone is not a sufficient criterion for its synthetic potential. The optimal molar ratio of oleic acid and 1-butanol was 2:1 for 1-butyl oleate synthesis. The 1-butyl oleate yield was unaffected by purification of the enzyme after 12 h.     

Phenol methylation over CrPO4 and CrPO4?AlPO4 catalysts

The vapor-phase catalytic alkylation of phenol with methanol and dimethyl carbonate on a series of differently prepared CrPO₄ (Cr/P=1) and CrPO₄-AlPO₄ (CrAIP) catalysts, has been studied at different temperatures (473–673 K). The reaction is first order in phenol, giving a mixture of O- and C-alkylated products (C-alkylation taking place preferentially at theortho-position). Moreover, dimethyl carbonate is a better methylating agent than methanol.     

Synthesis, characterization and antifungal activity of copper (II) complexes of sterically hindered o-diphenol derivatives

Cu (II) complexes with 3,5-di(tert-butyl)-1,2-benzenediol (I), 4,6-di(tert-butyl)-1,2,3-benzentriol (II) and sulfur-containing sterically hindered o-diphenol derivatives such as 4,6-di(tert-butyl)-3-(2-hydroxyethylsulfanyl)-1,2-benzenediol (III) and 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfanyl]acetic acid (IV) have been synthesized and characterized by means of elemental analysis, TG/DTA, FT-IR, ESR, XPS, XPD and conductivity measurements. Antifungal activities of these ligands and their respective Cu (II) complexes have been determined against Aspergillus niger, Fusarium sp., Penicillium lividum, Mucor sp. and Botrytis cinerea. Most of the compounds (both the free ligands and the complexes) exert pronounced antifungal activities (RI  70%), and virtually all of them (apart from the Cu(L^II)₂ complex) have the highest inhibitory properties (RI = 100%) against B. cinerea.     

Osmotic Coefficients of Aqueous Solutions of Some Poly(oxyethylene) Glycols at the Freezing Point of Solution

Summary. The freezing temperatures of dilute aqueous solutions of some poly(oxyethylene) glycols (PEG, HO–(CH₂CH₂O) _n –H, n varying from 4 to 117) were measured over a solute to solvent mass ratio from 0.0100 to 0.3900. The second and third osmotic virial coefficient (A ₂₂ and A ₂₂₂) of poly(oxyethylene) glycols in aqueous solution were determined. The molecular weight dependence of the second virial coefficient can be described by a simple relation A ₂₂=2×10^–5 M _n ^1.86, and the third virial coefficient is A ₂₂₂=0.038A ₂₂ ². The activity coefficients of the solute were calculated using the Gibbs-Duhem equation as applied by Bjerrum. From the osmotic and activity coefficients the excess Gibbs energies of solution, as well as the respective partial molar functions of solute and solvent and the virial pair interaction coefficients for the excess Gibbs energies were estimated. The second and the third osmotic virial coefficients are correlated with the Mc-Millan-Mayer virial coefficients.     

Structure—activity relationships for <Emphasis Type="Italic">in vitro</Emphasis> oxime reactivation of chlorpyrifos-inhibited acetylcholinesterase

Organophosphorus pesticides parathion, chlorpyrifos, and malathion inhibit the enzyme acetylcholinesterase (AChE; EC 3.1.1.7) via phosphorylation of its active site. AChE reactivators and anticholinergics are compounds used as antidotes in the case of intoxication by these AChE inhibitors. In this work, chlorpyrifos, a representative member of this pesticide family, was used to inhibit the AChE activity of rat brain. The effect of twenty-one structurally different AChE reactivators was tested in vitro and subsequently, the relationship between their chemical structure and biological activity was outlined.     

Synthesis and Cytotoxic Activity of 4-Substituted 3-Cyano-6,6-dimethyl-5,6-dihydro-2-pyranones

The respective 4-(arylvinyl)lactones and compounds of the Michael adduct type were synthesized by the condensation of substituted benzaldehydes with 3-cyano-4,6,6-trimethyl-5,6-dihydro-2-pyranone in the presence of catalytic amounts of sodium hydroxide. It was shown by the semiempirical AM1 method that the indicated products can be formed through one and the same intermediate compound. Some of the synthesized phenylvinyl-5,6-dihydro-2-pyranones have a cytotoxic effect, and this corresponds to the prognosis of the OREX expert system.     

含芳硫基的新三唑类化合物的合成及生物活性研究

许多三唑类化合物具有优良的杀菌和植物生长调节活性 ,如三唑酮、三唑醇、烯效唑、烯唑醇等 ,对常见真菌病害具有很好的防治效果 ,并具有增产、抗倒和生长调节作用 ,已成为重要的杀菌剂类型 [1] .为筛选新型高活性三唑类杀菌剂和探讨其活性与结构间的关系 ,我们利用生物等排体理论以常规三唑类杀菌剂三唑酮为先导物设计合成了 1 6个含芳硫基的新三唑类化合物 ,其合成路线如下 :RCCH2 BrO+HNNNB NRCCH2O NNHAC-Na ACBr2NRCCHOBrNN(1 ) (2 ) (3 )3 +SH 　R′B NRCCHOS　R′NN　 (4 )RCCH2 CH2 NMe2 .HClO+HNNNH2 O…     

Synthesis and herbicidal activities of methyl-1-(2,4-dichlorophenoxyacetoxy)alkylphosphonate monosalts

A series of 1-(2,4-dichlorophenoxyacetoxy)alkylphosphonic acid dimethyl esters 5 and its corresponding phosphonate monosalts 6 were synthesized as potential herbicide. The phosphonate monosalts can be prepared from 1-(2,4-dichlorophenoxyacetoxy)alkylphosphonic acid dimethyl esters 5, which were synthesized by the condensation of O,O-dimethyl-1-hydroxyalkylphosphonates with dichlorophenoxyacetic chloride. This method provides a simple and efficient procedure for the synthesis of phosphonate derivatives containing sensitive groups to acid, base or water such as carboxylate ester bond; and the herbicidal activity of title compounds was evaluated in a set of experiments in greenhouse. Most of the compounds exhibited notable herbicidal activity.