Thermodynamics of natural selection

It is shown that biological-natural-selection-like behavior can occur, as a general type of time evolution, in a statistical system where detailed balance is violated owing to the presence of metastable energy states. A model of a non-equilibrium phase transition corresponding to the spontaneous origin of self-reproduction in the system is suggested. After a phase transition, the system passes from one quasistationary distribution of self-reproducing subsystems to another, with an increase in the total organization, as long as the growth of the energy flow through the system or a reduction of energy dissipation in the system is possible. The entropy production is calculated for this process in terms of selective values of Eigen's theory for self-organization in autocatalytic systems. Correspondence of the extremal principle of Eigen's theory with the criterion of evolution in Prigogine's thermodynamics is established.     

Isolation of new quinidine metabolites and simultaneous determination of quinidine and its metabolites in blood and urine by direct injection HPLC analysis

Summary New quinidine metabolites, including 10,11-dihydrodiol quinidine N-oxide, 10,11-dihydrodiol quinidine and their glucuronides, were found in human urine. A quinidine monitoring HPLC method including these metabolites, is proposed by the direct injection of body fluid samples onto the precolumn for deproteinization followed by reverse phase separation in the analytical column with a column switching technique. The recovery of spiked quinidine and its metabolites in plasma was quantitative (98–102%) with good reproducibility (C.V.: 1.6–4.0%). Several clinical samples such as whole blood and urine were analyzed by the present method.     

N-(2-羧基-1,3,4-噻二唑-5-基)-N''-芳酰基硫脲与芳氧乙酰基硫脲的合成与生物活性

为了寻找高活性的杂环农药,用5-氨基-1,3,4-噻二唑-2-羧酸与芳酰基异硫氰酸酯及芳氧乙酰基异硫氰酸酯反应,合成出18种新的芳酰基硫脲与芳氧乙酰基硫脲,采用红外光谱、核磁共振氢谱和元素分析证明了其结构,初步的生物活性测定试验表明,部分目标化合物具有良好的植物生长调节活性,其中2c,2d,3b和3g具有良好的生长素活性.     

Large scale Biginelli reaction via water-based biphasic media: a green chemistry strategy

An important stage in process development is kilo scale preparation of the target compound. For this reason, a procedure involving water-based biphasic reaction media has been developed for conducting some exothermic reactions on a large scale. This protocol is illustrated by the energy-efficient and rapid preparation of dihydropyrimidinones by a solvent-free, green chemistry procedure applied to the Biginelli reaction using p-toluenesulfonic acid as catalyst.     

Crystal structure of a tetrabromo derivative of cyclopropyldihydroarglabin and its antifungal activity

A tetrabromo derivative of arglabin was synthesized stereoselectively. The molecular structure of the new compound was established using PMR and 13C NMR spectra and an x-ray structure analysis. Its antifungal activity was demonstrated. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 253–254, May–June, 2006.     

O-取代苯基-O-(2-硬脂酰胺基)乙基-N,N-二(2-氯乙基)磷酰胺的合成和生物活性

N-脂肪酰基乙醇胺(NAE)作为植物体内的一种内源物质, 在调节植物生长方面起着重要作用. 为了弥补其分子结构中长的脂肪链所带来的溶解性能以及在植物体内传导性能的缺陷, 我们将N-硬脂酰乙醇胺(NAE18)引入氮芥磷酸酯中, 合成了一系列标题化合物. 在合成工作中发现: 在NAE18与氮芥芳基磷酰氯的反应过程中, 4-二甲氨基吡啶(DMAP)起着关键性的催化作用. 在不加DMAP的相同实验条件下, 反应不能进行. 对所合成的标题化合物进行了植物生长调节和杀菌活性的测定, 初步生测结果表明: 经过结构修饰后, 大多数目标化合物的活性相对NAE18有所增强, 但有关生物活性仍有待进一步研究.     

Development of calixarene-based host molecules for peptides in aqueous media

We synthesized a peptidocalix[4]arene library consisting of 1000 members that was suitable for peptide recognition in aqueous media. Some peptidocalix[4]arenes in the library were host molecules for guest peptides. Electrostatic interaction between the host and guest molecules was the most important factor for binding in aqueous media.     

N′-5-四唑基-N-芳甲酰基硫脲的合成及其生物活性研究(I)

为寻找新的高活性农药 ,根据生物等排原理 ,设计合成了 10种未见文献报道的N′ 5 ( 1H 1,2 ,3 ,4 四唑基 ) N 芳甲酰基硫脲类化合物 .它们的结构经IR ,1HNMR和元素分析确证 .初步的生物活性测定结果表明 ,部分化合物具有优良的除草活性或植物生长调节活性 .     

Novel gallium-mediated C3-allylation of indoles and pyrroles in aqueous media promoted by Bu4NBr

A mild and efficient protocol for the coupling of indoles and pyrroles with allyl halides such as allyl bromide, crotyl bromide and propargyl bromide in the presence of gallium metal in a Bu₄NBr-DMF-H₂O system has been developed. The reaction is equally effective when cadmium is used in lieu of gallium and the corresponding 3-allyl indoles and 3-allyl pyrroles were obtained in almost comparable yields.     

Carbon Paste Electrode for the Potentiometric Flow Injection Analysis of Drotaverine Hydrochloride in Serum and Urine

A carbon paste electrode for drotaverine hydrochloride (DvCl) was prepared and fully characterized in terms of composition, life span, usable pH range, response time and temperature. The electrode was applied to the potentiometric determination of drotaverinium ions in pharmaceutical preparations and biological fluids in steady state and flow injection conditions (FIA). The electrode is based on a mixture of two ion exchangers, namely, drotaverinium-silicotungestate and drotaverinium-tetraphenylborate dissolved in tricresyl phosphate as pasting liquid. The modified electrode showed a near-Nernstian slope of 59.34±2mV over the concentration range of 5.0×10^–7–1.0 × 10^–2M. The electrode exhibits good selectivity for DvCl with respect to a large number of inorganic cations, organic cations, sugars and amino acids. Potentiometric titrations of DvCl with several titrants have been monitored using this modified carbon paste electrode as an end-point indicator electrode. The proposed electrode offers the advantages of simplicity, accuracy, automation feasibility and applicability to turbid and colored samples.