1-(乙酰水杨酰)苯并三氮唑的合成及其与聚乙烯醇的反应

<正> 聚乙烯醇(PVA)作为生物相容性的水凝胶被应用在生物医用材料上。乙酰水杨酸(阿斯匹林)是一般的退烧止痛药物,近年来发现它有抗血小板凝聚的效应,但将其高分子化以制备高分子药物的工作并不多。我们曾合成了在酯基上含有阿斯匹林的五种新的丙烯酸酯单体,并进行了它们的自由基聚合,这些聚合物的水解行为表明,它们可以作为通过水解而控制释放阿斯匹林的生物相容性材料。     

聚乙烯醇载体的研究 Ⅲ.由聚乙烯醇衍生的活性酰胺和活性酯及其作为亲合色谱载体的应用

<正> 亲合色谱法在现代生物学和医学上作为新的得力分离分析手段而方兴未艾。合色谱法是将相互在生物学上具有特异亲合力的某一化合物作为固定相接在水不溶性载体上,利用对此固定相的亲合力的差异以分离提纯另一化合物为目的的方法。常用的水不溶性载体如天然纤维素,葡聚糖凝胶,琼脂糖凝胶等或因成型不易,或因对酸,霉菌等的不     

STUDIES ON POLYVINYL ALCOHOL CARRIERS Ⅲ. ACTIVE AMIDES AND ESTERS DERIVED FROM POLYVINYL ALCOHOL AND THEIR APPLICATION IN AFFINITY CHROMATOGRAPHY

Polyvinyl alcohol carriers bearing active amide and active ester groups were prepared by acetaliza-tion of granular macro-reticular water-insolub1e PVA with glyoxylic acid or p-formylbenzoic acidand further activation reaction with benzotriazole or N-hydroxysuccinimide using DCCI as con-densation agent. The active amides or active esters obtained were easy to react with amines suchas n-butylamine or proteins under mild condition. Ovomucoid, an inhibitor of trypsin was immo-bilized on the above-obtained reactive PVA carrier to give effective affinity adsorbent for the separa-tion or purification of trypsin.     

A Novel Route to N-Styrylamides

A general synthesis of N-styrylamides starting from amides and phenylacetaldehyde is described. Condensation of the amide, aldehyde and benzotriazole affords N-(1-benzotriazol-l-yl-2-phenylethyl)amides 2 from which the benzotriazole molecule is smoothly eliminated.     

Detection of DNA probes using Diels Alder cycloaddition and SERRS

A number of methods for detecting specific DNA sequences have been used to provide data for use in diagnosis of disease states and examination of gene expression. This study shows how the use of labelled oligonucleotides created by Diels Alder cycloaddition can be used as surface enhanced resonance Raman scattering (SERRS) active probes that provide easily identifiable signals at low concentrations in a mixture. The probes were produced by first tagging the oligonucleotides with a furan residue at the 5'-terminus to act as the diene. Three specifically designed benzotriazole azo maleimide dyes were then used as dienophiles to undergo cycloaddition with the furan modified oligonucleotide to generate SERRS active probes. These probes gave excellent SERRS signals from a silver-PVA film. Surface mapping of the silver PVA film indicated that the distribution of the dyes was uniform and that the number of moles of probe detected at any one time was approximately in the attomole region.     

Synthesis of polyesters containing nucleic acid base derivatives as pending side chains

Preparations of four diol monomers containing nucleic acid bases and the corresponding model polymers of polynucleotides with linear polyester backbone and nucleic acid base derivative as pending side chains are described. N-(1′,3′-Dihydroxy-2′-methyl-2′-propyl)-2-(thymin-l-yl)propionamide ( Ia , HMPTPA), N-(1′,3′-dihydroxy-2-methyl-2′-propyl)-2-(uracil-l-yl)propionamide ( Ib , HMPUPA), and their isomers, N-(β,β′-dihydroxyethyl)-2-(thynin-1-yl)propionamide ( IIa , HETPA) and N-(β,β′-dihydroxyethyl)-2-(uracil-1-yl)propionamide ( IIb , HEUPA) were synthesized through the selective N-acylation of 2-methyl-2-amino-1,3-propanediol and diethanolamine with 2-(thymin-1-yl)propionic acid (TPA) and 2-(uracil-1-yl)propionic acid (UPA), respectively, by the active amide-benzotriazole method. Diol monomers I and II were polycondenzed with active amide of benzotriazole such as 1,1′-(isophthaloyl)bisbenzotriazole (IPBBT) in the presence of triethylamine and in DMF at 60°C, giving polyesters containing thymine and uracil derivatives as the side group. Prior to polymer synthesis, an O-acylation of Ia using the active monoamide l-benzoylbenzotriazole was carried out as a model compound study.     

Polyvinyl alcohol-modified graphene oxide as a support for bimetallic Pt–Pd electrocatalysts to enhance the efficiency of formic acid oxidation

The aim of this research was to study the efficiency of polyvinyl alcohol (PVA)-modified graphene oxide (GO) as a supporting material for catalysts that oxidize formic acid. The active metal catalysts (e.g., Pt and Pd) were electrodeposited on PVA/GO surfaces. The morphologies of the prepared catalysts were characterized by scanning electron microscopy and transmission electron microscopy, while their chemical compositions were identified by X-ray diffraction and X-ray photoelectron spectroscopy. The results show that compared with the other catalysts on GO, the prepared active PtPd alloy catalyst nanoparticles with 11.49–20.73 nm sizes were well dispersed on the PVA/GO surfaces. Electrochemical results indicate that the activities of the catalysts with PVA provided a higher current density than that of the catalysts without PVA. The bimetallic 3Pt3Pd/PVA/GO catalyst showed the greatest catalytic activity, stability, and CO oxidation when compared to those of other catalysts. The electronic, morphological, and structural properties promote the mass-charge transfer through the interaction. These results indicate that the PVA-modified GO provides a suitable site for active bimetallic catalyst surfaces, resulting in excellent formic acid oxidation and high CO elimination. The 3Pt3Pd/PVA/GO electrocatalyst is promising for enhancing formic acid oxidation.     

Synthetic utility of sydnones to couple pharmacologically important heterocycles for antitubercular activity

In the present investigation we have utilized the 3-arylsydnones 1a–c to couple two biodynamic moieties in amide derivatives 7–10. The 3-arylsydnones were brominated to 4-bromo-3-arylsydnones 2a–c which further were reacted with benzotriazole/benzothiazolin-2-thione/morpholine/diphenylamine to the corresponding final compounds. The structures of the amide derivatives were confirmed by the spectral (IR, ¹H NMR and Mass) and analytical data. Further, these were subjected to the antitubercular activity against Mycobacterium tuberculae (H37Rv). The morpholine 7a–c and benzotriazole 8a–c derivatives have exhibited good inhibition.     

Synthesis of poly(vinyl alcohol) containing asymmetric nucleic acid base derivatives as grafted pendants

The preparations of new model polymers of polynucleotides with linear poly(vinyl alcohol) (PVA) backbones and an optically active nucleic acid base derivative as a pending side chain are described. (±)-, (+)-, and (?)-2-(thymin-1-yl)propionic acid were grafted onto PVA through ester bonds by direct coupling with dicyclohexylcarbodiimide (DCC) in the presence of highly active catalyst 4-pyrrolidinopyridine (PPY) to give optically active graft polymers. The corresponding monomer and dimer models have been prepared.     

Simultaneous spectrophotometric determination of drugs in pharmaceutical preparations using multiple linear regression and partial least-squares regression, calibration and prediction methods

Two new methods for the simultaneous determination of acetylsalicylic acid, acetaminophen and caffeine based on total absorbance measurements and their processing by multiple linear regession and partial least-squares regression are proposed. The concentration ranges used to construct the calibration matrix were 4.0-12.0, 2.0-10.0 and 0.9-6.0 μg ml⁻¹ for acetylsalicylic acid, acetaminophen and caffeine respectively. The proposed methods were validated by using a set of synthetic sample mixtures and subsequently applied to the determination of the three active principles in three different pharmaceutical preparations.     

Zirconium Phosphate Nanoparticles for Solvent Free Acetylation of Phenols and Salicylic Acid: An Efficient and Eco‐friendly Solid Acid Catalyst for Synthesis of Acetyl Salicylic Acid (Aspirin)

A facile synthesis of zirconium phosphate (ZP) nanoparticles as an effective, eco‐friendly and recyclable solid acid catalyst were studied. PVA was used as the organic matrix which is the dispersing agent and acted as a template for the nanoparticle. It seems H‐bonds between ZP and PVA along polymer chains play an important role in the better dispersion of in situ formed ZP. The catalyst was characterized by several instrumental techniques such as BET, ICP‐OES, XRD, FT‐IR, SEM and TEM. The TPD‐NH₃ analysis suggests the presence of reasonable amount of Brönsted acid sites. The acidic properties of catalyst were studied in acetylation of phenols by acetic anhydride (AA), specifically synthesis of acetylsalicylic acid (ASA), commonly known as Aspirin, from salicylic acid (SA). The effects of reaction time, reaction temperature, mole ratio of reactants, as well as amount of catalysts on the synthesis of ASA were investigated, and the reaction conditions were therefore optimized. The excellent yield (96%) of the ASA was obtained under optimized reaction conditions. The catalyst was recovered from reaction media and reused for 4 times after that with a consistent high yield.     

New synthetic route to alternating copoly(aromatic ester–aliphatic amide)s

The preparation of three novel alternating copoly(aromatic ester–aliphatic amide)s containing the same ordered amide–amide–ester–ester (AAEE), the same para-disubstituted phenyl, and the different long methylene chain structure were described. 1,1′-(Adipoyl)bisbenzotriazole (AdBBT), 1,1′-(suberoyl)bisbenzotriazole (SuBBT), and 1,1′-(sebacoyl)bisbenzotriazole (SeBBT) were synthesized. These diacylbenzotriazoles were preferred to aminoethanol at the amino group because of the selective N-acylation of active acylamide of benzotriazole in excellent yield at room temperature to give diol monomers such as N,N′-bis(2-hydroxyethyl)adipic amide (HEAdA), N,N′-Bis(2-hydroxyethyl)subaric amide (HESuA), and N,N′-bis(2-hydroxyethyl)sebacic amide (HESeA). Polycondensation of 1,1′-(teraphthaloyl)bisbenzotrizole (tPBT) with HEAdA, HESuA, and HESeA gave the corresponding alternating copoly(aromatic ester–aliphatic amide)s: P(tPE–AdA), P(tPE–SuA), and P(tPE–SeA), respectively. The alternating copoly(aromatic ester–aliphatic amide)s were characterized by ¹H-NMR spectra. The resulting polymers have two different chain units; one is chain unit of poly(ethylene terephthalate) and the other is a chain unit of polyamide-2,6, polyamide-2,8, and polyamide-2,10; both are linked via a C? N bond.     

Selective substitution reactions of methoxycarbonylamino‐1‐(1‐benzotriazolyl)alkanes with active methylene compounds

Benzotriazole adducts methoxycarbonylamino‐1‐(1‐benzotriazolyl)alkanes 1 were derived from the condensation of an aldehyde, benzotriazole, and methylcarbamate. The leaving tendency of methoxycarbonylamino group (MeOCONH) and benzotriazole group (Bt) was investigated by treatment of the adducts with active methylene compounds under either Lewis acid‐catalyzed or basic conditions. In the presence of SmI₃, MeOCONH take priority over Bt in the leaving process, whereas in the presence of MeONa, the Bt was substituted in preference. Thus, the tunable substitution of the two leaving groups could be used for different synthetic purposes. J. Heterocyclic Chem., 00 , 00 (2011).     

Effect of high adhesive polyvinyl alcohol binder on the anodes of lithium ion batteries

High molecular weight (MW) polyvinyl alcohol (PVA) was synthesized by two-step polymerizations and employed as an anodic binder of lithium ion batteries (LIBs). Numerous hydroxyl groups in PVA formed strong hydrogen bonds with both active materials and the current collector. These strong hydrogen bonds led to an increase in the amount of binder covering the surface of active materials and significantly enhanced the adhesion strength of electrodes. The high MW PVA binder showed much better cyclic performance for silicon/carbon anodes than polyvinylidene fluoride (PVDF) and polyacrylic acid (PAA) binders.     

Effect of poly(amid–imide)/Al2O3 hybrid with various ratios on the physicochemical properties of poly(vinyl alcohol) nanocomposites films

To study the effect of the various ratios of poly(amide–imide)/Al₂O₃ nanocomposites (PANC)s on the mechanical and thermal properties of nanocomposites films, poly(vinyl alcohol) (PVA)/PANCs based on various ratios of 2, 4, and 6 wt% were prepared and characterized. In the first step, the surface of alumina nanoparticles was treated with 15 wt% of biosafe diacid and consequently, about 10 wt% of these modified nanoparticles were loaded into the poly(amide–imide) matrix. Then, various contents of the obtained PANCs were incorporated into a PVA solution using a sonochemical treatment. The effects of PANC on the structure and morphology of PVA matrix were studied using powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and thermal gravimetric analysis (TGA). The results show that the tensile strength and decomposition temperature were improved as the portion of PANC into PVA matrix are increased from 2 to 6 wt%. Also, AFM pictures of the fracture surfaces of PVA/PANCs showed a significantly rougher surface than the neat PVA.     

Modified MCM-41 as a drug delivery system for acetylsalicylic acid

The modification of prepared MCM-41 by different groups (amino, chloro and oxo) was studied. Prepared materials were treated by acetylsalicylic acid and hybrid materials were characterized, compared from the point of view of immobilized amount of active substance. The highest amount of acetylsalicylic acid was detected using methyl-tert- butyl ether as a solvent and MCM-41 without modification after 1 h (0.35 g per 1 g of the support) or MCM modified by amino group after 5 h (0.37 g per 1 g of the support) as a support. Using amino modified MCM, the longer treatment by acetylsalicylic acid converged to the equilibrium and after 24 h the immobilized amount was 0.3 g per 1 g. A dissolution in vitro study was carried out, comparing the stability of formed interactions. The slowest dissolution was detected using non-modified MCM-41 and oxo modified material.     

Reinforcement of poly(vinyl alcohol) with chiral poly(amide-imide)s nanoparticles containing S-valine under simple ultrasonic irradiation method

Nanostructured amino acid containing poly(amide-imide) (PAI) was synthesized from the direct polycondensation reaction of 2–(3,5–diaminophenyl)–benzimidazole and N,N′–(pyromellitoyl)–bis–phenylalanine diacid under green condition by using tetrabutylammonium bromide as molten ionic liquid. Field emission scanning electron microscopy images show that the average diameter of polymeric nanoparticles with spherical shape was around 20–35 nm. In the next step, these polymeric nanoparticles were used as nano-fillers for reinforcement of poly(vinyl alcohol) (PVA) for the first time. Bionanocomposite of PVA and various compositions of PAI nanoparticles were produced through ultrasound-assisted technique. Fourier transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy, and thermogravimetric analysis were utilized to characterize the obtained hybrid materials, morphology, and properties. Results of thermal properties indicated that the thermal stability is enhanced. The improvement of thermal properties was attributed to the homogeneous and good dispersion of PAI nanoparticles in the PVA matrix and the strong hydrogen bonding between O–H groups of PVA and the carbonyl of amide and imide groups of the used PAI nanoparticles.     

亚油酸酰化胰岛素的制备及飞行质谱分析

胰岛素侧链氨基的酰化是胰岛素化学修饰较常用的方法。天然胰岛素分子中有三个裸露的氨基,即G lyA1、PheB1的α-氨基和LysB29的ε-氨基,都可作为胰岛素化学修饰的位点。酰化试剂通常经由N-羟基琥珀酰亚胺酯对胰岛素进行修饰。N-羟基琥珀酰亚胺酯可由羧酸与N-羟基琥珀酰亚胺(HOS     

Coupling of solid-phase microextraction continuous bed (monolithic) capillaries with capillary zone electrophoresis for direct analysis of drugs in biological fluids

Hyperlink robust biocompatible solid-phase microextraction (SPME) devices were prepared using continuous bed (monolithic) restricted-access media (RAM) as the SPME capillary insert. The RAM-based SPME approach was able to simultaneously separate proteins from a biological sample, while directly extracting the active components of caffeine, paracetamol and acetylsalicylic acid from the drug NeoCitramonum. The devices were interfaced with a CZE system and fully automated analysis for sample preconcentration, desorption, separation and quantification of analytes was evaluated. Comparative study of in-line coupled SPME-CZE using RAM and RP capillary inserts was carried out. Using an SPME (RAM) insert, the calculated caffeine, paracetamol and acetylsalicylic acid LODs in a bovine plasma sample were 0.3, 0.8 and 1.9 ng/mL, respectively.     

聚乙烯醇与葡激酶的相互作用及其对葡激酶二级结构的影响

在生理条件下, 使用凝胶过滤色谱、荧光光谱、差示扫描量热分析、傅里叶变换红外光谱(FTIR)和葡激酶的纤溶活性分析研究了聚乙烯醇(PVA)和葡激酶的相互作用及其对葡激酶高级结构的影响. 凝胶过滤色谱研究结果表明, PVA与葡激酶之间形成了复合物; 荧光光谱和差示扫描量热分析结果提示, 葡激酶与PVA之间的相互作用没有破坏葡激酶的高级结构; 进一步使用红外光谱法结合可增强分辨率的傅里叶去卷积技术和高斯曲线拟合技术, 用于对葡激酶与PVA复合物冻干粉中葡激酶酰胺Ⅰ带的定量分析发现, 复合物冻干粉葡激酶分子中易导致蛋白质变性的分子间β-折叠组分含量明显减少. 纤溶活性分析结果进一步确认, PVA与葡激酶的相互作用未影响葡激酶的活性, 并对蛋白质的活性起保护作用.