C_(80)X_(12)(X=H,F,Cl,Br)的结构和稳定性

为了考察勒烯衍生物结构与稳定性关系,采用密度泛函理论方法对C80X12(X=H,F,Cl,Br)进行了系统计算究.结表明,在C80X12(X=H,F)异构体中,最低能量异构体都违反五元环分离规则.然而,在C80X12(X=Cl,Br)异构体中,最低能量异构体都满足五元环分离规则.由于van der Waals半径较小,H或F加成到碳笼上时外部原子之间排斥作用小,因此在其优结构中,H或F优先加成到2个五元环共用碳原子上.相反,对于氯化、溴化勒烯,为了避免外部加成原子之间在重空间排斥作用,其优结构中Cl或Br优先加成到1,4-位点上.计算结还显,氢化、卤化反应热(C80+6X2→C80X12)遵循如下顺序,即C80F12>C80Cl12>C80H12>C80Br12.这些结表明勒烯衍生物稳定性和衍生化模与加成原子尺和电性有关.     

基于与铁氰化钾和Zn~(2+)作用共振光散射法测定异烟肼

在酸性介质中,异烟肼能将铁氰酸根离子还原成亚铁氰酸根离子,后者与硫酸锌反应生成K2Zn3[Fe(CN)6]2粒子引起体系的共振光散射信号显著增强.在345nm处增强的散射信号强度ΔIRLS与异烟肼的浓度在0.01~1.0μg/mL范围内呈线性关系,据此建立了一种检测异烟肼含量的共振光散射(RLS)分析方法.线性回归方程为ΔIRLS=136.1+4239c(c,μg/mL),相关系数(r)为0.9984,检测限(3σ)为3.8ng/mL.该方法已成功用于异烟肼片剂及血清样品的测定.此外,文中还结合吸收光谱,动态光散射,扫描电子显微镜等表征手段对反应机理和RLS信号强度增强的原因进行了探讨.     

非水溶性药物潜在靶蛋白筛选方法探索

针对化学蛋白质组学在筛选非水溶性药物的靶蛋白中存在的问题,建立了以非水溶性药物颗粒为载体的靶蛋白筛选方法.通过避免药物固定化,不仅可以保留全部的药物官能团,而且减少了蛋白质在固载基质上的非特异性吸附,可提高获得数据的可信度.将非溶性药物地塞米松颗粒直接与人小细胞肺癌H446细胞提取蛋白质通过间歇性振荡孵育24h,然后采用缓冲液清洗药物颗粒,最后对药物颗粒特异性结合的蛋白质进行酶解和分离鉴定.结果表明,筛选出41个潜在的药物靶蛋白,参与了与DEX药物作用机理相关的多种蛋白质代谢通路和糖代谢通路,同时还发现部分蛋白质参与了帕金森症疾病过程.     

Determination of L-phenylalanine by cucurbit[7]uril sensitized fluorescence quenching method

The determination method of L-phenylalanine（LPA） by fluorescence quenching was developed.The assay was based on the combination of the cucurbit[7]uril（CB[7]） with palmatine hydrochloride（PAL） reaction.In the presence of CB[7],the fluorescence of PAL was quenched by LPA which can be employed to detect LPA.Under the optimal conditions,a linear range 3.63×10^-8- 9.68×10^-6mol/L and a detection limit 1.27×10^-8mol/L of LPA were obtained.The relative standard deviation（R.S.D） was 1.8%obtained from a series of 11 standards each containing 6.05×10^-6 mol/L of LPA.This paper also discusses the mechanism of fluorescence indicator probe.     

Two new kaempferol glycosides from the seeds of Camellia semiserrata Chi

Two new acetylated kaempferol glycosides were isolated from the seeds of Camellia semiserrata Chi,their structures were elucidated as kaempferol-3-O-[(3-O-acetyl)-α-L-rhamnopyranosyl(1→3)(4-O-acetyl)-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside] (1) and kaempferol-3-O-[(2-O-acetyl)-α-L-rhamnopyranosyl(1→3)(4-O-acetyl)-α-L-rhamnopyranosyl(1→6)-β-D-gluco -pyranoside](2) by spectral experiments(including ESI-MS,1D- and 2D-NMR).     

Copper and amine free Sonogashira cross-coupling reaction catalyzed by efficient diphosphane-palladium catalyst

The commercially available diphosphane ligand MeO-BIPHEP was first investigated in the palladium-catalyzed Sonogashira reaction in the absence of copper and amine.The coupling of various aryl bromides and aryl chlorides with phenylacetylene gave moderate to excellent yields.     

A clean and efficient cyclocondensation to pyrido[2,3-d]pyrimidine derivatives in aqueous media

A series of pyrido[2,3-d]pyrimidine derivatives were easily constructed by cyclocondensation reactions of 6-aminouracils or 6- aminothiouracil withα,β-unsaturated carbonyl compounds（aldehyde,ketone and ester） possessing a leaving group on theβposition,in H₂O under reflux conditions.     

高邻位高分子量热塑性酚醛树脂研制

改变传统合成工艺,在高温高压无催化剂条件下,合成了无金属杂质的高邻位高分子量热塑性酚醛树脂。考察了苯酚与甲醛加成缩合反应过程中原料种类、原料配比、反应温度及反应压力等因素对酚醛树脂结构性能的影响。通过软化点测试仪、核磁共振谱仪等研究了酚醛树脂合成过程中各个参数对酚醛树脂结构性能的影响。在酚／醛比为1：0．7,210℃、...     

Promoting effect of ethanol on the synthesis of N-（2-methylphenyl）-hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system

The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H₂O/CO₂ system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl）hydroxylamine increased from 71%to 90%when the reduction was carried out at 25℃under normal pressure of CO₂.     

Preparation and characterization of cross-linked β-cyclodextrin polymer/Fe_3O_4 composite nanoparticles with core-shell structures

Cross-linkedβ-cyclodextrin polymer/Fe₃O₄ composite nanoparticles with core-shell structures were prepared via cross linking reaction on the surface of carboxymethylβ-cyclodextrin（CM-β-CD） modified Fe₃O₄ nanoparticles inβ-cyclodextrin alkaline solution by using epichlorohydrin as crosslinking agent.The morphology,structure and magnetic properties of the prepared composite nanoparticles were investigated by transmission electron microscopy（TEM）,Fourier transform infrared（FTIR） spectrometry,X-ray diffraction（XRD） measurement,thermogravimetric analysis（TGA） and Vibrating sample magnetometry （VSM）,respectively.