3-N-丙酰基-2-芳基-5-(2-溴-5-氟苯基)-1,3,4-(噁)唑啉类衍生物的合成与结构表征

2-溴5-氟苯甲酰肼(1)与芳香醛缩合得到酰腙(2a～2i),再与丙酸酐环合成了3-N-丙酰基-2-芳基-5-(2-溴-5-氟苯基)-1,3,4-噁唑啉类衍生物(3a～3i),收率70%～83%。化合物的结构经元素分析、IR、1HNMR和MS确证。     

1-(5-溴吡啶-2-基)环丙烷羧酸甲酯的合成

以2-(5-溴-2-吡啶)乙腈和1,2-二溴乙烷为原料,二甲基亚砜为溶剂,经过烷基化反应获得1-(5-溴吡啶-2-基)环丙烷-1-腈(3),水解反应生成1-(5-溴吡啶-2-基)环丙烷羧酸(2),酯化反应生成1-(5-溴吡啶-2-基)环丙烷羧酸甲酯(1)。优化反应条件为：投料比n(1,2-二溴乙烷)∶n(2-(5-溴-2-吡啶)乙腈)=1.02∶1.00,n(氢氧化钾)∶n(3)=3.0∶1.0,溶剂二甲基亚砜用量1.8 L,双氧水滴加时间2.0 h,结晶温度-15℃,pH为8.0。优化条件下目标化合物1收率69.5%,纯度98.6%(HPLC)。目标化合物的结构经熔点和¹H NMR表征确证。     

丹皮酚吗啉杂合物的合成及抗血小板聚集活性

以丹皮酚为起始原料，在碱性条件下丹皮酚的2-位酚羟基与二溴烷烃经Williamson反应得到中间体丹皮酚溴代烷基醚2a～2e,化合物2a～2e与吗啉经N-烷基化反应得到丹皮酚吗啉杂合物3a～3e。目标化合物3a～3e经过核磁共振氢谱(¹H NMR)、红外(IR)和高分辨质谱(HRMS)表征。体外抗血小板聚集活性测试结果表明，所得目标化合物3a～3e对二磷酸腺苷(ADP)所诱导的血小板聚集均具有较强的抑制活性，优于阳性对照药阿司匹林。     

丹皮酚硝氧烷基醚类衍生物的合成及抗血小板聚集活性

以丹皮酚为原料,利用其2位羟基与二溴烷烃反应得到中间体丹皮酚溴代烷基醚(2a～2e),再将化合物2a～2e与硝酸银反应得到丹皮酚硝氧烷基醚类衍生物3a～3e.化合物3a～3e的结构经红外、核磁共振氢谱和高分辨质谱表征.体外抗血小板聚集活性测试结果表明,化合物3a～3e对二磷酸腺苷所诱导的血小板聚集均具有较强的抑制活性,...     

单参数法估算取代吡啶的电离常数和分配系数

用密度泛函理论(DFT)和B3LYP/3-21G基组,优化了24种已知取代吡啶类分子结构,发现吡啶环上氮原子的自然原子轨道电荷(NBO)值与其实验电离常数(logK a)值和正辛醇-水分配系数(logP)之间均存在较好的线性关系(R1=0.98,R2=0.88)。计算了10种未知logK a/logP值的多取代吡啶化合物的NBO参数,代入拟合出的单参数线性方程,发现与流行软件ACD Lab 6.0预测得到的多取代吡啶的logK a/logP值接近,相关系数R在0.80~0.90之间,相对偏差在1%~3%之间。     

环丙烷二酰胺类杂合药物的设计与合成

目的：设计合成一系列环丙烷二酰胺类杂合药物,并评价其对人肝癌肿瘤株(HepG-2)的体外抑制活性。方法：利用分子对接技术和药物拼合原理从九个先导化合物中,预测了化合物5a～5i与c-Met(3LQ8和4MXC)蛋白的亲和活性,筛选出六个打分结果最好的化合物5a～5f,并采用细胞增殖抑制实验法(MTT法)测定了5a～5f对人肝癌肿瘤株(HepG-2)的体外抑制活性。以1,1-环丙烷二羧酸为起始原料,依次经2步酰胺化反应和1步亲核取代反应,合成中间体2、中间体3、中间体4;再与结构不同的胺和酚经过亲核取代反应合成了6个环丙烷二酰胺类杂合药物(CPDAs),其结构经1H NMR、13C NMR及HR-MS表征。结果与结论：我们筛选出六个活性最好的杂合药物,并且发现当浓度大于2.5μg·mL^-1时,5f、5b和5e对HepG2人肝肿瘤细胞的抑制率均优于阳性对照药5-氟尿嘧啶(5-FU),抑制率分别为66.16%、60.98%及63.12%;浓度大于5μmol·L^-1时,5f、5b和5e对HepG2人肝肿瘤细胞的抑制率均大于60%。     

香豆素-3-羧酸乙酯衍生物的合成及抗血小板聚集活性

以间二苯酚为原料,经Vilsmeier-Haack,Knoevenagel等反应得到7-羟基香豆素-3-羧酸乙酯(3),利用其7位羟基与不同碳数的二溴烷烃反应得到7-溴代烷氧基-香豆素-3-羧酸乙酯(4a～4e),再将其与硝酸银反应得到7-硝氧烷氧基香豆素-3-羧酸乙酯(5a～5e)。化合物5a～5e经过红外光谱、核磁共振氢谱和质谱表证。体外抗血小板聚集活性测试结果表明,所得目标化合物对二磷酸腺苷(ADP)所诱导的血小板聚集均具有较强的抑制活性,抑制率达32.86%～40.71%,强于阳性对照药阿司匹林(19.33%)。     

系列双胍的合成及体外抗菌活性研究

以双氰胺和伯胺为原料,以浓硫酸为催化剂,合成系列酰基双胍(4-吡啶甲酰基双胍,B~1;3-吡啶甲酰基双胍,B~2;2-氟苯甲酰基双胍,B~3;氯乙酰基双胍,B~4;2,2,2-三氯乙酰基双胍,B~5;2-氯吡啶-3-甲酰基双胍,B~6)及3-吡啶双胍(M~1)。采用熔点、FT-IR、~1H NMR、~(13)C NMR及元素分析对产物B~(1～6)和M~1进行了表征,并对M~1进行单晶X-射线衍射结构分析。采用微量肉汤稀释法探究B~(1～6)及M~1分别对金黄色葡萄球菌(a)、大肠杆菌(b)以及白色念珠菌(c)的抗菌活性。结果表明,在B~(1～6)中,取代基为一氯代烷烃的B~4抗菌效果最好,其对三种菌的半抑制浓度(IC_(50))分别为1.30(a)、1.62(b)和4.51 mg/m L(c),且具有最低的最小抑菌浓度(MIC),其值分别为2.56(a)、2.56(b)和10.24(c)mg/m L;同时,B~4对三种菌具有较低的最低杀菌浓度,其MBC分别为5.12(a)、5.12(b)、10.24(c)mg/m L。不含羰基的M~1的抗菌效果优于B~(1～6),其对三种菌的IC_(50)分别为0.64(a)、1.01(b)和1.43(c)mg/m L,同时,M~1对三种菌种的MIC(2.56(a)、1.28(b)、2.56(c)mg/m L)及MBC(2.56(a)、1.28(b)、5.12(c)mg/m L)均低于B~4。     

两种1,1-二取代乙烯的简单合成

5-亚甲基二苯并[a,e]-环庚烷(2a)和5-亚甲基二吡啶并[1,2-b:5,4-b’]环戊烷(2b)分别应用两种不同的方法合成。方法一是通过酮与三苯基甲基溴化鳞反应(Wittig法)制备,方法二是通过酮与格氏试剂反应后再在酸性条件下发生消除反应制备。后者原料便宜,操作简单且产率高,是合成此类1,1-二取代乙烯的好方法。通过元素分析及NMR对产物的结构进行了表征。     

Br(o)nsted酸性离子液体中苯甲酸酯、苄酯的无溶剂微波合成

该文以1-甲基咪唑、吡啶、苄基氯、硫酸、磷酸为原料,合成了4种Brnsted 酸性离子液体:1-甲基-3-苄基咪唑硫酸氢根盐(a),1-甲基-3-苄基咪唑磷酸二氢根盐(b),N-苄基吡啶硫酸氢根盐(c),N-苄基吡啶磷酸二氢根盐(d),以它们作为催化剂和反应介质,考察了苯甲酸与系列脂肪醇、苄醇与系列脂肪酸、苯甲酸在无溶剂和微波辐射反应条件下的Fischer酯化反应,结果表明,当苯甲酸或苄醇与离子液体的摩尔比为1∶ 0.5时,无需外加催化剂,反应即可在化学计量条件下进行,12～20 min完成反应,苯甲酸酯与苄酯的收率分别为77%～98%和78%～98.5%,气相色谱纯度≥95%.离子液体循环使用3次,催化活性仅下降1.8%～3.4%.     

Aluminum,Arsenic, Beryllium,Cadmium, Chromium,Cobalt, Copper,Iron, Lead,Mercury, Molybdenum,Nickel, Platinum,Thallium, Titanium,Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl₂ causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.     

THERMOPLASTIC,FLEXIBLE, AND RECYCLABLE COMPOSITES,DESIGN, PREPARATION,AND CHARACTERIZATION

Glass fiber reinforced composites based on thermosets are the traditional materials used for many applications due to their good mechanical properties. The non-recyclability of these materials has led to the necessity to develop thermoplastic composites and industrial processes for their manufacture [1]. The present paper deals with the preparation of thermoplastic pre-pregs unidirectionally reinforced with Twarn® and their mechanical characterization.     

DUO-ICP-AES测定精对苯二甲酸中的钴、铬、铁、锰、钼、镍、钛

采用DUO-ICP-AES同时测定精对苯二甲酸中钴、铬、铁、锰、钼、镍、钛,并对仪器的分析线选择、背景校正、入射功率、雾化器压力、辅助气流量、冷却气流量、蠕动泵转速的影响及共存元素的干扰、硝酸铯灰化助剂等因素进行了详细的研究。方法的检测限:钴0.0097 mg/L;铬0.0021 mg/L;铁0.0078 mg/L;锰0.0012 mg/L;钼0.0027 mg/L;镍0.016 mg/L;钛0.0027 mg/L,回收率和精密度分别为93.0%～99.5%和0.37%～3.2%。该方法快速简便,具有良好的精密度和准确度,适用于进出口精对苯二甲酸的日常检验。     

Pd-, Ni-, Fe-, and Co-Catalyzed Cross-Couplings Using Functionalized Zn-, Mg-, Fe-, and In-Organometallics

The development of new methods for preparing polyfunctional organometallics has made a broad range of such reagents available for various transition metal-catalyzed cross-couplings. An overview of the most general preparation methods will be presented. Applications to practical cross-coupling procedures will be covered, emphasizing the functional group compatibility and the reaction scope.