An Original and Efficient Antibiotic Adjuvant Strategy to Enhance the Activity of Macrolide Antibiotics against Gram-Negative Resistant Strains

Gram-negative bacteria were reported as a significant cause of infections in both community and nosocomial settings. Considered as one of the greatest threats to public health, the spread of bacteria drug resistance and the lack of effective alternative treatment options remains problematic. Herein, we report a promising strategy to combat Gram-negative resistant strains consisting of the combination of a macrolide antibiotic with a polyaminoisoprenyl adjuvant derivative leading to a significant decrease of antibiotic resistance.     

吲哚-3-羧酸衍生物的合成及降糖活性研究

以4-苯甲氧基苯肼盐酸盐为原料,经过3步反应,以较高产率合成了9个新型吲哚-3-羧酸类化合物,其结构均经IR、1HNMR、13CNMR和ESI-MS表征确认。初步葡萄糖消耗活性试验表明,所合成化合物均对Hep G2细胞有一定的促葡萄糖消耗活性,其中化合物2-甲基-1-(4-甲氧基苯磺酰基)-5-苄氧基-吲哚-3-丙酸、2-甲基-1-(4-甲基苯磺酰基)-5-苄氧基-吲哚-3-丙酸及2-甲基-1-(4-硝基苯磺酰基)-5-苄氧基-吲哚-3-丁酸的促葡萄糖消耗活性强于先导化合物GY3与阳性对照二甲双胍,值得进一步深入研究。     

沉淀聚合法制备吲哚乙酸印迹聚合物及其吸附性能研究

以吲哚乙酸(IAA)为模板分子、乙腈为致孔剂,采用沉淀聚合法制备了其分子印迹聚合物,通过静态吸附实验研究了致孔剂乙腈的用量及4-乙烯基吡啶(4-VP)和丙烯酰胺(AA)两种不同性质的功能单体(M)对印迹聚合物吸附性能的影响。结果表明,以4-VP为M,乙腈的加入量分别为20、25、37.5和50 m L时,制备的印迹聚合物P1~P4均具有良好的分散性,且聚合物P4对IAA具有最显著的印迹效应(印迹因子IF=2.92);而在同样条件下以AA为M的印迹聚合物的印迹效应较小(IF=1.73)。选择性实验表明,聚合物P4能够从吲哚羧酸同系物中选择性结合IAA。Scatchard分析表明,聚合物P4对IAA表现出两类结合位点,其高亲和力与低亲和力结合位点的平衡离解常数分别为Kd1=0.798 mmol/L和Kd2=7.76 mmol/L,对应的最大结合量分别为21.0和90.7μmol/g。     

Motuporamine Derivatives as Antimicrobial Agents and Antibiotic Enhancers against Resistant Gram‐Negative Bacteria

Dihydromotuporamine C and its derivatives were evaluated for their in vitro antimicrobial activities and antibiotic enhancement properties against Gram‐negative bacteria and clinical isolates. The mechanism of action of one of these derivatives, MOTU‐N44, was investigated against Enterobacter aerogenes by using fluorescent dyes to evaluate outer‐membrane depolarization and permeabilization. Its efficiency correlated with inhibition of dye transport, thus suggesting that these molecules inhibit drug transporters by de‐energization of the efflux pump rather than by direct interaction of the molecule with the pump. This suggests that depowering the efflux pump provides another strategy to address antibiotic resistance.     

1H-茚-3-酮-1-甲酸类化合物的合成研究

以3-氧代-2,3-二氢-1H-茚-1-甲酸类化合物为原料,经过液溴单溴代、1,8-二氮杂二环[5.4.0]十一碳-7-烯(DBU)脱溴化氢两步反应,合成2个1H-茚-3-酮-1-甲酸类化合物。并采用正交实验法,优化溴代反应的工艺条件,收率达97%,合成工艺具应用价值。     

香豆素-3-羧酸-烟酸前药的设计、合成及抗血小板聚集活性的研究

设计、合成香豆素-3-羧酸-烟酸前药并研究其抗血小板聚集活性,以发现活性更高的新型抗血小板聚集剂。利用拼合原理,以不同的连接桥将香豆素-3-羧酸和烟酸偶联,合成目标化合物。通过体外抗血小板聚集试验对目标化合物进行抗血小板聚集活性评价。设计、合成了5个新的目标化合物,其结构经ESI-MS、IR及1 H NMR确证。体外抗血小板聚集活性结果表明,目标化合物的抗血小板聚集活性均强于阳性对照药阿司匹林,其中化合物6a的活性最强,值得进一步研究。     

3-Arylaziridine-2-carboxylic Acid Derivatives and (3-Arylaziridin-2-yl)ketones: The Aziridination Approaches

Aziridination reactions represent a powerful tool in aziridine synthesis. Significant progress has been achieved in this field in the last decades, whereas highly functionalized aziridines including 3-arylated aziridine-2-carbonyl compounds play an important role in both medical and synthetic chemistry. For the reasons listed, in the current review we have focused on the ways to obtain 3-arylated aziridines and on the recent advances (mainly since the year 2000) in the methodology of the synthesis of these compounds via aziridination.     

Non-Aziridination Approaches to 3-Arylaziridine-2-carboxylic Acid Derivatives and 3-Aryl-(aziridin-2-yl)ketones

Highly functionalized aziridines, including compounds with aromatic moieties, are attractive substrates both in synthetic and medical areas of chemistry. There is a broad and interesting set of synthetic methods for reaching these compounds. Aziridination represents the most explored tool, but there are several other more specific, less well-known, but highly promising approaches. Therefore, the current review focuses on recently described or updated ways to obtain 3-arylated aziridines via different non-aziridination-based synthetic methods, reported mainly since 2000. The presented methods belong to two main directions of synthesis, namely, cyclization of open-chain substrates and rearrangement of other heterocycles. Cyclization of open-chain substrates includes the classic Gabriel-Cromwell type cyclization of halogenated substrates with amines, base-promoted cyclization of activated aminoalcohols (or its analogues), and the oxidative cyclization of β-dicarbonyls. Rearrangements of other heterocycles are presented as the Baldwin rearrangement of 4-isoxazolines, the cycloaddition of 1.3-dipoles or dienes to 2H-azirines, and the addition of C- and N-nucleophiles to the double bond of azirines.     

3-甲基-4-吡唑甲酸和3,5-二甲基-4-吡唑甲酸的合成

吡唑甲酸衍生物是制备新型杀虫剂的中间体。为了简化工艺条件,降低生产成本,以乙酰乙酸乙酯与原甲酸三乙酯为原料,乙酸酐为溶剂,加热回流4 h,合成了乙氧亚甲基乙酰乙酸乙酯(Ⅰ),收率为75%;然后在0~5℃冰浴中缓慢滴加w(NH2NH2.H2O)=80%的水合肼,室温反应0.5 h,与Ⅰ环合生成3-甲基-4-吡唑甲酸乙酯,收率77%,熔点46~47℃;最后经w(NaOH)=10%的水溶液水解,制得目标产物3-甲基-4-吡唑甲酸,收率88%,熔点237~238℃。用类似的方法以乙酰乙酸乙酯和乙酰氯为原料,经缩合、环合和水解3步反应合成了3,5-二甲基-4-吡唑甲酸,3步反应的收率分别为52%、75%、85%。中间产物及目标产物的结构经熔点、IR、MS、1HNMR和13CNMR表征得以证实。在实验室小试的基础上,放大50倍进行了中试,目标产物的收率与小试结果一致。适合工业化生产。     

吲哚-3-乙酸分子印迹聚合物的合成及吸附性能分析

以吲哚-3-乙酸(indole-3-acetic acid,IAA)为模板、甲基丙烯酸为功能单体、乙腈为致孔剂,采用本体聚合法合成了对IAA有特异性识别的吲哚-3-乙酸分子印迹聚合物(IAA-MIP)。红外光谱分析表明,IAA是以氢键形式结合在聚合物的空腔中。等温吸附线及Scatchard分析表明,洗脱模板后的IAA-MIP结合IAA的能力比空白印迹聚合物(NIP)强,且有2种结合方式,其解离常数分别为KD1=1.04×10-6 mol·L-1和KD2=9.23×10-6 mol·L-1,最大表观结合位点分别为Bmax1=0.10μmol·g-1和Bmax2=0.28μmol·g-1。对植物样品的固相萃取实验表明,洗脱模板后的IAA-MIP对IAA具有较强的特异性吸附能力。     

DL-homoserinehydroxamic Acid,DL-homo-cystinedihydroxamic Acid,and Derivatives by Hydroxylaminolysis of γ-Hydroxy- and γ-Thio-Lactones

The reaction of α-amino-, α-carbamoylamino-, α-benzamido-, and α-benzyloxycarbonyl-amino-γ-butyrolactone with hydroxylamine led to the formation of DL-homoserinehydroxamic acid and α-N-acyl derivatives. α-N-Benzoyl-DL-homoserine-N-methyl-hydroxamic acid and O-benzylhydroxamic acid ester were prepared by reacting α-benzamido-γ-butyrolactone with N-methylhydroxylamine and with O-benzylhydroxylamine, respectively. Hydroxyl-aminolysis of DL-homocysteinethiolactone and of N-acyl-DL-homocysteinethiolactones gave homocystinedihydroxamic acid and N,N′-disubstituted derivatives. Relative reactivities of O- and S-lactones were compared.     

吡唑-3-甲酸钴的合成、晶体结构及其与牛血清白蛋白的相互作用

利用吡唑-3-甲酸为配体,通过溶液法与氯化钴反应合成出一种钴的配合物,用X射线单晶衍射仪对其进行表征。结果显示,该配合物为单斜晶系,空间群为P21/c,a=0.509 94(2)nm,b=1.139 55(5)nm,c=0.936 80(4)nm,β=95.925(5)°。钴与两个配体分子的N、O原子和水分子的氧原子配位,形成八面体结构。利用紫外-可见吸收光谱与荧光光谱研究它与牛血清白蛋白(BSA)的相互作用。结果表明,该配合物与BSA形成稳定的复合物,荧光猝灭属于静态猝灭,猝灭速率常数kq为3.54×1012L/(mol·s),结合常数K=7.06×105L/mol,结合位点n=1.259 5。     

Functional Characterization of 3-Aminobenzoic Acid Adenylation Enzyme PctU and UDP-N-Acetyl-d-Glucosamine: 3-Aminobenzoyl-ACP Glycosyltransferase PctL in Pactamycin Biosynthesis

Pactamycin is an antibiotic produced by Streptomyces pactum with antitumor and antimalarial properties. Pactamycin has a unique aminocyclitol core that is decorated with 3-aminoacetophenone, 6-methylsaliciate, and an N,N-dimethylcarbamoyl group. Herein, we show that the adenylation enzyme PctU activates 3-aminobenzoic acid (3ABA) with adenosine triphosphate and ligates it to the holo form of the discrete acyl carrier protein PctK to yield 3ABA-PctK. Then, 3ABA-PctK is N-glycosylated with uridine diphosphate-N-acetyl-d -glucosamine (UDP-GlcNAc) by the glycosyltransferase PctL to yield GlcNAc-3ABA-PctK. Because 3ABA is known to be a precursor of the 3-aminoacetophenone moiety, PctU appears to be a gatekeeper that selects the appropriate 3-aminobenzoate starter unit. Overall, we propose that acyl carrier protein-bound glycosylated 3ABA derivatives are biosynthetic intermediates of pactamycin biosynthesis.     

Effects of Indole-3-Lactic Acid,a Metabolite of Tryptophan,on IL-4 and IL-13-Induced Human Skin-Equivalent Atopic Dermatitis Models

Indole-3-lactic acid (I3LA) is a well-known metabolite involved in tryptophan metabolism. Indole derivatives are involved in the differentiation of immune cells and the synthesis of cytokines via the aryl hydrocarbon receptors for modulating immunity, and the indole derivatives may be involved in allergic responses. I3LA was selected as a candidate substance for the treatment of atopic dermatitis (AD), and its inhibitory effect on AD progression was investigated. Full-thickness human skin equivalents (HSEs) consisting of human-derived cells were generated on microfluidic chips and stimulated with major AD-inducing factors. The induced AD-HSEs were treated with I3LA for 7 days, and this affected the AD-associated genetic biomarkers and increased the expression of the major constituent proteins of the skin barrier. After the treatment for 14 days, the surface became rough and sloughed off, and there was no significant difference between the increased AD-related mRNA expression and the skin barrier protein expression. Therefore, the short-term use of I3LA for approximately one week is considered to be effective in suppressing AD.     

Antimicrobial Potential of Chiral Amide Derivatives of Ricinoleic and 3-Hydroxynonanoic Acid

The growing role of fatty acid amides in medicinal chemistry has recently been observed. Therefore, using simple and fast methods, a series of chiral amide derivatives (24 compounds) of ricinoleic and 3-hydroxynonanoic acid was obtained with 31–95% yields. Then, the evaluation of their antimicrobial activity against 13 microorganisms representing Gram-positive and Gram-negative bacteria, yeast, and molds was performed. The obtained compounds showed antimold potential; however, the tested species of molds were more susceptible to derivatives of 3-hydroxynonanoic acid than to amides obtained from ricinoleic acid (RA). Interestingly, hydroxamic acids derived from RA exhibited the best activity against Candida albicans and Candida tropicalis. On the other hand, hydroxamic acids derived from 3-hydroxynonanoic acid showed the best antimicrobial potential against the remaining tested microorganisms, especially against Pseudomonas cedrina. The obtained derivatives can be considered compounds of potential pharmacological significance, which is important due to the increasing problem of microbial resistance.     

Acidic Derivatives of Melamine as Template in Copolymerization of Aniline and Metanilic Acid

In this paper, new polymer composites were synthesized by template copolymerization of aniline and metanilic acid in the presence of prepared melamine triacetic acid and poly(melamine-co-citric acid) as polyacids and dopants. The properties of the poly(aniline-co-metanilic acid) composites were studied by Fourier transform infrared, X-ray diffraction, scanning electron microscope, CV, and differential scanning calorimeter analysis. The four-point probe technique was used for evaluating the electrical conductivity of the composites. The scanning electron micrographs disclosed that the products had the morphology with agglomerated distorted spherical shapes with the average size of 40–50?nm. Also, the solubility of the composites had been improved notably in organic solvents.     

Synthesis and Biological Evaluation of N‐Substituted Sophocarpinic Acid Derivatives as Coxsackievirus B3 Inhibitors

A series of novel N‐substituted sophocarpinic acid derivatives was designed, synthesized, and evaluated for their anti‐enteroviral activities against coxsackievirus type B3 (CVB3) and coxsackievirus type B6 (CVB6) in Vero cells. Structure–activity relationship analysis revealed that the introduction of a benzenesulfonyl moiety on the 12‐nitrogen atom in (E)‐β,γ‐sophocarpinic acid might significantly enhance anti‐CVB3 activity. Among the derivatives, (E)‐12‐N‐(m‐cyanobenzenesulfonyl)‐β,γ‐sophocarpinic acid ( 11 m ), possessing a meta‐cyanobenzenesulfonyl group, exhibited potent activity against CVB3 with a selectivity index (SI) of 107. Furthermore, compound 11 m also showed a good oral pharmacokinetic profile, with an AUC value of 7.29 μM h^?1 in rats, and good safety through the oral route in mice, with an LD₅₀ value of >1000 mg kg^?1; these values suggest a druggable characteristic. Therefore, compound 11 m was selected for further investigation as a promising CVB3 inhibitor. We consider (E)‐β,γ‐N‐(benzenesulfonyl)sophocarpinic acids to be a novel class of anti‐CVB3 agents.     

阿魏酸衍生物的设计、合成及除草活性

[目的]以天然产物阿魏酸为先导设计合成具有较强除草活性的衍生物.[方法]运用农药分子合理设计原理设计合成阿魏酸酰胺类似物,采用小杯法测定除草活性.[结果]合成了11个新型的阿魏酸衍生物;小杯法测定显示,在400 mg/L质量浓度下,化合物8f和8k的除草活性较好;半抑制浓度测定结果表明:8f对马唐根和茎的IC50值为分...