聚乙二醇衍生物及其蛋白药物修饰研究进展

聚乙二醇及其衍生物因其出色的亲水性、生物相容性、生物学惰性等特性而被广泛应用于蛋白药物修饰,其修饰可有效降低蛋白药物的免疫原性并延长体内半衰期。聚乙二醇衍生物的发展经历了第一代随机修饰,第二代特异性和功能性修饰,以及第三代分支型结构的应用。其应用也从简单的药物修饰扩展到生物传感、药物传输等方面。     

红景天苷衍生物的合成及其抗疲劳活性研究

目的 设计并合成系列4-取代的新型红景天苷衍生物并研究其抗疲劳作用。方法 通过五乙酰基葡萄糖与不同的4-取代苄基酪醇,经过糖苷化、脱乙酰基合成红景天苷衍生物;采用小鼠负重游泳为实验模型,通过观察测定小鼠的负重游泳时间研究合成衍生物的抗疲劳作用。结果 合成了10个新型红景天苷衍生物;小鼠负重游泳实验显示：阳性对照组（红景天苷）和3a-1组（苯乙基-β-D-葡萄糖苷）的小鼠游泳时间明显高于空白对照组（P<0.05）,差异有统计学意义;其余组均与空白对照组小鼠负重游泳时间相近,差异无统计学意义。结论 本实验设计的红景天苷衍生物合成方法简便、可行;红景天苷及其衍生物苯环上的4位羟基可能与其抗疲劳活性密切相关。     

壳聚糖的化学改性及其衍生物的抗氧化活性研究进展

摘 要壳聚糖是一种天然无毒的生物聚合物,主要经甲壳素的脱乙酰作用制得,具有良好的生物相容性、独特的抗氧化活性及生物可降解性等。由于壳聚糖在中性和碱性溶液中溶解性较差,其应用受到了一定限制,通常对其进行多种改性,拓宽其应用范围,提高其利用价值。近年来具有抗氧化能力的壳聚糖及壳聚糖衍生物表现出了优越的医用价值。本文综述了几种壳聚糖常用的改性方法,并介绍了壳聚糖及其衍生物作为抗氧化剂应用的研究进展。     

Anti-hyperalgesic effects of two sphingosine derivatives in different acute and chronic models of hyperalgesia in mice

Background

The study evaluated the effects of two sphingosine derivatives N-(2-tert-butoxycarbamylhexadecyl)glutaramide (AA) and N-(1-benzyloxyhexadec-2-yl)glutaramide (OA) in different models of hypersensitivity in mice.

N‐substituted hydroxynaphthalene imino‐oxindole derivatives as new class of PI3‐kinase inhibitor and breast cancer drug: Molecular validation and structure–activity relationship studies

N‐substituted hydroxynaphthalene imino‐oxindole derivatives ( 5a–g ) were emerged as the inhibitors of the phosphoinositide 3‐kinase (PI3K), which is a crucial regulator of apoptosis or programmed cell death. Electron donor‐/acceptor‐substituted indole‐imine ( 5a–g ) was achieved, and the structures were elucidated by FTIR, 1H NMR, 13C NMR and HRMS. Inhibition potency of PI3Ks was assessed by competitive ELISA. Subsequently, an anticancer activity against breast cancer (MCF‐7) cell lines was evaluated. In both activities, compounds 5c , 5d and 5f showed most potent activities. Percentage inhibition for anticancer activity was 78.22 ± 1.02 ( 5c ) and 78.98 ± 1.08 ( 5f ), and the IC₅₀ was 2.02 ± 0.92 μm ( 5c ) and 1.98 ± 0.18 μm ( 5f ). Compounds 5a and 5g were found inactive for both activities, and rest all showed a moderate activity. To get more insight into the binding mode and inhibitor binding affinity, 5a–g were docked into the active site of PI3Ks p110α (PDB ID: 2ENQ). Results suggested that the hydrophobic interactions in the binding pockets of PI3Ks conquered affinity of the most favourable binding ligands ( 5c and 5f : inhibitory constant (k_i) = 102.4 and 128.23 nm ). The SAR studies demonstrate the efficiency of 5a–g as the PI3Ks precise inhibitors with the impending to treat various cancers.     

槲皮素及其衍生物防治肝损伤作用及机制的研究进展

槲皮素是一种多羟基黄酮类化合物,广泛存在于多种药用植物中,具有抗氧化、抗病毒、抗菌、抗炎和抗肿瘤等多种药理作用。分析了近10年国内外有关槲皮素及衍生物防治肝损伤方面的文献,发现其对各种急、慢性肝损伤均具有良好的防治作用,其作用机制主要涉及抗氧化、抗炎、调节脂质代谢、抗凋亡及自噬、抗病毒等。主要对槲皮素及其衍生物防治不同类型肝损伤的作用及机制进行综述,以期为槲皮素保肝作用的深入研究提供较为全面的文献信息支持。     

A dual‐tracer study of extrastriatal 6‐[18F]fluoro‐m‐tyrosine and 6‐[18F]‐fluoro‐l‐dopa Uptake in Parkinson's disease

6‐[¹⁸F]‐Fluoro‐l ‐dopa (FDOPA) has been widely used as a biomarker for catecholamine synthesis, storage, and metabolism—its intense uptake in the striatum, and fainter uptake in other brain regions, is correlated with the symptoms and pathophysiology of Parkinson's disease (PD). 6‐[¹⁸F]fluoro‐m‐tyrosine (FMT), which also targets l ‐amino acid decarboxylase, has potential advantages over FDOPA as a radiotracer because it does not form catechol‐O‐methyltransferase (COMT) metabolites. The purpose of the present study was to compare the regional distribution of these radiotracers in the brains of PD patients. Fifteen Parkinson's patients were studied with FMT and FDOPA positron emission tomography (PET) as well as high‐resolution structural magnetic resonance imaging (MRI). MRI's were automatically parcellated into neuroanatomical regions of interest (ROIs) in Freesurfer ( http://surfer.nmr.mgh.harvard.edu ); region‐specific uptake rate constants (K_occ) were generated from coregistered PET using a Patlak graphical approach. The essential findings were as follows: (1) regional K_occ were highly correlated between the radiotracers and in agreement with a previous FDOPA studies that used different ROI selection techniques; (2) FMT K_occ were higher in extrastriatal regions of relatively large uptake such as amygdala, pallidum, brainstem, hippocampus, entorhinal cortex, and thalamus, whereas cortical K_occ were similar between radiotracers; (3) while subcortical uptake of both radiotracers was related to disease duration and severity, cortical uptake was not. These results suggest that FMT may have advantages for examining pathologic changes within allocortical loop structures, which may contribute to cognitive and emotional symptoms of PD. Synapse 68:325–331, 2014 . © 2014 Wiley Periodicals, Inc.     

Antimicrobial Activity of Novel C2-Substituted 1,4-Dihydropyridine Analogues

The antimicrobial activity of 3-methyl-5-isopropyl (or ethyl) 6-methyl-4-nitrophenyl-1,4-dihydropyridine-3,5-dicarboxylate derivatives was evaluated. Prokaryotes (bacteria) appeared to be more sensitive to their antimicrobial activity than were eukaryotes (filamentous fungi). The best antibacterial activity was shown by derivative 33, which was able to inhibit the growth of Mycobacterium smegmatis (MIC₃₃ = 9 μg.ml⁻¹), Staphylococcus aureus (MIC₃₃ = 25 μg.ml⁻¹), and Escherichia coli (MIC₃₃ = 100 μg.ml⁻¹). In addition, derivative 4 demonstrated its antibacterial power on the acid-fast bacterial species M. smegmatis and on Gram-positive S. aureus. Focusing on the structure-activity relationship, it appears that the increase in the substituent bulk at the C2 position improved the antibacterial activity of the set of compounds studied. Derivatives 33 and 4, carrying 2-cyano-3-oxo-3-phenylprop-1-en-1-yl and allyliminomethyl groups, respectively, showed significantly higher inhibition activities on all tested microorganisms in comparison with the rest of the derivatives. This enhancement was also in good correlation with different log P values (lipophilicity parameter).     

Assessment of the genotoxic and carcinogenic potentials of 3‐aminothiophene derivatives using in vitro and in silico methodologies

Thiophene derivatives, a class of compounds widely used in products such as pharmaceuticals, agrochemicals or dyestuffs, represent chemicals of concern. Indeed, the thiophene ring is often considered as a structural moiety that may be involved in toxic effects in humans. We primarily focus on the genotoxic/mutagenic and carcinogenic potentials of the methyl 3‐amino‐4‐methylthiophene‐2‐carboxylate (1), a precursor of the articaine local anesthetic (4) which falls within the scope of the European REACH (Registration, Evaluation, Authorisation and restriction of CHemicals) legislation. To discern some structure–toxicity relationships, we also studied two related compounds, namely the 3‐amino 4‐methylthiophene (2) and the 2‐acetyl 4‐chlorothiophene (3). Techniques employed to assess mutagenic and DNA‐damaging effects involved the Salmonella mutagenicity assay (or Ames test) and the single‐cell gel electrophoresis assay (or Comet assay). In the range of tested doses, none of these derivatives led to a positive response in the Ames tests and DNA damage was only observed in the Comet assay after high concentration exposure of 2. The study of their carcinogenic potential using the in vitro SHE (Syrian Hamster Embryo) cell transformation assay (CTA) highlighted the activity of compound 2. A combination of experimental data with in silico predictions of the reactivity of thiophene derivatives towards cytochrome P450 (CYP450), enabled us to hypothesize possible pathways leading to these toxicological profiles. Copyright © 2013 John Wiley & Sons, Ltd.