tosylation

甲苯糖基化
  • 文章类型: Journal Article
    我们开发了一种简便的方法,用于制造由两个块组成的可生物降解的递送系统:姜黄素和姜黄素。这是通过对甲糖基化对Curdlan进行化学官能化实现的,胺化,然后与姜黄素络合。对结构表征和组分稳定性的综合评估表明,Cur-cum配合物具有更好的抗癌性能,并具有增强的热性能。cur-cum复合物显示出pH敏感的持续释放行为,在酸性pH下有较高的释放,药物释放的动力学数据遵循Korsmeyer-Peppas模型。如MTT测定所揭示的,cur-cum复合物具有阻断MCF-7细胞系增殖的能力,这表明cur-cum复合物对这些细胞系的毒性增加。从蛋白质印迹分析获得的结果表明,cur和cum的共同给药有效地诱导了MCF-7细胞的凋亡。通过Bcl-2/Bax比率的显著上调观察到这种效果,LDHA的mRNA表达下降,乳酸和LDH活性水平。结果清楚地描述了官能化的Curdlan作为姜黄素递送的有效载体的作用,持续释放和提高生物利用度,从而提高整体抗癌活性。
    We developed a facile method for the fabrication of a biodegradable delivery system composed of two blocks: curdlan and curcumin. This was achieved by chemical functionalization of curdlan through tosylation, amination followed by complexation with curcumin. A comprehensive evaluation of structural characterization and component stability showed that cur-cum complex exhibited better anticancer properties with enhanced thermal properties. The cur-cum complex shows pH sensitive sustained release behaviour with higher release at acidic pH and kinetic data of drug release follows the Korsmeyer-Peppas model. The cur-cum complex has ability to block the proliferation of the MCF-7 cell line as revealed by MTT assay which showed increased toxicity of cur-cum complex against these cell lines. The results obtained from western blot analysis demonstrated that the co-administration of cur and cum effectively induced apoptosis in MCF-7 cells. This effect was observed by a considerable upregulation of the Bcl-2/Bax ratio, a decline in mRNA expression of LDHA, level of lactate and LDH activity. The results clearly depict the role of functionalized curdlan as efficient carrier for curcumin delivery with prolonged, sustained release and enhanced bioavailability, thereby improving the overall anticancer activity.
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  • 文章类型: Journal Article
    目的:开发了基于酰胺连接的直链淀粉的前药,用于甲芬那酸的结肠靶向释放。材料与方法:用分光光度法研究了前药的活化,酶联免疫吸附试验评价了不同浓度的前药对环氧合酶-1(COX-1)和环氧合酶-2(COX-2)的抑制作用,通过扫描电子显微镜监测前药在生理条件下的行为。结果:前药在无酶的模拟胃介质和模拟肠介质(SIM)中的活化能力较差,但在胰酶中预孵育,然后在含氨肽酶的SIM中处理导致前药的显着活化。结论:酰胺连接的直链淀粉-甲芬那酸缀合物在模拟胃介质中显示出缓慢释放,在SIM中显示出受控释放,而胰酶在药物释放中起重要作用。
    Aim: Amide-linked amylose-based prodrugs were developed for colon-targeted release of mefenamic acid. Materials & methods: Activation of prodrug was studied spectrophotometrically, enzyme-linked immunosorbent assay appraised cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition at different concentrations of the prodrug, the behavior of prodrug under physiological conditions was monitored by scanning electron microscopy. Results: Prodrug was poorly activated in the enzyme-free simulated gastric media and simulated intestinal media (SIM) but preincubation in pancreatin followed by treatment in aminopeptidase containing SIM led to a significant activation of prodrug. Conclusion: Amide-linked amylose-mefenamic acid conjugates showed a slow release in simulated gastric media and a controlled release in SIM with pancreatin playing an important role in drug release.
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  • 文章类型: Journal Article
    当前的研究有效地设计了新型交联的甲苯磺酰基-角叉菜胶/藻酸盐(Ts-Car/Alg)珠,以从其水溶液中去除Pb2离子。为了确认产生的矩阵的结构,XRD等表征方法,SEM,FTIR,使用了EDX。采用批量实验以进一步评估Pb2+离子的吸附效率。此外,各种变量,包括接触时间,溶液pH值,吸附剂用量,使用原子吸收研究了Pb2离子的初始浓度。这项研究的结果表明,在接触时间为120分钟后,在pH=5.3时,随着Pb2离子浓度的增加,吸附平衡增加。0.3g的Ts-Car/Alg具有74mg/g的最佳吸附能力。使用动力学和等温模型进一步检查吸附进程。相关系数为0.975,Freundlich模型被认为可以更好地拟合等温线研究中的Pb2离子吸附。此外,使用1/n比为0.683的伪二级模型研究了吸附动力学。这种Ts-Car/Alg吸附剂被认为是用于水处理的有效候选者,因为生产的珠子的可重复使用过程成功完成了两次,吸附剂保持了其去除Pb2+离子的能力。因此,所制备的Ts-Car/Alg珠是用作来自其水溶液的有效Pb2+离子吸附剂的优异候选物。至少在两个成功的循环中完成了Ts-Car/Alg珠的再生和可重复使用性研究,以去除重金属离子。
    The current study effectively designed novel cross-linked tosyl-carrageenan/alginate (Ts-Car/Alg) beads to remove Pb2+ ions from their aqueous solutions. To confirm the structure of the produced matrix, characterization methods such as XRD, SEM, FTIR, and EDX were used. Batch experiments were employed in order to further evaluate the adsorption efficiency of Pb2+ ions. Additionally, various variables, including contact time, solution pH, adsorbent dosage, and initial concentration of Pb2+ ions were investigated using atomic absorption. The results of this study showed that the adsorption equilibrium increased as Pb2+ ions concentration increased at pH = 5.3 after a contact time of 120 min, with 0.3 g of Ts-Car/Alg that having the best adsorption capacity at 74 mg/g. The adsorption progression was further examined using the kinetic and isothermal models. With a correlation coefficient of 0.975, the Freundlich model was thought to better fit Pb2+ ions adsorption from the isotherm investigation. Also, the adsorption kinetics were investigated using a pseudo-second-order model with 1/n ratio of 0.683. This Ts-Car/Alg adsorbent is regarded as an effective candidate to be used for water treatment because the reusability process of produced beads was successfully completed twice, and the adsorbent maintained its ability to remove Pb2+ ions. The prepared Ts-Car/Alg beads are therefore excellent candidates to be used as potent Pb2+ ions adsorbents from their aqueous solutions. The Ts-Car/Alg beads\' regeneration and reusability investigation for the removal of heavy metal ions was completed in at least two successful cycles.
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  • 文章类型: Journal Article
    在本文中,在β-d-Galp单元的C6处选择性修饰生物惰性琼脂糖以产生具有抗菌性质的氨基衍生物。合成路线涉及制备甲苯磺酰基和叠氮琼脂糖中间体。所有多糖衍生物均通过一维和二维1H和13CNMR和FT-IR分析进行了表征。通过部分酸水解产生水溶性氨基聚合物(Mw=39,000gmol-1,DSamino=0.50),显示出对铜绿假单胞菌的杀菌和抑菌活性(ATCC9027),金黄色葡萄球菌(ATCC6538),和大肠杆菌(ATCC25922),MIC值低于2.5mgmL-1,MBC值范围为2.5至5.0mgmL-1。
    In this paper, the biologically inert agarose was selectively modified at C6 of β-d-Galp units to produce an amino derivative with antibacterial property. The synthetic route involved the preparation of tosyl and azido agarose intermediates. All the polysaccharide derivatives were characterized by mono- and bidimensional 1H and 13C NMR and FT-IR analysis. A water-soluble amino polymer (Mw = 39,000 g mol-1, DSamino = 0.50) was produced by partial acid hydrolysis showing bactericidal and bacteriostatic activity against P. aeruginosa (ATCC 9027), S. aureus (ATCC 6538), and E. coli (ATCC 25922), with MIC values lower than 2.5 mg mL-1 and MBC values ranging from 2.5 to 5.0 mg mL-1.
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  • 文章类型: Comparative Study
    Alpha- and beta-linked 1,3-glucans have been subjected to conversion with p-toluenesulfonic acid (tosyl) chloride and triethylamine under homogeneous reaction conditions in N,N-dimethyl acetamide/LiCl. Samples with a degree of substitution of tosyl groups (DSTs) of up to 1.91 were prepared by applying 5 mol reagent per mole repeating unit. Hence, the reactivity of α-1,3-glucan is comparable with cellulose and starch, while the β-1,3-linked glucan curdlan is less reactive. The samples dissolve in aprotic dipolar media independent of the DSTs and possess a solubility in less polar solvents that depends on the DSTs. NMR studies on the tosyl glucans and of the peracylated derivatives showed a preferred tosylation of position 2 of the repeating unit. However, the selectivity is less pronounced compared with starch. It could be concluded that the α-configurated glycosidic bond directs tosyl groups towards position 2.
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  • 文章类型: Journal Article
    肿瘤被定义为异常组织肿块,导致这些异常组织肿块生长的最重要因素之一是血管内皮生长因子,通过在缺氧条件下释放细胞来刺激血管生成。缺氧在癌症治疗中起着至关重要的作用,因此监测缺氧非常重要。缺氧标志物匹莫硝唑(PIM)是癌症侵袭性的候选生物标志物。
    该研究旨在使用碘131(131I)对PIM进行放射性碘化,以加入治疗方法。为此,PIM被衍生为能够被放射性碘化的PIM-TOS。
    PIM通过甲苯磺酸化反应得到。衍生化产物(PIM-TOS)采用碘原法进行放射性碘化,并采用高效液相色谱和液相色谱-质谱联用进行分析。薄层放射色谱法用于其质量控制研究。
    在甲苯磺酸化反应后成功得到PIM。PIM-TOS的放射性碘化产率超过85%。
    在目前的研究中,使用131I的PIM的放射性碘化电位,作为一种潜在的治疗性缺氧药物进行了研究。应进行进一步的实验研究以开发新型的缺氧探针,包括治疗方法。
    Tumors are defined as abnormal tissue masses, and one of the most important factors leading to the growth of these abnormal tissue masses is Vascular Endothelial Growth Factor, which stimulates angiogenesis by releasing cells under hypoxic conditions. Hypoxia has a vital role in cancer therapy, thus it is important to monitor hypoxia. The hypoxia marker Pimonidazole (PIM) is a candidate biomarker of cancer aggressiveness.
    The study aimed to perform radioiodination of PIM with Iodine-131 (131I) to join a theranostic approach. For this purpose, PIM was derived as PIM-TOS to be able to be radioiodinated.
    PIM was derived via a tosylation reaction. Derivatization product (PIM-TOS) was radioiodinated by using iodogen method and was analyzed by High-Performance Liquid Chromatography and Liquid chromatography-mass spectrometry. Thin layer radiochromatography was utilized for its quality control studies.
    PIM was derived successfully after the tosylation reaction. The radioiodination yield of PIM-TOS was over 85%.
    In the current study, radioiodination potential of PIM with 131I, as a potential theranostic hypoxia agent was investigated. Further experimental studies should be performed for developing a novel hypoxia probe including theranostics approaches.
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  • 文章类型: Journal Article
    Differentiation of the isomeric haloanilines still remains a challenging and necessary analytic task due to their identical retention time in chromatography and similar mass spectra. In this work, p-tosylation of haloanilines by reaction of haloanilines with p-toluenesulfonyl chloride resulted in the corresponding N-tosyl haloanilines. Fragmentation of protonated N-tosyl haloanilines in electrospray ionization tandem mass spectrometry (ESI-MS/MS) mainly resulted in tosyl cation, haloaniline radical cation, and halohydroxyaniline radical cation. The MS/MS of the three group isomeric derivatives showed significant difference in abundance distribution of these product ions, respectively. Theoretical calculations showed that the stability of the ion-neutral complex (INC) is a key factor influencing the relative intensity of the product ions. The three group isomeric derivatives were also separated by high performance liquid chromatograph (HPLC) at conventional conditions. p-Tosylation combined tandem MS (or HPLC) technique were carried out to realize the differentiation of isomeric haloanilines.
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  • 文章类型: Journal Article
    聚乙二醇(PEG)是一种线性聚合物,在化学制造中具有广泛的应用,药物开发和纳米技术。PEG衍生物越来越多地用于共价修饰小分子和肽类药物,以及生物活性纳米材料,以提高在生物血清中的溶解度,降低免疫原性,并增强药代动力学特征。在这里,我们提出了PEG官能化的机械化学程序的发展,而不需要本体溶剂,为现有的基于解决方案的PEG程序提供更清洁和更可持续的替代方案。本文提出的机械化学程序能够快速和无溶剂衍生PEG与甲苯磺酰基,溴化物,硫醇羧酸或胺官能团具有良好至定量的产率,并且没有聚合物链低聚,证明了该方法的多功能性。
    Poly(ethylene glycol) (PEG) is a linear polymer with a wide range of applications in chemical manufacturing, drug development and nanotechnology. PEG derivatives are being increasingly used to covalently modify small molecule and peptide drugs, as well as bioactive nanomaterials in order to improve solubility in biological serum, reduce immunogenicity, and enhance pharmacokinetic profiles. Herein we present the development of mechanochemical procedures for PEG functionalization without the need for bulk solvents, offering a cleaner and more sustainable alternative to existing solution-based PEG procedures. The herein presented mechanochemical procedures enable rapid and solvent-free derivatization of PEG with tosyl, bromide, thiol, carboxylic acid or amine functionalities in good to quantitative yields and with no polymer chain oligomerization, proving the versatility of the method.
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  • 文章类型: Journal Article
    The homogeneous tosylation of agarose was studied with respect to the effects of reaction parameters, such as reaction medium, time, and molar ratio, on the reaction course, the degree of substitution (DS) with tosyl/chloro deoxy groups, and the molecular structure. Tosyl agaroses (TOSA) with DS tosyl ≤ 1 .81 could be obtained in completely homogeneous reactions by using N,N-dimethylacetamide (DMA)/LiCl or 1,3-dimethyl-2-imidazolidinone (DMI) as solvents. The products were characterized by FT-IR and NMR spectroscopy and it was demonstrated that two types of substitution pattern can be achieved: (i) non-preferential substitution at position 6 of the 1 → 3-linked β-d-galactose unit (G-6) and position 2 of the 1 → 4-linked 3,6-anyhdro-α-L-galactose unit (LA-2) and (ii) regioselective tosylation at G-6, depending on whether the reaction is performed with or without LiCl. Finally, the nucleophilic displacement reaction of TOSA was studied using azide and ethylenediamine as representative nucleophiles. Novel deoxy-agarose derivatives were obtained that showed an interesting solubility behavior and will be used for creating functional polysaccharide materials.
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