Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
Well-defined novel, linear, biodegradable, amphiphilic thermo-responsive ABA-type\ntriblock copolymers, poly[2-(2-methoxyethoxy) ethyl methacrylate-co-oligo(ethylene glycol)\nmethacrylate]-b-poly(�µ-caprolactone)-b-poly[2-(2-methoxyethoxy) ethyl methacrylate-co-oligo\n(ethylene glycol) methacrylate] [P(MEO2MA-co-OEGMA)-b-PCL-b-P(MEO2MA-co-OEGMA)] (tBPs),\nwere synthesized via a combination of ring-opening polymerization (ROP) of �µ-caprolactone\n(�µCL) and reversible addition-fragmentation chain transfer polymerization (RAFT) of MEO2MA\nand OEGMA comonomers. The chemical structures and compositions of these copolymers were\ncharacterized using Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic\nresonance (1H NMR). The molecular weights of the copolymers were obtained using gel permeation\nchromatography (GPC) measurements. Thermo-responsive micelles were obtained by self-assembly\nof copolymers in aqueous medium. The temperature sensitivity and micelllization behavior of\namphiphilic triblock copolymers solutions were studied by transmittance, fluorescence probe, surface\ntension, dynamic light scattering (DLS) and transmission electron microscopy (TEM). A hydrophobic\ndrug, anethole, was encapsulated in micelles by using the dialysis method. The average particle\nsizes of drug-loaded micelles were determined by dynamic light scattering measurement. In vitro,\nthe sustained release of the anethole was performed in pH 7.4 phosphate-buffered saline (PBS) at\ndifferent temperatures. Results showed that the triblock copolymerâ��s micelles were quite effective in\nthe encapsulation and controlled release of anethole. The vial inversion test demonstrated that the\ntriblock copolymers could trigger the sol-gel transition which also depended on the temperature, and\nits sol-gel transition temperature gradually decreased with increasing concentration. The hydrogel\nsystem could also be used as a carrier of hydrophobic drugs in medicine....
(âË?â??)-cis-N-Normetazocine represents a rigid scaffold able to mimic the tyramine moiety of\nendogenous opioid peptides, and the introduction of different N-substituents influences affinity and\nefficacy of respective ligands at MOR (mu opioid receptor), DOR (delta opioid receptor), and KOR\n(kappa opioid receptor). We have previously identified LP1, a MOR/DOR multitarget opioid ligand,\nwith an N-phenylpropanamido substituent linked to (âË?â??)-cis-N-Normetazocine scaffold. Herein, we\nreport the synthesis, competition binding and calcium mobilization assays of new compounds 10ââ?¬â??16\nthat differ from LP1 by the nature of the N-substituent. In radioligand binding experiments, the\ncompounds 10ââ?¬â??13, featured by an electron-withdrawing or electron-donating group in the para\nposition of phenyl ring, displayed improved affinity for KOR (Ki = 0.85ââ?¬â??4.80 Ã?¼M) in comparison to\nLP1 (7.5 Ã?¼M). On the contrary, their MOR and DOR affinities were worse (Ki = 0.18ââ?¬â??0.28 Ã?¼M and\nKi = 0.38ââ?¬â??1.10 Ã?¼M, respectively) with respect to LP1 values (Ki = 0.049 and 0.033 Ã?¼M). Analogous\ntrends was recorded for the compounds 14ââ?¬â??16, featured by indoline, tetrahydroquinoline, and\ndiphenylamine functionalities in the N-substituent. In calcium mobilization assays, the compound 10\nwith a p-fluorophenyl in the N-substituent shared the functional profile of LP1 (pEC50\nMOR = 7.01),\nalthough it was less active. Moreover, the p-methyl- (11) and p-cyano- (12) substituted compounds\nresulted in MOR partial agonists and DOR/KOR antagonists. By contrast, the derivatives 13ââ?¬â??15\nresulted as MOR antagonists, and the derivative 16 as a MOR/KOR antagonist (pKB\nMOR = 6.12\nand pKB\nKOR = 6.11). Collectively, these data corroborated the critical role of the N-substituent in\n(âË?â??)-cis-N-Normetazocine scaffold. Thus, the new synthesized compounds could represent a template\nto achieve a specific agonist, antagonist, or mixed agonist/antagonist functional profile....
The present work represents the synthesis, characterization, and antimicrobial studies of novel series of 2,4-bis(hydrazino)-6-\nsubstituted-1,3,5-triazine and their Schiff base derivatives. IR, NMR (1H and 13C), elemental analysis, and LC-MS characterized the\nprepared compounds.The biological activity of the target products was evaluated as well. Twenty-two of the prepared compounds\nwere selected according to their solubility in aqueous DMSO. Only eight compounds showed good activity against the selected\npathogenic bacteria and did not show antagonistic effect against fungus Candida albicans. Two compounds 4k and 5g have widerange\neffect presently in Gram-positive and Gram-negative bacteria while other compounds (4f, 4i, 4m, 5d, 6i, and 6h) showed\nspecific effect against theGram-negative orGram-positive bacteria.The minimuminhibitory concentration (MIC, ...
Four Zn(II) complexes containing a pyridyl triazine core (L1 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5ââ?¬Â²,5ââ?¬Â³-disulfonic acid\ndisodium salt and L2 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4ââ?¬Â²,4ââ?¬Â³-disulfonic acid sodium salt) were synthesized, and their\nchemical formulas were finalized as [Zn(L1)Cl2]Ã?·5H2OÃ?·ZnCl2 (1), [Zn(L1)2Cl2]Ã?·4H2OÃ?·2CH3OH (2), [Zn(L2)Cl2]Ã?·3H2OÃ?·CH3OH\n(3), and [Zn(L2)2Cl2] (4). The synthesized complexes are water soluble, making them good candidates for biological applications.\nAll four complexes have been characterized by elemental analysis and 1H NMR, IR, and UV-Vis spectroscopy. The IR stretching\nfrequency of NN and CN bonds of complexes 1ââ?¬â??4 have shifted to lower frequencies in comparison with free ligands, and\na bathochromic shift was observed in UV-Vis spectra of all four complexes. The binding studies of ligands and complexes 1ââ?¬â??4 with\nbovine serum albumin (BSA) resulted binding constants (Kb) of 3.09 Ã?â??104MâË?â??1, 12.30 Ã?â??104MâË?â??1, and 16.84 Ã?â??104MâË?â??1 for ferene,\ncomplex 1, and complex 2, respectively, indicating potent serum distribution via albumins....
The novel 3D edta-linked heterometallic complex [Sb2Er(edta)2(H2O)4]NO3Ã?·4H2O (H4edta ethylenediaminetetraacetic acid)\nwas synthesized and characterized by elemental analyses, single-crystal X-ray diffraction, powder X-ray diffraction (XRD), Fourier\ntransform infrared spectroscopy (FTIR), and thermal analysis.Thecomplex crystallizes in the monoclinic system with space group\nPm. In the complex, each erbium(III) ion is connected with antimony(III) ions bridging by four carboxylic oxygen atoms, and in\neach [Sb(edta)]âË?â?? anion, the antimony(III) ion is hexacoordinated by two nitrogen atoms and four oxygen atoms from the edta4âË?â??\nions, together with a lone electron pair at the equatorial position. The erbium(III) ion is octacoordinated by four oxygen atoms\nfrom four different edta4âË?â?? ions and four oxygen atoms from the coordinated water molecules. The carboxylate bridges between\nantimony and erbium atoms form a planar array, parallel to the (1 0 0) plane. There is an obvious weak interaction between\nantimony atom and oxygen atom of the carboxyl group from the adjacent layer. The degradation of the complex proceeds in\nseveral steps and the water molecules and ligands are successively emitted, and the residues of the thermal decomposition are\nantimonous oxide and erbium(III) oxide. The complex was evaluated for its antimicrobial activities by agar diffusion method, and\nit has good activities against the test bacterial organisms....
Loading....