Synthesis and comparative antibacterial studies of some benzylidene monosaccharide benzoates |
Author : Mohammed Matin, M.M.H. Bhuiyan, Md. Hossain, Mohammad Or Roshid |
Abstract | Full Text |
Abstract :Some 4,6-O-benzylidene protected 2,3-di-O-benzoates of methyl a-D-glucopyranoside and methyl a-D-mannopyranoside were prepared. All the compounds (1-7) were screened for in vitro antibacterial activity study against ten human pathogenic bacteria. The study revealed that the benzoylated mannopyranosides (5-7) are more prone towards antibacterial functionalities than that of the glucopyranosides (2-3). |
|
Synthesis and antioxidant activity of some novel derivatives of bis-2-azetidinones and bis-4-thiazolidinones |
Author : Avinash Shinde, Sainath Zangade, Shivaji Chavan, Sachin Tiwde |
Abstract | Full Text |
Abstract :In present study, several bis-2-azetidinones 2a-g and bis-4-thiazolidinones 3a-g have been synthesized from ethylenediaminebis-Schiff bases using conventional as well as microwave techniques. The newly synthesized compounds were established on the basis of spectroscopic techniques. Further, all compounds were screened for antioxidant activity; most of the titled compounds show potent activity. |
|
COPPER OCTOATE: A COMMERCIALLY AVAILABLE AND COST-EFFECTIVE HOMOGENEOUS CATALYST FOR THE FACILE SYNTHESIS OF 2,2’-ARYLMETHYLENEBIS(3-HYDROXY-5,5-DIMETHYL-2-CYCLOHEXENE-1-ONES) |
Author : Rahim Hekmatshoar, Mojgan Kargar, AbdolJalil Mostashari, Zahra Hashemi, Fereshteh Goli, Seyedehfarnoush Mousavizadeh |
Abstract | Full Text |
Abstract :A practical and convenient approach for the synthesis of 2,2’-arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-ones) was presented using copper octoate as a homogeneous catalyst. Copper octoate as an eco-friendly, low cost, and commercially available catalyst, reduced reaction times effectively to (16-50 min) while the reaction profiles were absolutely clean and no side products including dehydrated xanthene heterocycle were detected. Pure target compounds were obtained in very good to excellent yields (83-91%) via straightforward work-up procedure. The catalyst was recycled in the form of solution, up to four times, with no noticeable drop in activity. |
|
Synthesis and characterization of near-IR absorbing metal-free and zinc(II) phthalocyanines modified with aromatic azo groups |
Author : Mukaddes Özçesmeci |
Abstract | Full Text |
Abstract :Metal-free and zinc(II) phthalocyanine complexes bearing peripheral (E)-4-((2-hydroxynaphthalen-1-yl)diazenyl) units have been synthesized. Novel phthalonitrile derivative required for the preparation of phthalocyanine complexes was prepared by coupling 4-aminophthalonitrile and 2-naphthol. The structures of these new compounds were characterized by using elemental analyses, proton nuclear magnetic resonance, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, fluorescence spectroscopy and mass spectrometry. In the UV-Vis spectra a broad absorption band appears for phthalocyanine complexes at around 450–500 nm resulting from azo-group introduced onto the phthalocyanine ring. The photophysical properties of metal-free and zinc(II) phthalocyanines were studied in tetrahydrofuran. |
|
Theoretical Investigations for the Behavior of Hydrotropes in Aqueous Solution |
Author : Rabah Khalil, Al-hakam Zarari |
Abstract | Full Text |
Abstract :The presented paper introduces an attempt for finding a theoretical model capable for describing the critical aggregation concentration (cac) for some hydrotropes (a series of sodium-p-n-alkylbenzoates, n=0-8). Such a proposal was carried out through theoretical calculations based on density functional theory (DFT) for estimating some physical properties which might be helpful for supporting the recent published report as all of these hydrotropes are considered as surfactant like (see doi: 10.1021/la2025846). The estimated physical properties can be divided to three classes according to their effect: steric properties such as volume and surface area, electronic properties such as polarizability, and hydrophobic properties such as log P which represents the ratio of concentrations of a compound in two phases of octanol and water. The results show that both steric and hydrophobic properties play major roles in predicting the cac for the presented hydrotropes. The best model was found between cac and tail polarizability (PT) according to the following relation: cac = 1.52-1.09log PT ; with r2 equal to 0.96, S.E equal to 0.026M and significant cross validation correlation coefficient (0.943). A unique feature of the presented model is containing only one descriptor with excellent statistical parameters. This actually supports the recent (above mentioned) published results of that all of these hydrotropes can be considered as surfactant-like. The suggested models were applied to some randomly selected surfactants with reasonable results. The results are generally suggesting for the possibility of estimating the cac or critical micelle concentration (cmc) for amphiphilic molecules using computational chemistry software. |
|