Conformational Equilibria in Bimolecules of Carboxylic Acids: A Rotational Study of Fluoroacetic Acid–Acrylic Acid

2013 ◽  
Vol 4 (17) ◽  
pp. 2838-2842 ◽  
Author(s):  
Qian Gou ◽  
Gang Feng ◽  
Luca Evangelisti ◽  
Walther Caminati
1977 ◽  
Vol 55 (6) ◽  
pp. 1028-1038 ◽  
Author(s):  
Allan K. Colter ◽  
R. James Kersting

Rates of reaction of the five π donor acids indole-3-acrylic acid (IAA), indole-5-carboxylic acid (ICA), 3,4,5-trimethoxybenzoic acid (TMBA), 2,4-dihydroxybenzoic acid (DHBA), and 3,4,5-trihydroxybenzoic acid (THBA) with 4-chlorodiphenyldiazomethane (4-ClDDM) in ethanol at 30 °C were measured in the presence of the π acceptors 1,3,5-trinitrobenzene (TNB), benzotrifuroxan (BTF), and 1,2,4,5-tetracyanobenzene (TCNB) and in the absence of acceptor. For 12 of the 13combinations studied, added acceptor produced rate enhancements. The rate data were combined with independently-determined 1:1 acceptor – donor acid association constants to obtain second-order rate constants for reaction of the 1:1 acceptor – donor acid complexes. From the increase in the rate constant resulting from complexation, estimates of the increase in Ka(H2O, 25 °C) produced by complexation were obtained for 13 acceptor – donor acid combinations. Second-order rate constants for reaction of 4-ClDDM with 10 other carboxylic acids and p-toluenesulfonic acid in ethanol at 30°C were also measured and the pattern of reactivity shown to parallel very closely that of diphenyldiazomethane.


2020 ◽  
Vol 5 (1) ◽  
pp. 40-44
Author(s):  
Seema Pant

Two series of new 8-substituted-4-(4-tert-butylphenyl)-2,3-dihydro-1,5-benzothiazepine-2-carboxylic acids and 8-substituted-4-(4-acetamidophenyl)-2,3-dihydro-1,5-benzothiazepine-2-carboxylic acids have been synthesized by Michael condensation of 5-substituted-2-aminobenzenethiols with β-(4- tert-butylbenzoyl) acrylic acid or β-(4-acetamidobenzoyl) acrylic acid, in ethanol in acidic medium in a single step, in 58-64 % yield. The structures of the newly synthesized compounds were confirmed by their IR, 1H NMR and mass spectral analyses and micro analytical data. They were screened for antimicrobial activity, against the Gram-positive bacteria, Staphylococcus aureus, Gram-negative bacteria, Enterobacter cloacae and Escherichia coli, with respective reference compounds, vancomycin, polymyxin B, colistin-polymyxin B and against the fungus, Candida albicans with reference drug fluconazole. Most of the compounds showed activity against Staphylococcus aureus, Enterobacter cloacae and fungus Candida albicans, while none of the compounds showed activity against Escherichia coli.


2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Jindřiška Bočková ◽  
Lucy Vojtová ◽  
Radek Přikryl ◽  
Jan Čechal ◽  
Josef Jančář

AbstractA novel material for hard tissue implants has been prepared. The ultra-high molecular weight polyethylene (UHMWPE) was grafted with collagen I, to improve its biocompatibility with soft tissue in case of its usage in bone engineering. Before collagen immobilization, commercial grade UHMWPE was treated with air plasma to introduce hydroperoxides onto the surface and subsequently grafted with carboxylic acid to functionalize the surface. Acrylic acid and itaconic acid were used for surface functionalization. After graft polymerization of carboxylic acids, collagen was immobilized covalently through the amide bonds between residual amino and carboxyl groups in the presence of water-soluble carbodiimide/hydroxysuccinimide cross-linking system. Each step of modification was characterized using spectroscopic (EPR, ATR-FTIR, and XPS), microscopic (SEM and CLSM), and contact angle measurement methods. The experimental results showed that plasma treatment led to a generation of free radicals on the UHMWPE surface resulting in the formation of unstable hydroperoxides. These reactive species were used to graft unsaturated carboxylic acids onto UHMWPE. Consequently, collagen was grafted via the-NH2 and-COOH reaction. The obtained experimental data along with microscopic observations confirmed the success of graft poly-merization of itaconic as well as of acrylic acid and collagen immobilization onto the UHMWPE surface.


1970 ◽  
Vol 35 (4) ◽  
pp. 1080-1085 ◽  
Author(s):  
Irving. Listowsky ◽  
Gad. Avigad ◽  
Sasha. Englard

2012 ◽  
Vol 134 (46) ◽  
pp. 19281-19286 ◽  
Author(s):  
Gang Feng ◽  
Laura B. Favero ◽  
Assimo Maris ◽  
Annalisa Vigorito ◽  
Walther Caminati ◽  
...  

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