scholarly journals Symmetrical and unsymmetrical α,ω-nucleobase amide-conjugated systems

2010 ◽  
Vol 6 ◽  
Author(s):  
Sławomir Boncel ◽  
Maciej Mączka ◽  
Krzysztof K K Koziol ◽  
Radosław Motyka ◽  
Krzysztof Z Walczak
Keyword(s):  
Physicochemical Properties ◽  
Carboxylic Group ◽  
Aromatic Diamines ◽  
Conjugated Systems ◽  
Michael Adducts ◽  
Carboxylic Groups ◽  
A Subunit ◽  
Target Molecules ◽  
Hydrolysis Of ◽  
Substituted 1

We present the synthesis and selected physicochemical properties of several novel symmetrical and unsymmetrical α,ω-nucleobase mono- and bis-amide conjugated systems containing aliphatic, aromatic or saccharidic linkages. The final stage of the synthesis involves condensation of a subunit bearing carboxylic group with an amine subunit. 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) was found to be a particularly effective condensing agent. The subunits containing carboxylic groups were obtained by acidic hydrolysis of N-1 Michael adducts of uracils or N-9 Michael adducts of 6-chloropurine with methyl acrylate. The amines used were aliphatic/aromatic diamines, adenine, 5-substituted 1-(ω-aminoalkyl)uracils and 5′-amino-2′,5′-dideoxythymidine. The title compounds may find application as antiprotozoal agents. Moreover, preliminary microscopy TEM studies of supramolecular behaviour showed that target molecules with bolaamphiphilic structures were capable of forming highly ordered assemblies, mainly nanofibres.

Introduction of chlorogenic acid during extrusion affects the physicochemical properties and enzymatic hydrolysis of rice flour

2021 ◽  
Vol 116 ◽  
pp. 106652
Author(s):  
Yuxue Zheng ◽  
Xiuxiu Yin ◽  
Xiangli Kong ◽  
Shiguo Chen ◽  
Enbo Xu ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Physicochemical Properties ◽  
Chlorogenic Acid ◽  
Rice Flour ◽  
Hydrolysis Of

An Unequivocal Synthesis of 4-Amino-1,5,6,8-tetrahydropyrido[2,3-d]pyrimidine-2,7-diones and 2-Amino-3,5,6,8-tetrahydropyrido[2,3-d]pyrimidine-4,7-diones

1996 ◽  
Vol 61 (6) ◽  
pp. 901-909 ◽  
Author(s):  
José I. Borrell ◽  
Jordi Teixidó ◽  
Blanca Martínez-Teipel ◽  
Blanca Serra ◽  
Josep Lluís Matallana ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Unsaturated Ester ◽  
Michael Adducts ◽  
Hydrolysis Of

An unequivocal set of procedures for the synthesis of 4-amino-1,5,6,8-tetrahydropyrido[2,3-d]pyrimidine-2,7-diones (7) and 2-amino-3,5,6,8-tetrahydropyrido[2,3-d]pyrimidine-4,7-diones (8), in a maximum of four steps from an α,β-unsaturated ester 1, is reported. Thus, the acid hydrolysis of the 2,4-diaminopyrido[2,3-d]pyrimidines 3 yields the 4-amino-2-oxopyrido[2,3-d]pyrimidines 7 while the cyclization of the Michael adducts 9 (formed by reaction of 1 and methyl cyanoacetate) with guanidine affords the corresponding 2-amino-4-oxopyrido[2,3-d]pyrimidines 8. Both isomers were also obtained by hydrolysis of the 4-amino-2-bromo- and 2-amino-4-bromo-5,6-dihydropyrido[2,3-d]pyrimidin-7(8H)-ones 5 and 6, respectively.

scholarly journals Acid Hydrolysis of Bromazepam Catalyzed by Micelles, Reverse Micelles, and Microemulsions

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Ferdousi Begum ◽  
M. Yousuf A. Mollah ◽  
M. Muhibur Rahman ◽  
Md. Abu Bin Hasan Susan
Keyword(s):  
Physicochemical Properties ◽  
Acid Hydrolysis ◽  
Reverse Micelles ◽  
Cetyltrimethylammonium Bromide ◽  
Order Rate Constant ◽  
Excellent Correlation ◽  
Initial Decrease ◽  
Droplet Sizes ◽  
Kinetics Of ◽  
Hydrolysis Of

Kinetics of the acid hydrolysis of bromazepam (Bz) has been investigated in micelles, reverse micelles, and microemulcions of cetyltrimethylammonium bromide (CTAB) by spectrophotometric method. The rate of the acid hydrolysis of Bz was found to be enhanced both below and above the critical micelle concentration (CMC) of CTAB in aqueous solution. The pseudo-first-order rate constant (k′) shows an initial decrease for both low and high H+concentrations. With further increase in [CTAB], at low [H+], thek′attains an almost constant value, while, at high [H+], thek′passes through a maximum and then decreases. The kinetic data for catalysis by micelles of CTAB was interpreted with the pseudophase ion exchange (PIE) model. In CTAB/cyclohexane/1-butanol/water microemulsions, as the water to surfactant ratio (wo) increases, the physicochemical properties and droplet sizes of microemulsions significantly change and distinct changes in reaction environment can be marked. The rate of the hydrolysis reaction exhibits excellent correlation with the physicochemical properties and droplet sizes of the microemulsions and reverse micelles of CTAB. At [H+] = 0.001 M, in reverse micelles and microemulsions of CTAB, thek′of the acid hydrolysis of Bz decreases sharply followed by a slight increase with increasingwo.

The a subunit asymmetry dictates the two opposite rotation directions in the synthesis and hydrolysis of ATP by the mitochondrial ATP synthase

2015 ◽  
Vol 84 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Salvatore Nesci ◽  
Fabiana Trombetti ◽  
Vittoria Ventrella ◽  
Alessandra Pagliarani
Keyword(s):  
Atp Synthase ◽  
Mitochondrial Atp Synthase ◽  
A Subunit ◽  
Hydrolysis Of

Amorphous Calcium Phosphate Based Polymeric Composites: Effects of Polymer Composition and Filler's Particle Size on Composite Properties

2005 ◽  
Vol 284-286 ◽  
pp. 737-740 ◽  
Author(s):  
Drago Skrtic ◽  
S.Y. Lee ◽  
Joseph M. Antonucci ◽  
D.W. Liu
Keyword(s):  
Particle Size ◽  
Calcium Phosphate ◽  
Physicochemical Properties ◽  
Amorphous Calcium Phosphate ◽  
Fine Tuning ◽  
Polymer Composition ◽  
Ion Release ◽  
The Matrix ◽  
Carboxylic Groups ◽  
Composite Properties

This study explores how a) the resin grafting potential for amorphous calcium phosphate (ACP) and b) particle size of ACP affects physicochemical properties of composites. Copolymers and composites were evaluated for biaxial flexure strength (BFS), degree of vinyl conversion (DC), mineral ion release and water sorption (WS). Milled ACP composites were superior to unmilled ACP composites and exhibited 62 % and 77 % higher BFS values (dry and wet state, respectively). The average DC of copolymers 24 h after curing was 80 %. DC of composites decreased 10.3 % for unmilled Zr-ACP and 4.6 % for milled Zr-ACP when compared to the corresponding copolymers. The WS increased as follows: copolymers < milled Zr-ACP composites < unmilled Zr-ACP composites. The levels of Ca and PO4 released from both types of composites increased with the increasing EBPADMA/TEGDMA ratio in the matrix. They were significantly above the minimum necessary for the redeposition of HAP to occur. No significant consumption of released calcium by the carboxylic groups of methacryloxyethyl phtahalate (MEP) occurred at a mass fraction of 2.6 % of MEP in the resin. Improvements in ACP composite’s physicochemical properties are achieved by fine tuning of the resin and improved ACP’s dispersion within the polymer matrix after ball-milling.

Sign in / Sign up

Export Citation Format

Share Document