5396-24-7Relevant academic research and scientific papers
A study of modified betaines as cryoprotective additives
Lloyd,Olliff,Rutt
, p. 704 - 707 (1994)
Glycinebetaine and N-modified betaines have been previously shown to be effective at reducing leakage from liposomes on freeze-thaw procedures. This study involved the preparation of a series of other modified betaines and the comparison of their abilities to reduce leakage from frozen multilamellar liposomes. All the compounds investigated, with the exception of the octyl ester of betaine, reduced the degree of leakage on freezing and thawing with additive concentrations up to 0.6 M. The betaine esters were less effective than betaine as cryoprotective additives and caused an increase in the leakage from unfrozen liposomes. Taurinebetaine, a sulphobetaine, was also less effective at reducing leakage on freezing than betaine and again increased leakage from unfrozen liposomes. Increasing the number of methylene groups between the carboxylate group and the nitrogen improved the ability to reduce leakage, particularly at lower additive concentrations.
Discovery of novel triazolophthalazine derivatives as DNA intercalators and topoisomerase II inhibitors
Sakr, Helmy,Ayyad, Rezk R.,El-Helby, Ali A.,Khalifa, Mohamed M.,Mahdy, Hazem A.
, (2021/02/16)
A new series of triazolophthalazine derivatives was designed and synthesized as topoisomerase II (Topo II) inhibitors and DNA intercalators. The synthesized derivatives were evaluated in vitro for their cytotoxic activities against three human cancer cell lines: HepG2, MCF-7, and HCT-116 cells. Compound IXb was the most potent counterpart with IC50 values of 5.39 ± 0.4, 3.81 ± 0.2, and 4.38 ± 0.3 μM, as it was about 1.47, 1.77, and 1.19 times more active than doxorubicin (IC50 = 7.94 ± 0.6, 6.75 ± 0.4, and 5.23 ± 0.3 μM) against HepG2, MCF-7, and HCT-116 cells, respectively. Additionally, the binding affinity of the synthesized compounds toward the DNA molecule was assessed using the DNA/methyl green assay. Compound?IXb showed an excellent DNA binding affinity with an IC50 value of 27.16 ± 1.2 μM, which was better than that of the reference drug doxorubicin (IC50 = 31.02 ± 1.80 μM). Moreover, compound IXb was the most potent member among the tested compounds when investigated for their Topo II inhibitory activity. Furthermore, compound IXb induced apoptosis in HepG2 cells and arrested the cell cycle at the G2/M phase. Additionally, compound IXb showed Topo II poisoning effects at 2.5 μM and Topo II catalytic inhibitory effects at 5 and 10 μM. Finally, molecular docking studies were carried out against the DNA–Topo II complex and DNA, to investigate the binding patterns of the designed compounds.
New Diesters Derived from Piperine: In silico Study and Evaluation of Their Antimicrobial Potential
Barbosa-Filho, José M.,Brand?o, Maria Cláudia R.,Lima, Edeltrudes O.,Lira, Bruno F.,Neto, Hermes D.,Souza, Helivaldo D. S.,Trindade, Emmely O.,de Athayde-Filho, Petr?nio F.
, p. 1668 - 1678 (2020/10/09)
Piperine, previously extracted from black pepper (Piper nigrum L.), was used as a precursor for the synthesis of twelve new diester derivatives. The final products were obtained through the bimolecular nucleophilic substitution reaction (SN2) of the alkyl 2-chloroacetates and the salt of piperic acid, obtained from the basic hydrolysis of piperine. The compounds were synthesized with yields of 55-84% and characterized by infrared spectroscopy and 1H and 13C nuclear magnetic resonance. The evaluation of the compounds’ potential as new drug candidates was done through an in silico study of ADME properties (absorption, distribution, metabolization and excretion) and evaluation of antimicrobial activity against bacterial strains (Staphylococcus aureus and Pseudomonas aeruginosa), yeasts (Candida albicans and Candida tropicalis) and filamentous fungi (Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger). The in silico study showed that the compounds were good drug candidates and antimicrobial evaluation demonstrated that 9 of the 12 compounds exhibited a minimum inhibitory concentration (MIC) ranging 1024-256 μg mL?1
Synthesis, in silico Study and Antimicrobial Evaluation of New Diesters Derived from Phthaloylglycine
Alves, Francinara S.,Barbosa-Filho, José M.,Cordeiro, Laísa V.,Huang, Min-Fu N.,Lima, Edeltrudes O.,Neto, Hermes Diniz,Souza, Helivaldo D. S.,Trindade, Emmely O.,de Athayde-Filho, Petr?nio F.,de Lima, Priscila S. V.,de Oliveira, Rafael F.,de Sousa, Abra?o P.
, p. 953 - 962 (2020/10/14)
New diesters derived from phthaloylglycine (7a-7i) were synthesized and their structures characterized by infrared, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The compounds were evaluated in an in silico study, which demonstrated positive features indicating a possible drug candidate. The diesters showed antifungal activity ranging from moderate to strong against strains of Candida. Compounds 7a, 7b, 7c, 7e and 7i had a moderate minimum inhibitory concentration (MIC) of 1024 μg mL?1 against all fungal strains, while 7h showed a very good MIC of 256 μg mL?1 against Candida albicans, Candida parapsilosis and Candida krusei and 64 μg mL?1 against Candida tropicalis. However, only 7h and 7i were able to inhibit bacterial growth of strains of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli with an MIC of 1024 μg mL?1
Preparation method for 2,4-dichlorophenoxyacetic acid
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Paragraph 0063; 0064, (2018/09/08)
The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: a) reactinghalogenated acetate with 2,4-dichlorophenolate in the presence of a phase-transfer catalyst so as to obtain 2,4-dichlorophenoxyacetate; and b) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, oil-phase halogenated acetate reacts with 2,4-dichlorophenolate under the action of the phase-transfer catalyst to prepare 2,4-dichlorophenoxyacetate, and then 2,4-dichlorophenoxyacetate is hydrolyzed to obtain 2,4-dichlorophenoxyacetic acid and corresponding alcohols. Under the action of the phase-transfer catalyst, few hydrolysis by-products are produced during a reaction, fast reaction speed and high conversion rate and yield are obtained, and the amount of produced waste water is low; so industrial application of the preparation method can be easily implemented.
A method for preparing 2, 4 - dichlorophenoxyacetic acid (by machine translation)
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Paragraph 0038; 0039, (2018/09/08)
The invention provides a 2, 4 - dichlorophenoxyacetic acid preparation method, comprises the following steps: A) halogenated acetate with 2, 4 - dichlorophen salt reaction, to obtain 2, 4 - dichlorophenoxy ester; B) 2, 4 - dichlorophenoxy ester under the effects of catalyst hydrolysis reaction, to obtain 2, 4 - dichloro acid; said catalyst is selected from a polyether, a crown ether, quaternary ammonium salt, tertiary amine, [...], pyridine, titanate, inorganic acid, in organic acid one or more. The invention by halogenated acetate with 2, 4 - dichlorophen salt obtained by reaction of 2, 4 - dichlorophenoxy ester, and then in particular under the action of catalyst by hydrolysis reaction of the 2, 4 - dichloro acid. The invention specific reaction line combined with a specific catalyst such that the final preparation to obtain 2, 4 - dichlorophenoxyacetic acid purity and yield is relatively high, few by-products, the reaction route is simple, and is favorable for application. (by machine translation)
Preparation method for 2,4-dichlorophenoxyacetic acid
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Paragraph 0048; 0049, (2018/09/08)
The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting C2 or above-C2 alcohol with halogenated acetic acid soas to obtain halogenated acetate; B) reacting halogenated acetic acid with 2,4-dichlorophenolate so as to obtain 2,4-dichlorophenoxyacetate; and C) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, C2 or above-C2 alcohol reacts with halogenated acetic acid to obtain a halogenated acetate intermediate, the intermediate has good stability, few reaction by-products are produced, and high yield is realized; then the intermediate further reacts with 2,4-dichlorophenolate to obtain 2,4-dichlorophenoxyacetate; and finally, 2,4-dichlorophenoxyacetate is hydrolyzed to obtain 2,4-dichlorophenoxyacetic acid. Through a specific reaction route of the invention, the finally prepared 2,4-dichlorophenoxyacetic acid has high purity and yield, few by-products are produced, the reaction route is simple, and the application of the preparation method is facilitated.
A method for esterification reaction rate prediction of aliphatic monocarboxylic acids with primary alcohols in 1,4-dioxane based on two parametrical taft equation
Vojtko, Jan,Tomcik, Peter
, p. 189 - 196 (2014/02/14)
Esterification reaction rates of aliphatic monocarboxylic acids with primary alcohols in 1,4-dioxane as inert solvent were investigated. Acids were esterified with 1-propanol and alcohols with acetic acid as model reactants at a constant temperature of 60°C, at a fixed ionic strength and pH in a batch reactor with a constant volume. For evaluation of reaction rates, an exact kinetic equation for the equilibrium reaction was applied. Under these conditions and for low reactants, concentrations reaction rate depends only on the structure of reactants and, therefore, can be predicted by a correlation equation with two Taft coefficients (inductive and steric effects). From these equations, it is possible to estimate the esterification reaction rate constant for other acid-alcohol pairs. This methodology may also be suitable for other kinetic systems measured under comparable experimental conditions.
A simple criterion for gas chromatography/mass spectrometric analysis of thermally unstable compounds, and reassessment of the by-products of alkyl diazoacetate synthesis
Kornilova, Tatiana A.,Ukolov, Anton I.,Kostikov, Rafael R.,Zenkevich, Igor G.
, p. 461 - 466 (2013/03/14)
Rationale: A principal limitation of gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) is the thermal instability of analytes. We propose that the injector and column temperatures should not exceed the atmospheric pressure boiling point, without decomposition, of the highest homologue of the series being analyzed, instead of the time-consuming procedure of obtaining chromatograms using different temperatures. Methods: A series of thermally unstable diazocarbonyl compounds, alkyl diazoacetates (predicted limit of stability approx. 140 °C, the boiling point of ethyl diazoacetate), was selected for GC/MS analysis using standard equipment. Different GC separation conditions were selected so that the retention temperatures of target compounds were both below and above 140°C. Results: Analyzing alkyl diazoacetates within their thermal stability range permitted reanalysis of their typical synthesis by-products. No dialkyl fumarate or maleate impurities, principal decomposition products which have often been reported previously, were found. Instead, alkyl esters of glycolic acid nitrate, O2NOCH 2CO2R, and 'pseudo-dimeric' products, ROCO[C 2H3NO]CO2R, were discovered for the first time. Conclusions: Avoiding the decomposition of thermally unstable organic compounds during GC and/or GC/MS analysis requires estimating their degradation temperature limits. This limit can be estimated as being equal to the atmospheric pressure boiling point of the highest homologue in the homologous series under consideration that does not decompose on boiling. Copyright
Specific esterase activity of subtilisin toward esters of α-haloacids
Pugniere,Juan, C. San,Previero
, p. 4883 - 4886 (2007/10/02)
Esters of α-haloacids are specific substrates for subtilisin which catalyses their hydrolysis in aqueous media. The same esters undergo transesterifications in organic solvents in the presence of subtilisin immobilized on an alumina-phosphate complex.
