نتایج جستجو برای: assisted acids
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OBJECTIVE Assisted reproductive techniques are useful in helping infertile couples achieve successful conception. Initial studies have shown that sperm cryopreservation, one step in assisted reproduction, causes a dramatic reduction in sperm quality. This has been attributed to, among other things, free radical activities. The aim of the present study was to minimize this oxidative attack by ad...
The N-acylation of ethanolamine (2) with various fatty acids 1a-d and esters of fatty acids 1e-h using Candida antarctica B lipase (Novozym((R)) 435) are described and optimum conditions for selective N-acylation rather than O-acylation are also discussed. Microwave assisted solution phase, solid supported and conventional methods were investigated and results were compared. There is a synergy ...
Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the conversion process. They are the reversible imine formation, the internal resonance assisted Hydrogen Bonding (RAHB) and the additional hydrogen bonds between the amino acids and the...
In this work, we report the formation of a family of organic micro-/nano-pillars prepared from surface-assisted self-assembly processes and factors controlling the growth of the pillars. These acids include cyanuric acid (CA), 1,3,5-benzenetricarboxylic acid (TMA), 1,2,4,5-benzenetetracarboxylic acid (TA) and 3,4,9,10-perylenetetracarboxylic acid (PTA). Aqueous solutions mixed with acids and me...
Background: Sperm cryopreservation has been associated with over production of reactive oxygen species (ROS). Buffalo spermatozoa are susceptible to ROS inducing damages due to insufficient level of cytoplsmic antioxidant along with high amount of poly unsaturated fatty acids composition in membrane structure. Therefore, appropriate antioxidant in buffalo cryopreservation extender would reduce ...
Ultrasonic-assisted extraction was employed for highly efficient separation of aroma oil from raspberry seeds. A central composite design with two variables and five levels was employed and effects of process variables of sonication time and extraction temperature on oil recovery and quality were investigated. Optimal conditions predicted by response surface methodology were sonication time of ...
We report here the discovery and development of boron-assisted oxime formation as a powerful connective reaction for chemical biology. Oximes proximal to boronic acids form in neutral aqueous buffer with rate constants of more than 10 M 1 s , the largest to date for any oxime condensation. Boron's dynamic coordination chemistry confers an adaptability that seems to aid a number of elementary st...
The aim of present study was to compare the effects of ultrasound-assisted and microwave-assisted extraction with solvent extraction method on antioxidant activities of jujube (Ziziphus mauritiana Lam.) leaf extracts in stability of sunflower oil during deep frying. The antioxidant activities of the extracts were evaluated by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH˙) radical scavenging and β...
Matrix-assisted laser desorption/ionization (MALDI), a soft ionization method, coupling with time-of-flight mass spectrometry (TOF MS) has become an indispensible tool for analyzing macromolecules, such as peptides, proteins, nucleic acids and polymers. However, the application of MALDI for the analysis of small molecules (<700 Da) has become the great challenge because of the interference from...
The work described here is based on a comparative study of carotenoids and fatty acids extracted from Synechococcus sp. with 1) pure supercritical CO2; 2) CO2 with 5% (v/v) ethanol as cosolvent; and 3) ultrasound-assisted extraction using N, N-dimethylformamide (DMF). The effects of extraction conditions on supercritical CO2 extraction with and within cosolvent were analyzed at different temper...
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