scholarly journals In vitro enzymic hydrolysis of chlorogenic acids in coffee

2014 ◽  
Vol 59 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Joana Amarante da Encarnação ◽  
Tracy L. Farrell ◽  
Alexandra Ryder ◽  
Nicolai U. Kraut ◽  
Gary Williamson
Keyword(s):  
Chlorogenic Acids ◽  
Enzymic Hydrolysis ◽  
Hydrolysis Of

Covalent attachment of amino acids to casein. 1. Chemical modification and rates of in vitro enzymic hydrolysis of derivatives

1979 ◽  
Vol 27 (5) ◽  
pp. 1098-1104 ◽  
Author(s):  
Antoine J. Puigserver ◽  
Lourminia C. Sen ◽  
Elvira Gonzales-Flores ◽  
Robert E. Feeney ◽  
John R. Whitaker
Keyword(s):  
Amino Acids ◽  
Chemical Modification ◽  
Covalent Attachment ◽  
Enzymic Hydrolysis ◽  
Hydrolysis Of

Effect of 2,4-D on the Hydrolysis of Diclofop-Methyl in Wild Oat (Avena fatua)

Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 725-729 ◽  
Author(s):  
B. D. Hill ◽  
B. G. Todd ◽  
E. H. Stobbe
Keyword(s):  
Enzyme Preparation ◽  
Avena Fatua ◽  
Wild Oat ◽  
Enzymic Hydrolysis ◽  
Standard Assay ◽  
Rate Of Hydrolysis ◽  
Dichlorophenoxy Acetic Acid ◽  
Hydrolysis Of ◽  
Assay Conditions

The basis for 2,4-D [(2,4-dichlorophenoxy)acetic acid] antagonism of diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy) phenoxy] propanoate} toxicity to wild oat (Avena fatuaL.) was investigated by studying changes in the metabolism of diclofop-methyl in vitro. An esterase from wild oat, which hydrolyzes diclofop-methyl to the acid diclofop, was extracted, partially purified, and the reaction characterized. The rate of hydrolysis of14C-diclofop-methyl was 0.14 ηmoles/2 h at standard assay conditions of 0.25 mg lyophilized enzyme preparation (19.6% protein) in 0.1 ml phosphate buffer (0.1 M, pH 7.0), substrate 5 μM. The addition of 2,4-D to this reaction did not inhibit14C-diclofop formation. Higher levels of 2,4-D stimulated enzymic hydrolysis.14C-diclofop-methyl was rapidly metabolized to14C-diclofop and polar14C-conjugates when vacuum-infiltrated into wild oat leaf segments. The addition of 2,4-D caused small increases in the rates of both14C-diclofop-methyl de-esterification and14C-diclofop conjugation. It is concluded that 2,4-D does not inhibit the in vitro de-esterification of diclofop-methyl.

Dependence of in vitro Enzymic Hydrolysis of Alkyl(2-benzoyloxyethyl)dimethylammonium Bromides on the Alkyl Length

1998 ◽  
Vol 63 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Eva Olaszová ◽  
Ingrid Paulíková ◽  
Otto Helia ◽  
Emil Švajdlenka ◽  
Ferdinand Devínský ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Alkyl Chain ◽  
Ammonium Nitrogen ◽  
Acid Formation ◽  
Ester Bond ◽  
Enzymic Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Alkyl Length

Microsomal esterases were used in the study of the in vitro enzymic hydrolysis of the ester bond in alkyl(2-benzoyloxyethyl)dimethylammonium bromides. These compounds are potential "soft" disinfectants, easily biodegradable to nontoxic biologically inactive hydrolytic products, namely substituted choline and benzoic acid. Formation of the latter product was used to monitor the kinetics of the reaction. It has been found that the rate of enzymic hydrolysis is substantially influenced by different length of the alkyl chain on the ammonium nitrogen. At the same time, interspecies (rat-mouse) and interorgan (liver-kidney) variability has been observed.

Enzymic Hydrolysis of Stilbestrol Diphosphate in vitro and in vivo.

1961 ◽  
Vol 106 (2) ◽  
pp. 327-330 ◽  
Author(s):  
W. Johnson ◽  
R. Jasmin ◽  
G. Corte
Keyword(s):  
Enzymic Hydrolysis ◽  
Hydrolysis Of

ChemInform Abstract: Dependence of in vitro Enzymic Hydrolysis of Alkyl(2-benzoyloxyethyl)dimethylammonium Bromides on the Alkyl Length.

ChemInform ◽  
2010 ◽  
Vol 29 (25) ◽  
pp. no-no
Author(s):  
E. OLASZOVA ◽  
I. PAULIKOVA ◽  
O. HELIA ◽  
E. SVAJDLENKA ◽  
F. DEVINSKY ◽  
...  
Keyword(s):  
Enzymic Hydrolysis ◽  
Hydrolysis Of ◽  
Alkyl Length

scholarly journals SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO

1932 ◽  
Vol 15 (5) ◽  
pp. 491-495 ◽  
Author(s):  
J. M. Nelson ◽  
Elizabeth T. Palmer ◽  
B. G. Wilkes
Keyword(s):  
Yeast Cells ◽  
Enzymic Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Live Yeast

1. A method is given whereby the course of hydrolysis of sucrose by live yeast cells may be followed with precision equal to that found when invertase solutions prepared from autolyzed yeast are used to cause inversion. 2. The practical value of the equation of Nelson and Hitchcock as a means of following the course of enzymic hydrolysis of sucrose is hereby extended. 3. The inversion of sucrose by live yeast cells and by extracted invertase has been quantitatively compared. 4. The course of hydrolysis of sucrose by the invertase of Fleischmann's yeast has been found to be identical in vivo and in vitro.

Total Synthesis and Antibacterial Screening of (±)-6,8-Dihydroxy-3- undecyl-3,4-dihydroisochromen-1-one: A Structural Analogue of Metabolites from Ononis natrix

2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Structural Analog ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Antibacterial Screening ◽  
Maximum Inhibition ◽  
Bacillus Subtilus ◽  
Hydrolysis Of ◽  
Direct Condensation

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.

Studies on the mechanism of acute inhibition of thyroglobulin hydrolysis by iodine

1985 ◽  
Vol 108 (4) ◽  
pp. 511-517 ◽  
Author(s):  
Nandalal Bagchi ◽  
Birdie Shivers ◽  
Thomas R. Brown
Keyword(s):  
Time Course ◽  
Period 2 ◽  
Iodotyrosine Deiodinase ◽  
Rate Of Hydrolysis ◽  
Underlying Mechanisms ◽  
Excess Iodide ◽  
Sites Of Action ◽  
Hydrolysis Of

Abstract. Iodine in excess is known to acutely inhibit thyroidal secretion. In the present study we have characterized the time course of the iodine effect in vitro and investigated the underlying mechanisms. Labelled thyroid glands were cultured in vitro in medium containing mononitrotyrosine, an inhibitor of iodotyrosine deiodinase. The rate of hydrolysis of labelled thyroglobulin was measured as the proportion of labelled iodotyrosines and iodothyronines recovered at the end of culture and was used as an index of thyroidal secretion. Thyrotrophin (TSH) administered in vivo acutely stimulated the rate of thyroglobulin hydrolysis. Addition of Nal to the culture medium acutely inhibited both basal and TSH-stimulated thyroglobulin hydrolysis. The effect of iodide was demonstrable after 2 h, maximal after 6 h and was not reversible upon removal of iodide. Iodide abolished the dibutyryl cAMP induced stimulation of thyroglobulin hydrolysis. Iodide required organic binding of iodine for its effect but new protein or RNA synthesis was not necessary. The inhibitory effects of iodide and lysosomotrophic agents such as NH4C1 and chloroquin on thyroglobulin hydrolysis were additive suggesting different sites of action. Iodide added in vitro altered the distribution of label in prelabelled thyroglobulin in a way that suggested increased coupling in the thyroglobulin molecule. These data indicate that 1) the iodide effect occurs progressively over a 6 h period, 2) continued presence of iodide is not necessary once the inhibition is established, 3) iodide exerts its action primarily at a post cAMP, prelysosomal site and 4) the effect requires organic binding of iodine, but not new RNA or protein synthesis. Our data are consistent with the hypothesis that excess iodide acutely inhibits thyroglobulin hydrolysis by increasing the resistance of thyroglobulin to proteolytic degradation through increased iodination and coupling.

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