The hydrolytic activity of L-ascorbic acid

1976 ◽  
Vol 54 (11) ◽  
pp. 1018-1021
Author(s):  
J. N. Kanfer ◽  
C. H. Spielvogel
Keyword(s):  
Ascorbic Acid ◽  
Oleic Acid ◽  
Hydrolytic Activity ◽  
In Vitro Systems ◽  
Hydrolysis Of

The ability of L-ascorbic acid to catalyze the liberation of 4-methylumbelliferone from 4-methylumbelliferyl-β-D-N-acetylgiucosaminide, 4-methylumbelliferyl-β-D-glucuronide, 4-methlumbelliferyl-α-D-mannoside, and 4-methylumbelliferyl-β-D-galactoside is documented. There is an apparent metal and oxygen dependency. The cleavage of two lipids was shown in addition to the hydrolysis of these fluorogenic glycosides. Galactose was liberated from galactosyl-6-[3H]ceramide and oleic acid from cholesterol-[1-14C]oleate by L-ascorbic acid under conditions usually used for in vitro incubations. In common with most in vitro systems, only a small percentage of substrate was degraded.

scholarly journals DETERMINATION OF THE HYDROLYTIC ACTIVITY OF WHOLE SALIVA USING CHITOSAN ASCORBATE AS A SUBSTRATE

2018 ◽  
Vol XXIII ◽  
pp. 97-102
Author(s):  
Barbara Kochańska ◽  
Mirela Łukaszewska ◽  
Jolanta Ochocińska
Keyword(s):  
Ascorbic Acid ◽  
In Vitro Study ◽  
Hydrolytic Activity ◽  
Vitro Study ◽  
Whole Saliva ◽  
Unstimulated Whole Saliva

The aim of this work was to evaluate of hydrolytic activity of whole saliva using chitosan ascorbate as a substrate. In this aim, the concentrations of N-acetyl-D-glucosamine were determined in saliva before addition of chitosan ascorbate, directly after addition and during incubation with chitosan ascorbate by 20 hrs. In this in vitro study were used sterile chitosan ascorbate in the form of powder. Chitosan was obtained from krill chitin. The ratio of ascorbic acid to chitosan was 1:1. The unstimulated whole saliva showed the hydrolytic activity in the presence of the chitosan ascorbate as a substrate.

scholarly journals Metabolic Hydrolysis of Aromatic Amides in Selected Rat, Minipig, and Human In Vitro Systems

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Peter R. Bradshaw ◽  
Ian D. Wilson ◽  
Rachel Upcott Gill ◽  
Philip J. Butler ◽  
Clive Dilworth ◽  
...  
Keyword(s):  
In Vitro Systems ◽  
Hydrolysis Of

scholarly journals Identification of aSaccharomyces cerevisiaeGlucosidase That Hydrolyzes Flavonoid Glucosides

2011 ◽  
Vol 77 (5) ◽  
pp. 1751-1757 ◽  
Author(s):  
Sabine Schmidt ◽  
Sandra Rainieri ◽  
Simone Witte ◽  
Ulrich Matern ◽  
Stefan Martens
Keyword(s):  
High Performance ◽  
Hydrolytic Activity ◽  
Glycoside Hydrolases ◽  
Yeast Cells ◽  
Genome Database ◽  
Yeast Transformants ◽  
Product Verification ◽  
Layer Chromatography ◽  
Hydrolysis Of

ABSTRACTBaker's yeast (Saccharomyces cerevisiae) whole-cell bioconversions of naringenin 7-O-β-glucoside revealed considerable β-glucosidase activity, which impairs any strategy to generate or modify flavonoid glucosides in yeast transformants. Up to 10 putative glycoside hydrolases annotated in theS. cerevisiaegenome database were overexpressed with His tags in yeast cells. Examination of these recombinant, partially purified polypeptides for hydrolytic activity with synthetic chromogenic α- or β-glucosides identified three efficient β-glucosidases (EXG1, SPR1, and YIR007W), which were further assayed with natural flavonoid β-glucoside substrates and product verification by thin-layer chromatography (TLC) or high-performance liquid chromatography (HPLC). Preferential hydrolysis of 7- or 4′-O-glucosides of isoflavones, flavonols, flavones, and flavanones was observedin vitrowith all three glucosidases, while anthocyanins were also accepted as substrates. The glucosidase activities of EXG1 and SPR1 were completely abolished by Val168Tyr mutation, which confirmed the relevance of this residue, as reported for other glucosidases. Most importantly, biotransformation experiments with knockout yeast strains revealed that only EXG1 knockout strains lost the capability to hydrolyze flavonoid glucosides.

scholarly journals Metabolism of the diacetyl derivatives of stereoisomeric monoacyl-sn-glycerols by rat adipocytes in vitro

1986 ◽  
Vol 235 (3) ◽  
pp. 833-838 ◽  
Author(s):  
W W Christie ◽  
M L Hunter
Keyword(s):  
Oleic Acid ◽  
Significant Degree ◽  
Partial Hydrolysis ◽  
Unesterified Fatty Acid ◽  
Triacylglycerol Biosynthesis ◽  
Bonded Phase ◽  
High Degree ◽  
Hydrolysis Of ◽  
Derivatives Of

Diacetyl long-chain 1(3)- and 2-acyl-sn-glycerols containing either [9,10-3H]oleic acid or [1-14C]palmitic acid were synthesized by partial hydrolysis of the corresponding labelled triacylglycerols and acetylation. They were obtained in a high degree of stereochemical purity by preparative h.p.l.c. on a column containing a diol bonded phase. Each compound was rapidly metabolized by adipocyte preparations in vitro, and a high proportion of the label was recovered in the unesterified fatty acid and triacylglycerol fractions. Negligible amounts of intermediate products of hydrolysis were detected. Triacylglycerols were formed from [9,10-3H]oleic acid and from diacetyl-1(3)-[9,10-3H]oleoyl glycerol precursors at about the same rate, but the 2-isomer was metabolized rather more slowly. The results were consistent with the hypothesis that essentially complete hydrolysis occurred in the medium or at the plasma membrane, through the actions of lipoprotein lipase and monoacylglycerol lipase, and that subsequent esterification took place within the cell. To confirm that no putative intermediate monoacylglycerols were utilized for triacylglycerol biosynthesis via the monacylglycerol pathway, the positional distributions of fatty acids in triacylglycerols from each substrate were determined. No positional selectivity was observed. It was concluded that monoacylglycerols, of an origin exogenous to the tissue, e.g. those derived from plasma triacylglycerols, were not utilized to a significant degree for triacylglycerol biosynthesis in adipose tissue. The diacetyl derivatives of monoacylglycerols may serve as useful stereochemical probes in studies of triacylglycerol biosynthesis via the monoacylglycerol pathway in other tissues.

Dental optical coherence tomography: a comparison of two in vitro systems

1999 ◽  
Vol 29 (2) ◽  
pp. 85-89 ◽  
Author(s):  
L L Otis ◽  
B W Colston ◽  
M J Everett ◽  
H Nathel
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
In Vitro Systems

In vitro and in vivo reduction of erythrocyte sorbitol by ascorbic acid

Diabetes ◽  
1989 ◽  
Vol 38 (8) ◽  
pp. 1036-1041 ◽  
Author(s):  
J. A. Vinson ◽  
M. E. Staretz ◽  
P. Bose ◽  
H. M. Kassm ◽  
B. S. Basalyga
Keyword(s):  
Ascorbic Acid

IMPACT OF SORBITOL- INDUCED OSMOTIC STRESS ON SOME BIOCHEMICAL TRAITS OF POTATO IN VITRO

2020 ◽  
Vol 51 (4) ◽  
pp. 1038-1047
Author(s):  
Mawia & et al.
Keyword(s):  
Ascorbic Acid ◽  
Osmotic Stress ◽  
Cytoplasmic Membrane ◽  
Genotypic Variation ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Culture Collection ◽  
Nutritive Medium ◽  
Starting Point

This study had as principal objective identification of osmotic-tolerant potato genotypes by using "in vitro" tissue culture and sorbitol as a stimulating agent, to induce water stress, which was added to the  culture nutritive medium in different concentration (0,50, 110, 220, 330 and 440 mM).  The starting point was represented by plantlets culture collection, belonging to eleven potato genotypes: Barcelona, Nectar, Alison, Jelly, Malice, Nazca, Toronto, Farida, Fabulla, Colomba and Spunta. Plantlets were multiplied between two internodes to obtain microcuttings (in sterile condition), which were inoculated on medium. Sorbitol-induced osmotic stress caused a significant reduction in the ascorbic acid, while the concentration of proline, H2O2 and solutes leakage increased compared with the control. Increased the proline content prevented lipid peroxidation, which played a pivotal role in the maintenance of membrane integrity under osmotic stress conditions. The extent of the cytoplasmic membrane damage depends on osmotic stress severity and the genotypic variation in the maintenance of membranes stability was highly associated with the ability of producing more amounts of osmoprotectants (proline) and the non-enzymic antioxidant ascorbic acid in response to osmotic stress level. The results showed that the genotypes Jelly, Nectar, Allison, Toronto, and Colomba are classified as highly osmotic stress tolerant genotypes, while the genotypes Nazca and Farida are classified as osmotic stress susceptible ones.

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.

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