l-Galactono-1,4-lactone dehydrogenase (GLDH; E.C. 1.3.2.3), the enzyme responsible for the last step of l-ascorbate biosynthesis in plants, was cloned from strawberries (Fragaria × ananassa Duch, cv. Campineiro) and its activity and expression followed during fruit development and ripening. Pro...
The tiller of rice (Oryza sativa L.), which determines the panicle number per plant, is an important agronomic trait for grain production. Ascorbic acid (Asc) is a major plant antioxidant that serves many functions in plants. l-Galactono-1,4-lactone dehydrogenase (GLDH, EC 1.3.2.3) is an enzyme ...
L-galactono-1, 4-lactone dehydrogenase (GLDH) is an important enzyme that catalyzes the last step of the ascorbate biosynthetic pathways in plants. A full-length cDNA clone encoding GLDH was isolated from potato (Solanum tuberosum L. ‘Favorita’) leaf and subcloned into a binary vector, pBI121,...
DFT/B3LYP/6-311++G(d,p) calculations have been performed to obtain optimized structures for fourteen conformers of (3R,4R,5R,7S)-7-(hydroxymethyl)thiepane-3,4,5-triol. These conformers are considered as the twist-chair (TC) and twist-boat (TB) conformations. Among all conformers, the TCS5 and TC...
A stereoselective synthesis of (3R,4S,5R,7R)-7-(hydroxymethyl)azepane-3,4,5-triol hydrochloride from (−)-shikimic acid is described. The method involves the transformation of (−)-shikimic acid into (4S,5R)-2,2-dimethyl-5-((R)-1′,4′-di(tert-butyldimethylsilyl)oxy-3′-oxobutyl)-1,3-dioxolane-4-c...
Homochiral piperidines containing a quaternary carbon branch at C-2 of the piperidine ring may be made from readily available carbohydrate lactones containing a branched 2-C-hydroxymethyl substituent. This gives an easy access to the branched iminosugars. In particular a trihydroxypipecolic acid...
Swainsonine (9) is an important mannosidase inhibitor that has been examined clinically as an anticancer drug. The preparation of analogs of swainsonine bearing a hydroxymethyl group at C(3), i.e., (3R)-3-(hydroxymethyl)swainsonine [(10), (3R)-HMS] and (3S)-3-(hydroxymethyl)swainsonine [(11), (3...
A convenient approach for the preparation of (2S,3R,4R,5S,6R)-2-(3-(4-ethylbenzyl)-4-chlorophenyl)-6-(hydroxymethyl)-tetrahydro-2H-pyran-3,4,5-triol 1 is developed. The target compound via four steps is synthesized from 4-bromo-2-(bromomethyl)-1-chlorobenzene and the isomers of undesired ortho-p...
A divergent synthesis of the two novel polyhydroxylated azepanes (2R,3R,4R,5R,6R)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol and (2R,3R,4R,5R,6S)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol from d-mannose is described. The method involves a Henry reaction between dimethyl-tert-butylsilyl 2,3-O-isopro...
The absorption spectrum of arsenazo III in media containing K+, Mg2+ and Ca2+ is sharply influenced by pH in the range of 7.5–5.0. The effect of pH is particularly pronounced in the wavelength range 532–602 nm due to the large pH dependence of the dissociation constant of Mg-arsenazo III compl...
A macromolecular magnetic resonance contrast agent (MMCA) was prepared by linking bovine serum albumin (BSA) to gadolinium (Gd) via a chelating agent, diethylenetriaminepentaacetic acid (DTPA). Colorimetric testing with 2,7-bis(o-arsenophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid (ars...
Arsenazo III-loaded liposomes are in wide use as model systems in the study of Ca2+ transport. The most sophisticated method for quantitation of Ca2+ uptake [E. B. Smaal et al. (1985) Biochim. Biophys. Acta 816, 418] utilizes the absorbance changes (650–700 nm) elicited by sequential additions ...
The kinetics of extractive separation of La(III) and Ni(II) from nitrate medium in the presence of lactic acid (HLac) using di-2-ethylhexyl phosphoric acid (DEHPA) diluted in petrofin was investigated using a cell with constant interfacial area and continuous stirring. The effects of stirring sp...
Stopped-flow studies of the calcium-arsenazo III (Ar) system exhibit reaction time constants ranging from 4 to 20 ms, mainly caused by the formation of CaAr and CaAr2 complexes ([Ca]0 = 10 μM to 10 mM, [Ar]0 = 10 μM to 50 μM). At total concentrations [Ca]0 ≥ 100 μM an additional slow reacti...
Commercial samples of Arsenazo III were found to be appreciably impure even after purification as the barium salt. Chromatography on silica gel followed by crystallization yielded a pure sample of the ethanol solvate of the free acid. The dissociation constants of the acid were determined potent...
The interaction of C.I. Mordant Red 3 and bovine serum albumin was investigated using fluorescence and UV–vis absorption spectroscopy. Fluorescence quenching, from which binding parameters were evaluated, revealed that the quenching of the serum by C.I. Mordant Red 3 resulted from the formation...
The main churches of three monasteries in Thessalia, Central Greece are decorated with wall paintings from the post-Byzantine period. The main goal of the present study is to offer insights into the decorative technique of mordant gilding, especially the chemical composition of the mordants and ...
We report the synthesis of TiO2/Graphene oxide nanocomposites (2%, 4%, 6% and 8%) by liquid phase deposition of titania on graphene oxide (GO) nanosheets. This chemical method of synthesis was used due to hydrophobic/hydrophilic incompatibility of GO with metal oxides. The fabricated TiO2/GO nan...
The identification of both the organic and inorganic fraction of dyes and pigments is fundamental for their complete characterization and to assess the technologies used in their production.In this work, the feasibility of determining metallic elements used as mordant for dyed textiles was teste...
There has been a history of using metal mordants in conjunction with natural dyes. Hence, metal mordants play a very vital role in natural dyeing; however, due to ecological reasons, the use of metal salts of copper, chromium, and tin has been not so much in use anymore. The reactivity of a natu...
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