A g.l.c. method which makes possible the simultaneous analysis of the common types of acidic and neutral sugars is described. Particular advantages are achieved with hydroxy acids, ketoses, and uronic acids. Acids and lactones are first converted into their sodium salts. Free or potential aldehy...
The formation of borate complexes contributes significantly to the distribution coefficients obtained in the separation of polyhydroxy acids in borate medium. A study of a large number of straight-chain hydroxy acids shows that these contributions tend to increase with the number of vicinal hydr...
Degradation products from non-oxidative and oxidative treatment of d-galacturonic acid with alkali have been analysed by g.l.c.-m.s.; 13 hydroxy monocarboxylic acids and 26 dicarboxylic acids were identified in addition to several isomerisation products. In the absence of oxygen, the main degrad...
The oxidative decarboxylation of carbohydrate uronic or ulosonic acids with simultaneous replacement by an acetoxy group has been accomplished using the (diacetoxyiodo)benzene and iodine system under mild conditions. A general synthesis of derivatives of tetrodialdoses, and pentodialdoses in fur...
This article describes recent developments in the chemistry of an important family of complex monosaccharides which have diverse structures and participate in a wide range of biological processes. For example: 3-deoxy-d-manno-2-octulosonic acid (KDO) is a key component of the lipopolysaccharides...
The binding and reactivity of the hydrosulfide ion (HS−) to iron(II) porphyrinates has been examined for several synthetic meso-tetraphenylporphine (TPP) derivatives. In all cases, HS− coordinates to the iron centers in a 1:1 stoichiometry with formation constants (Kf) that reflect the electroni...
Hydrogen sulfide (H2S), which recently emerged as a potent regulator of tissues and organs, is broadly produced in mammalian cells but whether it can regulate bone cell function is still elusive. The main objective of this study was to establish the role of H2S in the regulation of human osteocl...
Cadmium (Cd) is a highly toxic element for plant. In order to reveal the effects of NaHS on Cd uptake, physiological and molecular responses of salix to Cd toxicity, NaHS-mediated hydroponics of salix under Cd stress was performed. The addition of NaHS reduces the salix biomass reduction caused ...
Hydrogen sulfide (H2S) is considered as a new emerging cell signal in higher plants. Hydrogen sulfide donor, sodium hydrosulfide, pretreatment significantly increased survival percentage of tobacco suspension cultured cells under heat stress and regrowth ability after heat stress, and alleviated...
Hypoxic encephalopathy is a common cause of neonatal seizures and long-term neurological abnormalities. Endogenous hydrogen sulfide (H2S) may have multiple functions in brain. The aim of this study is to investigate whether sodium hydrosulfide (NaHS), a H2S donor, provides protection against neo...
Hydrogen sulfide (H2S) has long been considered as a phytotoxin, but nowadays as a cell signal molecule involved in growth, development, and the acquisition of stress tolerance in higher plants. In the present study, hydrogen sulfide donor, sodium hydrosulfide (NaHS), pretreatment markedly impro...
Hydrogen sulfide (H2S) is an endogenous gasotransmitter in human physiology and inflammatory disease, however, with limited knowledge of how signal transduction pathways are involved in immune cells. To examine the effects of sulfide on relevant intracellular signaling in human peripheral blood ...
BackgroundInhalation of NO2 leads to a progressive airflow limitation and the development of emphysema-like lesions. We report on the efficacy of hydrogen sulfide (NaHS) for alleviating NO2-induced pulmonary impairment.
7-Lithio-3-tert-butylpyrazolo[5,1-c][1,2,4]triazines have been generated for the first time using one-pot nucleophilic addition and metal-halogen exchange reactions in 7-bromopyrazolo[5,1-c][1,2,4]triazines. It was found that the stability of 7-lithio species depends highly on the substitution p...
(3-tert-Butyl-4-R-1-R1-1,4-dihydropyrazolo[5,1-c][1,2,4]triazin-4-yl)lithiums (R = SEt, OMe, OEt; R1 = CF3CO, CF2ClCO, CF3CF2CF2CO, t-BuOCO, PhCH2) have been generated for the first time from the corresponding 1,4-dihydropyrazolo[5,1-c][1,2,4]triazines and LDA at −97 °C, and their reactivities ...
Benzyne has been generated from benzenediazonium-2-carboxylate in the presence of several 1,2,4-triazines 1 and isoquinolines 2 have been isolated in moderate yield. 1-Aminobenzotriazole was also used as the source of benzyne and isoquinolines were again isolated in moderate yield from these rea...
The Diels-Alder reaction of 1,2,4-triazines with cyclic vinyl ethers leads to a range of substituted pyridines with hydroxyalkyl and oxoalkyl side chains. With dihydrofuran the aromatization of the 1:1 adduct is inhibited by conformational factors and this allows 2:1 adducts to be isolated. Diff...
Several new 2,4-disubstituted pyrrolo[2,1-f][1,2,4]triazines and pyrazolo[5,1-c]-pyrimido[4,5-e][1,2,4]triazines are easily obtained from the reaction of N, N-dimethyldichloromethyleniminium chloride with 1-aminopyrrole-2-carbonitrile 1 and ethyl 4-amino-3-cyanopyrazolo[5,1-c][1,2,4]triazine-8-c...
Meanwhile 5-aryl-6-cyano-2,2′-bipyridines are very stable towards various nucleophiles, addition copper(II) chloride to the reactional mixture facilitates nucleophilic addition to the cyano group dramatically. The cyanobipyridines react easily with water, methanol, ethanolamine in the presence ...
Aryl thioamides undergo very rapid condensation in the presence of methyl bromocyanoacetate to provide quantitative yields of 3,5-diaryl-1,2,4-thiadiazoles with an easy work-up and a high degree of product purity. The method can be scaled up with no loss in efficiency.
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