Orthorhombic crystals from anhydrous acetone or glacial acetic acid or by sublimation in vacuo. Turns pink at 230 °C ... Hot aqueous solutions are yellow and become colorless on cooling
Dialuric acid is formed as a result of alloxan reduction. It is then re-oxidized back to alloxan establishing a redox cycle for the generation of superoxide radicals. The reaction between alloxan and dialuric acid is a process in which intermediate alloxan radicals and an unidentified compound with a maximum absorption at 305 nm is formed. The latter appears when alloxan is reduced by GSH. ... One of the targets of the reactive oxygen species is DNA of pancreatic islets.
Alloxan ... decays in the absence of reductants into alloxanic acid. In the presence of glutathione, it is reduced via the alloxan radical into dialuric acid, which autoxidizes back to alloxan. During this redox cycling process, reactive oxygen species are formed that destroy beta cells in the islets of Langerhans...
This in vitro study compares the frequency of redox cycling between alloxan and dialuric acid at different initial ratios of glutathione and alloxan. Alloxan oxidizes GSH to GSSG. The rate of GSH oxidation at a given initial GSH concentration of 2.0 mmol/L depends on the initial concentration of alloxan added. The higher the concentration of alloxan in relation to the initial concentration of GSH, the faster GSH oxidation proceeds, as well as oxygen consumption, and therefore, formation of reactive oxygen species. The highest rates of GSH oxidation, i.e. GSSG formation, were found at concentration ratios of between 2.0 mmol/L GSH and 0.2 and 0.04 mmol/L alloxan, respectively. Because 0.04 mmol/L alloxan oxidizes 2.0 mmol/L GSH completely, a frequency of at least 25 cycles between alloxan and dialuric acid within 3 hours can be assumed. During each redox cycle, two molecules of GSH are oxidized to one molecule of GSSG, and during each cycle one molecule of oxygen is reduced simultaneously to one molecule of hydrogen peroxide. In total, therefore, one molecule of alloxan oxidizes at least 50 molecules of GSH and forms about 25 molecules of hydrogen peroxide.
The extract of the methanolic leaves of Bauhinia cheilandra (BC) was tested on glucose loaded and alloxan-induced diabetic rats. In both tests, the methanolic extract at doses of 300, 600, and 900 mg/kg, has shown a statistically significant and considerable hypoglycemic activity.
This study analyzed the antidiabetic properties of an ethanol extract of the stem bark of Psidium guajava, an indigenous medicinal plant used to control diabetes in Indian System of Medicine. The anti-hyperglycemic activity of this plant on blood glucose levels of normal, normal glucose loaded (OGTT) and alloxan-induced hyperglycaemic rats was evaluated. The results showed that ethanol stem bark extract exhibited statistically significant hypoglycemic activity in alloxan-induced hyperglycemic rats but was devoid of significant hypoglycemic effect in normal and normal glucose loaded rats (OGTT).
Nicotinamide protected NMRI mice against alloxan-induced hyperglycemia when given 10 min before, but not 10 min after, the injection of the drug. Pretreatment in vivo with nicotinamide induced hyperglycemia at the time of alloxan injection, and this could account for the protective action of nicotinamide against alloxan diabetes.
The present study was carried out to investigate the effects of onion (Allium cepa Linn) and garlic (Allium sativum Linn) juices on biochemical parameters, enzyme activities and lipid peroxidation in alloxan-induced diabetic rats. Alloxan was administered as a single dose (120 mg/kg BW) to induce diabetes. A dose of 1 mL of either onion or garlic juices/100 g body weight (equivalent to 0.4 g/100 g BW) was orally administered daily to alloxan-diabetic rats for four weeks. The levels of glucose, urea, creatinine and bilirubin were significantly (p<0.05) increased in plasma of alloxan-diabetic rats compared to the control group. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and alkaline and acid phosphatases (AlP, AcP) activities were significantly (p<0.05) increased in plasma and testes of alloxan-diabetic rats, while these activities were decreased in liver compared with the control group. Brain LDH was significantly (p<0.05) increased. The concentration of thiobarbituric acid reactive substances and the activity of glutathione S-transferase in plasma, liver, testes, brain, and kidney were increased in alloxan-diabetic rats. Treatment of the diabetic rats with repeated doses of either garlic or onion juices could restore the changes of the above parameters to their normal levels...
/EPIDEMIOLOGY STUDIES/ ... Blood levels of alloxan in children with insulin-dependent diabetes mellitus were investigated. The observations were made in 68 children aged 6-15 years and in a control group of 44 healthy children in the same age range. ... The mean level of alloxan in blood from children with insulin-dependent diabetes mellitus was 8.76 +/- 9.64 ug/mL and in blood from healthy children was 1.53 +/- 1.10 ug/mL. The difference was statistically significant (P < 0.05). ... The results obtained suggest therefore that higher levels of alloxan in diabetic children are of significance in the onset of insulin-dependent diabetes mellitus.
The uptake of [2-(14)C]alloxan by the pancreatic gland was investigated in control and streptozotocin-induced diabetic (STZ) rats, using both in vitro and in vivo techniques. Whether after 10 to 60 min incubation of pieces of pancreas in the presence of [2-(14)C]alloxan or 60 min to 24 h after intravenous injection of [2-(14)C]alloxan to control and insulin-treated STZ rats, the radioactive content of the pancreas (dpm/mg wet weight) only represented, in the STZ rats, about two thirds of the reference value found in control animals. These findings indicate that insulin-producing islet B-cells participate to a sizeable extent to the overall uptake of [2-(14)C]- alloxan by the whole pancreatic gland, despite the fact that they account for no more than about one percent of the total pancreas mass. Hence, it should be possible to preferentially label the endocrine moiety of the pancreas, in the perspective of its imaging and quantification by a non-invasive procedure, by use of a suitable radiolabelled molecule selectively taken up by islet, as distinct from acinar, pancreatic cells.
[EN] FLAVIN DERIVATIVES<br/>[FR] DÉRIVÉS DE LA FLAVINE
申请人：BIORELIX PHARMACEUTICALS INC
公开号：WO2010019208A1
公开（公告）日：2010-02-18
The present invention relates novel flavin derivatives and other flavin derivatives, their use and compositions for use as riboswitch ligands and/or anti-infectives. The invention also provides method of making novel flavin derivatives.
Hypoglycemic 5-phenyl and 5-naphthyl oxazolidine-2,4-diones and the pharmaceutically-acceptable salts thereof; certain 3-acylated derivatives thereof; a method of treating hyperglycemic animals therewith; and intermediates useful in the preparation of said compounds.
An efficient multi-component synthesis of indazolophthalazine derivatives through the reaction of phthalhydrazide, 2-hydroxynaphthalene-1,4-dione or 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione and active carbonyl compounds under ultrasonic irradiation is reported. This chemistry provides an efficient and promising synthetic strategy to diversity-oriented construction of the indazolophthalazine skeleton with potential biological activities.
Facile synthesis of 1,2,3-tricarbonyls from 1,3-dicarbonyls mediated by cerium(IV) ammonium nitrate
作者：Akhil Sivan、Ani Deepthi
DOI：10.1016/j.tetlet.2014.01.145
日期：2014.3
A mild and efficient protocol for the synthesis of vicinal tricarbonyl compounds from β-dicarbonyls in a single step using cerium(IV) ammoniumnitrate as a catalytic oxidant is described. Ease of execution, wide substrate scope and the suitability for the synthesis of commercially important compounds like ninhydrin, alloxan and oxoline make this reaction particularly noteworthy.
A new facile, efficient synthesis and structure peculiarity of quinoxaline derivatives with two benzimidazole fragments
作者：Vakhid A. Mamedov、Nataliya A. Zhukova、Victor V. Syakaev、Aidar T. Gubaidullin、Tat'yana N. Beschastnova、Dil'bar I. Adgamova、Aida I. Samigullina、Shamil K. Latypov
DOI：10.1016/j.tet.2012.10.045
日期：2013.1
A highly efficient and versatile method for the synthesis of quinoxalinederivatives with two benzimidazole fragments have been developed on the basis of the ring contraction of 3-(benzimidazo-2-yl)quinoxalin-2(1H)-one with 1,2-diaminobenzene and its various types of substituted and condensed derivatives. Owing to the inter- and intramolecular processes, involving self association, proton exchange
基于3-（苯并咪唑-2-基）喹喔啉-2（1 H）-与1,2-的环收缩，已开发出一种高效且通用的具有两个苯并咪唑片段的喹喔啉衍生物的合成方法。二氨基苯及其各种类型的取代和稠合衍生物。由于分子间和分子内过程，涉及桥联和相邻碳原子的大多数双-苯并咪唑基喹喔啉信号的几种形式之间的自缔合，质子交换，构象和/或互变异构交换，且NMR光谱中的苯并咪唑片段变宽。苯并咪唑片段与分子的喹喔啉核心之间的共轭作用比喹喔啉衍生物（10c）与其噻二唑[ f ]-（17）和吡咯并[ a ]-（19）环化了衍生物，导致整个分子的平面度更大。
