Structure and Solution Equilibrium of N-Salicylidene-amino-sugars and Amino-alcohols.
作者:Shigeharu Inouye
DOI:10.1248/cpb.15.1540
日期:——
The structures and solution equilibria of twenty members of N-salicylidene-amino-sugars and -amino-alcohols were examined mainly in methanol, water and solid state. As the modeled compounds were examined simultaneously three members of N-salicylidene-alkylamines and eight members belonged to the o-methoxybenzylidene, 3-methoxysalicylidene, 3, 5-dibromosalicylidene and 2-hydroxynaphthylidene derivatives. From the comparative studies on the electronic, infrared, NMR spectra and equilibrium position, it was shown that the solution equilibrium consisted of the phenolimine and the ketoamine species, the latter being stabilized by the intra- and intermolecular hydrogen bonding involving the alcoholic hydroxyl groups and protic solvents. The acid-base equilibria of the two tautomers in methanol and the ketoamine-ion-pair equilibrium in water were discussed.
Glucosaminol, ein Reduktionsprodukt des Glucosamins
作者:P. Karrer、J. Meyer
DOI:10.1002/hlca.19370200192
日期:——
No abstract is available for this article.
本文没有摘要。
A method for reductive cleavage of N-glycosylamide carbohydrate-peptide bond
作者:Leonid M. Likhosherstov、Olga S. Novikova、Vladimir E. Piskarev、Elena E. Trusikhina、Varvara A. Derevitskaya、Nikolay K. Kochetkov
DOI:10.1016/0008-6215(88)80108-3
日期:1988.7
formed were easily isolated by gel filtration and cation-exchange chromatography in 60–80% yields. The reaction was accompanied by the intense reductivecleavage of peptide bonds with formation of amino alcohols, but N -deacetylation of hexosamine was completely excluded. The optimal conditions of this reaction were chosen by use of a model glycopeptide, 2-acetamido-4- O -(2-acetamido-2-deoxy-β- d -glucopyranosyl)-1-
摘要从糖蛋白中分离N连接寡糖的一种温和的新方法包括在25m m LiOH-50m m柠檬酸70%溶液中用2 m LiBH 4处理糖蛋白(卵类粘液,黄素蛋白,核糖核酸酶B,血凝素或转铁蛋白)。用叔丁醇水溶液洗涤(5小时,45°),然后用乙酸水溶液水解所得糖基胺。形成的寡糖很容易通过凝胶过滤和阳离子交换色谱分离,产率为60-80%。该反应伴随着肽键的强烈还原性切割和氨基醇的形成,但是己胺的N-脱乙酰化被完全排除。此反应的最佳条件是通过使用模型糖肽选择的,
THE SYNTHESIS AND BIOLOGICAL ACTIVITIES OF SOME ANALOGS OF STREPTOZOTOCIN
作者:BRIAN BANNISTER
DOI:10.7164/antibiotics.25.377
日期:——
The α- and β-methyl glycosides (IV and V, respectively) of the antibiotic streptozotocin (I) have been synthesized. In addition, analogs involving epimeric changes at C2 (III) and C4 (II), and of two C1 analogs, 3-β-Dglucopyranosyl-1-methyl-1-nitrosourea (XXIII) and the corresponding D-galactopyranosyl compound (XXV), together with their tetra-O-acetates (XXII and XXIV, respectively) have been prepared. An open-chain analog was obtained by the synthesis of 1-deoxy-1-(3-methyl-3-nitrosoureido)-D-glucitol (XXIX), but the 2-deoxy-D-glucitol derivative (XXVII) decomposed on attempted isolation. Epimerization at C2 reduces the antibacterial activity markedly; all other changes made destroy it. All of the analogs show cytotoxic activity in the range of streptozotocin or higher, and all are devoid of diabetogenicity.
Nonionic triiodobenzoyl amino acyl derivatives of polyhydroxy amines. Such amines are useful as nonionic X-ray contrast agents. For Example 2-(3-acetamido-2,4,6-triiodo-5-N-methylacetamidobenzoyl glycylamino)-2-deoxy-D-glucitol is especially useful in angiography.