10257-32-6Relevant articles and documents
Reactions of Adenine Nucleosides with Aqueous Alkalies: Kinetic and Mechanism
Lehikoinen, Pertti,Mattinen, Jorma,Loennberg, Harri
, p. 3819 - 3823 (1986)
The hydrolysis of adenosine in aqueous alkali has been studied by liquid chromatography (LC), NMR spectroscopy, and isotopic labeling techniques.The first step of the multistage reaction pathway has been shown to be a nucleophilic attack of hydroxide ion on the C8 atom with concomitant opening of the imidazole ring.The equilibrium mixture of 4-amino-5-formamido-6-(ribosylamino)pyrimidines obtained undergoes three competitive reactions, viz., intramolecular cyclization to adenine nucleosides and N6-ribosyladenines and degradation to nonchromophoric products, most probably via intermediary formation of 4,5-diamino-6-(ribosylamino)pyrimidines.Isomeric N6-ribosyladenines are further hydrolyzed to adenine and D-ribose.The rate constants for the different partial reactions have been determined at various concentrations of hydroxide ion.The mechanisms of individual steps are discussed.Comparative kinetic studies with 2'-deoxy-, 2',3'-O-isopropylidene-, and 5'-O-methyladenosine and 9-β-D-arabinofuranosyladenine and its 5'-O-methyl derivative are interpreted to indicate that the glycon moiety hydroxyl groups do not play any important role in the alkaline cleavage of adenine nucleosides.
New flavonoid glycosides from Xanthium strumarium with their protein tyrosine phosphatase 1B inhibitory activity
Jiang, Pei-Jing,Lu, Mei-Jiao,Xi, Yi-Yuan,Chen, Jun,Zheng, Ju-Jia,Xu, Xiang-Wei
, p. 45 - 51 (2021/01/25)
Two new flavonoid glycosides named 6-hydroxy-3-methoxy-apigenin 7-O-α-?-rhamnopyranoside (1) and 3-hydroxyl-apigenin 8-C-β-?-xylopyranoside (2), along with five known compounds (3-7), were isolated from Xanthium strumarium. Their structures were elucidate
Mimonoside D: a new triterpenoid saponin from Mimosa diplotricha Sauvalle (Fabaceae)
Dzoyem, Jean Paul,Kemkuignou, Blondelle Matio,Kenmogne, Claudie Fokou,Opatz, Till,Ponou, Beaudelaire Kemvoufo,Tchuenguem, Roland T.,Kühlborn, Jonas,Tapondjou, Léon Azefack,Teponno, Rémy Bertrand
, (2021/12/02)
A new triterpenoid saponin (Mimonoside D: 3-O-α-L-arabinopyranosyl-3β-hydroxyolean-12-en-28-oic acid 28-O-β-D-xylopyranosyl-(1→2)-β-D- glucopyranoside ester (1)) was isolated from the aerial parts of Mimosa diplotricha Sauvalle together with nine known compounds: 7,4′-dihydroxyflavone (2), kaempferol (3), lupeol (4), betulinic acid (5), β-sitosterol (6), β-sitosterol-3-O-β-D-glucopyranoside (7), lutein (8), 5,2′-dihydroxy-7,4′,5′-trimethoxyflavone (9) and vitexin (10). Their structures were elucidated on the basis of spectroscopic (1D and 2D nuclear magnetic resonance) and high-resolution mass spectrometric data as well as by comparison of their spectral data with those of related compounds. Compounds 2, 7 and 8 had already been isolated from M. diplotricha, while compounds 3, 4, 5 and 6 have been isolated from other Mimosa species. Compound 2 moderately inhibited Proteus mirabilis (MIC = 32μg/mL), weakly inhibited Pseudomonas aeruginosa (MIC = 64μg/mL) and very weakly inhibited Staphylococcus aureus (MIC = 128μg/mL) and Enterococus faecalis (MIC = 128μg/mL).