41242-94-8Relevant articles and documents
Studies on the formation of methylglyoxal from dihydroxyacetone in Manuka (Leptospermum scoparium) honey
Atrott, Julia,Haberlau, Steffi,Henle, Thomas
, p. 7 - 11 (2012)
Dihydroxyacetone (DHA) and methylglyoxal (MGO) are unique carbohydrate metabolites of manuka honey. A method for the reliable quantification of DHA in honey samples was established, based on derivatization with o-phenylenediamine (OPD) and subsequent RP-HPLC with UV detection. The previously unknown reaction product of DHA and OPD was identified as 2-hydroxymethylquinoxaline by spectroscopic means. DHA was exclusively determined in 6 fresh manuka honeys originating directly from the beehive as well as 18 commercial manuka honey samples, ranging from 600 to 2700 mg/kg and 130 to 1600 mg/kg, respectively. The corresponding MGO contents varied from 50 to 250 mg/kg in fresh and 70 to 700 mg/kg in commercial manuka honey samples. A good linear correlation between DHA and MGO values in commercial manuka honeys was observed, resulting in a mean ratio of DHA to MGO of 2:1. In contrast to this, the DHA-to-MGO relation was much higher in fresh manuka honeys but approximated to a ratio of 2:1 while honey ripening. Heating experiments revealed that MGO formation based on thermal treatment as a consequence, for example, of caramelization in honey does not occur. DHA and MGO can serve as suitable unique quality parameter for manuka honey.
Discovery of potent and specific dihydroisoxazole inhibitors of human transglutaminase 2
Kl?ck, Cornelius,Herrera, Zachary,Albertelli, Megan,Khosla, Chaitan
supporting information, p. 9042 - 9064 (2015/03/14)
Transglutaminase 2 (TG2) is a ubiquitously expressed enzyme that catalyzes the posttranslational modification of glutamine residues on protein or peptide substrates. A growing body of literature has implicated aberrantly regulated activity of TG2 in the pathogenesis of various human inflammatory, fibrotic, and other diseases. Taken together with the fact that TG2 knockout mice are developmentally and reproductively normal, there is growing interest in the potential use of TG2 inhibitors in the treatment of these conditions. Targeted-covalent inhibitors based on the weakly electrophilic 3-bromo-4,5-dihydroisoxazole (DHI) scaffold have been widely used to study TG2 biology and are well tolerated in vivo, but these compounds have only modest potency, and their selectivity toward other transglutaminase homologues is largely unknown. In the present work, we first profiled the selectivity of existing inhibitors against the most pertinent TG isoforms (TG1, TG3, and FXIIIa). Significant cross-reactivity of these small molecules with TG1 was observed. Structure-activity and -selectivity analyses led to the identification of modifications that improved potency and isoform selectivity. Preliminary pharmacokinetic analysis of the most promising analogues was also undertaken. Our new data provides a clear basis for the rational selection of dihydroisoxazole inhibitors as tools for in vivo biological investigation.
Hydroxymethylations of aryl halides by Pd-catalyzed cross-couplings with (benzoyloxy)methylzinc iodide - Scope and limitations of the reaction
Hasník, Zbyněk,?ilhár, Peter,Hocek, Michal
, p. 543 - 546 (2008/12/22)
Palladium-catalyzed cross-coupling reactions of (benzoyloxymethyl)zinc iodide with diverse (het)aryl halides leading to (benzoyloxymethyl)(het)arenes were studied to define the scope of this reaction. It has been found that this reaction is only applicable for electron-deficient aryl halides and the most efficient it is for 2-halopyridines and 4-halopyrimidines. Deprotection of the intermediates gives (hydroxymethyl)pyridines and -pyrimidines in high yields. Georg Thieme Verlag Stuttgart.
