55557-13-6Relevant articles and documents
Oxidation of isohumulones induces the formation of carboxylic acids by hydrolytic cleavage
Rakete, Stefan,Berger, Robert,Boehme, Steffi,Glomb, Marcus A.
, p. 7541 - 7549 (2014/08/18)
The degradation of isohumulones in mechanistic experiments was investigated. Incubation of trans-isohumulone in the presence of l-proline led to the formation of carboxylic acids and their corresponding proline amides. In the context of isohumulones unknown amides were verified first in model incubations and then in beer for the first time by comparison with authentic reference standards via LC-MS analyses. Carboxylic acids and amides were formed preferably under oxidative conditions and increasing pH. Stable isotope experiments excluded the incorporation of molecular oxygen into carboxylic acids, strongly indicating a hydrolytic mechanism via β-dicarbonyl cleavage. The proposed mechanism includes oxidation and thereby incorporation of molecular oxygen to the isohumulone ring structure followed by hydrolytic cleavage leading to acids and amides.
The degradation mechanism of toxic atractyloside in herbal medicines by decoction
Chen, Liang-Yu,Hu, Anren,Chang, Chih-Jui
, p. 2018 - 2028 (2013/04/10)
Atractyloside (ATR) is found in many Asteraceae plants that are commonly used as medicinal herbs in China and other eastern Asian countries. ATR binds specifically to the adenine nucleotide translocator in the inner mitochondrial membrane and competitively inhibits ADP and ATP transport. The toxicity of ATR in medical herbs can be reduced by hydrothermal processing, but the mechanisms of ATR degradation are not well understood. In this study, GC-MS coupled with SPE and TMS derivatisation was used to detect ATR levels in traditional Chinese medicinal herbs. Our results suggest that ATR molecules were disrupted by decomposition, hydrolysis and saponification after heating with water (decoction) for a long period of time. Hydrothermal processing could decompose the endogenous toxic compounds and also facilitate the detoxification of raw materials used in the Chinese medicine industry.
SYNTHESE DE MONODIOXOLANNES DE DICETONES-1,4 ET DE DICETONES-1,4 AU MOYEN DES ANHYDRIDES MIXTES CARBOXYLIQUES ET CARBONIQUES: APPLICATION A LA PREPARATION DE LA DIHYDROJASMONE, DE LA Z-JASMONE ET DE LA DEHYDROJASMONE
Moreau, J.-L.,Couffignal, R.,Arous-Chtara, R.
, p. 307 - 310 (2007/10/02)
Levulinic acid 1 is easily converted by two steps into mixed carboxylic and carbonic anhydride 3 which reacts with the organolithium reagent issued from trimethylsilyl esters.Monoethylene acetal of 1,4-diketones 4 can be prepared; it is also possible to obtain 1,4-diketones 5 in one step by hot acid hydrolysis.The preparation of the dihydrojasmone 6d, Z-jasmone 6e and dehydrojasmone 6f shows the efficiency of the process.