53197-55-0Relevant academic research and scientific papers
A convenient synthesis of 14C-labelled resveratrol
Zeng, Dongli,Mi, Qixi,Sun, Hongfang,Wang, Haifang
, p. 167 - 174 (2007/10/03)
Resveratrol (trans-3,4′,5-trihydroxystilbene) is a naturally occurring phytoalexin and polyphenol existing in grapes and various plants. It shows remarkable beneficial bioactivities in the prevention of cancer, inflammation and platelet aggregation, etc. This paper reports the synthesis of [β-14C]-trans-resveratrol using 14C-formic acid (exchanged with sodium 14C-formate) and 3,5-dihydroxybenzoic acid as the starting materials. [14C-formyl]-4-methoxybenzaldehyde and diethyl 3,5-dimethoxy benzylphosphonate reacted following the Wittig-Horner reaction to give trans-3,4′,5-[β-14C]-trimethoxystilbene. The final product was obtained through the demethylation of trans-3,4′ ,5-[β-14C]-trimethoxystilbene and identified by TLC and UV spectroscopy. Adoption of the whole procedure provided 14C-resveratrol with a specific radioactivity of 40.8 μCi/mmol, chemical yield of 15.3% and radiochemical yield of 12.5%. Copyright
N-dealkylation of an N-cyclopropylamine by horseradish peroxidase. Fate of the cyclopropyl group
Shaffer,Morton,Hanzlik
, p. 8502 - 8508 (2007/10/03)
Cyclopropylamines inactivate cytochrome P450 enzymes which catalyze their oxidative N-dealkylation. A key intermediate in both processes is postulated to be a highly reactive aminium cation radical formed by single electron transfer (SET) oxidation of the nitrogen center, but direct evidence for this has remained elusive. To address this deficiency and identify the fate of the cyclopropyl group lost upon N-dealkylation, we have investigated the oxidation of N-cyclopropyl-N-methylaniline (3) by horseradish peroxidase, a well-known SET enzyme. For comparison, similar studies were carried out in parallel with N-isopropyl-N-methylaniline (9) and N,N-dimethylaniline (8). Under standard peroxidatic conditions (HRP, H2O2, air), HRP oxidizes 8 completely to N-methylaniline (4) plus formaldehyde within 15-30 min, whereas 9 is oxidized more slowly (14C]-3, [1′-13C]-3, and [2′,3′-13C]-3 as substrates, radiochemical and NMR analyses of incubation mixtures revealed that the complete oxidation of 3 by HRP yields 4 (0.2 mol), β-hydroxypropionic acid (17, 0.2 mol), and N-methylquinolinium (16, 0.8 mol). In buffer purged with pure O2, the complete oxidation of 3 yields 4 (0.7 mol), 17 (0.7 mol), and 16 (0.3 mol), while under anaerobic conditions, 16 is formed quantitatively from 3. These results indicate that the aminium ion formed by SET oxidation of 3 undergoes cyclopropyl ring fragmentation exclusively to generate a distonic cation radical (14+?) which then partitions between unimolecular cyclization (leading, after further oxidation, to 16) and bimolecular reaction with dissolved oxygen (leading to 4 and 17 in a 1:1 ratio). Neither β-hydroxypropionaldehyde, acrolein, nor cyclopropanone hydrate are formed as SET metabolites of 3. The synthetic and analytical methods developed in the course of these studies should facilitate the application of cyclopropylamine-containing probes to reactions catalyzed by cytochrome P450 enzymes.
