Didier Poullain

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Several nutritional studies have shown the in vivo conversion of the 9c,12t-18:2 and 9t,12c-18:2 into long chain polyunsaturated fatty acids (PUFA) containing 20 carbons (geometrical isomers of eicosadienoic and eicosatetraenoic acids). In the present work, some in vitro studies were carried out in order to have precise information on the conversion of(More)
Several grams of labelled trans linoleic and linolenic acids with high chemical and isomeric purities (>97%) have been prepared for human metabolism studies. A total of 12.5 g of (9Z, 12E)-[1-(13)C]-octadeca-9,12-dienoic acid and 6.3 g of (9Z,12Z, 15E)-[1-(13)C]-octadeca-9,12,15-trienoic acid were obtained in, respectively, seven steps (7.8% overall yield)(More)
The addition of a trans isomer of arachidonic acid (20:4 delta 14trans) to rat platelet suspensions inhibited the aggregation induced by 7.5 microM of arachidonic acid. This inhibitory effect of 20:4 delta 14trans was significant at concentrations of 7.5-22.5 microM and the range of inhibition was 20% at an inhibitor/substrate ratio (I/S) 1 to 66% when I/S(More)
Trans polyunsaturated fatty acids are formed during processing of vegetable oils such as deodorization and frying. The oxidative metabolism of linoleic and alpha-linolenic acids and of their mono-trans isomers (9cis,12trans-18:2, 9trans,12cis-18:2 and 9cis, 12cis,15trans-18:3, 9trans,12cis,15cis-18:3, respectively) was studied in fasting rats. A single dose(More)
Several years ago, it was established that the Δ15 trans isomer of α-linolenic acid is converted in vivo into fatty acids containing 20 and 22 carbons (geometrical isomers of eicosapentaenoic and docosahexaenoic acids). The present study focused on the in vitro Δ6 desaturation, the first step of the biosynthesis of the n-3 long-chain polyunsaturated fatty(More)
Three trans isomers of eicosapentaenoic acid (EPA) were added to rat platelets stimulated with arachidonic acid (AA) in order to compare their effects on platelet aggregation and on AA oxygenation with those of EPA. The production of metabolites from radiolabelled 20:5delta 17trans was studied also. EPA induced an inhibition of platelet aggregation of 26.7(More)
Incubation of Vicia sativa microsomes, containing cytochrome P450-dependent lauric acid omega-hydroxylase (omega-LAH), with [1-(14)C]11-dodecynoic acid (11-DDYA) generates a major metabolite characterized as 1,12-dodecandioic acid. In addition to time- and concentration-dependent inactivation of lauric acid and 11-DDYA oxidation, irreversible binding of(More)
In this paper, N-arylations between two heteroaryl compounds were studied. Conditions were found to generate selectively either 3- or 5-heteroarylamino-1,2,4-triazines by investigating anionic processes (use of bases such as 2,2',6,6'-tetramethylpiperidine/tBuOK/nBuLi) or Pd-catalyzed N-arylations [Pd(OAc)(2), xantphos]. These methods were successfully(More)
Because of its reactivity, malonic acid diamide (1) was initially identified as an alternative precursor for the development of a new class of high-density insensitive energetic materials possessing low sensitivity to thermal decomposition and detonation by impact. Nitration of 1 was studied under different conditions and led to three different tautomeric(More)
Tetrazine-based organic species are interesting intermediates for organic synthesis and represent a source of new materials bearing specific properties with potential applications in biology and material science. 1H, 13C, 15N NMR measurements carried out in solution and in the solid-state have been used to characterize a series of 3,6-disubstituted(More)