排序方式: 共有32条查询结果,搜索用时 31 毫秒
1.
Enantiopure nitrogen mustards which mimic (L)-carnitine framework are prepared by a multi-step synthesis from the (R)-di-tert-butyl malate and their antitumor properties evaluated. 相似文献
2.
Michel Perbost Marc Lucas Claude Chavis Jean-Louis Imbach 《Nucleosides, nucleotides & nucleic acids》2013,32(8):1489-1505
Abstract The synthesis of racemic diethyl succinate and dimethyl adipate substituted in their 2 and 3 position respectively by usual heterocyclic bases are described via the Michael addition of nucleobases on diethyl maleate and dimethyl (E)-3-hexene-1, 6-dioate. The Michael adducts are further reduced to afford the corresponding carboacyclonucleosides. 相似文献
3.
C Chavis P Godard F B Michel A Crastes de Paulet M Damon 《Prostaglandins, leukotrienes, and essential fatty acids》1991,42(2):95-100
The mechanism involved in amplification of the local inflammatory process, characteristic of asthma, was investigated through the role of human alveolar macrophages. During asthma attacks, mast cells and eosinophils are known to be activated in order to release arachidonic acid derived inflammation mediators such as sulfidopeptide leukotrienes. It is now known that these metabolites, particularly leukotriene C4, are present in bronchoalveolar lavage from asthmatic patients. Alveolar macrophages, recovered by bronchoalveolar lavage and purified by adherence, are able to transform LTC4 into LTE4. In four asthmatic patients with severe local inflammation as determined by fibrobronchoscopy, these phagocytes, incubated in the presence of LTC4, also generated LTB4 and 5-HETE, which remained within the cells. These preliminary results are discussed relative to amplification of the local process, involving cooperation between the different cells involved in airway responsiveness. 相似文献
4.
T Radeau C Chavis M Damon F B Michel A Crastes de Paulet P H Godard 《Prostaglandins, leukotrienes, and essential fatty acids》1990,41(2):131-138
In stable state asthmatic patients (AP) without any airway obstruction, the capacity of peripheral blood polymorphonuclear neutrophils (PMN) to produce 5-lipoxygenase metabolites and to migrate, was investigated and compared with the response in healthy subjects (HS). After calcium-ionophore A23187 stimulation, PMN from AP and HS produced LTB4, its hydroxylated derivatives: omega-OH-and omega-CO2H-LTB4) (omega-LTB4, i.e 6-trans-LTB4 and 5,6-diHETE isomers, and 5-HETE. We found an increase in LTB4 (+59%), omega-LTB4 (+39%), 6-trans-LTB4 (+128%), and free 5-HETE (+63%) generation of AP as compared with HS. Unstimulated migration was enhanced in AP (122 +/- 27 PMN/10 high power fields (hpf) in AP versus 74 +/- 25 PMN/10 hpf in HS, p less than 0.025) and suggested a greater capacity of PMN from AP to migrate. This was confirmed by the PAF-induced chemotaxis studies which showed, in AP, a greater PAF-sensitivity of PMN (10(-6) M versus 10(-5) M in HS) and a greater chemotaxis response (600 +/- 50 PMN versus 200 +/- 35 PMN in HS). In AP, we compared the capacity of PMN to generate LTB4 and 5-HETE with their capacity to migrate. We found an inverse correlation (r = 0.86, p less than 0.007) of intracellular free 5-HETE with chemotaxis to PAF. 相似文献
5.
Purification and mass spectrometry identification of leukotriene D4 synthesized by human alveolar macrophages 总被引:3,自引:0,他引:3
M Damon C Chavis P Godard F B Michel A Crastes de Paulet 《Biochemical and biophysical research communications》1983,111(2):518-524
Human AM obtained by BAL from normal subjects and asthmatic patients converted [1-14C]-AA into a polar labeled metabolite. The structure of this metabolite, after two successive purifications on TLC (silicagel plates then reversed phase plates) and mass spectrometric analysis was shown to be identical to an authentic sample of LTD4. The amount of LTD4 recovered in the culture medium of AM was attempted to be related to pathological lung profile. In our experimental conditions AM from allergic asthmatics synthetized more LTD4 than cells from healthy subjects and from aspirin sensitive asthmatic patients. 相似文献
6.
M.J. Dembl-Duchesne H. Thaler-Dao C. Chavis A. Crastes de Paulet 《Prostaglandins & other lipid mediators》1981,22(6):979-1002
The conversion of (1-14C) PGH2 was studied in human placental and fetal membrane cellular preparations (tissue fragments, homogenate, cytosol, microsomes). Placental and amnion homogenates convert labelled PGH2 into PGE2 through a very active PGE2 isomerase. However isolated placental microsomes do not metabolise PGH2 into PGE2 but into T×A2 (identified as T×B2 by GC-MS) and presumably 12-HHT. This microsomal T×A2 synthetase is not active in the whole tissue nor in the homogenate. Placental cytosol gives mainly PGD2. No conversion into PGI2 (identofied as 6 keto PGF1α) nor PGF2α was observed in any fraction.Some aspects of PG synthesis regulation by the placental cytosol were studied: the cytosol contains a heat-stable factor that inhibits T×A2 synthesis and shifts PGH2 placental microsome metabolism towards PGE2. In addition the placental cytosol inhibits human platelet-aggregation through a heat-labile factor which is not PGI2 nor PGD2. A multiple step regulation of the various PG metabolites synthetised from arachidonic acid in the placenta can be outlined and its physiological implications are discussed. 相似文献
7.
Abstract Monothiophosphate analogs of dinucleoside tetraphosphates have been synthesized i n order to study their resistance towards the specific hydrolase of E. Coli. 相似文献
8.
Muhammad Azymah Claude Chavis Alain Fruchier Marc Lucas Jean-Louis Imbach 《Nucleosides, nucleotides & nucleic acids》2013,32(9):1607-1620
Abstract Reaction of (±)but-3-en-1,2-diol (3) with ethyl diazoacetate afforded two cyclopropyl compounds (5) and (6). Their relative trans stereochemistry at C-2 and C-3 has been determined by high-field and computational NMR spectroscopy. (±)Trans-1-(1′,5′-dihydroxy-3′,4′-methylenyl-pent-2′-oxy)methyl]thymine (1d) or -cytosine (1b) and (±)trans-9-(1′,5′-dihydroxy-3′,4′-methylenylpent-2′-oxy)-methyl]adenine (la) or -guanine (1c) have been obtained through a regiospecific alkylation procedure and their antiviral evaluation is reported. 相似文献
9.
I Vachier P Chanez C Bonnans P Godard J Bousquet C Chavis 《Biochemical and biophysical research communications》2002,290(1):219-224
Eicosanoids have been historically involved in the pathogenesis of various inflammatory diseases. Lipoxins (LXs) and epi-LXs show physiological effects relevant to inflammation regulation. In this study, we focused on LX precursors based on the hypothesis that their entrance and metabolism into the cell may facilitate their targeting at the inflammation site. Because compound chirality is of considerable importance in the efficacy of therapeutic agents, our aim was to study the anti-inflammatory effects of various epimers of LXA(4) precursors compared to LXA(4). Blood polymorphonuclear cells (PMNs) were incubated with 15(S)- or 15(R)-hydroxyeicosatetraenoic acid (HETE), 14(R)-,15(S)-, or 14(S),15(S)-diHETE, and LXA(4) and then stimulated with the calcium ionophore A23187. We found that 15(R)-HETE rather than 15(S)-HETE was preferentially metabolized and that 15-epi-LXs were produced in larger amounts than LXs. In contrast, when PMNs were incubated with the diastereoisomers of 14,15(S)-diHETE, 14-epi-LXB(4) was produced in lower amounts than LXB(4). Enantiomers of 15-HETE and diastereoisomers of 14,15-diHETE and LXA(4) were able to significantly decrease LTB(4) release by PMNs. These results suggest a potential resolution of the inflammatory process through endogenous anti-inflammatory mediators released by the way of trans-cellular metabolism. 相似文献
10.
H. Thaler-Dao M. Saintot M. Ramonatxo C. Chavis A.Crastes de Paulet 《Prostaglandins & other lipid mediators》1982,23(3):347-359
Prostaglandin biosynthesis was studied in the rat uterus during the oestrous cycle. Uterine homogenates were incubated for 20 minutes in the presence of exogenous substrate (2.10−5M). PGF2α and PGE2 were measured by R.I.A.. A sharp peak PGF2α and a smaller peak of PGE2 were observed at prooestrus, 20 h. Another small PGE2 peak occurred at dioestrus II, 15 h. The lowest values of both PGs were found on dioestrus, 15 h. Plasma oestradiol concentration were highest at proestrus, 15 h and 20 h. A sharp progesterone peak occurred at prooestrus, 20 h. The PGF2α peak is next to the oestradiol peak and is superimposable or lags slightly beyond the progesterone peak.Incubation with 14C arachidonic acid and subsequent analysis of extracts by TLC and scanning showed that the major metabolite is PGI2, identified as 6 keto PGF1α. The conversion rate of arachidonic acid into 6 keto PGF1α is 5 times higher than into PGF2α. 6 keto PGF1α was further identified by GC/MS. No significant difference was observed between 6 keto PGF1α production during oestrus and dioestrus. 相似文献