Zobrazeno 1 - 10
of 80
pro vyhledávání: '"Bhupesh C. Das"'
Autor:
Laurent Frédéric Gil, Christian Marazano, Bhupesh C. Das, Berangere Guilloteau‐Bertin, Delphine Compere
Publikováno v:
European Journal of Organic Chemistry. 2000:1391-1399
Treatment of salts 1a-b with Grignard reagents gives, after reduction of the resulting unstable dihydropyridines 7, the tetrahydropyridines 8a-c, with modest selectivities but in very few steps and under practical conditions. Higher stereo- and regio
Autor:
Karine Jakubowicz, Marie-Thérèse Martin, Ali Al Mourabit, Alice Gateau-Olesker, and Christian Marazano, Bhupesh C. Das, Matthias Herdemann, Kamel Ben Abdeljelil
Publikováno v:
The Journal of Organic Chemistry. 64:7381-7387
Recent results from our laboratory have prompted us to introduce a modification of the original Baldwin proposal for the biosynthesis of manzamine alkaloids. In this new model, aminopentadienal derivatives of general structures 2 or 3 can not only cy
Publikováno v:
The Journal of Organic Chemistry. 64:4528-4532
Autor:
Renaud Dumas, Laurent Serani, Frédéric Halgand, Eric Forest, Olivier Laprévote, Bhupesh C. Das
Publikováno v:
European Journal of Biochemistry. 259:356-359
The macromolecular complexes formed by the enzyme acetohydroxy acid isomeroreductase with NADPH, magnesium ions and the competitive inhibitor N-hydroxy-N-isopropyloxamate (IpOHA) were analysed by electrospray mass spectrometry. Each ligand was added
Publikováno v:
Rapid Communications in Mass Spectrometry. 12:1182-1186
The influence of pH and in-source collisional energy variations on interactions between a model protein and sodium or cesium ions has been studied by electrospray ionization mass spectrometry. Behavioural differences regarding cationization have been
Autor:
Christian Marazano, Dino Gnecco, Yung-Sing Wong, Angèle Chiaroni, Claude Riche, Bhupesh C. Das, A. Billion
Publikováno v:
Tetrahedron. 54:9357-9372
An enantioselective access to 2,3,6-trialkylpiperidines 5 is described. This sequence is illustrated by the four-step syntheses, from salts 1, of piperidine 6 and indolizidines 7 and 8. The overall yields are in the range 10–15%. The stereochemistr
Autor:
Jacques Royer, Laurent Serani, Henri-Philippe Husson, Denise Dugat, Bhupesh C. Das, Olivier Laprévote
Publikováno v:
Tetrahedron Letters. 39:3125-3128
The 14-membered diacetal dilactam ring 1 undergoes, at low pH and under fast-cesium ions bombardment, a substitution of its two acetal methoxy groups by a single molecule of glycerol (matrix) whereas near-neutral pH conditions lead only to protonatio
Autor:
Anita Caille, Henri Labbé, Bhupesh C. Das, Jean-Marc Bonmatin, Monique Genest, Jean Wallach, Françoise Peypoux, Régine Maget-Dana, Marius Ptak, Isabelle Grangemard
Publikováno v:
Journal of Peptide Science. 3:145-154
The biosynthesis of bacterial isoleucyl-rich surfactins was controlled by supplementation of L-isoleucine to the culture medium. Two new variants, the [Ile4,7]- and [Ile2,4,7]surfactins, were thus produced by Bacillus subtilis and their separation wa
Publikováno v:
Journal of Mass Spectrometry. 31:1149-1155
Energy-resolved mass spectrometry (ERMS) using electrospray ionization and in-source collisional activation is a very promising approach to structural investigations of positional isomers and stereoisomers. This method was applied successfully in the
Autor:
Bhupesh C. Das, Laurent Frédéric Gil, Xavier Baucherel, Marie-Thérèse Martin, Christian Marazano
Publikováno v:
Tetrahedron Letters. 36:6231-6234
As a model for condensation reactions of macrocycles of type 1 , which are possibly implicated in the biosynthesis of a number of new alkaloids recently extracted from sponges, we now report that treatment of dihydropyridinium salt 13 with triethylam