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Your search keyword '"Cantacuzene, D."' showing total 77 results
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77 results on '"Cantacuzene, D."'

1. Synthesis of alpha- and beta-biotinylated T-antigen

Author

Bay, S., Berthier-Vergnes, O., Cantacuzene, D., and Laviron, Nathalie

Subjects
[SDV.BC] Life Sciences [q-bio]/Cellular Biology
Abstract

The T-antigen [beta-D-Gal-(1-->3)-D-Ga1NAc] has been linked to biotin through a C6 spacer arm for the detection of a specific 'T-antigen-lectin' complex at the surface and/or on the migration pathway of melanoma cells. When 4,6-di-O-acetyl-2-azido-2-deoxy-3-O-(2,3,4, 6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha- or -beta-D-galactopyranosyl halides were treated with N-benzyloxycarbonyl or N-fluorenylmethoxycarbonyl protected aminohexanols (used as the spacer arm), unusual stereoselectivities were observed for the synthesis of the alpha and beta anomers. The synthesis of the alpha anomer could only be achieved, in reasonable yields, with the Schiff base of aminohexanol.

Published
1997

6. Synthesis of alpha and beta-glycopyranosyl-serine derivatives by enzymic transglycosylation

Author

Cantacuzene, D., Attal, S., Bay, S., Chimie Organique, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: beta-Galactosidase, Glycosylation, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, alpha-Galactosidase, beta-Glucosidase, Glycopeptides, Serine, MESH: beta-Glucosidase, MESH: Serine, MESH: alpha-Galactosidase, beta-Galactosidase, MESH: Glycosylation, MESH: Glycopeptides
Abstract

International audience; The transglycosylation from raffinose and lactose to Aloc-Ser-OMe is catalyzed respectively by alpha and beta galactosidases. Transglycosylation from cellobiose has been achieved with beta-glucosidase. The simplicity of the enzymatic synthesis, the stereospecificity of the condensations in one-pot reactions and the ease of purification give the method value for large scale preparation of beta-linked derivatives. The protective groups of the serine residue can be cleaved under mild conditions: the ester group has been removed quantitatively by papain catalyzed hydrolysis and the Aloc group by a Pd (0) hydrostannolytic cleavage.

Published
1991

11. Alcoxy-2, aryloxy-2, acyloxy-2 cyclohexanones. Synthèse et étude de leur équilibre conformationnel

Author

Cantacuzene, D. and Tordeux, M.

Abstract

We show a linear Hammett correlation in the conformational equilibrium of 2-aryloxycyclohexanones when the X substituent located paraon the phenyl ring is electron withdrawing. This leads to the prediction of the equatorial position of the substituent in the 2-acyloxycyclohexanones. The conformational equilibria of 2-alcoxycyclohexanones (R = CH3to C(CH3)3) also are examined.

Published
1976
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13. Effects of ring fluorination on the cardiovascular actions of dopamine and norepinephrine in the dog.

Author

Goldberg, L I, Kohli, J D, Cantacuzene, D, Kirk, K L, and Creveling, C R

Abstract

The 2-, 5- and 6-fluoro (F) analogs of dopamine (DA) and (+/-)-norepinephrine (NE) were compared with the respective parent molecules for alpha, beta-1 and beta-2 adrenergic and vascular DA activities in pentobarbital-anesthetized dogs. 2-F and 5-F DA were equipotent while 6-F DA was about 4-fold less active than DA in causing renal vasodilation in phenoxybenzamine pretreated dogs (vascular DA activity). The three analogs were indistinguishable from DA for vasoconstrictor activity in the femoral vascular bed (alpha adrenergic activity). 2-F and 6-F DA were equipotent to DA while 5-F was about 2-fold more active than DA in inotropic activity (beta-1 adrenergic activity). In contrast, F NE analogs showed marked differential activities. 2-F NE resembled isoproterenol in increasing cardiac contractility, lowering diastolic blood pressure and causing vasodilation in the femoral vascular bed. The 5-F analog was the most potent for (beta-1 adrenergic activity and produced biphasic effects on blood pressure and the femoral vascular bed. 6-F NE exerted no inotropic activity in dose 50- to 80-fold higher than the threshold dose of l-NE and caused vasoconstriction. Thus, fluorine substitution in either of the three positions in the benzene ring of DA induced only minor, if any, differences in receptor activation when compared with DA. On the other hand, fluorine substitution in the benzene ring of NE yielded compounds with marked differential receptor activity. These data indicate that the differences between the effects of F substitution on DA and NE analogs must be related to the only structural difference between the two catecholamines, the presence of a beta-hydroxyl group in NE.

Published
1980

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