- N-Sulfonyl homoserine lactones as antagonists of bacterial quorum sensing
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A series of 11 N-sulfonyl homoserine lactones has been synthesised. Some of them were found to competitively inhibit the action of 3-oxohexanoyl-L- homoserine lactone, the natural inducer of bioluminescence in the bacterium Vibrio fischeri. Molecular modeling suggests a possible explanation based on the prevention of structural rearrangements necessary for the formation of the active dimer of LuxR.
- Castang, Sandra,Chantegrel, Bernard,Deshayes, Christian,Dolmazon, René,Gouet, Patrice,Haser, Richard,Reverchon, Sylvie,Nasser, William,Hugouvieux-Cotte-Pattat, Nicole,Doutheau, Alain
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p. 5145 - 5149
(2007/10/03)
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- Cyclodextrin Inclusion Complexes of 1-Pyrenebutyrate: The Role of Coinclusion of Amphiphiles
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Several inclusion complexes with various stoichiometries are formed from 1-pyrenebutyrate ion (P) and the different cyclodextrins (α-, β-, and γ-CD).With α- and β-CD, the initially formed 1:1 complexes lead to the formation of 1:2 complexes (P*α2 and P*β2).As P can be only partially included in the small cavity of α-CD, the equilibrium constants for the formation of both complexes of α-CD are about an order of magnitude smaller than those of β-CD.For the same reason, P*β2, to which we assign a "barrel" configuration, is also an order of magnitude more effective than P*α2 in protecting singlet-excited P against quenching by triethanolamine.We had shown earlier that with γ-CD the 1:1 complex (P*γ) dimerizes to a 2:2 complex (P2*γ2), to which we also assigned a barrel configuration.The lack of efficient 1:2 complex formation in this case is attributed to the large size of the "barrel" enclosed by two γ-CD molecules.The extra space next to a single P molecule in such a cavity would have to be filled with water.However, the formation of a 1:2 inclusion complex between P and γ-CD can be induced by the coinclusion of a molecule with a hydrophobic moiety such as sodium hexanesulfonate (X).This replaces the water within the cavity and leads to the formation of P*X*γ2.This complex provides the highest degree of protection against quenching of excited P in these inclusion complexes.
- Herkstroeter, William G.,Martic, Peter A.,Evans, Ted R.,Farid, Samir
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p. 3275 - 3280
(2007/10/02)
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- One-Step Synthesis of Esters of Aliphatic β-Chloro Sulfonic Acids. Their Sequential Conversion to Other Sulfonic Acid Derivatives
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A one-step synthesis of methyl 2-chlorohexane-1- and 2-chlorooctane-1-sulfonate by the novel free-radical addition of methyl chlorosulfonate to 1-hexene and 1-octene, respectively, is reported.These products were converted by standard techniques into the corresponding sodium and benzylthiuronium β-chlorosulfonic acid salts and sulfonyl chlorides.Dehydrochlorination of these latter products with triethylamine affored regiospecific formation of trans-α,β-unsaturated sulfonyl chlorides, which were transformed by conventional methods into sodium and benzylthiuroniumunsaturated and saturated sulfonic acid salts.Eleven new compositions of matter are reported.
- Heller, Morgan S.,Lorah, Dennis P.,Cox, Charles G.
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p. 134 - 137
(2007/10/02)
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