- Synthesis and biological evaluation of novel N-α-haloacylated homoserine lactones as quorum sensing modulators
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Novel N-α-haloacylated homoserine lactones, in which a halogen atom was introduced at the α-position of the carbonyl function of the N - acyl chain, have been studied as quorum sensing (QS) modulators and compared with a library of natural N - acylated homoserine lactones (AHLs). The series of novel analogues consists of α-chloro, α-bromo and α-iodo AHL analogues. Furthermore, the biological QS activity of the synthetic AHL analogues compared to the natural AHLs was evaluated. Halogenated analogues demonstrated a reduced activity in the Escherichia coli JB523 bioassay, with the α-iodo lactones being the less active ones and the α-chloro AHLs the most potent QS agonists. Most of the α-haloacylated analogues did not exhibit a significant reduction when tested in the QS inhibition test. Therefore, these novel analogues could be utilized as chemical probes for QS structure-activity studies.
- Syrpas, Michail,Ruysbergh, Ewout,Stevens, Christian V.,De Kimpe, Norbert,Mangelinckx, Sven
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p. 2539 - 2549
(2015/02/19)
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- Mesoionic 5-alkyl-1,3-dithiolium-4-thiolates: Synthesis and brine shrimp toxicity
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A series of twelve 1,3-dithiolium-4-thiolate mesoionic compounds were synthesized and characterized. The synthetical approach starting from α-bromoalkanoic acids to obtain the corresponding 2-N-morpholino-dithiocarbamoyl-carboxylic acids that by on-pot reaction with carbon disulfide and acetic anhydride in triethylamine formed not isolate intermediates, 1,3-dithiolium-4-olates. After, the 2-N-morpholino-5-alkyl-1,3-dithiolium-4-thiolates were obtained by retro 1,3-dipolar addition reactions. The alkyl moiety linked to C-5 of heterocyclic ring permitted the increase of the hydrophobic character and this effect was evaluated on Artemia salina lethality. The results indicated a bell-shaped relationship between the number of carbon of side chain in mesoionic derivatives and LD50 in brine shrimp toxicity assays.
- De Almeida, Paulo Afonso,Da Silva, Tania Maria Sarmento,Echevarria, Aurea
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p. 593 - 600
(2007/10/03)
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