Cell wall component and mycotoxin moieties involved in binding of fumonisin B1 and B2 by lactic acid bacteria.

International audienceAims: The ability of lactic acid bacteria (LAB) to bind fumonisins B1 and B2 (FB1, FB2) in fermented foods and feeds and in the gastrointestinal tract could contribute to decrease their bioavailability and toxic effects on farm animals and humans. The aim of this work was to identify the bacterial cell wall component(s) and the functional group(s) of FB involved in the LAB-FB interaction. Methods and Results: The effect of physicochemical, enzymatic and genetic treatments of bacteria and the removal/inactivation of the functional groups of FB on toxin binding were evaluated. Treatments affecting the bacterial wall polysaccharides, lipids and proteins increased binding, while those degrading peptidoglycan (PG) partially decreased it. In addition, purified PG from Gram-positive bacteria bound FB in a manner analogue to that of intact LAB. For FB, tricarballylic acid (TCA) chains play a significant role in binding as hydrolysed FB had less affinity for LAB. Conclusions: Peptidoglycan and TCA are important components of LAB and FB, respectively, involved in the binding interaction. Significance and Impact of the Study: Lactic acid bacteria binding efficiency seems related to the peptide moiety structure of the PG. This information can be used to select probiotics with increased FB binding efficiency

Synthesis and biological evaluation of diversely substituted indolin-2-ones

International audienceThe synthesis of indolin-2-one derivatives substituted in the 3-position by an aminomethylene group bearing either an ornithine or a lysine residue is described. The inhibitory activities of these compounds toward a panel of eight kinases were examined. Furthermore, the antibacterial activities of the prepared compounds were tested against two Gram-positive bacteria Bacillus cereus and Streptomyces chartreusis, a Gram-negative bacterium Escherichia coli and a yeast Candida albicans

Synthesis and antiproliferative activities of indolin-2-one derivatives bearing amino acid moieties.

A convenient synthesis of indolin-2-ones substituted in the 3 position by an aminomethylene group bearing different amino acid moieties is described. Their antiproliferative activities were evaluated toward a panel of human solid tumor cell lines (PC 3, DLD-1, MCF-7, M4 Beu, A549, PA 1) and healthy cell lines (a murine fibroblast L929 and a human fibroblast primary culture

Synthesis and biological evaluation of oxindoles and benzimidazolines derivatives

The synthesis of new oxindoles and benzimidazolinones derivatives bearing a sugar residue on the aromatic nitrogen is described. The presence of the glycoside moiety should enhance the solubility of these heterocyclic compounds and/or improve the interaction with the active site of the biological targets. The inhibitory activities of these new compounds toward five kinases were examined: KDR (VEGFR-2), FGFR-1, PDGFR-β, EGFR and Tie 2. Furthermore, the antibacterial activities of the prepared compounds were tested against two Gram-positive bacteria Bacillus cereus and Streptomyces chartreusis, a Gram-negative bacterium Escherichia coli and a yeast Candida albican

Synthesis, in vitro antiproliferative activities, and Chk1 inhibitory properties of pyrrolo[3,4-a]carbazole-1,3-diones, pyrrolo[3,4-c]carbazole-1,3-diones, and 2-aminopyridazino[3,4-a]pyrrolo[3,4-c]carbazole-1,3,4,7-tetraone

The synthesis of substituted pyrrolo[3,4-a]carbazole-1,3-diones, pyrrolo[3,4-c]carbazole-1,3-diones, and 2-aminopyridazino[3,4-a]pyrrolo[3,4-c]carbazole-1,3,4,7-tetraone is reported. Their inhibitory properties toward Checkpoint 1 kinase (Chk1) have been evaluated and their in vitro antiproliferative activities toward three tumor cell lines: murine leukemia L1210, human colon carcinoma HT29 and HCT116 have been determined. From the biological results, it appears that, in contrast with the upper E heterocycle, the lower D heterocycle is not absolutely required for Chk1 inhibition. The ATP binding pocket of Chk1 seems to be adaptable to substitution of the nitrogen of the imide E heterocycle with a hydroxymethyl group, allowing the fundamental hydrogen bond with the Glu85 residue of the enzym

Bis-imide granulatimide analogues as potent Checkpoint 1 kinase inhibitors.

Granulatimide and isogranulatimide, natural products isolated from an ascidian, were found to be abrogators of the cell cycle G2-M phase checkpoint by inhibition of Checkpoint 1 kinase (Chk1). In the course of structure–activity relationship studies on granulatimide analogues, we have synthesized a series of bis-imides, in which the imidazole moiety was replaced by an imide heterocycle. Various modifications have been introduced on one or both imide heterocycles, on the benzene ring, and on the indole nitrogen. Moreover, aza bis-imide analogues were synthesized in which the indole moiety was replaced by a 7-azaindole. Compared to those of granulatimide and isogranulatimide, the Chk1 inhibitory activities of some of the bis-imide carbazoles were stronger. In particular, 1,3,4,6-tetrahydro-10-hydroxy-7H-dipyrrolo[3,4-a:3,4-c]carbazole-1,3,4,6-tetraone 11 exhibited an IC50 value on purified full length Chk1 of 2 nM, which makes it a more potent Chk1 inhibitor than granulatimide and isogranulatimide. To get an insight into the selectivity of this new family of compounds, the inhibitory activities of 1,3,4,6-tetrahydro-7H-dipyrrolo[3,4-a:3,4-c]carbazole-1,3,4,6-tetraone A have been evaluated on a panel of 15 kinases, the strongest inhibitory potency was found for Chk1. The inhibitory activities of compounds A, 5 and 11 toward Src tyrosine kinase and the cytotoxicity of various tumor cell lines were also evaluate

Criblage virtuel : valorisation d'une chimiothèque sur des cibles anticancéreuses

Poste

Synthesis and in vitro antiproliferative activities of quinoline derivatives

International audienceThe synthesis of new di- and trimeric quinoline derivatives is described as well as their in vitro antiproliferative activities toward a human fibroblast primary culture and two human solid cancer cell lines (MCF-7 and PA 1)

Substrate specificity study of aspartate aminotransferase kinetics and modeling

Poste

Synthesis of new hydroxybenzo[Α]carbazoles

International audienc