Marie-Renee Nourrisson

N-pyridinyl-indole-3-(alkyl)carboxamides and derivatives as potential systemic and topical inflammation inhibitors

N-substituted-(indol-3-yl)carboxamides 10-15 and alkanamides 16-18 were prepared starting from the corresponding acids and submitted to screening for evaluation of their anti-inflammatory activity. None of the considered carboxamides exhibited significant inhibitory effect in the carrageenin-induced rat paw oedema after oral administration of 0.1 mM x kg(-1); nevertheless introduction of an alkyl chain, leading to alkanamides 16-18, induced moderate to high activity: 46-95% inhibition. The efficacy of these compounds in the inhibition of topical inflammation was confirmed by measuring reduction of ear thickness in the acute tetradecanoyl phorbol acetate (TPA)-induced mouse ear swelling assay. Preliminary pharmacomodulation brought to the fore that toxic effects induced, at 0.4 mM x kg(-1), by N-(pyridin-4-yl)(indol-3-yl)propanamide (17) could be attenuated or suppressed by 5-fluorination or introduction of a methoxycarbonylborane moiety, leading to 18 and 21.

Structural investigation and elucidation of new communesins from a marine-derived Penicillium expansum Link by liquid chromatography/electrospray ionization mass spectrometry

Penicillium expansum is a ubiquitous species for which there are only few reports for chemical investigation in marine environments. Among the numerous secondary metabolites produced by this species, communesins represent a new class of cytotoxic and insecticidal indole alkaloids. In this study, we investigated a marine P. expansum strain exhibiting neuroactivity on a Diptera larvae bioassay. Bio-guided purification led to the isolation and the identification of communesin B as the main active compound by HRMS and 1H and 13C NMR. Liquid chromatography analyses with detection by electrospray ionization coupled with tandem mass spectrometry (LC/ESI-MS/MS) and high-resolution tandem mass spectrometry (LC/HRMS/MS) allowed the identification and characterization of four other known communesins (A, D, E and F) in the crude extract. A fragmentation model for dimethyl epoxide communesins was proposed after detailed interpretation of their MS/MS spectra. Further analyses of the extract using the modelled fragmentations led to the detection of seven new communesins found as minor compounds. Chemical structural elucidation of these new derivatives is discussed based on their fragmentation characteristics.

New N -pyridinyl(methyl)-indole-2- and 3-(Alkyl)carboxamides and Derivatives Acting as Systemic and Topical Inflammation Inhibitors

A series of novel N -substituted-(indol-2-yl)carboxamides (12 - 18) and (indol-3-alkyl)carboxamides (25 - 31) were synthesized and evaluated as inhibitors of the inflammation process. Pharmacomodulation at the level of the amidic nitrogen by incorporation of the previously described pharmacophoric moieties 6-aminolutidine, β -picolylamine, 4-aminopyridine and piperazine was investigated; only two compounds (12) and (31) exhibited significant (~40%) inhibitory effect in the carrageenan-induced rat paw edema after oral administration of a dose of 0.1 mM kg −1. Replacement of the indole core by indazole failed to increase activity. Incorporation of an alkyl chain spacer led to more efficient compounds (46 - 52) especially in the indolepropanamide sub-series. Determination of the efficiency of the most active compounds on topical inflammation, by measuring reduction of ear thickness in the acute tetradecanoyl phorbol acetate (TPA)-induced mouse ear swelling assay, confirmed the high potency of propanamides (49) and (51) after oral administration: ID50 =0.041 ± 0.013 and 0.042 ± 0.016 mM kg −1 respectively. The less toxic propanamide (51) exerted a high level of inhibitory activity after topical application of 2 × 100 μg/ear: 78 ± 2%.

Potential Inhibitors of Angiogenesis. Part I: 3-(Imidazol-4(5)-ylmethylene)indolin-2-ones

The synthesis and pharmacological evaluation of new 3-(imidazol-4(5)-ylmethylene)indolin-2-ones, analogues of SU-5416, are reported. The final compounds 20-51 were obtained by Knoevenagel coupling between the substituted indolin-2-ones 1-15 and either the formylimidazole derivatives 16-18 or 2-formyl-3,5-dimethylpyrrole 19. Methylation at the nitrogen atom of the indolin-2-one and/or imidazole moities was carried out in the presence of the couple NaH/DMF. A Mannich reaction afforded the 1-dimethylaminomethyl derivatives 43 and 48. The antiangiogenic activity of these compounds was evaluated in a three dimensional in vitro rat aortic ring assay. In this test, compound 20 induced a decrease of angiogenesis comparable to that observed with SU-5416; the vascular density indexes at 1 μM were 30±18 and 22±4 % of control, respectively. The compounds were also evaluated, in an independent manner, as inhibitors of the human EGF-receptor tyrosine kinase activity. As expected, only minor activities were observed with four compounds, out of thirty-one, exerting inhibitory effects in the range of 40-55 % at 10 μM concentration.

Synthesis, antileishmanial activity and cytotoxicity of 2,3-diaryl- and 2,3,8-trisubstituted imidazo[1,2-a]pyrazines

A series of original 2-phenyl-3-(pyridin-4-yl)imidazo[1,2-a]pyrazines and the 3-iodo precursors, bearing a polar moiety at the C-8 position, was synthesized and evaluated for their antileishmanial activities. Two derivatives exhibited very good activity against the promastigote and the amastigote forms of Leishmania major in the micromolar to submicromolar ranges, coupled with a low cytotoxicity against macrophages and 3T3 mouse fibroblast cells. Through LmCK1 inhibition assay, investigations of the putative molecular target of these promising antileishmanial compounds will be discussed.

Indole carboxamides inhibit bovine testes hyaluronidase at pH 7.0 and indole acetamides activate the enzyme at pH 3.5 by different mechanisms

Hyaluronidases are enzymes controlling many crucial physiological processes. Imbalanced enzymatic activity is connected with severe diseases. Because there is limited availability of drugs modulating hyaluronidase activity, the search for hyaluronidase interacting compounds is getting more and more important. A series of fifteen indole carboxamides and acetamides were synthesized and tested on inhibition of bovine testes hyaluronidase. In vitro assays were performed using stains-all at pH 7 and the Morgan-Elson reaction at pH 3.5. At neutral pH, the most active inhibitory compound was N-(Pyridin-4yl)-[5-bromo-1-(4-fluorobenzyl)indole-3-yl]carboxamide (20) with an IC50 value of 46 μM. Surprisingly, inhibition of all compounds was completely abolished by a decrease in pH. At pH 3.5 the activity of the enzyme was increased up to 134% by compound N-(4,6-Dimethylpyridin-2yl)-(1-ethylindole-3-yl)acetamide (24) at a concentration of 100 μM. The known activating effect of bovine serum albumine (BSA) on hyaluronidase activity was verified in the assay and compared to the effect of compound 24. Structure-activity relationships are discussed and a model is proposed, which explains the increase in activity at pH 3.5 by bonding of the protonated form of N-(4,6-Dimethylpyridin-2yl)-(1-ethylindole-3-yl)acetamide (24) to hyaluronic acid. The bonding results in an elongated form of the substrate with easier enzymatic access.

Synthesis and biological evaluation of 3-(azolylmethyl)-1H-indoles and 3-(α-azolylbenzyl)-1H-indoles as selective aromatase inhibitors

This present study identifies a number of azolyl-substituted indoles as potent inhibitors of aromatase. In the sub-series of 3-(azolylmethyl)-1H-indoles, four imidazole derivatives and their triazole analogues were tested. Imidazole derivatives 11 and 14 in which the benzyl moiety was substituted by 2-chloro and 4-cyano groups, respectively, were the most active, with IC50 values ranging between 0.054 and 0.050 μM. In the other sub-series, eight 3-(α-azolylbenzyl)-1H-indoles were prepared and tested. Compound 30, the N-ethyl imidazole derivative, proved to be an aromatase inhibitor, showing an IC50 value of 0.052 μM. All target compounds were further evaluated against 17α-hydroxylase/C17,20-lyase to determine their selectivity profile.

New N-pyridinyl(methyl)-N1-substituted-3-indolepropanamides acting as topical and systemic anti-inflammatory agents.

N-Pyridinyl(methyl)-N1-substituted-3-indolepropanamides (17–32) were prepared starting from the corresponding acids and screened for their anti-inflammatory activity. Pharmacomodulation was carried out on the indole and amidic nitrogens by incorporation of substituents associated with higher potency in previously synthesized related 3-indolepropanamides series. In the inhibition of topical inflammation determined by reduction of ear thickness in the acute PMA mouse ear swelling test, high levels of activity (ID50∼0.030 mMol kg-1) were noticed for the five propanamides 17, 21, 22, 27 and 31. A comparative study showed the positive influence of a methyl group at the indole nitrogen in the 4-pyridinyl sub-series (1→21) and of a 4-fluorobenzyl group in the 3-pyridinylmethyl sub-series (19→31), at least after oral administration. After topical application, although compounds 17, 21, 22, 27 and 31 exerted significant (50%) ear œdema inhibition at 2×50 μg/ear, they remained less potent than 24, 29 and 30 (almost 70% inhibition). Among these eight amides, only 17, 21, 22 and 27 showed a significant activity in the carrageenan rat paw œdema model at 0.2 mMol kg-1. Finally, although less active than the N-(4-pyridinyl) amide 21, the N-4,6-dimethyl-2-pyridinyl derivatives 17 and 27 were devoid of the toxic effects observed with 21 and to a lesser extent with 22.

Design, synthesis and evaluation of new 6-substituted-5-benzyloxy-4-oxo-4H-pyran-2-carboxamides as potential Src inhibitors

Src family kinases (SFKs) are nonreceptor tyrosine kinases that are reported to be critical for cancer progression. Inhibiting the catalytic activity of these proteins has become one of the major therapeutic concepts in contemporary drug discovery. We report here the design and the synthesis of novel 6-substituted-5-benzyloxy-4-oxo-4H-pyran-2-carboxamides as potential inhibitors of Src kinase. The synthesis of these derivatives and the preliminary results of biological activity will be discussed.