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In the context of our ongoing studies on 3-nitroimidazo[1,2-a]pyridine derivatives as potent antileishmanial compounds, we isolated a new unexpected compound from the spontaneous cycloaddition of N-[2-(8-bromo-6-chloro-3-nitroimidazo[1,2-a]pyridin-2-yl)-1-(4-chlorophenyl)ethyl]-4-methylbenzenesulfonamide. The molecular structure was fully characterized by using 1H and 13C NMR, X-ray crystallography, and HRMS. [ABSTRACT FROM AUTHOR]

A series of 61 thiazolidine-2,4-diones bearing a styryl group at position 5 was synthesized in 2–5 steps and their structure was proved by elemental and spectral analyses. The compounds obtained were evaluated in vitro against the promastigote stage of the kinetoplastid parasite Leishmania infantum and the human HepG2 cell line, to determine selectivity indices and to compare their activities with those of antileishmanial reference drugs. The study of structure–activity relationships indicated the potential of some derivatives bearing a nitro group on the phenyl ring, especially when located at the meta position. Thus, among the tested series, compound 14c appeared as a hit compound with good antileishmanial activity (EC50 = 7 µM) and low cytotoxicity against both the hepatic HepG2 and macrophage THP-1 human cell lines (CC50 = 101 and 121 µM, respectively), leading to good selectivity indices (respectively, 14 and 17), in comparison with the reference antileishmanial drug compound miltefosine (EC50 = 3.3 µM, CC50 = 85 and 30 µM, SI = 26 and 9). Regarding its mechanism of action, among several possibilities, it was demonstrated that compound 14c is a prodrug bioactivated, predominantly by L. donovani nitroreductase 1, likely leading to the formation of cytotoxic metabolites that form covalent adducts in the parasite. Finally, compound 14c is lipophilic (measured CHI LogD7.7 = 2.85) but remains soluble in water (measured PBS solubility at pH7.4 = 16 µM), highlighting the antileishmanial potential of the nitrostyrylthiazolidine-2,4-dione scaffold. [ABSTRACT FROM AUTHOR]

The Group for the Promotion of Pharmaceutical Chemistry in Academia (GP2A) held its 31st annual conference in August 2023 at the Faculty of Pharmacy of Aix-Marseille University, Marseille, France. There were 8 keynote presentations, 10 early career researcher oral presentations and 23 poster presentations. Among them, four awards were delivered, two for best oral communications and two for the best poster presentations. [ABSTRACT FROM AUTHOR]

In continuation of our research program to develop original synthetic methods using TDAE methodology on nitroheterocyclic substrates, we were able to generate for the first time a stable carbanion in position 2 of the 5-nitroimidazole scaffold. Starting from a 2-chloromethyl-4-phenylsulfonylmethyl-5-nitroimidazole intermediate, prepared by the vicarious nucleophilic substitution of hydrogen (VNS) reaction, we selectively introduced a N-tosylbenzylimine moiety at position 2 without reducing the sulfone at position 4, leading to the formation of N-[1-(2-chlorophenyl)-2-{1-methyl-5-nitro-4-[(phenylsulfonyl)methyl]-1H-imidazol-2-yl}ethyl]-4-methylbenzenesulfonamide in 47% yield. This new synthetic method using TDAE should allow access to new 2-substituted 5-nitroimidazole derivatives with various electrophiles such as carbonyls and other N-tosylbenzylimines. [ABSTRACT FROM AUTHOR]

As part of our ongoing antikinetoplastid structure–activity relationship study focused on positions 2 and 8 of the 3-nitroimidazo[1,2-a]pyridine scaffold, we were able to introduce a phenylthioether moiety at both position 2 and position 8 in one step. Using a previously reported synthetic route developed in our laboratory, we obtained 6-chloro-3-nitro-8-(phenylthio)-2-[(phenylthio)methyl]imidazo[1,2-a]pyridine in 74% yield. The in vitro cell viability of this compound was assessed on the HepG2 cell line, and its in vitro activity was evaluated against the promastigote form of L. donovani, the axenic amastigote form of L. infantum and the trypomastigote blood stream form of T. b. brucei. It showed low solubility in HepG2 culture medium (CC50 > 7.8 µM), associated with weak activity against both the promastigote form of L. donovani (EC50 = 8.8 µM), the axenic amastigote form of L. infantum (EC50 = 9.7 µM) and the trypomastigote blood stream form of T. b. brucei (EC50 = 12.8 µM). [ABSTRACT FROM AUTHOR]

As part of our ongoing scaffold-hopping work on an antikinetoplastid 3-nitroimidazo[1,2-a]pyridine scaffold, we explored 3-nitroimidazo[1,2-b]pyridazine as a potential new antikinetoplastid series. Using conditions previously described by our lab, we obtained 6-chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine with 54% yield. In vitro activity of this compound was evaluated against both the promastigote form of Leishmania donovani, the axenic amastigote form of Leishmania infantum and the trypomastigote blood stream form of Trypanosomabrucei brucei, and its influence on cell viability was assessed on the HepG2 cell line. However, despite good activity against the trypomastigote blood stream form of T. b. brucei (EC50 = 0.38 µM), it showed poor solubility in both HepG2 (CC50 > 7.8 µM) and L. infantum axenic amastigotes (EC50 > 1.6 µM) culture media, associated with a loss of activity against the promastigote form of L. infantum (EC50 > 15.6 µM). [ABSTRACT FROM AUTHOR]

An antileishmanial structure–activity relationship (SAR) study focused on positions 2 and 8 of the imidazo[1,2-a]pyridine ring was conducted through the synthesis of 22 new derivatives. After being screened on the promatigote and axenic amastigote stages of Leishmania donovani and L. infantum, the best compounds were tested against the intracellular amastigote stage of L. infantum and evaluated regarding their in vitro physicochemical and pharmacokinetic properties, leading to the discovery of a new antileishmanial6-chloro-3-nitro-8-(pyridin-4-yl)-2-[(3,3,3-trifluoropropylsulfonyl)methyl]imidazo[1,2-a]pyridine hit. It displayed low cytotoxicities on both HepG2 and THP1 cell lines (CC50 > 100 µM) associated with a good activity against the intracellular amastigote stage of L. infantum (EC50 = 3.7 µM versus 0.4 and 15.9 µM for miltefosine and fexinidazole, used as antileishmanial drug references). Moreover, in comparison with previously reported derivatives in the studied series, this compound displayed greatly improved aqueous solubility, good mouse microsomal stability (T1/2 > 40 min) and high gastrointestinal permeability in a PAMPA model, making it an ideal candidate for further in vivo studies on an infectious mouse model. [ABSTRACT FROM AUTHOR]

series of new quinazoline derivatives bearing a vinylic chloride group on the 2-position was prepared by using a consecutive SRN1 / ERC1 radical strategy. [ABSTRACT FROM AUTHOR]