New one-pot synthesis of anti-tuberculosis compounds inspired on isoniazid.

A library of thirty N-substituted tosyl N'-acryl-hydrazones was prepared with p-toluenesulfonyl hydrazide, methyl propiolate and different aldehydes in a one-pot synthesis via an aza-Michael reaction. The scope of the reaction was studied, including aliphatic, isoprenylic, aromatic and carbocyclic aldehydes. The prepared collection was tested against Mycobacterium tuberculosis H37Rv. Nine analogs of the collection showed Minimum Inhibitory Concentration ≤10 µM, of which the most active members (MIC of 1.25 µM) were exclusively E isomers. In order to validate the mechanism of action of the most active acrylates, we tested their activity on a M. tuberculosis InhA over-expressing strain obtaining MIC that consistently doubled those obtained on the wild type strain. Additionally, the binding mode of those analogs on M. tuberculosis InhA was investigated by docking simulations. The results displayed a hydrogen bond interaction between the sulfonamide and Ile194 and the carbonyl of the methyl ester with Tyr 158 (both critical residues in the interaction with the fatty acyl chain substrate), where the main differences on the binding mode relays on the hydrophobicity of the nitrogen substituent. Additionally, chemoinformatic analysis was performed to evaluate in silico possible cytotoxicity risk and ADME-Tox profile. Based on their simple preparation and interesting antimycobacterial activity profile, the newly prepared aza-acrylates are promising candidates for antitubercular drug development.

11a-N-tosyl-5-carbapterocarpans: Synthesis, antineoplastic evaluation and in silico prediction of ADMETox properties.

11a-N-tosyl-5-carbapterocarpans (5a-c and 6a-c), 9-N-tosyl-4,4a,9,9a-tetrahydro-3H-carbazole (7), 11a-N-tosyl-5-carbapterocarpen (8) analogues of LQB-223 (4a), were synthesized through palladium catalyzed azaarylation of substituted dihydronaphtalenes (14a-c) and cyclohexadiene (15), respectively, with N-tosyl-o-iodoaniline (11). In order to understand the role of the N-tosyl moiety for the pharmacological activity, the azacarbapterocarpen (9) was also synthesized by Fischer indol reaction. The structural requirements at the A and D-rings for the antineoplastic activity toward human leukemias and breast cancer cells were evaluated as well. Substitutions on the A-ring of 4a and analogues alter the effect on different breast cancer subtypes. On the other hand, A-ring is not essential for antileukemic activity since compound 7, which does not contain the A-ring, showed efficacy with high selectivity indices for drug-resistant leukemias. On the other hand, substitutions on the D-ring of 4a for fluorine or iodine did not improve the antileukemic activity. In silico studies concerning Lipinskís rule of five, ADMET properties and drug scores of those compounds were performed, indicating good physicochemical properties for all compounds, in special for compound 7.