Calixarene based chiral solvating agents for α-hydroxy carboxylic acids

MoS2-Calix[4]arene Catalyzed Synthesis and Molecular Docking Study of 2,4,5-Trisubstituted Imidazoles As Potent Inhibitors of Mycobacterium tuberculosis

A MoS2-supported-calix[4]arene (MoS2-CA4) nanocatalyst was used for efficient synthesis of 2,4,5-trisubstituted imidazole derivatives from 1-(4-nitrophenyl)-2-(4-(trifluoromethyl)phenyl)ethane-1,2-dione, aldehydes and ammonium acetate under solvent-free conditions. Reusability of the catalyst up to five cycles without any significant loss in the yields of the product is the unique feature of this heterogeneous solid catalysis. Furthermore, the noteworthy highlights of this method are safe reaction profiles, broad substrate scope, excellent yields, economical, solvent-free, and simple workup conditions. All synthesized compounds were evaluated for their in vitro antitubercular (TB) activity against Mycobacterium tuberculosis (Mtb) H37Rv. Among the screened compounds 3c, 3d, 3f, 3m, and 3r had MIC values of 2.15, 2.78, 5.75, 1.36, and 0.75 μM, respectively, and exhibited more potency than the reference drugs pyrazinamide (MIC: 3.12 μM), ciprofloxacin (MIC: 4.73 μM), and ethambutol (7.61 μM). Besides, potent compounds (3c, 3d, 3f, 3m, and 3r) have been tested for inhibition of MabA (β-ketoacyl-ACP reductase) enzyme and cytotoxic activity against mammalian Vero cell line. A molecular docking study was carried out on the MabA (PDB ID: 1UZN) enzyme to predict the interactions of the synthesized compounds. The results of the in vitro anti-TB activity and docking study showed that synthesized compounds have a strong anti-TB activity and can be adapted and produced more effectively as a lead compound.

Enantioselective recognition of carboxylic acids by novel fluorescent triazine-based thiazoles

Hydrogen bonding and π-π interactions take special part in the enantioselectivity task. In this regard, because of having both hydrogen acceptor and hydrogen donor groups, melamine derivatives become more of an issue for enantioselectivity. In the light of such information, triazine-based chiral, fluorescence active novel thiazole derivatives L1 and L2 were designed and synthesized from (S)-(-)-2-amino-1-butanol and (1S,2R)-(+)-2-amino-1,2-diphenylethanol. The structural establishment of these compounds was made by spectroscopic methods such as FTIR, ¹ H, and ¹³ C NMR. While the solution of these compounds in DMSO did not show any fluorescence emission, it was observed that the emission increased 44-fold for L1 and 55-fold for L2 in 95% water, similar to the aggregation-induced emission (AIE) characterized compounds. In this regard, enantioselective capabilities of these compounds against carboxylic acids were tested, and in experiments carried out at a ratio of 40/60 DMSO/H₂ O, it was determined that R-2ClMA increased the fluorescence emission of L1 chiral receptor by 2.59 times compared to S-isomer.