Novel Schiff bases–based thiophenes: Design,synthesis and biological evaluation

2-amino-5-(3-fluoro-4-methoxyphenyl)thiophene-3-carbonitrile derivatives have been synthesized from 1-(3-fluoro-4-methoxyphenyl)ethanone, malononitrile, mild base, and sulfur powder using the Gewald method through a multistep reaction sequence. The structures of newly synthesized compounds were established on the basis of their elemental analyses, IR, ¹H NMR, ¹³C NMR, and mass spectral data, and then synthesized compounds were screened for their in vitro antimicrobial activity. Among them, derivatives 3b (thiphene), 3f (pyrazole), and 3d (halogen) showed good activity and remaining derivatives exhibited moderate activity.     

Design,synthesis, molecular docking,and biological evaluation of novel selenium containing lumefantrine analogues

A new series of 1-(9-benzylidene-2,7-dichloro-9H-fluoren-4-yl)-2-(methylselanyl)ethanol was synthesized by a simple Knoevenagel condensation of 1-(2,7-dichloro-9H-fluoren-4-yl)-2-(methylselanyl)ethanol with different substituted aromatic aldehydes in basic media. These synthesized compounds were confirmed on the basis of their elemental analyses, infrared (IR), ¹H NMR, ¹³C NMR, and mass spectral data and screened for the antibacterial and antifungal activity. The preliminary antibacterial and antifungal screening revealed that the compounds 8c (dichloro), 8d (fluoro), 8e (chloro), 8i (methoxy), and 8l (methyl) displayed moderate to good activity. The antibacterial results of these compounds were further supported by in silico molecular docking studies, for the inhibition of Escherichia coli MurB enzyme (PDB code: 2MBR), wherein they showed higher binding energy and good affinity towards the active pocket of the enzyme compared with that of the standard drug Ciprofloxacin. Thus, the plausible mechanism of their antibacterial activity was owed to their inhibitory action of the bacterial MurB enzyme.