Synthesis, molecular docking and antibacterial evaluation of new 1,4-naphthoquinone derivatives contains carbazole-6,11-dione moiety

A new series of new 1,4-naphthoquinone derivatives containing carbazole-6,11-dione moiety, which has not been reported yet, has been synthesized from 1,4-naphthoquinone and 4-aminophenylsulfone involving a Michael addition, benzoylation, and Pd-catalyzed coupling. This set of compounds has been evaluated for in vitro antibacterial studies against different Gram-positive and Gram-negative bacteria, and most of the synthesized compounds exhibited good antibacterial activity and the minimum inhibitory concentrations (MICs) are compared with the standard drugs used. Compound 7 exhibited good antibacterial activity among all the molecules studied with the best MIC of 2.1 μg/mL against Bacillus subtilis. To understand the molecular interactions with targeted proteins, the molecular docking of all the synthesized compounds were carried out; between 14 molecules docked, compound 7 was the one with the best glide and E model score of -7.73 and -95.37, respectively. In all docked molecules, compound 5 exhibited least glide and E model score of -4.55 and -101.56, respectively. Figureᅟ

E(2)-Elimination in the Decomposition of N-Bromoamino Acid Anions

The kinetics of oxidation of eight structurally different amino acids by hypobromite ion (BrO(-)) in the presence of hydroxide ion has been studied. The reactions proceed through the rapid formation of N-bromoamino acid anion which then decomposes in the rate-limiting step. The decomposition of N-bromoamino acid anions is found to proceed through an unimolecular and a base-catalyzed reaction. The large negative values of DeltaS() and the products formed suggest that the hydroxide ion-catalyzed reactions proceed through an E(2) mechanism. N-Bromoamino acid anion gives an absorption spectrum with lambda(max) at approximately 290 nm.