Natural organic pigments such as carotenoids, betalains, anthocyanins, and carminic acid are notably found as safer food preservatives compared to other harmful synthetic chemicals. Due to glycosylation and acylation, betalains exhibit a broad-spectrum antimicrobial functionality with protection against degenerative diseases. Thus, betalains have been investigated as a potential bacterial inhibitor for food preservative applications. Initially, 36 betalain derivatives have been taken for primary screening using molecular docking. Afterward, the top ten ligands are taken for further study and analysis. The results of Prediction of Activity Spectrum of Substances (PASS) assured the antibacterial capabilities of betalains, and Lipinski's rule-of-five ensures the acceptability of the selected ligands as antibacterial inhibitors. The bacterial pathogens, such as C. botulinum (3FIE), E. coli (2ZWK), and S. typhi (3UU2) are selected for molecular docking by these betalain pigments. Furthermore, ADMET investigations and QSAR studies are performed to check insights into the bacterial inhibition process. Most active and common binding sides were observed at GLY159, ASN165, and SER166 for C. botulinum, at ASP8, LYS40, and TRP50 for E. coli; and at ARG37, GLN5, and ARG74 for S. typhi. The present study clearly shows an excellent insight towards the invention of plant-based new organic inhibitors to face the challenges of bacterial-resistant common food preservatives.

A convenient and efficient synthesis of a series of ethyl-1-(6-(4-substitutedacetylatedpiperazin-1-yl)pyrimidin-4-yl)-5-amino-1H-pyrazole-4-carboxylate (8a-8j) has been developed by five steps which include activation of a methylene group, hydrazinolysis, cyclisation and chloro-amine coupling reactions. Moreover, our proposed mechanism was confirmed in this study demonstrating that ethyl 5-amino-1-(6-chloropyrimidin-4-yl)-1H-pyrazole-4-carboxylate is the key intermediate to fulfill the desired outcomes. In silico and in vitro studies were carried out to identify the active agents among the developed adducts against mycobacterium tuberculosis (PDB ID:4TRO). Compound 8a (Docking Score: -26.81 and MIC: 1.6 ug/mL) was found to be the most potent among the synthesized molecules. All the synthesized compounds showed acceptable drug-like properties which make them suitable for further lead modification using in silico design approaches.

A simple and efficient method for the synthesis of fifteen novel ketene dithioacetals (2-(6-amino5-cyano-4-aryl-4H-1,3-dithiin-2-ylidene) malononitrile) via a one-pot three-component reaction of activated methylene group malononitrile with carbon disulfide in the presence of arylidene malononitriles were reported. The effects of LiOH.H₂O as a base at different concentrations have been investigated and can provide products in good yields at 40-50ºC temperature (54-89%). All the synthesized ketene dithioacetals compounds (MCB1-MCB15) were checked for favorable pharmacokinetic param¬eters along with toxicities which are based on drug-likeness explained by Lipinski’s rule of five by Med chem designer software correlated with that of pkCSM online tool. Explorations of synthesized ketene dithioacetals compounds for the antimicrobial study were found to be effective towards Staphylococcus aureus (MCB5 and MCB13) with a zone of inhibition at 26mm and 22mm which is compared to that of standard ciprofloxacin (26mm). This made our study to explore the inhibition mechanism with the help of molecular docking studies with possible binding energies (-6.4 to -8.9 kJ/mol) by pyrx 0.8 software to represent a good prediction of interactions between the ligand and protein (2XCT). Further evaluation of druggability and ADMET predictions compounds MCB5 and MCB13 were found to be effective. Based on the in-vitro and in-silico studies a series of ketene dithioacetals compounds may be helpful for further studying SAR and designing more potent antimicrobials.

A sequence of pyrano[2, 3-c]pyrazoles was constructed through promoting an eco-friendly, green, and efficient approach. M1-M25 derivatives were developed by a base-catalyzed one-pot reaction involving application of hydrazine hydrate 96%, β-keto ester as ethyl acetoacetate or diethyl malonate, aryl/heteroaryl aldehyde or isatin, and enolizable active methylene compounds with isolation of unexpected compound M2. Further on, intramolecular cyclization of compounds M10, M13 with formic acid, acetic anhydride, and formamide leads to the corresponding pyrimidine derivatives M26-M31. Afterwards, the antimicrobial activity of the compounds was evaluated and fortunately, the vast majority of the compounds showed outstanding anti-bacterial results. Besides, the potential mode of action of the synthesized compounds was determined by employing a molecular-docking study against penicillin-binding protein implicated in anti-bacterial action. Compound M21 was one of the most promising anti-bacterial agents with potential binding affinity against the penicillin-binding protein. This study shed light on novel compounds for further antimicrobial drug development.

Sulfonamides are a very good antibacterial agent that targets essential bacterial enzymes specifically DNA gyrase. The objective of the present work was to investigate the molecular docking of the (4-(tert-butyl)-N,N-diethylbenzenesulfonamide) with the DNA gyrase of S. aureus. The energy-free topoisomerase activity of the A subunit, which breaks the DNA, is inhibited by 4-quilones such as nalidixic acid and ciprofloxacin. The energy transducing activity of the B subunit is inhibited by novobiocin and other coumarin antibiotics. Single crystal X-ray diffractometer study was carried out to understand the structure, physical and chemical reactive parameters, the title compound is crystallized under monoclinic crystal system with the space group of P21/C. To understand the behaviour of the title compound in living organism, Absorption, Distribution, Metabolism, Excretion analysis was done using Swiss ADME and Osiris data warrior tool. Further, Toxicity of the title compound was predicted by using PKCSM online software.

O-Acyl substituted derivatives of 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride which is a structural analog of vitamin B₁ were synthesized and evaluated towards acetylcholinesterase and butyrylcholinesterase in vitro. The inhibition properties of the O-substituted compounds depend on nature of substituents at position 3 and 5 of the thiazolium ring. Some of the thiazolium salts showed high potency in the inhibition of only one of the two enzymes. The selective effects of these inhibitors are governed by substituent at position 5. Kinetic studies and molecular docking simulation were performed for elucidating mechanisms of enzyme-inhibitor complex formation.