Anti-lung Cancer Activity of Synthesized Substituted 1,4-Benzothiazines: An Insight from Molecular Docking and Experimental Studies.

BACKGROUND: Thiazine, a 6-membered distinctive heterocyclic motif with sulfur and nitrogen atoms, is one of the heterocyclic compounds that functions as a core scaffold in a number of medicinally significant molecules. Small thiazine-based compounds may operate simultaneously on numerous therapeutic targets and by employing a variety of methods to halt the development, proliferation, and vasculature of cancer cells. We have, herein, reported a series of substituted 1,4 benzothiazines as potential anticancer agents for the treatment of lung cancer. METHODS: In order to synthesize 2,3-disubstituted-1,4 benzothiazines in good yield, a facile green approach for the oxidative cycloaddition of 2-amino benzenethiol and 1,3-dicarbonyls employing a catalytic amount of ceric ammonium nitrate has been devised. All the molecules have been characterized by spectral analysis and tested for anticancer activity against the A-549 lung cancer cell line using various functional assays. Further in silico screening of compound 3c against six crucial inflammatory molecular targets, such as Il1-α (PDB ID: 5UC6), Il1- ß (PDB ID: 6Y8I), Il6 (PDB ID: 1P9M), vimentin (PDB ID: 3TRT), COX-2 (PDB ID: 5KIR), Il8 (PDB ID: 5D14), and TNF-α (PDB ID: 2AZ5), was done using AutoDock tool. RESULTS: Among the synthesized compounds, propyl 3-methyl-3,4-dihydro-2H-benzo[b][1,4]thiazine-2- carboxylate (3c) was found to be most active based on cell viability assays using A-549 lung cancer cell line and was found to effectively downregulate various pro-inflammatory genes, like Il1-α, Il1-ß, Il6, vimentin, COX-2, Il8, and TNF-α in vitro. The ability of the molecule to effectively suppress the proliferation and migration of lung cancer cells in vitro has been further demonstrated by the colony formation unit assay and wound healing assay. Molecular docking analysis showed the maximal binding affinity (- 7.54 kcal/mol) to be exhibited by compound 3c against IL8. CONCLUSION: A green unconventional route for the synthesis of 2,3-disubstituted-1,4 benzothiazines has been developed. All the molecules were screened for their activity against lung cancer and the data suggested that the presence of an additional unbranched alkyl group attached to the thiazine ring increased their activity. Also, in vitro and in silico modeling confirmed the anti-cancer efficiency of compound 3c, encouraging the exploration of such small molecules against cancer.

Anti-cancer potential of natural products containing (6H-dibenzo[b,d]pyran-6-one) framework using docking tools.

To explore complex biological and chemical systems, pharmaceutical research has effectively included several molecular modeling tools into a range of drug development initiatives. Molecular docking methods are widely employed in current drug design to investigate ligand conformations within macromolecular targets' binding sites. This method also estimates the ligand-receptor binding free energy by assessing critical phenomena involved in the intermolecular recognition process. In an attempt, several natural products have been synthesized in our laboratory. All the synthesized compounds containing (6H-Dibenzo[b,d]pyran-6-one) framework were subjected to molecular docking studies for the inhibition of CYP1B1 and BCL2 proteins using Auto Dock Vina software and the interacting amino acid residues were visualized using Discovery Studio, to look into the binding modalities that might influence their anticancer properties. The in silico molecular docking study outcomes showed that all the synthesized compounds having optimum binding energy and have a decent affinity to the active pocket, thus, they may be considered as a respectable inhibitor of CYP1B1 and BCL2 proteins.