Design, synthesis and biological evaluation of substituted 2-amino-1,3-thiazine derivatives as antituberculosis and anti-cancer agents

Anticancer Potential of β-Carboline Alkaloids: An Updated Mechanistic Overview

his comprehensive review is designed to evaluate the anticancer properties of β-carbolines derived from medicinal plants, with the ultimate goal of assessing their suitability and potential in cancer treatment, management, and prevention. An exhaustive literature survey was conducted on a wide array of β-carbolines including, but not limited to, harmaline, harmine, harmicine, harman, harmol, harmalol, pinoline, tetrahydroharmine, tryptoline, cordysinin C, cordysinin D, norharmane, and perlolyrine. Various analytical techniques were employed to identify and screen these compounds, followed by a detailed analysis of their anticancer mechanisms. Natural β-carbolines such as harmaline and harmine have shown promising inhibitory effects on the growth of cancer cells, as evidenced by multiple in vitro and in vivo studies. Synthetically derived β-carbolines also displayed noteworthy anticancer, neuroprotective, and cognitive-enhancing effects. The current body of research emphasizes the potential of β-carbolines as a unique source of bioactive compounds for cancer treatment. The diverse range of β-carbolines derived from medicinal plants can offer valuable insights into the development of new therapeutic strategies for cancer management and prevention.

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- β (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-β, 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.

Multicomponent reaction (MCR) for constructing bis-spirocyclohexane skeletons using β-nitrostyrene derived MBH acetates, 1,3-indanedione and aldehydes via [1 + 1 + 1 + 3] annulation

An AB2C type four-component quadruple cascade reaction has been established between nitroallylic MBH acetate, 1,3-indanedione and aldehyde for generating bis-spirocyclohexanes. This reaction progressed in an unusual [1 + 1 + 1 + 3] annulation manner via a Knoevenagel/Michael/Michael/Michael sequence, resulting in the generation of three/four chiral centres, and two all-carbon quaternary centres through the formation of 3 new C-C bonds.

Synthesis of trans N-Substituted Pyrrolidine Derivatives Bearing 1,2,4-triazole Ring

BACKGROUND

1,2,4-triazoles scaffolds display significant biological activities due to hydrogen bonding, solubility, dipole character, and rigidity.

OBJECTIVE

The core motif of 1,2,4-triazoles plays a vital role in clinical drugs such as Rizatriptan (anti-migraine), Ribavirin (antiviral), anastrozole (anticancer), etizolam (anxiolytic), estazolam (anticonvulsant), alprazolam (anti-hypnotic), letrozole (aromatase inhibitor), loreclezole (anticonvulsant), trazadone (antidepressant) etc. Method: Epoxide ring opening of tert-butyl 6-oxa-3-azabicyclo [3.1.0] hexane-3-carboxylate followed by methylation under basic conditions and de-protection gave the corresponding trans 1-(4-methoxypyrrolidin-3-yl)-1H-1,2,4-triazole hydrochloride salt as the precursor. This precursor on reaction with substituted benzoyl chlorides and benzyl bromides gave the desired amide and amine products.

RESULTS

A library of 14 N-substituted pyrrolidine derivatives i.e. trans3-methoxy-4-(1H-1,2,4-triazol-1-yl) pyrrolidin-1-yl) (phenyl)methanone and trans 1-benzyl-4-methoxypyrrolidin-3-yl)-1H-1,2,4-triazole were prepared.

CONCLUSION

Eight novel amides (6a-h) and six amines (8a-f) derivatives were synthesized using 1-(4-methoxypyrrolidin-3-yl)-1H-1,2,4-triazole 4 salt with substituted benzoyl chlorides and benzyl bromides.

Influence of ligand lipophilicity in Pt(II) complexes on their antiproliferative and apoptotic activities in tumour cell lines

One of the most widely used strategies for drug development is the coordination of bioactive ligands to transition metals, which could improve biological activity. Moreover, the incorporation of aromatic groups to ligands may allow an enhanced lipophilicity that can influence the cellular uptake and accumulation of the metallodrugs, thus increasing their activity. Herein, we have reported the synthesis and characterization of four Pt(II) complexes [PtCl₂(L)], where L = 2-(1-pyrazolyl)-2-thiazoline (PzTn), 2-(1-pyrazolyl)-1,3-thiazine (PzTz), 2-(3,5-diphenyl-1-pyrazolyl)-2-thiazoline (DPhPzTn) or 2-(3,5-diphenyl-1-pyrazolyl)-1,3-thiazine (DPhPzTz). The study was aimed at analysing their potential anticarcinogenic ability in epithelial cervix carcinoma HeLa, human promyelocytic leukemia HL-60 and human histiocytic lymphoma U-937 tumour cell lines as well as checking whether the structural factors of the organic ligand may influence their biological activity. Our findings showed that PtDPhPzTn and PtDPhPzTz were far more effective in terms of cytotoxicity than their less lipophilic counterparts (PtPzTn and PtPzTz), especially in cells derived from solid cervical tumours, thereby suggesting that modulating the lipophilicity of the ligands can help improve the cytotoxic effect of the metal complexes.

2-Aminoaryl-3,5-diaryl pyrazines: Synthesis, biological evaluation against Mycobacterium tuberculosis and docking studies

Rationally designed Mycobacterium tuberculosis (Mtb) inhibitors were synthesized under Buchwald conditions using Pd₂ (dba)₃ /xantphos and the compounds were investigated for their biological activity against the Mtb standard strain H37Rv and two other clinically isolated multidrug-resistant strains with different drug resistance patterns. Compounds 5e, 6e, 7e, and 8e exhibited excellent antituberculosis activity against H37Rv with a minimum inhibitory concentration (MIC) value of 15 μg/ml. Compounds 5a, 6c, 7b, 8a, 8b, and 8d also displayed their potency with a MIC value in the range of 15-25 μg/ml. In addition to the Mtb studies, compounds 4e, 5e, 7e, and 8e were tested for cytotoxicity on HEK-293 cells and compounds 7e and 8e were identified to have low toxicities of up to 200 and 300 μM, respectively. The synthesized compounds docked with the 2FUM protein of Mtb and the docking studies revealed that compounds 5e, 6e, 7e, and 8e can bind strongly in the active site of the enzyme and showed binding energies of -9.62, -10.7, -11.48, and -12.06 kcal/mol, respectively. Compound 7e forms four hydrogen bonds, whereas compound 8e forms five hydrogen bonds with amino acids, respectively. Based on these results, compounds 7e and 8e might be considered potential lead compounds with good anti-Mtb potency.

A Three Component Protocol for the Synthesis of Aziridines using BF3·(OEt)2

Synthesis of N-(1R,2S)-2-(bromo-3-oxo-1,3-diphenylpropyl)-4-methylbenzene sulfonamide and N-(1R,2S)-(2-bromo-3-oxo-1,3-diphenylpropyl)-4-methylbenzene sulfonamide was carried out by a three component reaction using phenacyl bromide, p-toluenesulfonamide and carboxyaldehyde in presence of mild Lewis acid such as BF3·(OEt)2 in dichloromethane. The synthetic utility of this protocol was carried out with syn-isomer to yield corresponding cis-aziridines. This protocol was operationally simple for a wide variety of substituted carboxaldehydes and substituted phenacyl bromides.