Design, graph theoretical analysis, density functionality theories, Insilico modeling, synthesis, characterization and biological activities of novel thiazole fused quinazolinone derivatives

Design, synthesis, graph theoretical analysis and molecular modelling studies of novel substituted quinoline analogues as promising anti-breast cancer agents

The most promising class of heterocyclic compounds in medicinal chemistry are those with the quinolin-2-one nucleus. It is a versatile heterocyclic molecule that has been put together with numerous pharmaceutical substances and is crucial in the creation of anticancer medications. In this view, the present research work deals with design, synthesis, and characterization of various analogous of quinolin-2-one nucleus and evaluation of their anticancer activity against MCF-7 cells (adenoma breast cancer cell line). Fourteen new compounds have been synthesised using suitable synthetic route and are characterized by FTIR, 1H NMR, 13C NMR and Mass spectral data. Molecular docking studies of the title compounds were carried out using PyRx 0.8 tool in AutoDock Vina program. All the synthesised compounds were exhibited well conserved hydrogen bonding with one or more amino acid residues in the active pocket of EGFR tyrosine kinase (PDB ID: 1m17). The docking score of the derivatives ranged from - 6.7 to - 9.5 kcal mol-1, standard drug Imatinib with - 9.6 kcal mol-1 and standard active ligand 4-anilinoquinazoline with - 7.7 kcal mol-1. The designed compound IV-A1 showed least binding energy (- 9.5 kcal mol-1) against EGFR tyrosine kinase receptor. Further, top scored compound, IV-A1 found to be most significant against MCF-7 cells with IC50 value of 0.0870 µM mL-1, TGI of 0.0958 µM mL-1, GI50 of 0.00499 µM mL-1, LC50 of 1.670 µM mL-1.

Design, Synthesis, Pharmacological Evaluation, In silico Modeling, Prediction of Toxicity and Metabolism Studies of Novel 1-(substituted)-2-methyl- 3-(4-oxo-2-phenyl quinazolin-3(4H)-yl)isothioureas

BACKGROUND

Although exhaustive efforts to prevent and treat tuberculosis (TB) have been made, the problem still continues due to multi-drug-resistant (MDR) and extensively drugresistant TB (XDR-TB). It clearly highlights the urgent need to develop novel "druggable" molecules for the co-infection treatment and strains of MDR-TB and XDR-TB.

OBJECTIVE

In this approach, a hybrid molecule was created by merging two or more pharmacophores. The active site of targets may be addressed by each of the pharmacophores and proffers the opportunity for selectivity. In addition, it also reduces undesirable side effects and drug-resistance.

METHODS

In this study, a novel quinazolinone analog was designed and synthesized by substituting thiourea nucleus and phenyl ring at N-3 and C-2 position of quinazoline ring, respectively. All title compounds were tested for antitubercular activity by in vitro M. tuberculosis and anti-human immunodeficiency virus (HIV) activity by MT-4 cell assay method. The agar dilution method was used to test the antibacterial potency of entire prepared derivatives against various strains of grampositive and gram-negative microorganisms.

RESULTS

The title compounds, 1-(substituted)-2-methyl-3-(4-oxo-2-phenyl quinazolin-3(4H)-yl) isothioureas (QTS1 - QTS15) were synthesized by the reaction between key intermediate 3-amino- 2-phenylquinazolin-4(3H)-one with various alkyl/aryl isothiocyanates followed by methylation with dimethyl sulphate. Among the series, compound 1-(3-chlorophenyl)-2-methyl-3-(4-oxo-2-phenyl quinazolin- 3(4H)-yl) isothioureas (QTS14) showed the highest potency against B. subtilis, K. pneumonia and S. aureus at 1.6 μg/mL. The compound QTS14 exhibited the most potent antitubercular activity at the MIC of 0.78 μg/mL and anti-HIV activity at 0.97 μg/mL against HIV1 and HIV2.

CONCLUSION

The results obtained from this study confirm that the synthesized and biologically evaluated quinazolines showed promising antimicrobial, antitubercular and anti-HIV activities. The new scaffolds proffer a plausible lead for further development and optimization of novel antitubercular and anti-HIV drugs.

Design, In Silico Modelling, and Functionality Theory of Novel Folate Receptor Targeted Rutin Encapsulated Folic Acid Conjugated Keratin Nanoparticles for Effective Cancer Treatment

OBJECTIVE

Site-specific and toxic-free drug delivery, is an interesting area of research. Nanoengineered drug delivery systems possess a remarkable potential for effective treatment of various types of cancers.

METHODS

In this study, novel Folic Acid (FA) conjugated keratin nanoparticles (NPs) were assembled with encapsulation and delivery of Rutin (Rt) into breast cancer cells through the overexpressed folate receptor. The biocompatible, Rt encapsulated FA conjugated keratin NPs (FA@Ker NPs) were successfully formulated by a modified precipitation technique. Their morphological shape and size, size distribution, stability, and physical nature were characterized and confirmed. The drug (Rt) encapsulation efficiency, loading capacity and release kinetics were also studied.

RESULTS

The observed results of molecular docking and density functionality theory of active drug (Rt) showed a strong interaction and non-covalent binding of the folate receptor and facilitation of endocytosis in breast cancer cells. Further, in vitro cytotoxic effect of FA@Ker NPs was screened against MCF-7 cancer cells, at 55.2 µg/mL of NPs and found to display 50% of cell death at 24h. Moreover, the NPs enhanced the uptake of Rt in MCF-7 cells, and the apoptotic effect of condensed nuclei and distorted membrane bodies was observed. Also, NPs entered into the mitochondria of MCF-7 cells and significantly increased the level of ROS which led to cell death.

CONCLUSION

The developed FA@Ker NPs might be a promising way to enhance anti-cancer activity without disturbing normal healthy cells.

Design, in silico modelling and functionality theory of folate-receptor-targeted myricetin-loaded bovine serum albumin nanoparticle formulation for cancer treatment

Targeted drug delivery systems are a promising field of research. Nano-engineered material-mediated drug delivery possesses remarkable potential for the treatment of various malignancies. Here, folic acid (FA)-conjugated bovine serum albumin (BSA) nanoparticles (NPs) were used to encapsulate myricetin (Myr). Subsequently, the delivery of Myr via naturally overexpressed folate receptor (FR) to FR-positive breast cancer cells was studied. Myr-loaded BSA NPs were assembled by modified desolvation cross-linking technique. An FA-conjugated carrier, N-hydroxysuccinimide (NHS)-FA ester, was successfully synthesized. Its functional and structural characteristics were confirmed by ultraviolet, Fourier-transform infrared, and proton nuclear magnetic resonance spectroscopy. Biocompatible FA-conjugated, Myr-loaded BSA NPs (FA-Myr-BSA NPs) were successfully formulated using a carbonate/bicarbonate buffer. Their morphology, size, shape, physiological stability, and drug release kinetics were studied. Molecular docking studies revealed that FA-Myr-BSA NPs readily bound non-covalently to folate receptors and facilitated active drug endocytosis. FA-Myr-BSA NPs could trigger fast release of Myr in an acidic medium (pH 5.4), and showed high biocompatibility in a physiological medium. FA-Myr-BSA NPs effectively decreased the viability of MCF-7 cells after 24 h with 72.45 μg ml^-1 IC₅₀ value. In addition, FA-Myr-BSA NPs enhanced the uptake of Myr in MCF-7 cells. After incubation, a typical apoptotic morphology of condensed nuclei and distorted membrane bodies was observed. The NPs also targeted mitochondria of MCF-7 cells, significantly increasing reactive oxygen species release and contributing to the loss of mitochondrial membrane integrity. The observed results confirm that the newly developed FA-Myr-BSA NPs can serve as a potential carrier for Myr to increase the anticancer activity of this chemotherapeutic.

Microwave Assisted Synthesis of 4-Phenylquinazolin-2(1H)-one Derivatives that Inhibit Vasopressor Tonus in Rat Thoracic Aorta

Quinazolinones have pharmacological effects on vascular reactivity through different mechanisms. We synthesized 4-phenylquinazolin-2(1H)-one derivatives under microwave irradiation and tested them on the rat thoracic aorta. The prepared compounds 2a–2f were obtained in about 1 h with suitable yields (31–92%). All derivatives produced vasorelaxant effects with IC₅₀ values ranging from 3.41 ± 0.65 µM to 39.72 ± 6.77 µM. Compounds 2c, 2e and 2f demonstrated the highest potency in endothelium-intact aorta rings (IC₅₀ 4.31 ± 0.90 µM, 4.94 ± 1.21 µM and 3.41 ± 0.65 µM respectively), and they achieved around 90% relaxation (30 μM). In aorta rings without an endothelium, the effect of compound 2f was abolished. Using the MTT assay to test for cell viability, only compound 2b induced cytotoxicity at the maximum concentration employed (30 µM). The results show that vasorelaxation by 4-phenylquinazolin-2(1H)-one derivatives might depend on the activation of a signalling pathway triggered by endothelium-derived factors.