METHODS: Ten ligands with reported in vitro and/or in vivo activities against GAPDH were evaluated for their binding interactions through molecular docking studies using AutoDock 4.2 program. The ligand with the best binding energy was then modified to produce 10 derivatives, which were redocked against GAPDH using previous protocols. BIOVIA Discovery Studio Visualizer 2019 was used to explore the ligand-receptor interactions between the derivatives and GAPDH.
RESULTS: Among the 10 ligands, curcumin, koningic acid and folic acid showed the best binding energies. Further analysis on the docking of two folic acid derivatives, F7 (γ-{[tert-butyl-N-(6-aminohexyl)]carbamate}folic acid) and F8 (folic acid N-hydroxysuccinimide ester) showed that the addition of a bulky substituent at the carboxyl group of the glutamic acid subcomponent resulted in improved binding energy.
CONCLUSIONS: Folic acid and the two derivatives F7 and F8 have huge potentials to be developed as targeting agents against the GAPDH receptor. Further study is currently on-going to evaluate the effectiveness of these molecules in vitro.
OBJECTIVE: A series of new pyrazolines containing novel 2,5-dichloro-3-acetylthiophene chalcone moiety (PZT1-PZT20) have been synthesized, characterized by 1HNMR and 13CNMR and evaluated for them in vitro antitubercular activity against M. tuberculosis H37Rv strain and in vitro anticancer activity against DU-145 prostate cancer cell lines and all compounds were also screened for molecular docking studies against specific targeted protein domains.
METHODS: All compounds were screened for potential activity against Mycobacterium tuberculosis H37Rv (MTB) strain and anticancer activity against DU-149 prostate cancer cell lines using MTT cytotoxicity assay.
RESULTS: Among the series, compound PZT5 with 2", 4"-dichlorophenyl group at 5-position on the pyrazoline ring exhibited the most potent antitubercular activity (MIC=1.60 µg/mL) and compounds PZT2, PZT9, PZT11, PZT15, and PZT20 showed similar antitubercular activity against standard pyrazinamide (MIC=3.12 µg/mL) by broth dilution assay. PZT15 and PZT17 with 4"- pyridinyl and 2"-pyrrolyl groups on pyrazoline ring were found to exhibit better anticancer activity against DU-149 prostate cancer cell lines with IC50 values of 2.0±0.2 µg/mL and 6.0±0.3 µg/mL respectively by MTT assay. The preliminary structure-activity relationship has been summarized. The molecular docking studies with crystalline structures of enoyl acyl carrier protein reductase InhA interaction with target protein (2NSD; PDB and 3FNG; PDB) of Mycobacterium tuberculosis H37Rv (MTB) strain have also exhibited good ligand interaction and binding affinity. Ligand interaction and binding affinity were estimated using crystal structures of both types of enoyl acyl carrier protein reductase InhA (3FNG.pdb) and found to be much higher (-16.70 to - 19.20 kcal/mol) compared with pyrazinamide (-10.70 kcal/mol) as a standard target molecule. Whereas the binding affinities of six active compounds with crystal structure of other type of enoyl acyl carrier protein reductase InhA (2NSD.pdb) were much similar and higher (-9.30 to - 11.20 kcal/mole) than pyrazinamide (-11.10 kcal/mole).
CONCLUSION: These new pyrazolines would be promising potent inhibitors of drug sensitive and drug resistant Mycobacterium tuberculosis strain and potential anticancer agents against prostate cancer and other prototypes of cancers.
MATERIALS AND METHODS: The 344OH employed in present study was synthesized based on the protocol in previous study. The vascular responses towards the cumulative addition of 344OH were evaluated using in vitro rat aortic rings assays.
KEY FINDINGS: The pEC50 and Rmax values were found to be 4.33 ± 0.05 and 106 ± 3.99%, respectively. Results showed that the vasorelaxation of 344OH were predominated by G-protein-coupled muscarinic- (M3) and β2-adrenergic receptors, followed by PGI2/AC/cAMP- and NO/sGC/cGMP-dependent pathways. It was also identified that 344OH employed voltage-activated- (Kv), calcium-activated- (Kca) and inwardly-rectifying (Kir) potassium channels and act as an antagonist for both VOCC and IP3R while regulating the action potential in the vasculature.
SIGNIFICANCE: The different position of hydroxyl substituent located in A-ring of the stilbenoid backbone in 344OH compared to resveratrol resulted in a significant difference in mechanistic actions that lead to 344OH's fast-acting and less time-dependent vasorelaxation behaviour. This has substantially increased the potential of 344OH to be developed as an effective antihypertensive drug in future. Present findings further strengthen our inferences where the SARs study approach should be carried out as the mainstream methodology in future drug development research.