Biological evaluation of gallic acid and quercetin derived fromCeriops tagal: insights from extensivein vitroandin silicostudies

Gallic acid (PubChem CID: 370) and quercetin (PubChem CID: 5280343) are major phenolic compounds in many mangrove plants that have been related to health cure. In the present study, the active fractions namely gallic acid (1)and quercetin (2)were isolated from the methanolic extract of leaves ofCeriops tagalin a Tropical mangrove ecosystem of Andaman and Nicobar Island (ANI), India. The chemical structures were determined by spectroscopic analysis: Fourier-Transform Infrared spectroscopy (FT-IR),H-1,C-13 Nuclear Magnetic Resonance (NMR) spectroscopy, and High-resolution mass spectrometry (HRMS). The anticancer activity of isolated compounds (1)and (2)were evaluated byin vitroassays against two human cancer cell lines namely, HeLa (Cervical) and MDA-MB231 (Breast) cancer cells revealed that IC(50)values of gallic acid (HeLa: 4.179197 +/- 0.45 mu g/ml; MDA-MB231: 80.0427 +/- 0.19 mu g/ml at 24 h) and quercetin (HeLa: 99.914 +/- 0.18 mu g/ml; MDA-MB231: 18.288382 +/- 0.12 mu g/ml at 24 h), respectively. Antioxidant properties of gallic acid (1) and quercetin (2) are found to be IC(50)value of 0.77 +/- 0.41 mu g/ml and 1.897 +/- 0.81 mu g/ml, respectively. Molecular docking results explained that gallic acid (1) and quercetin (2) showed estimated binding free energy (Delta G) of -5.4 and -6.9 kcal/mol towards drug target Bcl-B protein, respectively. The estimated inhibition constant (Ki) for these two molecules are 110 and 8.75 mu M, respectively. The MD simulation additionally supported that quercetin molecule is significantly improved the structural stability of Bcl-B protein. The present study provides key insights about the importance of polyphenols, and thus leads to open the therapeutic route for anti-cancer drug discovery process. Communicated by Ramaswamy H. Sarma