ABSTRACT
In cyanobacteria, carbonic anhydrase (zinc metalloenzyme) is a major enzyme that converts CO2 to HCO3- maintaining the carbon concentration around the vicinity of RuBisCo, leading to cyanobacterial biomass generation. Anthropogenic activities, disposal of leached micro nutrients effluents from industries into the aquatic environment results in cyanobacterial blooms. The harmful cyanobacteria release cyanotoxins in open-water system which on ingression through oral route causes major health issues like hepatotoxicity and immunotoxicity. A database was prepared consisting of approximately 3k phytochemicals curated from previous literatures, earlier identified by GC-MS analysis. The phytochemicals were subjected to online servers to identify the novel lead molecules which followed ADMET and drug-like candidates. The identified leads were optimized by density functional theory method using B3YLP/G* level of theory. Carbonic anhydrase chosen as target to observe the binding interaction through molecular docking simulations. From the molecules included in the database the highest binding energy exhibited by alpha-tocopherol succinate and mycophenolic acid were found to be -9.23 kcal/mol and -14.41 kcal/mol and displayed interactions with GLY A102, GLN B30, ASP A41, LYS A105 including Zn2+ and their adjacent amino acids CYS 101, HIS 98, CYS 39 in both chain A and chain A-B of carbonic anhydrase. The Identified molecular orbitals decipher computed global electrophilicity values (Energy gap, electrophilicity and Softness) of alpha-tocopherol succinate and mycophenolic acid were found to be (5.262, 1.948, 0.380) eV and (4.710, 2.805, 0.424) eV demonstrates both molecules are effective and stable. The identified leads may serve as a better anti-carbonic anhydrase agent because they accommodate in the binding site and hampers the catalytic activity of Carbonic anhydrase thus inhibiting the generation of cyanobacterial biomass. This identified lead molecules may serve as a substructure to design novel phytochemicals against carbonic anhydrase present in cyanobacteria. Further in vitro study is necessary to evaluate the efficacy of these molecules.
ABSTRACT
Cancer is the world's second leading cause of death, and there are no approved herbal therapies. The epidermal growth factor receptor tyrosine kinase (EGFR-TK) receptor is a transmembrane protein with eight domains that is found in almost every cancer type and plays an important role in abnormal cell cellular function and causes malignant outcomes. The current study aimed to virtually screen phytochemicals from the NPACT database against EGFR-TKD and also to identify potential inhibitors of this transmembrane protein among plant candidates for anticancer drug development. The docking scores of the chosen phytochemicals were compared with the control (erlotinib). Kurarinone, (2S)-2-methoxykurarnione, and Sophoraflavanone-G exhibited a stronger binding affinity of -18.102 kcal/mol, -14.243 kcal/mol, and -13.759 kcal/mol than erlotinib -12.783 kcal/mol. Moreover, several online search engines were used to predict ADME and toxicity. The drug-likeness of selected phytochemicals was higher than the reference (erlotinib). A 100 ns molecular dynamic (MD) simulation was also applied to the docked conformations to examine the stability and molecular mechanics of protein-ligand interactions. Furthermore, the calculated molecular mechanics Poisson Boltzmann surface area energy of (2S)-2-methoxykurarnione was found to be -129.555 ± 0.512 kJ/mol, which approximately corresponds to the free energy of the reference molecule -130.595 ± 0.908 kJ/mol. We identify phytoconstituents present in Sophora flavescens from the NPACT database, providing key insights into tyrosine kinase inhibition and may serve as better chemotherapeutic agents. Experimental validation is required to determine the anti-EGFR potency of the potent lead molecules discussed in this study.Communicated by Ramaswamy H. Sarma.
