An expedient synthesis spectral characteristic computational studies and target prediction through insilco studies of 24α-ethylcholest-5, 22E-dien-3-yl-2- mercapto-benzoate and 11, 17 di-hydroxy preg-4-ene-3, 20-dione-21-yl-2-mercapto-benzoate

Abstract

In the current work (24α-ethylcholest-5, 22E-dien-3-yl-2- mercapto-benzoate) (3) and (11, 17 di-hydroxy-preg-4-ene-3, 20-dione-21-yl-2-mercapto-benzoate) (4) were synthesized from Stigmasterol (1) and Hydrocortisone (2), respectively isolated as a major components from chloroform extract of stem part of the plant Allamandaviolacea. The synthesized compound (3) and (4) have been characterized with the aid of 1H, 13C, UV, FT-IR spectroscopy. Density functional theory (DFT) is used to reckonthe molecular geometry of synthesized compounds with B3LYP functional and 631 G (d,p) basis set in ground state.1H and 13C NMR chemical shifts were premeditated in ground state by means of Gauge-Including Atomic Orbital (GIAO) method and these values were correlated with experimental interpretations. Time dependent Density Functional Theory (TD-DFT) is employed in computing electronic properties such as HOMO and LUMO. AIM (Atom in molecule) analysis is used in evaluation of strength of H-bonding and its intra molecular interactions. Global reactivity descriptors were calculated to study the reactive sites within molecules. Dipole moment, polarizability and first hyperpolarizability values have been determined for interpretation of nonlinear optical (NLO) property of the synthesized compounds. Molecular electrostatic potential (MEP) has also been performed.The potential of both the compounds were evaluated against quorum sensing protein of Gram negative bacteria LsrB (1TM2), LsrK (5YA2), LasR (2UV0) and LuxS (5E68). Binding energy ranging from -8.40133 to -12.49721 kcal/mol and virtual score from -9.67971 to -13.81495 suggest that the compounds can play important role in controlling the unwanted growth of Gram negative bacteria by inhibiting their quorum sensing system.