Molecular Structure, NMR, HOMO, LUMO, and Vibrational Analysis of O-Anisic Acid and Anisic Acid Based on DFT Calculations

Abstract

This work deals with the vibrational spectroscopy of O-Anisic acid (OAA) and Anisic acid (AA). The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT) with standard B3LYP/6-31G** method and basis set combinations. The vibrational spectra were interpreted, with the aid of normal coordinate analysis based on a scaled quantum mechanical force field. The infrared and Raman spectra were also predicted from the calculated intensities. The effects of carbonyl and methyl substitutions on the structure and vibrational frequencies have been investigated. Comparison of simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes. The13C and1H NMR chemical shifts of the DFA and CA molecules were calculated using the gauge-invariant-atomic orbital (GIAO) method in DMSO solution using IEF-PCM model and compared with experimental data.

Novel adamantyl clubbed iminothiazolidinones as promising elastase inhibitors: design, synthesis, molecular docking, ADMET and DFT studies

“…The inhibition activity of elastase (elastase from porcine pancreas) was determined by following the methods of ref. 34 and 35 with minor modifications as discussed in our previously reported article. 36 By measuring the absorbance of the solution at 410 nm, the amount of released p -nitroaniline, which had been hydrolyzed by the substrate ( N -succinyl-Ala-Ala-Ala- p -nitroanilide), could be used to determine the elastase inhibition activity.…”

“…To determine the mode of inhibition, a kinetic analysis was performed using our previously published method 34 in the following manner: the compound 5g was chosen based on its high IC 50 value and high potency. It was possible to study the kinetics of compound 5g by varying the concentration of N -succinyl-Ala-Ala-Ala- p -nitroanilide in the presence of various concentrations of compound 5g (0.00, 0.062, 0.124, and 0.248 μM).…”

Multistage Extraction of Star Anise and Black Pepper Derivatives for Antibacterial, Antioxidant, and Anticancer Activity

“…1 H NMR and 13 C NMR spectra of methyl anisate is given in Figures 3A,B, respectively. The FTIR spectrum of methyl anisate in Figure 3C exhibits the absorption peaks at 2,852 and 1,684 cm −1 attributed to O-CH 3 stretching vibration and C=O stretching vibration, separately (Mathammal et al, 2013). The skeletal vibrations of the benzene ring were at 1,654, 1,558, 1,506, 1,457 cm −1 (Jeyakumar and Narayanasamy, 2020).…”

A combined experimental and theoretical analysis on molecular structure and vibrational spectra of 2,4-dihydroxybenzoic acid

“…Hydroxybenzoic acids are commonly used in pharmaceutical and perfumery industry because of their activities in the biological system [1]. Dihydroxybenzoic acids are the important materials in the production of disinfectants and antipyretic drugs [2][3][4], and in the synthesis of organic compounds such as resins, polyesters, plasticizers, dyestuff and rubber chemicals. As an intermediate, 2,4-DHBA plays an important role in the production of cosmetics and dyes [5,6].…”