Spectroscopic (FT-IR, FT-Raman, 1H- and 13C-NMR), Theoretical and Microbiological Study of trans o-Coumaric Acid and Alkali Metal o-Coumarates

Abstract

This work is a continuation of research on a correlation between the molecular structure and electronic charge distribution of phenolic compounds and their biological activity. The influence of lithium, sodium, potassium, rubidium and cesium cations on the electronic system of trans o-coumaric (2-hydroxy-cinnamic) acid was studied. We investigated the relationship between the molecular structure of the tested compounds and their antimicrobial activity. Complementary molecular spectroscopic techniques such as infrared (FT-IR), Raman (FT-Raman), ultraviolet-visible (UV-VIS) and nuclear magnetic resonance (1H- and 13C-NMR) were applied. Structures of the molecules were optimized and their structural characteristics were calculated by the density functional theory (DFT) using the B3LYP method with 6-311++G** as a basis set. Geometric and magnetic aromaticity indices, atomic charges, dipole moments and energies were also calculated. Theoretical parameters were compared to the experimental characteristics of investigated compounds. Correlations between certain vibrational bands and some metal parameters, such as electronegativity, ionization energy, atomic and ionic radius, were found. The microbial activity of studied compounds was tested against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris and Candida albicans.

Protective Effect of Phenolic Compounds Isolated from Mugwort (Artemisia argyi) against Contrast-Induced Apoptosis in Kidney Epithelium Cell Line LLC-PK1

“…Fraction TH5-57-4 (377.8 mg) was fractionated by silica gel CC and eluted with a gradient condition of n -hexane–EtOAc (1:0 to 1:1) to yield 7 fractions designated as TH5-61-1 to -7. TH5-61-1 (138.1 mg) was separated by preparative HPLC (35–80% MeOH) to produce 4-hydroxybenzoic acid ( 10 , 17.1 mg) [50], 3-(2-hydroxyphenyl)acrylic acid ( 11 , 70 mg) [52], and salicylic acid ( 12 , 10.9 mg) [53]. TH5-57-5 (50.9 mg) was separated by preparative HPLC (25–85% MeOH) to produce 1H-indole-3-carboxylic acid ( 9 , 4.1 mg) [54].…”

Newly Synthesized Doxorubicin Complexes with Selected Metals—Synthesis, Structure and Anti-Breast Cancer Activity

“…The third aspect is the study of synergistic effects, in other words mutual reinforcement of antineoplastic action of metal and ligand (with proven cytotoxic activity). The influence of metals on the distribution of electronic charge (determining biological properties) of selected ligands has been described in our earlier articles [ 24 , 25 , 26 , 27 ].…”

Molecular interactions of milk protein with phenolic components in oat‐based liquid formulations following UHT treatment and prolonged storage

“…(b) is characterized by sharp peaks at 1690 cm −1 (CO stretch carboxylic acid), 1620 and 1516 cm −1 (CC stretch aromatic), 1458 cm −1 (antisymmetric and symmetric COO − ) and 1276 cm −1 (COH stretch carboxylic acid) . PA exhibits sharp peaks at 1668 cm −1 (CO stretch carboxylic acid), 1629 cm −1 (CC stretch) and 1168 cm −1 (COH stretch) . Inclusion of phenolic acids (0.5 mmol L −1 ) in the heated milk protein solution results in a significant decrease in the intensity of amide I and amide II spectra compared to the heated protein signal (Fig.…”