Investigation of Non-Covalent Binding Interactions Between 2-methoxybenzoic acid and C-alkyl calix[4]resorcinarenes: it’s application in antioxidant, antibacterial and antifungal studies

The non-covalent binding interactions of host–guest inclusion complexes between 2-methoxybenzoic acid with CRA, CMRA, CERA and CPRA calix[4]resorcinarene derivatives were investigated through spectral and molecular modelling studies. Biological studies such as antioxidant, antibacterial and antifungal activity were analysed for 2-methoxybenzoic acid in the presence of CRA, CMRA, CERA and CPRA. The absorption band at 267.0 nm and the emission band at 340.0 nm in water were significantly moved in the wavelength depending on the studied supramolecules. The calculated binding constant was found to be higher value for CRA-2MBA inclusion complex using the Bindfit method. The stretching frequency, crystalline and surface morphology of all were demonstrated for 2-methoxybenzoic acid before and after with CRA, CMRA, CERA and CPRA. The proposed structure of all was examined with the help of density functional theory. CPRA-2MBA inclusion complex exhibited greater antioxidant activity with IC₅₀ value of 11.08 μg/mL. CMRA-2MBA inclusion complex noticed antibacterial activity in all bacterial stains.