A comparative encapsulation behaviour analysis and biological studies of C- alkyl calix[4]resorcinarenes-4-hydroxybenzoic acid inclusion complexes

In this work, we are reported the comparative encapsulation behaviour analysis and biological applications of C-alkyl calix[4]resorcinarenes:4-hydroxybenzoic acid (C4RAs-4HBA) inclusion complexes. The solvent evaporation method was applied to prepare the solid C4RAs-4HBA (5a-5d) inclusion complexes. Phase solubility analysis and jobs plot method was used to identify the stoichiometric binding ratio, stability constant (K), complexation efficiency (CE) and type of phase solubility diagram formed between the aqueous solution of C4RAs (3a-3d) and 4HBA (compound 4). From the results of UV-Visible, fluorescence, ¹ H-NMR, ¹³ C-NMR, PXRD and SEM imaging analysis was confirmed by formation of 1:1 ratio of C4RAs-4HBA inclusion complexes between C4RAs (3a-3d) and 4HBA (compound 4). In gas phase DFT/B3LYP 3-21G method of molecular modeling studies were applied to identify the more stable and reactive binding orientation (A or B) from the values of band gap energy, energy and complexation energy values. A redox a reaction of phosphomolybdate assay was used to find out the informations of total antioxidant capacity (TAC), % total antioxidant capacity (% TAC) and IC ₅₀ values. Kirby-Bauer antibacterial activity and Disc diffusion antifungal activity of C4RAs, 4HBA and their inclusion complexes were compared with the standard antibacterial (amikacin) and antifungal (nystain) drugs.