Photophysical Evaluation Of Β-Caryophyllene Cyclodextrin Inclusion Complexes Through Benesi-Hildebrand Analysis

Abstract

Host-guest complexation is a powerful molecular strategy to enhance the physicochemical behavior of natural bioactives with limited aqueous solubility. In this study, β-caryophyllene (BCP), a pharmacologically active sesquiterpene isolated from Aegle marmelos leaves, was investigated for its inclusion interactions with α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD). Absorption and fluorescence emission spectroscopy were employed to monitor spectral variations of BCP in the presence of increasing cyclodextrin concentrations. Quantitative analysis was performed using the Benesi-Hildebrand method, where linear plots confirmed 1:1 stoichiometry of the inclusion complexes. The stability constants obtained demonstrated notable differences between BCP:α-CD and BCP:β-CD systems, underscoring the influence of cavity dimensions and molecular fit on host-guest affinity. These findings provide spectroscopic evidence of differential binding efficiency and establish a framework for evaluating cyclodextrin assisted modulation of bioactive natural products.