Preparation, characterization and antimicrobial activity of inclusion complex of biochanin A with (2-hydroxypropyl)-β-cyclodextrin

Abstract

Abstract Objectives An inclusion complex of biochanin A (BCA) with (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) was prepared in the ethanol solution to improve its water solubility. Methods Using the FTIR, 1H-NMR, XRD, DSC and SEM methods, the structural characterization of the prepared complex was analysed. Key findings The phase-solubility study has shown that the solubility of BCA was increased twofold in 42% (v/v) ethanol solution after complexation with HP-β-CD. The complex between BCA and HP-β-CD was prepared in the molar ratio of 1 : 1. The antibacterial activity of the inclusion complex was investigated against the various bacteria, fungus and yeast using the microdilution method. The minimal inhibitory concentration values for the analysed strain of bacteria were in the range of 0.84–1.69 mg/cm3, whereby the prepared inclusion complex exhibited less effect on the reduction of the number of Escherichia coli and Klebsiella pneumoniae species compared to pure BCA. The inclusion complex of BCA was significantly more active against Candida albicans than pure BCA. Biochanin A and its inclusion complex has not expressed the activity against Aspergillus niger. Conclusions Based on the obtained results, it can be concluded that the antimicrobial activity of BCA was remained unchanged after complexation.