Host–Guest Inclusion System of Scutellarin with Polyamine-β-Cyclodextrin: Preparation, Characterisation, and Anti-cancer Activity

Abstract

The inclusion complexation behaviours of scutellarin (SCU) with four polyamine-modified β-cyclodextrins (NH2-βCD, EN-βCD, DETA-βCD, and TETA-βCD; EN = ethylenediamine; DETA = diethylenetriamine; TETA = triethylenetetramine) have been investigated in both solution and solid state by photoluminescence spectroscopy, 1H and two-dimensional NMR spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. The results showed that, with the increase in the number of amino groups, the hosts polyamine-modified β-cyclodextrins (NH2-βCD, EN-βCD, DETA-βCD, TETA-βCD) were able to solubilise SCU to higher levels than native β-CD (9.0 mg mL–1) up to 15.8, 20.4, 44.6, 50.7 mg mL–1 (calculated as SCU), respectively. Besides, the anti-tumour activity of SCU obviously increased after formation of the inclusion complexes. The SCU/CD complexes will be potentially useful for the design of a novel formulation of SCU for clinical treatment.