ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

β-Cyclodextrin as water-solubility enhancer for butylated hydroxytoluene

Marcin Lukasiewicz, Stanislaw Kowalski, Anna Ptaszek, and Pawel Ptaszek

Department of Carbohydrate Technology, University of Agriculture in Krakow; ul. Balicka 122; 30-149 Krakow, Poland

E-mail: rrlukasi@cyf-kr.edu.pl

Abstract: The phenomenon of the increase in solubility of the non-polar phenolic antioxidant - butylated hydroxytoluene (BHT) - in aqueous solutions containing β-cyclodextrin (CD) was studied. The complexation of BHT by CD was investigated using a phase solubility study. This method makes it possible to calculate the apparent formation constant for the host-guest complex. In addition, the thermodynamic properties were evaluated, revealing a spontaneous endothermic process of complex formation. Two solubility models were also used to verify their applicability to predicting the BHT concentration in solution. Those models included the modified Apelblat and Buchowski-Ksiazczak equations. In order to investigate the antioxidant properties of the BHT/CD/water ternary systems, a radical scavenging activity using a DPPH stable radical was performed. The experiments indicated that the antioxidant activity is temperature- and CD concentration-dependent. It was shown that complexation may inhibit the radical scavenging by BHT or change the scavenging stoichiometry.

Keywords: cyclodextrin – butylated hydroxytoluene – complexation – solubility – antioxidant

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0078

Chemical Papers 69 (5) 747–755 (2015)