Determination of the inclusion complex constant between oleuropein and cyclodextrins by complexation theory

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Carlos Eduardo Barao (Author) Other; Fatima Paiva Martins (Author) FCUP; Gisella Maria Zanin (Author) Other; Flavio Faria De Moraes (Author) Other

Journal

Title: Journal of Inclusion Phenomena and Molecular Recognition in Chemistry

Vol. 78

Pages: 465-470

ISSN: 0923-0750

Publisher: Kluwer Academic Publishers

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 5 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-009-B4P

DOI: 10.1007/s10847-013-0318-x

Abstract (EN): Oleuropein (OLE) is a major phenolic compound of olive leaf (Olea europaea) and has many therapeutic properties associated with olive leaf extracts. This work concerns the determination of the inclusion complex constant between OLE and cyclodextrins (CDs), based on the competition of two guests for the CD cavity, one being a dye and the other OLE. The dye used was methylorange (MO) and pH 3 was selected, since MO molar absorptivity at 500 nm is at maximum in this condition. A solution of MO, OLE, and alpha-CD or beta-CD, with citrate buffer was used for determining the absorbance values. From these data and by appropriate mathematical modeling, the equilibrium constant for the formation of OLE: CD complexes were obtained: for OLE:alpha-CD K = 1,352.4 L mol(-1) (R-2 = 0.9975) and for OLE:beta-CD K = 1,827.9 L mol(-1) (R-2 = 0.9991). The results show that OLE has a greater affinity for beta-CD than for alpha-CD and given the relatively high constants, OLE:CD complexes have potential for giving longer shelf lives for OLE medicinal and food additive preparations.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6