Enhanced physicochemical properties of isoflavone derivatives through enzymatic encapsulation using cyclodextrin glucanotransferase

Abstract

To establish the encapsulation parameters applicable to isoflavones, inclusion complexes (cycloamylose-genistein (CA-GNT), CA-daidzein (CA-DDZ), CA-equol (CA-EQ)) were synthesized for three varieties of plant-derived isoflavones via the cyclization catalysis of cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19). Subsequently, an analysis of their physicochemical properties and functional characteristics was performed to ascertain their retained intrinsic activity within the encapsulated milieu. These encapsulation complexes were purified via preparative high-performance liquid chromatography and confirmed through MALDI TOF mass spectrometry for molecular weight analysis. The water solubility of CA-GNT, CA-DDZ, and CA-EQ increased approximately 15,000, 89,000, and 90 times, respectively, compared to the original compounds. Furthermore, in a 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity assay, the CA-GNT, CA-DDZ, CA-EQ encapsulated complexes exhibited 6.4-, 6.9-, and 4.2-fold higher levels of scavenging activity compared to the original material in aqueous solution, respectively. The mRNA level of estrogen receptor α increased with increasing treatment concentration of the encapsulated complexes in MC3T3 cells, which was similar to the effect of the original compounds. CA-EQ remained stable under external conditions of varying pH and high temperature, and a decrease in nitric oxide (NO) production was observed as the treatment concentration increased in RAW 264.7 cells.