Enzymatic Preparation of Kaempferol from Green Tea Seed and Its Antioxidant Activity

Abstract

Among the flavonols in green tea, kaempferol has many biological activities but kaempferol of plant origin is too expensive to be used in commercial products. Recently, we confirmed that green tea seed (GTS) contained a reasonable amount of kaempferol glycoside. After conducting structure analysis, two kaempferol glycosides were identified, kaempferol-3-O-[2-O-beta-D-galactopyranosyl-6-O-alpha-L-rhamnopyranosyl]-beta-D-glucopyranoside (compound 1) and kaempferol-3-O-[2-O-beta-D-xylopyranosyl-6-O-alpha-L-rhamnopyranosyl]-beta-D-glucopyranoside (compound 2), respectively. Also, a commercially useful method for kaempferol preparation was suggested by enzymatic hydrolysis using these two flavonoids. After several enzyme reactions were performed for the complete bioconversion of compounds 1 and 2 to kaempferol, we found that the optimum enzyme combination was reaction with beta-galactosidase and hesperidinase. Finally, we produced pure kaempferol with over 95% purity. We also compared the antioxidant effect of these two GTS flavonoids and its aglycone, kaempferol. Kaempferol is a more efficient scavenger of 1,1-diphenyl-2-picrylhydrazyl radicals and a better inhibitor of xanthine/xanthine oxidase than the two glycosides.

Guava: phytochemical composition of a potential source of antioxidants for cosmetic and/or dermatological applications

“…Kaempferol 3-O-xylosyl-rutinoside was identified in methanolic extracts of seven onion varieties (Lee, Zweigenbaum, Mitchell, 2013). It has an antioxidant as well as hypoglycemic effect (De Sousa et al, 2004;Park et al, 2006;Torel, Cillard, Cillard, 1986).…”

Inhibitory effects of flavonoids on TNF-α-induced IL-8 gene expression in HEK 293 cells

“…TNF-α induces the activation of several transcriptional factors, including NF-κB, through TNF-α receptor (TNFR)-dependent signaling pathways (9-11, 15, 16). Flavonoids are widely used to inhibit the activation of NF-κB (17,18), and several studies have shown that flavonoids inhibit the expression of proinflammatory genes in response to inflammatory mediators such as TNF-α (6,19). However, the potential involvement of flavonoids in the regulation of TNF-α -induced IL-8 gene expression in HEK 293 cells has not yet been fully explored.…”

Preparation of a Lemon Flavonoid Aglycone and its Suppressive Effect on the Susceptibility of LDL to Oxidation Following Human Ingestion

“…It is converted from hesperidin, with low solubility, to hesperetin 7-O-β-glucoside, which is easy to dissolve in water compared to hesperidin (Sanchez et al, 1987 Mandalari et al, 2006;. Naringinase and hesperidinase have been reported for preparation of aglycones from flavonoid glycosides such as isoliquirtin and kaempferol glycoside (Sato, et al, 2007;Park et al, 2006). Enzymes having pervasive substrate specificity have been reported for preparation of aglycones from flavonoid glycosides.…”