title: Effect of a labile methyl donor on the transformation of 5-demethyltangeretin and the related implication on bioactivity.
abstract: Polymethoxyflavones (PMFs) belong to a subgroup of flavonoids that particularly exist in the peels of citrus fruits. Despite their many health-beneficial biofunctionalities, the lipophilic nature of PMFs limits their water solubility and oral bioavailability. To investigate the effect of the delivery system on the improvement of PMF bioavailibility, a lecithin-based emulsion was formulated for the delivery of two PMF compounds, tangeretin and 5-demethyltangeretin. While the emulsion system improved the digestion kinetics and the total solubilized PMF concentrations in in vitro lipolysis studies, the concentration of 5-demethyltangeretin decreased due to chemical transformation to its permethoxylated counterpart, tangeretin. The emulsifier lecithin used in this emulsion formulation contained a choline headgroup as a labile methyl group donor. The presence of a methyl donor potentially caused the transformation of 5-demethyltangeretin and reduced its anti-cancer-cell-proliferation activities. Moreover, this is the first report in the literature of the transformation from 5-demethyltangeretin to tangeretin in a lecithin-based emulsion during lipolysis, and the mechanism underlying this phenomenon has also been proposed for the first time.
authors.affiliation: Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901, USA.
authors.forename: Yuwen
authors.initials: Y
authors.lastname: Ting
authors.forename: Colin C
authors.initials: CC
authors.lastname: Li
authors.forename: Min-Hsiung
authors.initials: MH
authors.lastname: Pan
authors.forename: Chi-Tang
authors.initials: CT
authors.lastname: Ho
authors.forename: Qingrong
authors.initials: Q
authors.lastname: Huang
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D001682:Biological Availability; D049109:Cell Proliferation / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D047309:Flavones / Q000737:chemistry* / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D015394:Molecular Structure
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D047309:Flavones; D005419:Flavonoids; C000591222:gardenin B; C059006:tangeretin