title: Structural changes of 6a-hydroxy-pterocarpans upon heating modulate their estrogenicity.
abstract: The isoflavonoid composition of an ethanolic extract of fungus-treated soybean sprouts was strongly altered by a combined acid/heat treatment. UHPLC-MS analysis showed that 6a-hydroxy-pterocarpans were completely converted to their respective, more stable, 6a,11a-pterocarpenes, whereas other isoflavonoids, from the isoflavone and coumestan subclasses, were affected to a much lesser extent (loss of ∼15%). Subsequently, mixtures enriched in prenylated 6a-hydroxy-pterocarpans (pools of glyceollin I/II/III and glyceollin IV/VI) or prenylated 6a,11a-pterocarpenes (pools of dehydroglyceollin I/II/III and dehydroglyceollin IV/VI) were purified, and tested for activity on both human estrogen receptors (ERα and ERβ). In particular, the response toward ERα changed, from agonistic for glyceollins to antagonistic for dehydroglyceollins. Toward ERβ a decrease in agonistic activity was observed. These results indicate that the introduction of a double bond with the concomitant loss of a hydroxyl group in 6a-hydroxy-pterocarpans extensively modulates their estrogenic activity.
authors.affiliation: Laboratory of Food Chemistry, Wageningen University , P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: Milou G M
authors.initials: MG
authors.lastname: van de Schans
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Vincken
authors.forename: Toine F H
authors.initials: TF
authors.lastname: Bovee
authors.forename: Alfredo David
authors.initials: AD
authors.lastname: Cervantes
authors.forename: Madelon J
authors.initials: MJ
authors.lastname: Logtenberg
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
mesh_terms: D004967:Estrogens / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry*; D036343:Pterocarpans / Q000737:chemistry*; D011960:Receptors, Estrogen / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry*
chemical_list: D004967:Estrogens; D010936:Plant Extracts; D036343:Pterocarpans; D011960:Receptors, Estrogen
keywords: dehydroglyceollin; estrogen receptor; glyceollin; pterocarpene; thermal degradation