title: Structural determinants of plant lignans for the formation of enterolactone in vivo.
abstract: The quantity of mammalian lignans enterolactone (ENL) and enterodiol (END) and of plant lignans secoisolariciresinol (SECO) and 7-hydroxymatairesinol (HMR) excreted in a 24-h rat urine sample was measured after a single p.o. dose of an equivalent quantity of secoisolariciresinol diglycoside (SDG), secoisolariciresinol (SECO), matairesinol (MR), 7-hydroxymatairesinol (HMR) and ENL. Plant lignans (SECO and HMR) were partially absorbed as such. The aglycone form of SECO was more efficiently converted into mammalian lignans END and ENL than the glycosylated form, SDG. Of plant lignans, MR produced the highest quantities of ENL: the quantity was over twofold compared with HMR or SDG. The majority of the animals, which had been given SECO, excreted higher quantities of END than ENL into urine, but ENL was the main lignan metabolite after SDG. The highest quantities of ENL in urine were measured after the administration of ENL as such. The (-)SECO isolated from Araucaria angustifolia was converted into (-)ENL only. The administration of (-)SDG, which was shown to produce (+)SECO, resulted in excretion of (+)ENL only and (-)HMR was converted into (-)ENL only. This confirmed that the absolute configurations at C8 and C8' are not changed during the microbial metabolism. Whether the biological effects are enantiomer-specific, remains to be resolved.
authors.affiliation: Department of Anatomy, Institute of Biomedicine, University of Turku, FIN-20520, Turku, Finland.
authors.forename: Niina M
authors.initials: NM
authors.lastname: Saarinen
authors.forename: Annika
authors.initials: A
authors.lastname: Smeds
authors.forename: Sari I
authors.initials: SI
authors.lastname: Mäkelä
authors.forename: Jenni
authors.initials: J
authors.lastname: Ammälä
authors.forename: Kristo
authors.initials: K
authors.lastname: Hakala
authors.forename: Juha-Matti
authors.initials: JM
authors.lastname: Pihlava
authors.forename: Eeva-Liisa
authors.initials: EL
authors.lastname: Ryhänen
authors.forename: Rainer
authors.initials: R
authors.lastname: Sjöholm
authors.forename: Risto
authors.initials: R
authors.lastname: Santti
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000096:biosynthesis* / Q000737:chemistry / Q000652:urine; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D017705:Lignans / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology* / Q000652:urine; D008297:Male; D013058:Mass Spectrometry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D017705:Lignans; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone