Structural determinants of plant lignans for the formation of enterolactone in vivo.
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.
Saarinen
Niina M
NM
Department of Anatomy, Institute of Biomedicine, University of Turku, FIN-20520, Turku, Finland.
Smeds
Annika
A
Mäkelä
Sari I
SI
Ammälä
Jenni
J
Hakala
Kristo
K
Pihlava
Juha-Matti
JM
Ryhänen
Eeva-Liisa
EL
Sjöholm
Rainer
R
Santti
Risto
R
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
D017705:Lignans; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone