Biotransformation of pinoresinol diglucoside to mammalian lignans by human intestinal microflora, and isolation of Enterococcus faecalis strain PDG-1 responsible for the transformation of (+)-pinoresinol to (+)-lariciresinol.
By anaerobic incubation of pinoresinol diglucoside (1) from the bark of Eucommia ulmoides with a fecal suspension of humans, eleven metabolites were formed, and their structures were identified as (+)-pinoresinol (2), (+)-lariciresinol (3), 3'-demethyl-(+)-lariciresinol (4), (-)-secoisolariciresinol (5), (-)-3-(3", 4"-dihydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butane-1, 4-diol (6), 2-(3', 4'-dihydroxybenzyl)-3-(3", 4"-dihydroxybenzyl)butane-1, 4-diol (7), 3-(3"-hydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butane-1, 4-diol (8), 2-(3', 4'-dihydroxybenzyl)-3-(3"-hydroxybenzyl)butane-1, 4-diol (9), (-)-enterodiol (10), (-)-(2R, 3R)-3-(3", 4"-dihydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butyrolactone (11), (-)-(2R, 3R)-2-(3', 4'-dihydroxybenzyl)-3-(3", 4"-dihydroxybenzyl)butyrolactone (12), (-)-(2R, 3R)-3-(3"-hydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butyrolactone (13), 2-(3', 4'-dihydroxybenzyl)-3-(3"-hydroxybenzyl)butyrolactone (14), 2-(3'-hydroxybenzyl)-3-(3", 4"-dihydroxybenzyl)butyrolactone (15) and (-)-(2R, 3R)-enterolactone (16) by various spectroscopic means, including two dimensional (2D)-NMR, mass spectrometry and circular dichroism. A possible metabolic pathway was proposed on the basis of their structures and time course experiments monitored by thin-layer chromatography. Furthermore, a bacterial strain responsible for the transformation of (+)-pinoresinol to (+)-lariciresinol was isolated from a human fecal suspension and identified as Enterococcus faecalis strain PDG-1.
Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Toyama, Japan.
Li-Hua
LH
Xie
Teruaki
T
Akao
Kenjiro
K
Hamasaki
Takeshi
T
Deyama
Masao
M
Hattori
D016588:Anticarcinogenic Agents / Q000378:metabolism*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003640:Dealkylation; D013293:Enterococcus faecalis / Q000302:isolation & purification / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D005663:Furans / Q000378:metabolism*; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D017705:Lignans / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D024301:Plant Bark / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D016588:Anticarcinogenic Agents; D005663:Furans; D017705:Lignans; C013200:pinoresinol diglucoside; C060282:lariciresinol