The excretion of lignans in rats — evidence for an intestinal bacterial source for this new group of compounds

Abstract

The lignans are a class of compound with a dibenzylbutane skeleton [l] and which until recently had only been found in higher plants [2]. The first lignans to be identified in humans and monkeys were described in [3,4], their structures differing from all known plant lignans in having me&substitution in the benzyl groups. The two principal lignans identified were 2,3-bis(3’-hydroxybenzyl)butyrolactone (HBBL) and 2,3&(3’hydroxybenzyl)-butane-1,4diol (HBBD) and their structures are shown in fig.1. The quantitative excretion of HBBL and HBBD was found to exhibit a cyclic pattern during the menstrual cycle of humans [3-61 and monkeys [7], maximum excretion occurring in the luteal phase and elevated levels were found in urine collected during early pregnancy [6]. Circumstantial data suggested lignans were possibly of ovarian origin or their production was modulated by ovarian function [3]. HBBL was also identified in human pregnancy and suggested to be of ovarian source or produced by ovarian stimulus [8].