
%0 Journal Article
%A Gregson, RP 
%A Daly, JJ 
%T Polyhydroxy biphenyl ethers from the brown alga <I>Cystophora congesta</I>
%J Australian Journal of Chemistry
%D 1982/03/01
%V 35
%N 3
%P 649-657
%K 
%R https://doi.org/10.1071/CH9820649
%U https://www.publish.csiro.au/paper/CH9820649 
%X Two new phloroglucinol polymers have been isolated from the aqueous extract of the brown alga Cystophora congesta. They are the linear trimer 2,2',4,6,6'-pentahydroxy-1'-(3,5-dihydroxyphenoxy)- biphenyl ether (1)* and the isomeric angular trimer 3,4',5,6'- or 3,3',5,5'-tetrahydroxy-2'-(3,4,5-tri-hydroxyphenoxy)biphenyl ether which was characterized as its heptaacetoxy derivative (4). Structures were elucidated principally from an analysis of 13C n.m.r. chemical shifts and 13C-1H spin-spin coupling data. X-ray analysis was performed on the heptaacetoxy derivative of (1) to distinguish it from a regio-isomer (3). 
