PSEUDOFUHALOLS FROM THE BROWN ALGA SARGASSUM-SPINULIGERUM

In addition to a large number of fuhalols and phlorethols previously i dentified in an ethanolic extract of Sargassum spinuligerum, a new cla ss of fuhalols was isolated in form of their peracetyl derivatives and identified by means of spectral analysis. Fuhalols typically consist of phloroglucinol units linked by ether bridges. The pseudofuhalols de scribed are isomers of known fuhalols with a different substitution pa ttern. The peracetyl derivatives from pseudotrifuhalol-A, pseudotetraf uhalol-A, pseudopentafuhalols-A-D, pseudohexafuhols-A-C, pseudoheptafu halols-A-D and psuedooctafuhalols-B-D were isolated, Also an efficient method for conversion of peracetylated polyphenols into free phenols via reductive ester cleavage is described. (C) 1997 Elsevier Science L td.