PHYSODES AND PHENOLIC COMPOUNDS OF BROWN-ALGAE - ISOLATION AND CHARACTERIZATION OF PHLOROGLUCINOL POLYMERS FROM FUCUS-VESICULOSUS L

A series of vanillin-reactive compounds was isolated from extracts of the brown alga F. vesiculosus. The 1st three members of this series were examined by mass spectrometry, NMR spectrometry and chemical methods, and were shown to be phloroglucinol, its phenyl-linked dimer, and a trimer also composed of phloroglucinol units. Evidence is presented for the presence of tetrameric, pentameric and hexameric phloroglucinol derivatives. Polymeric vanillin-reactive compounds were isolated and separated into 2 fractions. Oxidative hydrolysis of the major one produced phloroglucinol and related oligomers in low yields. The classical vanillin reactivity of physodes may thus be attributed to phloroglucinol-containing derivatives, as originally proposed by Crato (1892).