Halogenated phlorethols and fucophlorethols from the brown alga Cystophora retroflexa

• Published in: Natural toxins 1999-01, Vol.7 (2), p.57-62
• Main Authors: Sailler, B, Glombitza, K-W
• Format: Article
• Language: English
• Subjects: Cystophora retroflexa; fucophlorethols; halogenated compounds; phlorethols
• ISSN: 1056-9014
• DOI: 10.1002/(SICI)1522-7189(199903/04)7:2<57::AID-NT42>3.3.CO;2-6

From an ethyl acetate fraction of the brown alga Cystophora retroflexa several halogenated phlorotannins were isolated. Most of the compounds are derivatives of diphlorethol penta-acetate and triphlorethol-A hepta-acetate. The majority turned out to be chlorinated and/or brominated. Only one iodinated substance, 2-iodophloroglucinol triacetate, was isolated. The structure of this derivative and the following compounds have been characterized previously: 2 sub([D])-bromodiphlorethol penta-acetate, 3 sub([A1])-bromodiphlorethol penta-acetate, 4 sub([D])-bromo-diphlorethol penta-acetate, 4 sub([D])-chlorodiphlorethol penta-acetate, 3 sub([A1])-chlorotriphlorethol-A hepta-acetate, 4 sub([D])-bromotriphlorethol-A hepta-acetate and 4 sub([D])-chlorobisfucopentaphlorethol-A nonadeca-acetate. Ten halogenated phlorethols and two chlorinated fucophlorethols are described for the first time and characterized as their acetates: 2 sub([B])-bromotriphlorethol-A hepta-acetate, 2 sub([D])-bromotriphlorethol-A hepta-acetate, 2 sub([B]), 2 sub([D])-dibromotriphlorethol-A hepta-acetate, 3 sub([A1]), 5 sub([A1])-dichlorotriphlorethol-A hepta-acetate, 3 sub([A1]), 4 sub([D])-dichlorotriphlorethol-A hepta-acetate, 3 sub([A1])-chloro-4 sub([D])-bromotriphlorethol-A hepta-acetate. 2 sub([B]), 4 sub([D])-dichlorotriphlorethol-A hepta-acetate, 2 sub([D]), 3 sub([A1])-dibromotriphlorethol-A hepta-acetate, 3 sub([A1])-bromo-2 sub([D])-chlorotriphlorethol-A hepta-acetate, 2 sub([D])-bromotetraphlorethol-C nona-acetate, 4 sub([D])-chlorofucotriphlorethol-B dodeca-acetate and 4 sub([D])-chlorobisfucotetraphlorethol-A heptadeca-acetate.