STEREOCHEMICAL FEATURES OF SESQUITERPENE METABOLITES AS A DISTINCTIVETRAIT OF RED SEAWEEDS IN THE GENUS LAURENCIA

Red seaweeds in the genus Laurencia may be classified into four lineag es according to the stereochemical features of their metabolites, i.e. the known obtusane (like obtusol (+)-1), isoobtusane (like isoobtusol (+)-2) and rogiolane (like rogiolol (-)-3) and - structurally revised and renamed here - cartilagineane chamigrene sesquiterpenes (like car tilagineol 10), in a vision that encompasses also biogenetic descendan ts, like cuparane sesquiterpenes, and fits ideas of historical conting ency. (C) 1997 Elsevier Science Ltd.