Variation de la composition en diterpènes deBifurcaria bifurcatasur les côtes atlantiques françaises

Summary Geographical variations in the diterpene composition of the diethyl ether extract from the brown alga Bifurcaria bifurcata are described in algae collected on the French Atlantic coasts. They are then compared with those in same algae from the coasts of Morocco. Several types of extracts have been found, and they vary according to where they are collected, thus delimiting more or less extensive geographical zones. Altogether, five diterpenes (1 to 5) have been isolated, identified and analysed in the different extracts. Two of them had not, so far, been recorded in this alga (4 and 5).