The organic extract of the red alga Sphaerococcus coronopifolius, collected
along the Atlantic coast of Morocco, was tested for biological activities
and exhibited antibiotic and antimalarial. activities. Two new bromoditerpe
nes have been isolated from S. coronopifolius, sphaerolabdadiene-3,14-diol
(1) and bromosphaerone (2), along with the known compounds 12S-hydroxybromo
sphaerodiol (3) and sphaerococcenol A (4). Bromosphaerone and 12S-hydroxybr
omosphaerodiol showed antibacterial activity against the Gram-positive bact
erium species Staphylococcus aureus with a minimum inhibitory concentration
of 0.104 and 0.146 muM, respectively. Sphaerococcenol A (4) was responsibl
e for the antimalarial activity of the extract, against the chloroquine res
istant Plasmodium falsciparum FCB1 strains with an IC50 of 1 muM. Their str
uctures have been assigned using 1 and 2 D NMR and HRMS.