Chemical similarity between Dictyota caribaea and Dictyota menstrualis (Dictyotaceae, Phaeophyceae) from the coast of Rio de Janeiro, Brazil

• The chemical similarity between two Southeastern Brazilian Dictyota species is proposed: Dictyota caribaea and Dicyota menstrualis.
• The two species are observed in the South American Tropical areas.
• D. caribaea and D. menstrualis produce pachydictyol A, dichotomanol, dichotomol acetate and cycloxenianol acetate diterpenes.
• Molecular biology confirms the chemical results.