Chem. Pharm. Bull. 52(12) 1487-1488 (2004)

important class of naturally occurring compounds. They are found in plants, fungi and bacteria. These compounds are aromatic rings with two ketone substitutions. Large number of quinones has been associated with antitumor, antibacterial, antimalarial and antifungal activities. The antitumor activity is exhibited predominantly by three main groups of naturally occurring quinones such as benzoquinone, naphthoquinone and anthraquinone. Mitomycin and streptonigrin possess p-benzoquinone moiety with heterocyclic groups whereas anthracyclines, doxorubicin and daunorubicin consist of anthraquinone moiety. Some naphthaquinone antibiotics such as lapachol and lapinone are also found to be cytotoxic to tumor cells. Plants of the Eriocaulaceae family are widespread in the region of the Serra do Cipó, State Minas Gerais, Brazil. Several plants from this family are known as ‘everlasting plants’ because they appear to be alive even for years after being haversted. Paepalanthus is the largest genus of this family with approximately 500 species. Among there more than 400 species are endemic in Brazil. In previous works we have described some biological activity (cytotoxicity, antimicrobial and antioxidant) from naphthopyrones isolated from the capitula of P. bromelioides. In this work we describe the isolation, structure determination and the cytotoxic effect in vitro of a new 1,4-naphthoquinone isolated from the capitula of Paepalanthus latipes.