A new anthraquinone and cytotoxic curvularins of a Penicillium sp. from the rhizosphere of Fallugia paradoxa of the Sonoran desert.

In the course of screening rhizosphere microflora of Sonoran desert plants for potential anticancer agents1,2), an unidentified Penicillium sp. (Trichonaceae) isolated from the rhizosphere of the apache plume (Fallugia paradoxa D. Don; Rosaceae) was found to produce several cytotoxic substances. Fractionation of the cytotoxic EtOAc extract led to the isolation of a new anthraquinone (1), a known anthraquinone (2), and cytotoxic curvularins, 3-5. This is the first report of the natural occurrence of 2. Curvularins 3-5 have been reported as metabolites of several fungi including Penicillium sp.3,4) This paper briefly describes the isolation of 1-5, structure elucidation of 1, and evaluation of 1-5 for their ability to inhibit the growth of three sentinel tumor cell lines. Materials and Methods