Cytotoxic and other metabolites of Aspergillus inhabiting the rhizosphere of Sonoran desert plants.

In a study to discover potential anticancer agents from rhizosphere fungi of Sonoran desert plants cytotoxic EtOAc extracts of four Aspergillus strains have been investigated. Two new metabolites, terrequinone A (1) and terrefuranone (2), along with Na-acetyl aszonalemin (LL-S490β) (3) were isolated from As. terreus occurring in the rhizosphere of Ambrosia ambrosoides, whereas As. terreus inhabiting the rhizosphere of an unidentified Brickellia sp. afforded dehydrocurvularin (4), 11-methoxycurvularin (5), and 11-hydroxycurvularin (6). As. cervinus isolated from the rhizosphere of Anicasanthus thurberi contained two new compounds, 4R*,5S*-dihydroxy-3-methoxy-5-methylcyclohex-2-enone (7) and 6-methoxy-5(6)-dihydropenicillic acid (8), in addition to penicillic acid (9). Penicillic acid was also isolated from As. wentii occurring in the rhizosphere of Larrea tridentata. The structures of 1−9 were elucidated by spectroscopic methods and chemical derivatizations. Acetylation of 2 afforded 14-acetylterrefuranone...