|MELENDEZ-GONZALEZ, CLAUDIO - Universidad Nacional Autonoma De Mexico|
|MURIA-GONZALEZ, M JORDI - Universidad Nacional Autonoma De Mexico|
|ANAYA, ANA LUISA - Universidad Nacional Autonoma De Mexico|
|HERNANDEZ-BAUTISTA, BLANCA - Universidad Nacional Autonoma De Mexico|
|HERNANDEZ-ORTEGA, SIMON - Universidad Nacional Autonoma De Mexico|
|GONZALEZ, MARIA - Instituto De Biologia|
|Glenn, Anthony - Tony|
|HANLIN, RICHARD - University Of Georgia|
|MACIAS-RUBALCAVA, MARTHA - Universidad Nacional Autonoma De Mexico|
Submitted to: Chemistry and Biodiversity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2014
Publication Date: 5/25/2015
Citation: Melendez-Gonzalez, C., Muria-Gonzalez, M., Anaya, A., Hernandez-Bautista, B.E., Hernandez-Ortega, S., Gonzalez, M.C., Glenn, A.E., Hanlin, R.T., Macias-Rubalcava, M.L. 2015. Acremoxanthone E, a Novel Member of Heterodimeric Polyketides with a Bicyclo[3.2.2]nonene Ring, Produced by Acremonium camptosporum W. Gams (Clavicipitaceae) Endophytic Fungus. Chemistry and Biodiversity. 12(1):133-147.
Interpretive Summary: Bioactivity-directed fractionation of the organic mycelium extract of the endophytic fungus Acremonium camptosporum W. Gams (Clavicipitaceae) isolated from the leaves of Bursera simaruba (Burseraceae), led to the isolation of six major heterodimeric polyketides, including one not previously characterized acremoxanthone derivative. In addition, the already known acremoxanthone C, acremonidins A and B, and acremoxanthones A and B were obtained. The structure of the new compound was established by extensive NMR studies, including DEPT, COSY, NOESY, HSQC, and HMBC methods. The trivial name proposed for this compound is acremoxanthone E. In addition, the structure of acremoxanthone C was unequivocally confirmed for the first time, through X-ray crystal structure analysis. The anti-oomycete activity of the pure compounds was tested against four economically important phytopathogenic oomycetes. Inhibitory concentration for 50% diameter growth reduction (IC50) values for the four phytopathogens ranged from 6–38 µM. Also, in parallel, the cytotoxic activity against six cancer cell lines was assayed showing an IC50 values similar to cisplatin. To our knowledge, this is the first report of three different groups of heterodimeric polyketides linked by a bicyclo[3.2.2]nonene, such as xanthoquinodins, acremonidins, and acremoxanthones, which are isolated by an endophytic fungus. In addition, a common biosynthetic origin could be assumed.
Technical Abstract: The fungus Acremonium camptosporum was isolated as an endophyte from the leaves of the plant Bursera simaruba. Extracts from cultures of the fungus were shown to have inhibitory effects on the growth of plant pathogenic oomycetes. The chemical compounds in the extracts were identified, and a group of related compounds were identified. These were various forms of acremoxanthones and acremonidins. A new compound, acremoxanthone E was characterized using various techniques, and the structure of acremoxanthone C was conclusively resolved for the first time. The purified compounds were shown to have anti-oomycete activity in the concentration range of 6-38 µM. The compounds also were shown to be toxic to six cancer cell lines.