|De Lucca Ii, Anthony|
Submitted to: Phytochemistry and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2010
Publication Date: 11/12/2010
Citation: Sobolev, V.S., Neff, S.A., Gloer, J.B., Khan, S.I., Tabanca, N., De Lucca Ii, A.J., Wedge, D.E. 2010. Pterocarpenes elicited by Aspergillus caelatus in peanut (Arachis hypogaea) seeds. Phytochemistry and Agriculture. 71:2099-2107. Interpretive Summary: Many plants from the family Leguminosae produce compounds that defend the plants from several pathogens, including fungi. These plants are commonly produce so called pterocarpans. In addition to their defensive antifungal functions, pterocarpans possess diverse biological activity, such as antibacterial, antiinflamatory, antitumor, antioxidant, antiallergic, antiparasitic, as well as activity against adult mosquitoes and common cutworm. The peanut plant that belongs to the same family of plants, has not been systematically investigated for its ability to produce pterocarpans and related compounds, such as pterocarpenes. Our previous research on peanut defensive mechanisms revealed unidentified compounds that were detected only in fungus-challenged seeds and therefore, could have played a role in peanut defense against pathogens. Spectral properties of these compounds were similar to those of known pterocarpenes, and therefore were suggested to be related to this group of compounds. Two compounds have been isolated and their structures were unambiguously elucidated from the spectroscopic evidence. These compounds have not been reported from any plants and as new compounds were named aracarpene-1and aracarpene-2. Because of the importance of knowledge of the role of new pterocarpenes as potential defensive compounds in peanuts as well as knowledge of their presumably beneficial properties, a systematic study of biological activity of the new compounds is planned. The study will evaluate the pterocarpenes’ cytotoxicity against important cancer cells, activity against several key plant pathogens, as well as insecticide activity.
Technical Abstract: Two new substituted pterocarpenes named aracarpene-1 and aracarpene-2 have been isolated from wounded peanut seeds challenged by a strain of Aspergillus caelatus. The structures of these new putative phytoalexins were determined by interpretation of NMR and MS data. Together with peanut stilbenoids that are also produced in the challenged seeds, these new compounds may represent a new class of peanut phytoalexins that could play a defensive role against pathogenic microorganisms.