|KRAUSERT, NICOLE - University Of Iowa|
|GLOER, JAMES - University Of Iowa|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2015
Publication Date: 1/16/2016
Citation: Sobolev, V., Krausert, N.M., Gloer, J.B. 2016. New monomeric stilbenoids from peanut (Arachis hypogaea) seeds challenged by an Aspergillus flavus strain. Journal of Agricultural and Food Chemistry. 64:579-584.
Interpretive Summary: The peanut plant responds to fungal infection by producing defensive chemicals, so called phytoalexins. Detailed knowledge of phytoalexin production may help to reveal natural mechanisms of peanut disease and pest resistance. It is conceivable that such mechanisms could be manipulated to improve early natural field resistance of the plant to pests. In addition, the potential medical importance or health benefits of phytoalexins from peanuts have been acknowledged by several research groups. Present research on the peanut ability to produce phytoalexins revealed production of several unidentified compounds. Those compounds were suggested to be new peanut defensive phytoalexins as they were only produced by infected peanut seeds. The structures of three new isolated compounds were unambiguously deduced by modern spectroscopic means. As no reference to these compounds was found in the literature, they were considered new natural compounds and were named arahypin-13, arahypin-14, and arahypin-15. New compounds may play a protective role against soil fungi. Investigation of biological activity of the new compounds is planned.
Technical Abstract: Two new stilbene derivatives have been isolated from peanut seeds challenged by an Aspergillus flavus strain, along with chiricanine B that has not been reported from peanuts, as well as a stilbenoid that has been known as a synthetic product. The structures of these new putative phytoalexins were determined by analysis of 1H and 13C NMR, HRESIMS, MSn, and UV data. The new stilbenoids were named arahypin-13, arahypin-14, and arahypin-15. Together with other known peanut stilbenoids that were also produced in the challenged seeds, these new compounds may play a defensive role against invasive fungi. In addition, based on their structures, new stilbenoids may possess health beneficial properties.