Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/10/2008
Publication Date: 12/8/2008
Citation: Sobolev, V.S., Neff, S.A., Gloer, J.B. 2008. New Stilbenoids from Peanut (Arachis hypogaea) Seeds Challenged by an Aspergillus caelatus Strain. Journal of Agricultural and Food Chemistry. 57(1):62-68. Interpretive Summary: The peanut plant has been introduced around the world and has become an economically and nutritionally important crop. Peanuts are host to many soil molds, among which Aspergillus flavus and A. parasiticus are of particular agricultural significance due to their ability to produce the carcinogenic aflatoxins. As the result, peanut seeds often become contaminated with the aflatoxins. Under favorable conditions, the peanut plant can resist mold attacks by promptly producing antibiotic compounds called phytoalexins. Such natural phytoalexin-based mechanism of peanut resistance attracts the attention of researchers because, once understood, this mechanism of resistance could be manipulated to obtain a greater peanut resistance to pests. Such knowledge may be crucial for breeding new mold-resistant peanut cultivars. A number of peanut phytoalexins have been reported. However, peanuts may be capable of producing several other important bioactive compounds. The purpose of this research was to isolate and characterize further new and/or known peanut kernel compounds that may act as phytoalexins. The present study revealed the production of four new phytoalexins by mold-challenged peanut kernels. In addition, two compounds that have been reported previously from other sources are reported in peanuts for the first time. New phytoalexins may play a protective role against molds.
Technical Abstract: Four new stilbene derivatives termed arahypins have been isolated from peanut kernels challenged by an Aspergillus caelatus strain, along with two known stilbenoids that have not been previously reported in peanuts. The structures of these new putative phytoalexins were determined by analysis of NMR, MS, and UV spectral data. Together with other known peanut stilbenoids that were also produced in the challenged kernels, these new compounds may play a defensive role against invasive fungi.