Abstract
Isolation and characterization of plant constituents responsible for insect resistance are of the utmost importance for better understanding of insect-host plant interactions, for selection and breeding of resistant plant varieties, and for development of natural insecticides to be used in future sustainable agriculture and food production. In this study, 3-O-cellobiosyl-cochalic acid (1), 3-O-cellobiosyl-gypsogenin (3), and 3-O-cellobiosyl-4-epihederagenin (4) were isolated from the glabrous type of Barbarea vulgaris var. arcuata exhibiting resistance to the flea beetle Phyllotreta nemorum. In addition to the new constituents, 3-O-cellobiosyl-hederagenin (2), a known insect repellant, was identified. The structures were established by one-and/or two-dimensional homo-and heteronuclear NMR experiments acquired at 800 MHz and by fragmentation and high-resolution mass spectrometric analysis. Compounds 1, 3, and 4 are glycosides of cochalic acid, gypsogenin, and 4-epihederagenin, respectively, none of which have previously been identified in Brassicaceae. Compounds 3 and 4 have both recently been targeted as unidentified constituents exhibiting correlation with P. nemorum resistance, but this is the first report of their structures.
| Original language | English |
|---|---|
| Journal | Journal of Agricultural and Food Chemistry |
| Volume | 58 |
| Issue number | 9 |
| Pages (from-to) | 5509-5514 |
| Number of pages | 6 |
| ISSN | 0021-8561 |
| DOIs | |
| Publication status | Published - 12 May 2010 |
