Verification of presence of caprolactam in sprouted achenes of Fagopyrum esculentum Moench and its influence on plant phenolic compound content

The presence of caprolactam, a precursor of Nylon-6, among those synthetic polymers which are widely-spread throughout the environment, could be the reason for its being found in plants. The aim of this work was to confirm the previously described presence of caprolactam in dry and sprouted achenes, as well as in achene exudates of common buckwheat (Fagopyrum esculentum Moench). When the lyophilized sprouted and dry buckwheat achenes, along with exudates from growth experiments, with caprolactam-free medium were analysed by HPLC, no caprolactam was found. After addition of caprolactam into the growth medium, we confirmed the uptake of caprolactam in the lyophilized sprouted buckwheat achenes. The uptake of caprolactam is also a function of light conditions during the growth experiments. Caprolactam also inhibits the content of phenolic compounds; especially rutin, vitexin, isovitexin, orientin, and homoorientin in buckwheat plants.