Three Distinct Chemotypes of X. strumarium Glandular Trichomes Discovered
2013-10-22
Xanthanolides, as the sesquiterpene lactones, are reportedly the major components for the pharmacological properties of X. strumarium L. species. Phytochemical studies indicated that the glandular structures on the surface of plant tissues would form the primary sites for the accumulation of this class of the compounds. As the interface between plants and their natural enemies, glandular trichomes may vary with respect to which of their chemicals are sequestered against different herbivores in different ecologies. However, to date, no data are available on the chemical characterisation of X. strumarium glandular cells.
Under the supervision of Prof. ZHANG Yansheng, CHEN Fangfang and LI Changfu from
For the first time three distinct chemotypes of X. strumarium glandular trichomes were discovered along with the qualitative and quantitative evaluations of their presence of xanthanolides. These were designated glandular cell Types I, II, and III, respectively. This study showed that the main xanthanolides in Type I cells were 8-epi-xanthatin and xanthumin while no xanthatin was detected. Xanthatin, 8-epi-xanthatin, and xanthumin dominated in Type II cells with comparable levels of each being present. For Type III cells, significantly higher concentrations of 8-epi-xanthatin or xanthinosin (relative to xanthatin) were detected with xanthinosin only being observed in this type. Further research would focus on understanding the ecological and molecular mechanism causing these chemotype differences in X. strumarium glandular structures.
Relevant results were published in PlosOne 2013, 8(10), e76621) entitled “Identifying Three Ecological Chemotypes ofXanthium strumariumGlandular Trichomes Using a Combined NMR and LC-MS Method”.
LC-MS analysis of the extracts from three chemotypes of X. strumarium glandular trichomes (Image by WBG)
