Contact allergens of an urban shrub Wigandia caracasana

Abstract

The principal dermatitic constituents of W. caracasana were isolated from the glandular hairs and identified as unusual prenylated quinones and prenylated phenols. Potentials to elicit irritant and allergic contact dermatitis reactions were evaluated with guinea pigs.

Plants and Plant Products

“…The genera Phacelia and Wigandia belonging to the Hydrophyllaceae family yield alkenyl hydroquinones. Prenylated quinones and prenylated phenols were identified in W. caracasana Kunth [155], and geranylhydroquinone in P. crenulata Torrey (Fig. 16); this molecule does not crossreact with poison oak or ivy [156].…”

Mineralized trichomes in Boraginales: complex microscale heterogeneity and simple phylogenetic patterns

“…Mineralized trichomes are thought to play a crucial role in physical plant defence, e.g. via restricting herbivore movement in general and their access to vegetative and reproductive organs in particular (Reynolds and Rodriguez, 1981;Reynolds et al, 1986Reynolds et al, , 1989He et al, 2012;Szyndler et al, 2013). Additional, nondefence functions of trichomes comprise a protection against water loss, high temperature and UV-B radiation (Bickford, 2016).…”