Careful fractionation of extracts prepared from barley coleoptiles gave small amounts of pure hordatines A and B and substantial amounts of a mixture of their glucosides. The structures of the hordatines were deduced by degradative and spectroscopic studies and by the synthesis of some degradation products. A synthesis of racemic hordatine A analogous to its probable biogenesis was achieved by the oxidative coupling of coumaroylagmatine.The possible role of the hordatines in lignification is briefly discussed.
The hordatines, antifungal substances previously isolated from barley seedlings grown in the dark, are also produced under conditions which approximate those in the field. The compounds, and some of their derivatives, inhibit the spore germination of a number of fungi in concentrations as low as 10−5 M. Inhibition is reversed by the addition of some divalent cations; this observation supports the identity of the hordatines with the natural defense agents of barley which have been demonstrated in earlier work.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.