Study on the phenolic components of <i>Pontederia vaginalis</i> Burm. f

<i>Pontederia vaginalis</i> Burm. f. is an aquatic plant widely distributed in East and Southeast Asia, where its young leaves and stems are traditionally consumed. Despite its regional use as a food source, the phytochemical constituents of this species have remained largely unexplored. In particular, it has not been determined whether <i>P. vaginalis</i> contains phenylphenalenone-type compounds, which are known from related species such as <i>P. crassipes</i> (syn. <i>Eichhornia crassipe</i>s). In this study, phytochemical investigation on <i>P. vaginalis</i> led to the isolation of two novel diallylheptanoids—pontevagonols A (<b>1</b>) and B (<b>2</b>)—as well as a naturally occurring phenylphenalenone, 2-hydroxy-4-methoxy-9-phenylphenalen-1-one (<b>3</b>), and eight known phenolic derivatives. This represents the first report of these compound types from <i>P. vaginali</i>s, and clarifies the phenolic composition of the Pontederiaceae family.