Simultaneous determination of cucurbitacins B, D, and E in <i>Cucurbita</i> seed oils by HPLC-DAD

Cucurbitacins are triterpene bioactive constituents of natural products, particularly in the Cucurbitaceae plant family. The presence of cucurbitacins in seeds of the <i>Cucurbita</i> genus (pumpkin) has been only little studied. In this work, the content of cucurbitacins B, D, and E in seed oils from three cucurbits (<i>Cucurbita moschata</i> Duch, <i>Cucurbita pepo</i> Linn, and <i>Cucurbita maxima</i> Linn) was studied. An analytical method based on HPLC-DAD for the detection and quantification of these three cucurbitacins in seed oils was developed and validated according to ICH guidelines. The method showed good linearity, accuracy, and precision for the simultaneous quantification of cucurbitacins B, D, and E using <i>C.moschata</i> seed oil as a reference. When applied to <i>C.pepo</i> and <i>C.maxima</i> seed oils, cucurbitacin B and D were quantified but to a lesser extent. This is the first report of a simple, repeatable, and reproducible analytical tool to identify cucurbitacins in oilseeds from <i>Cucurbita</i> spp.