Rapid Detection of Cucurbitacins in Tissues and in vitro Cultures of Ecballium elaterium (L.)

Introduction: Cucurbitacins are highly oxygenated compounds abundantly found in Cucurbitaceous genera such as Citrullus, Cucumis, Cucurbita and Luffa (11). A relatively common cucurbitacin found in Cucurbitaceous species is cucurbitacin E (CuE). Although cucurbitacins exhibit positive effects both pharmacologically (1-3, 6, 14, 17) and in protecting the plants from certain diseases (5), they have a high degree of bitterness even at concentrations lower than 10 ppb (10). With the emergence of new cultivars, the expression of the genes that favor the production of cucurbitacins can be enhanced leading to the production of an inedible cultivar. To determine the efficacy of a method that detects these cucurbitacins in plant tissues we have selected an “indicator plant” that stores an abundance of these compounds. Locally, the squirting cucumber (Ecballium elaterium) is also being used as a rootstock in general practice to graft cucurbitaceous crops, owing to the disease resistance of the squirting cucumber to several pests and diseases. The reference cucurbitacin, in this study, was CuE.