Isolation, stability and bioactivity of Jatropha curcas phorbol esters

Jatropha curcas seed oil, which can be utilized for biodiesel production upon transesterification, is also rich in phorbol esters (PEs). In this study, PEs from J. curcas oil (Jatropha factors C1 and C2 (purified to homogeneity), Jatropha factors C3 and (C4 + C5) (obtained as mixtures) and PE-rich extract (containing all the above stated Jatropha factors) were investigated. The concentrations of Jatropha PEs were expressed equivalent to Jatropha factor C1. In the snail (Physa fontinalis) bioassay, the order of potency (EC50, μg/L) was: PE-rich extract < factor C3 mixture < factor C2 < factor C1 < factor (C4 + C5). In the Artemia salina bioassay, the order of potency (EC50, mg/L) was: factor C2 < factor C3 mixture < factor C1 < factor (C4 + C5) mixture. In addition, Jatropha PEs exhibited platelet aggregation (ED50, μM, factor C2 < factor C3 mixture < factor C1 < factor (C4 + C5) mixture. The stability of a PE-rich extract was evaluated and found to be low at room temperature but favourable in ethanol over a range of temperatures. By integrating the isolation methodology developed in this study in the Jatropha biodiesel industry, PEs could be obtained as value-added co-products.

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