NEMATOCIDAL ACTIVITY OF TURMERIC - SYNERGISTIC ACTION OF CURCUMINOIDS

A new curcuminoid, cyclocurcumin (IV), was isolated from the nematocid ally active fraction of turmeric, the rhizome of Curcuma longa, togeth er with three known curcuminoids, curcumin (I), demethoxycurcumin (II) and bisdemethoxycurcumin (III). The structure of IV was elucidated on the basis of spectral data and confirmed by the partial synthesis fro m curcumin (I). Although the above curcuminoids were ineffective when they were applied independently, the nematocidal activity increased re markably when they were mixed, suggesting a synergistic action between them.