Activity-guided fractionations of black tubers of Tropaeolum tuberosum led to the isolation of 3-[3-(3-pyridinyl)-1,2,4-oxadiazol-5-yl] benzonitrile (1) and [3,5-Bis (1,1-dimethylethyl)-4-hydroxyphenyl] ethenylidene] bis-phosphonic acid tetraethyl ester (2).