Mosquito larvicidal activity of Piper longum fruit-derived materials against the fourth-instar larvae of Aedes aegypti was examined. A crude methanol extract of P. longum fruits was found to be active against the larvae, and the hexane fraction of the methanol extract showed a strong larvicidal activity of 100% mortality. The biologically active component of P. longum fruits was characterized as pipernonaline by spectroscopic analyses. The LC(50) value of pipernonaline was 0.25 mg/L. The toxicity of pipernonaline is comparable to that of pirimiphos-methyl as a mosquito larvicide. In tests with available components derived from P. longum, no activity was observed with piperettine, piperine, or piperlongumine.

Fungicidal activity of Curcuma longa rhizome-derived materials against Botrytis cineria, Erysiphe graminis, Phytophthora infestans, Puccinia recondita, Pyricularia oryzae, and Rhizoctonia solani was tested using a whole plant method in vivo. It was compared with synthetic fungicides and four commercially available compounds derived from C. longa. The response varied with the tested plant pathogen. At 1000 mg/L, the hexane extract of C. longa showed fungicidal activities against E.graminis, P. infestans, and R. solani, and the ethyl acetate extract of C. longa showed fungicidal activities against B. cineria, P. infestans, Pu. recondita, and R. solani. Curcumin was isolated from the ethyl acetate fraction using chromatographic techniques and showed fungicidal activities against P. infestans, Pu. recondita, and R. solani with 100, 100, and 63% control values at 500 mg/L and 85, 76, and 45% control values at 250 mg/L, respectively. In the test with components derived from C. longa, turmerone exhibited weak activity against E. graminis, but no activity was observed from treatments with borneol, 1,8-cineole, sabinene, and turmerone. In comparison, potent fungicidal activity with chlorothalonil against P. infestans at 50 mg/L and dichlofluanid against B. cinerea at 50 mg/L was exhibited. These results may be an indication of at least one of the fungicidal actions of curcumin derived from C. longa.