Antinematodal activities of ingenane diterpenes from Euphorbia kansui and their derivatives against the pine wood nematode (Bursaphelenchus xylophilus).

Under the bioassay-guided method, two diterpenes, 3-O-(2",3"-dimethylbutanoyl)-13-O-dodecanoylingenol (1) and 3-O-(2",3"-dimethylbutanoyl)-13-O-decanoylingenol (2) isolated from Euphorbia kansui, showed a pronounced antinematodal activity against the nematode Bursaphelenchus xylophilus at the same minimum effective dose (MED) of 5 microg per cotton ball and still displayed antinematodal activity at a dose of 2.5 microg per cotton ball. Compounds 3-6 were obtained, and the structure of the new compound 6 was elucidated based on 1D- and 2D-NMR analyses and physicochemical data.

Termiticidal activity of diterpenes from the roots of Euphorbia kansui.

Five ingenane compounds, 1-5, kansuinins A and B, isolated from Euphorbia kansui, and their derivatives 7 and 9 were tested for termiticidal activity against the Japanese termite, Reticulitermes speratus. At 72 hours after treatment, the ingenane compounds 1 to 5 caused 100% mortality in R. speratus at 50, 25 and 12.

Repellent from traditional Chinese medicine, Periploca sepium Bunge.

By using a new bioassay-guided method, 2-hydroxy-4-methoxybenzaldehyde isolated from the root bark of Periploca sepium, a traditional Chinese medicine, showed repellent activity against the olive weevil (Dyscerus perforatus) at 62.5, 125, 250 and 500 microg/disc, respectively. In addition, it also exhibited antinematodal activity against Bursaphelenchus xylophilus at a minimum effective dose of 200 microg/ball.

Three antinematodal diterpenes from Euphorbia kansui.

Three compounds, 20-O-acetyl-[3-O-(2'E,4'Z)-decadienoyl]-ingenol (1), 20-O-acetyl-[5-O-(2'E,4'Z)-decadienoyl]-ingenol (2) and 3-O-(2'E,4'Z)-decadienoylingenol (3), were isolated from Euphorbia kansui under the bioassay-guided method. Each compound showed the same antinematodal activity against the nematode, Bursaphelenchus xylophilus, at a minimum effective dose (MED) of 5 microg/cotton ball.