SYNTHESIS AND ANTINEMATODAL ACTIVITY STUDIES OF SOME FUSED TRIAZINOBENZIMIDAZOLES

4-Aryl-3,4-dihydro[1,3,5]triazino[1,2-a]benzimidazole-2-amines 3a-f were synthesized in the reaction of cyclocondensation between 2-guanidinobenzimidazole and versatilebenzaldehydes. Structures of all prepared compounds were confirmed by IR, 1H NMR spectroscopyand elemental analysis.Antinematodal activity in vitro of the substances was investigated using isolated Trichinella spiralis muscle larvae. The tested triazonobenzimidazoles showed different activity depending on the substituent R in their moleculeas the derivatives substituted with a hydroxyl group demonstrated the best anti-Trichinella spiralis activity in the series.

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-Ododecanoylingenol (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 μg per cotton ball and still displayed antinematodal activity at a dose of 2.5 μg 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. Preliminary structure-biological activity relationships of ingenane-type compounds were deduced.

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 μg/disc, respectively. In addition, it also exhibited antinematodal activity against Bursaphelenchus xylophilus at a minimum effective dose of 200 μg/ball. The three related compounds obtained were also evaluated for the above-mentioned bioactivities.

Antinematodal Activity of Some Tropical Rainforest Plants against the Pinewood Nematode, Bursaphelenchus xylophilus

Sixty five methanolic extracts of Sumatran rainforest plants representing 63 species of 21 families were assayed in vivo for antinematodal activity against Bursaphelenchus xylophilus using our cotton ball-fungal mat method. Extracts of 27 plants species from 14 families exhibited antinematodal activity, while 37 species were inactive. Among them, three extracts of Bischofia javanica, Knema hookeriana and Areca catechu exhibited very strong activity at minimum effective dose (MED ) of 0.7 mg/cotton ball (mg/bl.). Eight extracts from Allamanda cathartica, Ervatamia corymbosa, Hoya diversifolia, Bischofia javanica, Derris malacensis, Melastoma melabathricum, Ophiorriza konsteleary and Brucea sumatrana also showed strong activity (MED, 5 mg/bl.).