Inhibition of acetylcholinesterase and glutathione S-transferase of the pinewood nematode (Bursaphelenchus xylophilus) by aliphatic compounds

To determine the nematicidal mode of action of aliphatic compounds against the pinewood nematode (Bursaphelenchus xylophilus), we evaluated the inhibition activity of 63 aliphatic compounds on B. xylophilus acetylcholinesterases (BxACEs) and glutathione S-transferase. In the primary inhibition assay using B. xylophilus crude proteins, more than 65% of BxACE inhibition activity was observed for C-6, C-9, C-10, and C-12 2E-alkenals. Other compounds showed moderate or weak inhibition activity. The inhibition activity against 3 recombinant BxACEs was subsequently evaluated using active compounds in a primary inhibition assay. C-12 2E-alkenal showed the strongest inhibition activity against BxACE-1, followed by C-9, C-6, and C-10 2E-alkenals. The IC50 values of C-12, C-6, C-10, and C-9 2E-alkenal against BxACE-2 were 0.0059, 0.57, 0.86, and 0.99 mg/ml, respectively. C-12 2E-alkenal showed the strongest inhibition activity against BxACE-3 followed by C-6 2E-alkenal. In an inhibition activity test using glutathione S-transferase from the pinewood nematode, Cm, C-9, and C-6 2E-alkenals and C-12 alkanoic acid showed >45% inhibition activity. (C) 2013 Elsevier Inc. All rights reserved.