Five new sulphur-containing amides from Glycosmis lucida with antifeedant activity against Tribolium castaneum

Five new sulphur-containing amides (2, 5-8) and three known analogue compounds (1, 3-4) were isolated from the leaves of Glycosmis lucida which were collected in Yunnan province, China. Their structures were elucidated with NMR spectroscopy and mass spectrometry. The compounds were identified as N-(p-hydroxyphenethyl)-3-(methylsulfonyl)-propenamide (1), N-[2(4- hydroxyphenyl)-ethyl]-3-methanesulfonyl-N-methyl-propionamide (2), methylgerambullin (3), methylisogerambullone (4), methylgerambullindiol (5), N-{2-[4-(6,7-hydroxy-3,7-dimethyl-oct- 2-enyloxy)-phenyl]-ethyl}-3-methanesulfonyl-N-methyl-acrylamide (6), N-{2-[4-(6,7-dihydroxy- 3,7-dimethyl-oct-2-enyloxy)-phenyl]-ethyl}-3-methanesulfonyl-N-methyl-propionamide (7), (E)-N-{2-[4-(6-hydroxy-7-dimethyl-oct-2-enyloxy)-phenyl]-ethyl}-3-methanesulfinyl-N-methyl- acrylamide (8). Feeding deterrent activities of these surphur-containing derivatives against Tribolium castaneum were assayed for the first time. Compound 2, 3, 6 possessed significant feeding deterrent activities against T. castaneum adults (EC50 =311.6, 244.9 and 108.3 ppm, respectively). These results demonstrated that some sulphur-containing amides are promising candidates as insect antifeedant agents. (C) 2015 Elsevier B.V. All rights reserved.