Repellent activity of compounds from Murraya alata Drake against Tribolium castaneum

Abstract Murraya alata Drake is a shrub that is distributed in the underwood of sandy areas near sea level in China and Vietnam. Twenty-two compounds were isolated from the leaves and stems of M. alata , including six new coumarins ( 6 , 8–10 , 17 , 19 ) named muralatins L–Q. The structures were identified on the base of NMR and MS spectral analysis. Furthermore, the repellent activity against Tribolium castaneum was tested for fourteen isolated compounds. A statistic model-grey relational analysis was introduced to evaluate repellent activity directly based on relative correlation degree. This statistical analysis was suitable for complex problems of multiple indexes. The testing compounds exhibited various repellent activities against T. castaneum . Among them, compounds 1 (meranzin), 2 (phebalosin) and 16 (muralatin K) showed significant repellent activity against T. castaneum with r i values of 0.7047, 0.6990 and 0.6884, respectively, comparable to that of the positive control, N, N -diethyl-3-methylbenzamide (DEET, r i  = 0.7013). The optimal compounds might be considered as potential leading compounds for the development of natural repellents.