Chemical Constituents From The Roots Of Wikstroemia Chamaedaphne Meissn. And Their Pesticidal Activities

Wikstroemia chamaedaphne,a toxic plant belonging to the genus Rutaceae,its leaves,flowers and other parts can all be used for medicine and can also be used to control pests.At present,the researches were mainly focus on the chemical constituents and pharmacological activities from the flowers of Wikstroemia chamaedaphne Meissn.The roots of Wikstroemia chamaedaphne as a non-medicinal part,which has the advantages of abundant resources and low economic cost.In order to screen novel plant pesticide,the investigation on the chemical constituents and its agricultural activities of the roots of Wikstroemia chamaedaphne was carried out.The plant was extracted with methanol.Separation by silica gel column chromatography,high performance liquid chromatography and recrystallization,18compounds were finally obtained from the methanol extract.By comparing the NMR and MS data of the compounds with the data in literatures,15 compounds of them were identified as 1-hexanoic acid-2,3-stearic acid triglycerid?1?,Methyl linoleate?2?,?-sitosterol?3?,dodecanol?4?,cis-octadeca-9-enoic acid?5?,?2E?-heptyl-3-?3,4-dihydroxyphenyl?acrylate?6?,?-?-pluviatolide?7?,1?-hydroxy-10?-H-guaia-4,11-dien-3-one?8?,isochamaejasmin?10?,neochamaejasmin B?11?,stelleranol?12?,glyceryl monopalmitate?13?,?+?-nortrachelogenin?14?,dihydrodaphnodorinB?15?and naringenin-7-O-?-D-glucopyranoside?18?.Among them,4,5,7,8,10-15 and 18 were isolated from this plant for the first time.The results of biological activity indicated that?1?isochamaejasmin?10?,neochamaejasmin B?11?,compound 16 and compound 17 showed significant inhibitory effects on the spore germination and the mycelial growth of Phytophthora infestans.The EC₅₀ values were 25.14?g/mL,13.97?g/mL,66.28?g/mL and 112.52?g/mL for the spore germination of P.infestans.And the EC₅₀0 values were 68.36?g/mL,44.90?g/mL,134.38?g/mL and 231.26?g/mL,respectively,for the growth of P.infestans;at the same time,these four compounds can effectively against the spread of potatolate blight on detached leaves and showed a good protective effect on potato plants.In addition,isochamaejasmin?10?,neochamaejasmin B?11?,compound 16 and compound 17 also showed antibacterial activity on Bacillus cereus,Escherichia coli,Staphyloccocus aureus,Erwinia carotovora and Ralstonia solanacearum,especially the inhibition effect on Escherichia coli,their MIC values were 12.5?g/mL,6.25?g/mL,25?g/mL and 50?g/mL.?2?The isochamaejasmin?10?,neochamaejasmin B?11?,compound 16 and compound 17 have no obvious toxicity on the third-instar larvae of the Mythimna siparata,but have a certain contact activity on Aphis fabae and Tetranychus cinnabarinus.The LC₅₀ values were 531.01?g/mL,380.23?g/mL,622.29?g/mL and 1061.51?g/mL for Aphis fabae and LC₅₀ values were 426.67?g/mL,214.42?g/mL,464.10?g/mL and 758.74?g/mL for Tetranychus cinnabarinus,respectively.The inhibitory activity of neochamaejasmin B on Phytophthora infestans was first discovered.As a non-medicinal part,the roots of Wikstroemia chamaedaphne has abundant resources,low economic cost and diverse agricultural activities.So it has a good development value.