title: Larvicidal spirobisnaphthalenes from the endophytic fungus Berkleasmium sp. against Aedes albopictus.
abstract: BACKGROUND
  In our screening programme for new agrochemicals from endophytic fungi, the ethyl acetate extract of an endophytic Berkleasmium sp. isolated from the medicinal plant Dioscorea zingiberensis was found to possess strong larvicidal activity against the Asian tiger mosquito, Aedes albopictus.
  
  
  RESULTS
  Bioassay-guided fractionation of the fungal extract has led to the isolation of seven spirobisnaphthalenes, including palmarumycins C8, C12, C15 and B6 and diepoxins γ, δ and ζ. Among them, palmarumycins C8 and B6 showed strong larvicidal activity against the fourth-instar larvae of A. albopictus, with LC50 values of 8.83 and 11.51 µg mL(-1) respectively. Interestingly, only spirobisnaphthalenes with a chlorine substituent possessed strong larvicidal activity.
  
  
  CONCLUSIONS
  The results indicated that the spirobisnaphthalenes derived from the endophytic fungus Berkleasmium sp. could be promising leads for the development of new larvicides against A. albopictus.
authors.affiliation: MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Tian
authors.affiliation: Department of Entomology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
authors.forename: Xin Chao
authors.initials: XC
authors.lastname: Liu
authors.affiliation: Department of Entomology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
authors.forename: Zhi Long
authors.initials: ZL
authors.lastname: Liu
authors.affiliation: MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
authors.forename: Daowan
authors.initials: D
authors.lastname: Lai
authors.affiliation: MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000254:growth & development; D000818:Animals; D001203:Ascomycota / Q000737:chemistry*; D027742:Dioscorea / Q000382:microbiology; D060026:Endophytes / Q000737:chemistry*; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D009032:Mosquito Control; D009281:Naphthalenes / Q000302:isolation & purification / Q000494:pharmacology*; D013141:Spiro Compounds / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D009281:Naphthalenes; D013141:Spiro Compounds
keywords: Aedes albopictus; Berkleasmium sp; endophytic fungus; larvicidal activity; mosquito; spirobisnaphthalene