Larvicidal Spirobisnaphthalenes From The Endophytic Fungus Berkleasmium Sp Against Aedes Albopictus

BACKGROUNDIn 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.RESULTSBioassay-guided fractionation of the fungal extract has led to the isolation of seven spirobisnaphthalenes, including palmarumycins C-8, C-12, C-15 and B-6 and diepoxins , and . Among them, palmarumycins C-8 and B-6 showed strong larvicidal activity against the fourth-instar larvae of A. albopictus, with LC50 values of 8.83 and 11.51 mu g mL(-1) respectively. Interestingly, only spirobisnaphthalenes with a chlorine substituent possessed strong larvicidal activity.CONCLUSIONThe 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. (c) 2015 Society of Chemical Industry