Study On The Secondary Metabolites From Paecilomyces Lilacinus 518

Biological pesticide is an important object of reseach in the application area of beneficial microorganisms of agriculture which was produced and processed with beneficial microorg-anisms or metabolites of microorganisms. Biodiversity of microbial resources determines structural diversity and variety of biological activities of their metabolites. As an important member of the microflora, fungi have immense number of species, extremely wide distribution, as well as miscellaneous biological activities for their secondary metabolites, such as antimicrobial, antitumor, regulating plant growth and so on.In this study, strain 518 was investigated. Strain 518 preserved in our lab, which has been isolated from the rhizosphere soil of tomato in Suqian, Jiangsu Province, China. Strain 518 was identified as Paecilomyces lilacinus. according to colony morphology and molecular biological methods.According to antagonistic test in vitro, the petroleum ether extracts of fermentation products of strain 518 exhibited favorable activities against B. cinerea, Fusarium omysporum and had obvious inhibitory effects against Botrytis cinerea, particularly. We further validated the potential value of strain 518 in terms of biological control efficacy against grey mould for tomato in the greenhouse. Moreover, according to colony morphology and homology analysis of ITS sequence, strain 518 was identified as Paecilomyces lilacinus. Accession number in GenBank of NCBI is lcl|29577. Solid-state fermentation of strain 518 was carried out on wheat bran media, fermented materials were extracted by mixture of chloroform/methanol (1:1, v/v) and then evaporated the solvent in vacuo to give crude extract, resuspended in water, and then extracted with petroleum ether, ethyl acetate, butanol. After that,6.3 g of the petroleum ether extract was separated by silica gel column (200 g,200-300 mesh) eluated by gradient of acetone: petroleum ether with grandient of 0:100â†'1:100â†'5:100â†'10:100â†' 20:100â†'40:100->60: 100â†'80:100â†'100:100â†'100:0. Ten fractions were obtained, then each fraction was separated by column chromatography, thin layer chromatography(TLC), high-performance liquid chromatography (HPLC), recrystallization, etc, obtaining four compounds (compound 1-4). The configuration of compounds was determined by mass spectrometry (HR-ESI-MS, ESI-MS), magnetic resonance (1H-NMR,13C-NMR, DEPT 13C-1H-HSQC, 13C-1H-HMBC,1H-1H COSY) etc, and finally we have determined them as sterols or cerebrosides.Compound 1-4, which were separated from Paecilomyces lilacinus 518, are ergosterol, D-mannitol,3 β,5 a,6 β-trihydroxyergosta-7,22-diene (cereviosterol) and beauvericin, respectively.Ergosterol, cereviosterol and beauvericin were firstly isolated from Paecilomyces lilacinus. Beauvericin, which is a mycotoxin derived from the mould beauveria bassiana strains and other moulds, belongs to the enniatin family of antibiotics. Beauvericin is active against Gram+ bacteria, mycobacteria, insects and shows cytotoxic, immunosuppressant and apoptotic activity.