The Insecticidal Ingredients From Ramaria Eryuanensis

There are many agricultural compounds from higher fungi. With the rapid development of naturally occurring pesticides, high fungi may become a emphasis in pesticide field after botanical pesticides and microbial pesticides. The insecticidal activity of extract from Ramaria eryuanensis against Plutella xylostella was studied by the Research and Development Center of Biorational Pesticide (RDCBP) of Northwest A&F University. Based on the research result obtained by RDCBP, insecticidal compounds were isolated from the fruits bodies of Ramaria eryuanensis. The results were as follows. 1. The fruit bodies of Ramaria eryuanensis were extracted with methanol and chloroform(V:V=1:1), then separated gradationally by 4 different polar solvents. The extracts of fruits bodies, petroleum ether, chloroform, ethyl acetate and butanol were obtained. The insecticidal activities of fruits bodies and 4 different polar solvent extracts were tested by Leaf Disc method. Bioasssy showed that, the fruits bodies extract and ethyl acetate extract displayed higher toxic activities against Plutella xylostella, the morality ratio in 72h up to 100%, the petroleum ether partition showed higher toxic activities against Mythimna separate, the morality ratio in 72h up to 100%. Moreover, the chloroform extract and ethyl aceteta extract had inhibiting rate up to 80% against hyphal growth of Fusarium graminearum. 2. Pre-testing with Filter-Paper Disc method, the chemical components of Ramaria eryuanensis include steroids, terpenes, volatile oil, anthraquinone, coumarin, amino acid and carbohydrate. 3. The petroleum ether extract was isolated and purified through normal pressure silica gel pillar chromatographys, and one compound was gained. The LC50 value of the compound against the 3rd instars larvae of Plutella xylostella in 48h was 3.5415 mg/mL. The molecular structure was identified by FAB-MS, 1HNMR, 13CNMR, DEPT and compared with the references, as it was ergosta-7,22-dien-β,5a,6β-triol. 4. Fraction　B103 was isolated from the petroleum ether extract, which showed higher toxic activities against Mythimna separata. The toxic and contact activities of B103 were investigated against the 3rd instar larvae of Mythimna separate. At the concentration of 2.6 mg/mL, the toxic morality ratio in 72h was 100%, and at the concentration of 5.5 mg/mL, the contact morality ratio in 72h was 48.28%. Fraction B103 was analyzed by GC-MS, and 34 compounds were defined, including elaidic acid methyl ester(40.06%), palmitic acid methyl ester(31.07%), stearic acid methyl ester(8.22%), margaric acid methyl ester(2.89%), linoleic acid methyl ester(2.64%), pentadecanoic acid methyl ester(2.34%) and tetracosanoic acid methyl ester(1.01%). Based on the result, it is reasonable to infer that fatty acid methyl ester may have the toxic and contact activities against the 3rd instar larvae of Mythimna separate.