The Further Studies On The Insecticidal And Antifungal Constituents Of The Buddleja Albiflora H.

Buddleja albiflora Hemsl belongs to Buddleja family. So far, more than 100 species have been found in Buddleja family around the world, and half of them can be found in China. Based on the achievement made by predecessors, this paper did further studies on chemical constituents isolation in Buddleja albiflora, and made preliminary research on fungicidal activity of this plant. By orthogonal experiment design, The SFE-CO₂ optimal combination extracting of leaf oil and flower oil from Buddleja albiflora Hemsl were established, and then the fumigating toxicity of leaf oil and flower oil extracted with different SFE-CO₂ conditions were detected by flask method with the 3rd-instar of M.separatea as tested insects. The main results are as follows:1. Six compounds(C11^C16) were isolated from petroleum extract and ethyl acetate extract of Buddleja albiflora Hemsl by means of silica gel column chromatography, crystallization and recrystallization. Five structures of them were identified asα-amyrin acetate(C11), ursolic acid(C12), quercetin(C13), kumatakenin(C14) and stigmasterol(C15). C11 and C14 were obtained from Buddleja albiflora Hemsl for the first time. The components of S1 and S2 were analyzed by GC/MS. The results showed that the main compounds of S1 were esters, and the ones of S2 were identified primarily to be alkanes.2. The fungicidal activities of Buddleja albiflora Hemsl against plant pathogenic fungi and bacteria were evaluated by mycelium growth rate, plant organization experiment, pot trails and cylinder-plate method. The results of mycelium growth rate method showed that under the concentration of 50 mg(dry sample)/mL, The mycelium growth inhibition rate of ethanol extract from B.albiflora H. was over 50% to 11 tested plant pathogenic fungi and this rate could be over 70% to six of them. But no inhibition activities were shown to tested bacteria. Potted plant experiment showed that petroleum extract,ethyl acetate extract and 95% ethanol extract of Buddleja albiflora Hemsl exhibited a protective efficacy of 70.83%, 77.51% and 73.56% against S. sclerotiorum under the concentration of 5 mg/mL; And under the same concentration, the protective efficiency of petroleum extract,ethyl acetate extract and 95% ethanol extract against B. graminis were 56.02%, 50.91% and 58.90% respectively. The efficacy of S9, Y2 against B. graminis were 63.50% and 51.91% in tissue experiment. 3. By orthogonal experiment design, The SFE-CO₂ optimal combination extracting of leaf oil and flower oil from Buddleja albiflora Hemsl were researched. Results showed that the optimal combination of leaf oil was as follows: extracting pressure: 5000 psi, temperature of extracting storehouse: 50℃, extracting time: 30 min, CO₂ volume: 40 mL; and the optimal combination of flower oil were as follows: extracting pressure 3000 psi, temperature of extracting storehouse 50℃, extracting time 20 min, CO₂ volume: 40 mL. Under the SFE-CO₂ optimal combination extracting conditions, when the sample size distribution was 60⁸0 mesh, the extracting rate of leaf oil and flower oil both can achieve maxumum value, is 8.56% and 6.58% respectively. The results of fumigating toxicity of Buddleja albiflora leaf oil and flower oil extracted with different SFE-CO₂ conditions against the 3rd-instar of M.separatea by flask method showed that Buddleja albiflora flower oil exhibited higher activity against the 3rd-instar of M.separatea than Buddleja albiflora leaf oil under the concentration of 2 mg/mL.