Studies On Botanical Fungicide For Controlling Fusarium Oxysporumf.sp. Lycopeersici

In this paper, studies were conducted to screen the antifungal plants from the Chinese herb F to control Fusarium oxysporum f.sp. lycopersici. The main activity compound was isolated from the herb F by liquid- liquid extraction and liquid solid column chromatography , which named 2006-HS. The results were summarized as follows:1. Using 95% ethanol as the extracting solvent, the main activity compound was isolated by soaking method. Medium dilution method was introduced to bioassay the activity compound on petroleum ether. The results indicated that the activity compound had the higher antifungal activity on Fusarium oxysporum f.sp. lycopersici, and its EC₅₀ value were 0.224g/L in 3d and 0.206g/L in 4d.2. Some pigment and impurity were eliminated by liquid- liquid extraction of petroleum ether and 70% ethanol (V:V=1:3). The activity compound was concentrated, which EC₅₀ value was 0.176g/L in 3d and 0.164 g/L in 4d.3. Crystalloid was isolated from the crude extract by liquid solid column chromatography filled silicagel,which eluented for petroleum ether and ethyl acetate.The crystalloid showed strong activity on Fusarium oxysporum f.sp. lycopersici, which EC₅₀ value was 0.037 g/L in 3d and 0.044 g/L in 4d and 0.049 g/L in 5d.4. Crystalloid took on one spot after spreaded by TLC under ultraviolet at 365nm, which appeared single chromatogram peak with the retention time 8.601min by the means of HPLC.5 The result showed that the activity material 2006-HS was composed of C(74.25%),H(6.90%) and O (18.85%),which molecular weight was 244.28 . molecular formula:C₁₅H₁₆O₃6.The data of infrared spectrum indicated that the molecular structural formula middle of 2006-HS contained the group of C = O and—CH3 and benzene ring. Based on the result of NMR ,the chemical structural formula of 2006-HS was ascertained.