Studies On Antifungal Activity Of Extract From Herbs To Several Phytopathogens

In this paper,studies were conducted to screen the antifungal activity of organic solvent extract from seven kinds herbs on the three plant pathogen (Venturia inaequalis (Cooke)Wine,Fusarium oxysporum f.sp.lycopeerisci (Sacc.) Syder et.hanson),Colletotrichum gloeosporioides (Penz) Penz and Sacc.),The results were summarized as follows :l.The extract efficiency of Soxhlet method and Supersonic method was superior to the other methods by the same solvent .In the same method,the extract efficiency of chlorioform and 95% ethanol is higher. As far as antifungal activity was concerned,the antifungal activity of every method extract was similar by the same solvent,but Soxhlet method and supersonic method were a little better.2.Seven kinds of herbs were screened,and the extract of herb CCB had strong antifungal activity on the Colletotrichum gloeosporioides and the ECso of which were 0.5474g/L and 1.4785g/L respectively in 72 hours by chlorioform and 95% ethanol;the extract of 95% ethanol was isolated by liquid extraction method,the fraction of petroleum ether and ethyl acetate had strong antifungal activity on the Colletotrichum gloeosporioides,the ECso of which were 2.8092 g/L and 0.3264g/L respectively;the fraction of ethyl acetate was isolated by liquid solid column chromatography,The effluent Cl showed strong antifungal activity,the ECso of which was 0.058g/L,which showed that antifungal substance was intermoderate polarity;The effluent Cl was isolated further by Preparative TLC,two band were showed,one had colour in visual light range,which had nearly no antifungal activity,the other was red band in UV light of 254 nm,which had antifungal activity on the Colletotrichum gloeosporioides,the ECso was 0.18g/Land the Rf was 0.5.So we can conclude that the substance of Rf=0.5 was the antifungal substance traced in experiment.3.The extracts of fresh sample and dry sample of herb CCB and its every part were tested,and the antifungal activity of fresh sample and dry sample was nearly similar on the Colletotrichum gloeosporioides,but the antifungal activity of fresh sample and dry sample was higher than that of root,stem and leaf. The antifungal activity of leaf was the lower on the Colletotrichum gloeosporioides than that ofrroot and stem.4. Compared with chemical fungicides including carbendazim and mancozeb,antifungal activity of extact from herb CCB was lower. The ECso of two fungicides were 0.13mg/L,24.4728 mg/L respectively,but the ECso of the effluent Cl from liquid solid column chromatography of herb CCB was only 58 mg/L.5.The control efficiency of the crude extract of herb CCB to apple anthracnose in vivo was studied,which showed that the extract of the herb CCB had protective and therapeutic action for apple anthracnose,with the protective action superior to therapeutic action.The protective ation of herb CCB was highest,when the apple was incubated after 1 d,which was conducted by extract of herb CCB. Compared with carbendazim,the control efficiency of the crude extract of herb CCB(10g/L) and carbendazim(100mg/L) was nearly similar,and the lasting period of latter was longer,but the control efficiency of both was not as great.6.The herb CCB powder was extracted by 95% ethanol .the extract of 95% ethnol was defatted with petroleum ether,then followed by solvent partition to obtain ethyl acetate extract which was fractioned on a column of silica gel with gradient petroleum ether-ethyl acetate -methanol system .It was found the effluent Cl possessed the antifungal substance .Therefore the effluent Cl was rechromatographed on PTLC with benzen-methanol system as a mobile phase (28+5,v/v),and obtained active substance which was analyzed and identified by means of chemical reaction,UV,HPTLC,HPLC,GC,GC-MS,suggesting the active substance may be flavonoids.