Study On Inhibition Of Hypocrellin A On14Pathogenic Fungi

Hypocrellin A （HA）, as a good Perylenequinonoid photosensitizer, is unique to China. HA has beendeveloped and utilized major in medicine, as a kind of phototherapy drug, which has anti-inflammatory,antiviral, antitumor and other biological functions. The development and study of nascentphoto-activation pesticide in recent years has found that HA has a significant bacteriostatic activity andhas promising application that been developed into a green phtoactivation pesticides, but so far studiesof HA on pathogenic fungi inhibition have been rare at home and abroad.This paper adopts the single factor and orthogonal experiment, optimizes the extraction process ofHA, evaluates HA and HA-TX-100in aqueous solution on plant pathogen inhibition rate by myceliumgrowth rate method. The main results are as follows:1. The optimal extraction of HA process: the best extraction solvent is acetone, the ratio of materialand liquid is1:30, extraction time is3.0h, extraction temperature is40℃. Under the condition of theextraction process, the HA yield can reach0.61%.2. Under the condition of dark,10mg.L^-1HA to14kinds of testing plant pathogenic fungi inhibitoryactivity is quite weak or even no activity, and the intensity of light is7200Lx, HA for plant pathogenicfungi owns certain inhibition, among Rhizoctonia solani、 Fusarium graminearum、 Fusariumgraminearum Schwabe、 Lecanosticta acicola、Fusarium oxysporum f. sp. vasinfectum、Botrytiscinerea、Valsa mali、Sclerotinia sclerotiorum of8kinds of selected fungi inhibition rate are allmore than50%. HA for the8kinds of the tested strains median inhibitory concentration, respectively:6.9161mg.L^-1、4.2933mg.L^-1、6.8587mg.L^-1、2.5773mg.L^-1、7.2223mg.L^-1、3.9497mg.L^-1、4.2511mg.L^-1、6.4766mg.L^-1.3. Preparation of HA-TX-100aqueous solution, under the condition of the light intensity is lessthan3600Lx to cold storage and heat storage processing, HA retention rate is almost100%, its stabilityis excellent; however, when the light intensity is increased to7200Lx, along with the illumination time,the aqueous solution has been gradually photolysised until HA retention rate of15.33%.4. While light intensity is7200Lx,50mg.L^-1HA-TX-100aqueous solution of Botrytis cinerea、Lecanosticta acicola、Sclerotinia sclerotiorum and Fusarium graminearum inhibition rates all more than50%; For inhibition rates more than50%, aqueous solution of1000mg.L^-1HA-TX-100in vivoprotective effect of inoculation of tomato Botrytis cinerea inhibition rate is72.05%, therapeuticinhibition rate is64.73%, and respectively higher than the1000mg.L^-1of carbendazim aqueous solutioninhibition rates are61.37%and64.44%.The results are useful in developing green high performance bio-pesticides for HA to providetheoretical basis.