Research On Fungicidal And Insecticidal Effect Of Light-activated Chemical Hypocrellin

Hypocrellin is an excellent photosentisizer which has been used in medical because of its high ligh-active and low toxicity.And it has potential to be used in agriculture and forestry.However, the related research is not enough.The potential of hypocrellin as green pesticide need to be explored.In this paper,Inhibition effect of hypocrellin to some fungi and insects have been studied .And hypocrellin and HP-β-CD inclusion complex have been made.The main results are as follows:1 Inhibit rate of hypocrellin A to 18 fungi were tested by mycelium growth rate method.It appears that there are some inhibit effects to tested fungi.The EC₅₀ to Macrophoma caryae and Lecanosticta acicola is 0.6mg/L and 0.77mg/L respectively .2 Insecticidal activity of hypocrellin A have been tested .It is found that hypocrellin A has strong insecticidal effection to Bursaphelenchus xylophilus under light and no insecticidal acitivity in the dark.The LC₅₀ is 0.15mg/L in the light . Pesticidal effects can be observed to aphis and yellow meal worms in the light.3 There is a certain correlation between inhabit rate of mycelium and luminous intensity but no correlation betweeen inhabit rate of mycelium and luminous time .However,linear relationship between reduced biomass inhibited by hypocrellin A and the square of the illumination time have been found.4 Hypocrellin and HP-β-CD inclusion complex has been made by oscillation.And the character of the inclusion complex have been measured. It is found that the max UV absorption peak has shift in red. The inclusion helps to reduce the photodegradation and thermal degradation of hypocrellin. Fungicidal activity of hypocrellin in inclusion complex are similar to in ethanol.5 Hypocrellin photodegradate significately in water while stable in ethanol.It is found that light and oxygen are key factors to photodegradate which can be consider as photosensitized oxidation The inclusion rate calculation method of Hypocrellin-HP-β-CD inclusion complex has been proposed according to the phenomenon.