Inhibitory Effects Of Secondav Metabolltes Obtained From Boletus Rubellus Krombh And Gyropous Castaneu On Phenoloxidase Of Spodoptera Exigua

Higher fungi is the very productive biologically source which produces a large and diverse varity of secondary metabolites. And these are very impotant for the searching work of some medicine and agriculture chemical leading compounds. In order to find some leading compounds and structures with bioactivities, the chemical constituents of two higher fungi species of Boletus rubellus Krombh and Gyropous castaneu have been investigated. And a review on the chemical constituents of higher fungi in the last decade is presented in the thesis.Phenoloxidase (PO) (EC.1.14.18.1) also known as tyrosinase, is a structure-complex and multifunctional copper-containing enzyme, which widely distributed among animals, plants, fungi, and prokaryotes. PO is thought to be involved in many biological processes of invertebrates, such as consenescence of human body, wound healing, fruits and vegetables browning and pigment formation. It is one of the key enzymes in the development process of insects, the enzyme possesses an important function in metamorphism developing and immunity system. Currently, many studies focused on this field.Based on the present paper, the writer studied the chemical constitutes of two kinds of high fungi, and eight compounds that isolated in our laboratory were selected as the PO inhibitors to determine the inhibitory effects against the enzyme of Spodotera exigua. The contents and results were summarized as follows:1. From the ethanol extract of the two higher fungi, fifteen compounds have been isolated by means of chromatographic methods. Five compounds are elucidated on basis of spectral(MS, ID & 2D-NMR, IR, UV) and chemical methods, including two steroids, one ceramide compounds, 3-pyridinecarbo- xylic acid and D-allitol.2. Select eight compounds that isolated in our laboratory, and tested their inhibitory effects against the enzyme of Spodotera exigua. The eight compounds are : two steroidsâ… andâ…¡, three sesquiterpenesâ…¢,â…£andâ…¤aromatic compoundâ…¥,flavone glycosidesâ…¦and triterpenoidsâ…§.The effects of the eight compounds on phenoloxidase (PO) of Spodotera exigua were also investigated. The results indicated that the eight compounds showed different inhibitory effects on the PO ,and the inhibitor concentrations leading to 50% (IC50) activity lost of compoundsâ… toâ…§were estimated to be 4.5 mmol/L,4.3 mmol/L,3.08 mmol/L,0.55 mmol/L,3.88 mmol/L,2.04 mmol/L,0.83 mmol/L and 0.32 mmol/L one by one.