Animal experiment: The Ocean Institute has made a breakthrough in using marine biological polysaccharides to transform traditional pesticides

  Recently, the Marine Biological Products Research Group of the Institute of Marine Science of the Chinese Academy of Sciences has made new breakthroughs in the conversion of organic copper pesticides and synthesized a series of new polymeric copper formulas with new structures and important activities. -In some samples, the inhibition rate of the chitosan-based copper complex to Phytophthoracapsici (Phytophthoracapsici) reached 100% at a concentration (200 ppm) far lower than that of commercial copper preparations such as copper thiazolium.

  Bordeaux mixture is a traditional pesticide with a history of hundreds of years. In 1878, botanist Pierre Marie Alexis Miralde discovered it in Bordeaux, a famous wine-producing region in France. A suspension of mold, lime hydrate and copper sulfate solution reduced the yield of grapes. I discovered by accident that the disease can be effectively prevented and treated. The results of the study were published in 1885 and achieved great success. After that, the Bordeaux region became the "Vineyard World". This suspension became a mixture of famous pesticides and Bordeaux, which greatly increased agricultural production around the world. Yes contribution. However, the long-term use of this inorganic copper formulation has obvious disadvantages. Because it is alkaline, it cannot be mixed with other acidic pesticides. Copper sulfate is toxic and easily produces phytotoxicity. It is inconvenient to store and use. It can only be used on site, not in metal containers. Many scientists have tried to develop alternatives to organic copper preparations, but have made little progress. In this article, we clarified the ionic complexing mode and structure-activity relationship of the chitosan-based copper complex, discussed its antibacterial mechanism, and designed and synthesized the water-soluble polymer chitosan-based and its copper. Through structural calculation and spectral characterization, the complex forms a large π bond between the benzene ring of the long chain side group of chitosan and the carbon nitrogen p-π conjugated group of the copper complex to form different benzenes. Ring substituents. I found. Three-dimensional damage to copper ions leads to the formation of coordination bonds with large π-bonded carbon atoms. Steric hindrance also affects the internal angle of the large π bond, thereby affecting the conjugation effect. As the internal angle increases, the bond energy of the coordination bond decreases, the release effect of copper ions is enhanced, and the antibacterial effect is significantly improved. Compared with traditional copper-containing disinfectants, this copper compound is an organic chelated copper-containing disinfectant, which has the advantages of rapid action, low phytotoxicity, high stability and easy storage. It is expected to develop into a new generation of organic substances. Copper disinfectant. The characterization method of the compounds used in this study provides a new research direction for the structural analysis of high molecular weight organometallic complexes, as well as new ideas for the transformation of traditional pesticides.