tailieunhanh - BIOLOGICALLY ACTIVE NATURAL PRODUCTS: AGROCHEMICALS - CHAPTER 2

Terpenoid với sử dụng tiềm năng là Templates1 thuốc trừ cỏ tự nhiên . Giữa 60 và 70% thuốc trừ sâu được sử dụng trong nông nghiệp ở các nước đang phát triển Ở Mỹ, nơi mà thuốc diệt cỏ chiếm ưu thế bán hàng thuốc trừ sâu, doanh số bán hàng của $ 4 tỷ USD dự kiến của năm 2000,3 Thuốc diệt cỏ đã giúp nông dân | 2 Terpenoids with Potential Use as Natural Herbicide Templates1 Francisco A. Macias José . Molinillo Juan . Galindo Rosa M. Varela Ascension Torres and Ana M. Simonet CONTENTS Introduction Monoterpenes Sesquiterpenes Sesquiterpene Lactones Diterpenes Triterpenes Steroids Acknowledgments References KEY WORDS allelopathy terpenoids monoterpenes sesquiterpenes diterpenes steroids commercial herbicides bioassay phytotoxicity standard target species STS Lactuca sativa L. Lycopersicon esculentum L. Daucus carota L. Lepidium sativum L. Allium cepa L. Triticum aestivum L. Hordeum vulgare L. Zea mays L. Helianthus annuus L. Melilotus messarenis L. coefficient of variation CV . Introduction Between 60 and 70 of the pesticides used in agriculture in developed countries are In the . where herbicides dominate pesticide sales sales of 4 billion are expected by the year Herbicides have helped farmers to increase yields while reducing labor. Indeed without herbicides labor would be a major cost of crop production in developed countries. Nevertheless the indiscriminate use of herbicides has provoked an increasing incidence of resistance in weeds to some herbicides changes in weed population to species more related to the crop environmental pollution and potential health hazards. New more efficient and target-specific herbicides are needed. One of the following strategies may be used. 1999 by CRC Press LLC 1. Biochemically directed synthesis strategies supported by the knowledge of biochemistry and biotechnology. 2. New structural types synthesis of new compounds for broad biological screening. 3. New ideas in known areas add new values to existing classes of chemicals. 4. Natural products as a source of new structural types of compounds. Plants have their own defense mechanism and allelochemicals are in fact natural herbicides. Allelopathy is officially defined by the International Allelopathy Society4 as The science that