tailieunhanh - BIOLOGICALLY ACTIVE NATURAL PRODUCTS: AGROCHEMICALS - CHAPTER 7

glucosinolates là một nhóm các hợp chất thứ cấp được sản xuất bởi các thành viên của Brassicaceae (crucifer hoặc gia đình mù tạt) và ít nhất 10 họ thực vật hai lá mầm khác. Glucosinolates là enzym thủy phân glucohydrolase thioglucosidase để hình thành isothiocyanates thay thế, nitriles, và thioxyanat. Glucosinolates và các sản phẩm thủy phân của họ từ lâu đã được quan tâm dược lý và độc tính và chịu trách nhiệm chính cho mùi hôi đặc trưng và hương vị của thực vật họ cải | 7 Glucosinolates As Natural Pesticides Steven F. Vaughn CONTENTS Chemistry and Occurrence Pesticidal Activity Stimulation Repression of Glucosinolate Levels Toxicity to Insects and Nematodes Antimicrobial Activity Phytotoxicity Glucosinolate-Containing Plants as Pest-Suppressive Crops Glucosinolate-Containing Seedmeals as Soil Amendments Involvement in Allelopathy Conclusions References ABSTRACT Glucosinolates are a group of secondary compounds produced by members of the Brassicaceae the crucifer or mustard family and at least 10 other dicotyledonous plant families. Glucosinolates are enzymatically hydrolyzed by thioglucosidase glucohydrolase to form substituted isothiocyanates nitriles and thiocyanates. Glucosinolates and their hydrolysis products have long been of pharmacological and toxicological interest and are primarily responsible for the characteristic odors and flavors of cruciferous plants. Due to the potential loss of soil fumigants such as methyl bromide the use of glucosinolate-con-taining plants as green manures or soil amendments to suppress weeds and soilborne pathogens is currently an area of active research. This chapter will focus on the pesticidal activity of glucosinolates and their degradation products. Chemistry and Occurrence Glucosinolates are a group of plant secondary compounds whose biologically active hydrolysis products are produced when cells containing them are ruptured and the glucos-inolates contained in vacuoles are hydrolyzed by the enzyme myrosinase a-thioglucosi-dase glucohydrolase EC which is stored away from the vacuole in the cell walls endoplasmic reticulum Golgi vesicles and mitochondria Figure .1-4 These products include substituted isothiocyanates nitriles thiocyanates and oxazolidinethiones. Which 1999 by CRC Press LLC FIGURE Localization of glucosinolates . sinigrin and myrosinase in horseradish root FIGURE Major enzymatic hydrolysis products .