tailieunhanh - BIOLOGICALLY ACTIVE NATURAL PRODUCTS: AGROCHEMICALS - CHAPTER 14

Sản phẩm tự nhiên Chứa Phenylalanine Bioherbicides tiềm năng Nghiên cứu trước đây của chúng tôi maculosin (I, cyclo-TyrPro), một chất độc chủ nhà cụ thể được sản xuất bởi Alternaria alternata trên phát hiện cây xa cúc (Centaurea maculosa), cho thấy rằng một số lượng tương tự phenylalanine của tôi có hoạt động tương tự, tương tự unsubstituted (cyclo-PhePro, II) là tích cực nhất. Thật thú vị, II xuất hiện khả năng chống lại nhiều loại thực vật | 14__ Natural Products Containing Phenylalanine as Potential Bioherbicides Mikhail M. Bobylev Ludmila I. Bobyleva and Gary A. Strobel CONTENTS Introduction Maculosin-I and -II Maculosin-I and -II Analogs Biological Activity Role of Phenylalanine Acknowledgments References ABSTRACT Our previous study of maculosin I cyclo-TyrPro a host specific toxin produced by Alternaria alternata on spotted knapweed Centaurea maculosa showed that a number of phenylalanine analogs of I possess similar activity the unsubstituted analog cyclo-PhePro II being the most active. Interestingly II appeared to be active against a wide variety of plants. We suggested that protected phenylalanine and not a diketopiperazine is an active moiety of II and other analogs. To prove this idea we synthesized and tested two compounds 1 where the proline carbonyl was cut off of the pyrrolidine ring and 2 where in addition the pyrrolidine ring itself was cut to form diethylamine. Both compounds produced the same symptoms on spotted knapweed plants as II. KEYWORDS natural products phenylalanine herbicides maculosin spotted knapweed Introduction Natural products comprise a voluminous source of new and strikingly diverse bioactive compounds for pharmaceutical and agrochemical development. In medicine they have already been heavily used for many years and form a very substantial part of prescribed drugs antibiotics being one very good example. However this is not the case in plant protection. Very few natural products or their derivatives are currently used as agrochemicals pyrethroids are probably the only example of true success. There are three major reasons for this drastic dearth of natural products in the plant protection area complex structure insufficient stability and sometimes high toxicity. 1999 by CRC Press LLC Indeed many of the natural bioactive compounds have very complex structure and therefore are very difficult to synthesize in