School of Chemical and Mathematical Sciences, Murdoch University, Murdoch, Western Australia.
J Agric Food Chem. 2010 Sep 22;58(18):10147-55. doi: 10.1021/jf101827v.
Essential oils and their constituents have potential as ecologically acceptable pesticides that may also have novel modes of action. In this work hydroxy and ester derivatives of the naturally occurring monoterpenoids 1,8-cineole 3, the main component in most eucalyptus oils, and 1,4-cineole 4 were prepared and their pre-emergence herbicidal activity against annual ryegrass (Lolium rigidum) and radish (Raphanus sativus var. Long Scarlet) investigated in laboratory-based bioassays. 1,8-Cineole, eucalyptus oil and all derivatives showed a dose-dependent herbicidal activity against annual ryegrass and radish with many of the derivatives showing improved herbicidal activity relative to 1,8-cineole and high-cineole eucalyptus oil. Increased activity of cineole ester derivatives compared to their associated hydroxy-cineole and carboxylic acid was not observed. No relationship between lipophilicity of the carboxylic acid portion of cineole ester derivatives and herbicidal activity was observed. The results indicate that these cineole derivatives could be environmentally acceptable herbicides.
精油及其成分具有作为生态可接受的杀虫剂的潜力，它们也可能具有新的作用模式。在这项工作中，天然单萜 1,8-桉树脑 3（大多数桉树油中的主要成分）和 1,4-桉树脑 4 的羟基和酯衍生物被制备，并在实验室生物测定中研究了它们对一年生黑麦草（Lolium rigidum）和萝卜（Raphanus sativus var. Long Scarlet）的芽前除草活性。1,8-桉树脑、桉树油和所有衍生物对一年生黑麦草和萝卜均表现出剂量依赖性的除草活性，许多衍生物表现出比 1,8-桉树脑和高桉树脑桉树油更高的除草活性。与相应的羟基桉树脑和羧酸相比，桉树脑酯衍生物的活性没有增加。未观察到桉树脑酯衍生物中羧酸部分的亲脂性与除草活性之间存在关系。结果表明，这些桉树脑衍生物可能是环境可接受的除草剂。
