The effect of heterocyclic compounds of isoxazolone series on the growth and development of wheat seedlings (Triticum aestivum L.)

Abstract

Arylidenisoxazolones have been known since the second half of the 20th century and still retain their relevance as biologically active compounds and the basis for further transformations. Biological testing of synthetic heterocyclic compounds – 4-arylidene-3-methylisoxazol-5-ones, which diff er in nature, position and number of substituents in the aryl fragment, was carried out: 4-(4-methoxybenzylidene)-3-methylisoxazol-5-one, 4- (4-chlorobenzylidene)-3-methylisoxazol-5-one, 4-(4-dimethylaminobenzylidene)-3-methylisoxazol-5-one, 4-(4-hydroxy-3-methoxybenzylidene)- 3-methylisoxazol-5-one, 4-(3,4-dimethoxybenzylidene)-3-methylisoxazol-5-one. The compounds were obtained at the Department of Organic and Bioorganic Chemistry of the Saratov National Research State University named after N.G. Chernyshevsky in order to identify the relationship between structure and biological action. The paper presents the characteristics of the tested compounds and a modifi ed method for the synthesis of arylidenisoxazolones. Seedlings of spring soft wheat Triticum aestivum L. cv. Saratovskaya 36 served as test objects. To assess the physiological activity of the tested compounds, we used the seed germination index, analysis of the morphometric data of the seedling, the root-to-shoot ratio and the root index. The inhibitory eff ect of some compounds on seed germination has been established. The most pronounced eff ect was manifested during seed germination in a solution of 4-(4-hydroxy-3-methoxybenzylidene)-3-methylisoxazol-5-one at a concentration of 10-7M. No signifi cant eff ect of isoxazolone derivatives on the growth of the fi rst leaf of the test object was found. All tested 4-arylidene-3-methylisoxazol5-ones had a stimulating eff ect on the growth of the root system in length. The direct nature of the dependence of this eff ect on the concentration of a solution of 4-(4-chlorobenzylidene)-3-methylisoxazol-5-one and 4-(3,4-dimethoxybenzylidene)-3-methylisoxazol-5-one was determined. A positive eff ect of the tested compounds on the root-to-shoot ratio of seedlings was revealed (with the exception of 4-(4-dimethylaminobenzylidene)- 3-methylisoxazol-5-one). The root index of seedlings was determined and it was found that the presence of methoxyl groups has an inhibitory eff ect on the value of this indicator. Based on the data obtained, it can be concluded that 4-(4-dimethylaminobenzylidene)-3-methylisoxazol-5-one and 4-(4-chlorobenzylidene)-3-methylisoxazol-5-one are promising compounds for further research.

Keywords

• phytotesting
• heterocyclic compounds
• isoxazole derivatives
• arylideneisoxazolones
• triticum aestivum l.