Synthesis of New Phytogrowth‐Inhibitory Substituted Aryl‐p‐Benzoquinones

Abstract

Reaction of [(2-alkyloxy)methyl]-1,4-dimethoxybenzene 10 (alkyl=butyl, hexyl, decyl, tridecyl, tetradecyl, hexadecyl, and octadecyl) with ceric ammonium nitrate in order to produce p-benzoquinones (=cyclohexa-2,5-diene-1,4-diones) afforded 5-[(alkyloxy)methyl]-2-(4-formyl-2,5-dimethoxyphenyl)benzo-1,4-quinones 12a-12g in yields that varied from 46 to 97%, accompanied by 2-[(alkyloxy)methyl]benzo-1,4-quinones 11a-11g in only small quantities (< or =5%). These quinones resemble the natural phytotoxic compound sorgoleone, found in Sorghum bicolor. This reaction exemplifies a general procedure for the synthesis of novel aryl-substituted p-benzoquinones. The selective effects of compounds 12a-12g, at the concentration of 5.5 ppm, on the growth of Cucumis sativus, Sorghum bicolor, Euphorbia heterophylla, and Ipomoea grandifolia were evaluated. All compounds caused some inhibition upon the aerial parts and root growth of the tested plants. The most active compound, 2-(4-formyl-2,5-dimethoxyphenyl)-5-[(tridecyloxy)methyl]-benzo-1,4-quinone (12d), caused between 3 and 18%, and 12 and 29% inhibition on the roots and aerial parts development of Cucumis sativus and Sorghum bicolor, respectively, and between 77 and 85%, and 34 and 52% inhibition on the roots and aerial parts growth of Euphorbia heterophylla and Ipomoea grandifolia, respectively.

Chemical Variability and Biological Activities of Eucalyptus spp. Essential Oils

“…Natural products have also been directly utilized as pest control agents. Moreover, they have served as models for the development of new pesticides with potential commercial applications [7,8,9,10,11,12,13].…”

Evaluation of Chalcone Derivatives as Photosynthesis and Plant Growth Inhibitors

“…Although most chalcone derivatives show no activity on aerial part dry biomass reduction, compounds 6a and 6j demonstrated similar or better results on the I. grandifolia root biomass experiment compared to other synthetic compounds described in the literature [46–53] . For example, the α,β‐unsaturated carbonyl compounds such as the enaminopyran‐2,4‐dione derivatives reduced the root dry biomass by an average of 32 % to 83 % at 500 μM, [49] and the pyridazin‐3(2 H )‐one derivatives reduced the root dry biomass by an average of 28 to 76 % at 200 μM [54] .…”

Synthesis and Phytogrowth Properties of Oxabicyclic Analogues Related to Helminthosporin

“…Within the frame of a long-established research of new active principles to control weeds [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], and taking into consideration the phytotoxic activities associated with compounds 1 - 3 previously mentioned, we have undertaken the synthesis of several analogues related to the toxins 1-3 . The effect of the synthesized compounds on monocotyledonous and dicotyledonous have been evaluated [ 21 , 22 , 23 ].…”