Aromatics growth inhibition

When reacted with dimethyl acetylenedicarboxylate, the amines produced ben-zotriazolylaminobutendioates 188 accompanied by A-benzotriazolyl substituted 2-pyridones only in the case of 5-amino-2-methyl-2//-benzotriazole, the triazolo-9,10-dihydrobenzo[d]azepine and an unusual cyclization product, triazolo-2-oxindole (convertible into 2-methyltriazolo[4,5-/]carbostyril-9-carboxylate) were formed. The quinolones 189 were aromatized to chloroesters 190 these in turn were hydrolyzed to chloroacids 191 and decarboxylated to 9-chlorotriazolo[4, 5-/]quinolines 192 (Scheme 58) (93H259). The chlorine atom could be replaced with 17 various secondary amines to give the corresponding 9-aminoalkyl(aryl) derivatives 193, some of which exhibit both cell selectivity and tumor growth inhibition activity at concentrations between 10 and 10 " M (95FA47). 

Davis (184) selected a large number of mutants of Escherichia coli requiring two or more aromatic amino acids for growth, and then tested a large number of substances to see if any could relieve the growth inhibition. Success was attained with shikimic acid (215, 268), at that time a relatively obscure natural product. This indicated either that shikimic acid (structure diagram 1) was a true aromatic precursor or that it could readily be transformed into a true precursor. The likelihood that shikimic acid was a true precursor was increased when other mutants were found to accumulate shikimic acid in the medium, from which it could be isolated (184, 185). 

Jaworski (4) reported that growth inhibition of both plant and microbes by glyphosate could be reversed by aromatic amino acids. Further work of Amrhein and his coworkers revealed that glyphosate inhibits the shikimate pathway enzyme, 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase (5). This enzyme catalyzes the reaction shown in Figure 1. Glyphosate-treated plant and bacterial cultures accumulate shikimate and/or shikimate 3-phosphate (S3P), confirming that inhibition of EPSPS is at least a part of the in vivo mechanism of action of this herbicide (6, 7). 

These conclusions are supported by studies in our laboratory in which we found only a minimal reversal of glyphosate-caused growth inhibition by root-fed aromatic amino acids (71). 

The next significant advances were made by attempts to use substituent constants rather than physical measurements on the whole molecule. In 19 f0 Hammett (16) developed the (o ) substituent constants, which measure the degree of electron release/withdrawcil of aromatic substituents. Based on the Hammett equation, Hcinsen (17) correlated bacterial growth inhibition of a series of compounds with their Hammett [Pg.178]

Cineoles are monoterpenes present in the essential oils of many aromatic plants (e.g. Laurus nobilis L., Salvia spp., Eucalyptus spp., Xanthoxylum rhetsa D. C., and Artemisia spp). Many classes of volatile monoterpenes inhibit plant growth (e.g. [36]). Growth inhibition of grasses by volatile monoterpenes released by Salvia leucophylla is most effective during seedling development and establishment [6]. 

Alkio, M. Tabuchi, T.M. Wang, X. Colon-Carmona, A. 2005. Stress responses to polycyclic aromatic hydrocarbons in Arabidopsis include growth inhibition and hypersensitive response-like symptoms. Journal of Experimental Botany, v.56, p.2983-2994. 

The mode of action is by inhibiting 5-enolpymvyl-shikimate-3-phosphate synthase. Roundup shuts down the production of the aromatic amino acids phenylalanine, tyrosine, and tryptophane (30). Whereas all these amino acids are essential to the survival of the plant, tryptophane is especially important because it is the progenitor for indole-3-acetic acid, or auxin, which plays an important role in growth and development, and controls cell extension and organogenesis. 

In China, the plant affords a tonic remedy particularly recommended for chest complaints. Indonesians use the leaves medicinally because they are strongly aromatic. The pharmacological potentials of this plant are, to date, unknown. Note that 6 3-hydroxy-3-oxo-lup-20(29)-en-28-oic acid and 3,1 l-dioxoolean-12-en-28-oic acid from the stem bark of Liquidambar styraciflua, as well as 25-acetoxy-3a-hydroxyolean-12-en-28-oic acid, inhibited the growth of several cancer cell lines (43). What is the activity of 25-acetoxy-3a-hydroxyolean-12-en-28-oic acid against topoisomerase ... 

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