Ch3cocooh

Figure 8.5 Aromatic compounds from chorismic acid. Mechanism a in the top left structure leads to anthranilic acid and tryptophan, while mechanism b leads to p-aminobenzoic acid. The route from chorismic acid to tryptophan is found in plants and micro-organisms only. Glomerine is a millipede defensive compound, dimethylquinazoline is found in Triatoma bugs. Indole and skatole are used in various insects as pheromones

Figure 8.5 Aromatic compounds from chorismic acid. Mechanism a in the top left structure leads to anthranilic acid and tryptophan, while mechanism b leads to p-aminobenzoic acid. The route from chorismic acid to tryptophan is found in plants and micro-organisms only. Glomerine is a millipede defensive compound, dimethylquinazoline is found in Triatoma bugs. Indole and skatole are used in various insects as pheromones more stages, tryptophan. Many insect compounds and related substances are derived from this pathway. Displacement of hydroxyl on the other side of the ring of chorismic acid by ammonia as in Figure 8.5 (mechanism b), and the same steps gives /7-aminobenzoic acid.

Dimethylquinazoline is from Triatoma bugs which carry trypanosomiasis parasites, and indole and skatole are evil-smelling compounds found as trail pheromones in ants and defensive secretion of caddis flies (Trichoptera). Methyl anthranilate has been found in the mandibular gland of males of the ant Camponotus nearticus, and is one component of the trail pheromone (with methyl nicotinate) of the ant Aenictus rotundatus.

Glomerine (Figure 8.5) and pseudoglomerine, from anthranilic acid, form the defensive secretion of the myriapod Glomeris marginata that is toxic to mice and causes paralysis in spiders. It was shown that o

N "C2H5

Figure 8.6 Anthranilic acid labelled with 14C in the carboxyl group gives labelled glomerine and pseudoglomerine. The label is still found in the carboxyl goup of N-methylanthranilic acid produced by degradation of glomerine

N "C2H5

pseudoglomerine

N CH3 Ch3 glomerine degradation degradation

NH CH3

Figure 8.6 Anthranilic acid labelled with 14C in the carboxyl group gives labelled glomerine and pseudoglomerine. The label is still found in the carboxyl goup of N-methylanthranilic acid produced by degradation of glomerine anthranilic acid labelled with 14C in the carboxyl group was incorporated into both compounds. When the labelled glomerine was hydrolyzed, N-methylanthranilic acid was recovered with approximately the same level of activity as the glomerine, showing that all the radioactivity was still located in the carboxyl group (Figure 8.6).

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