Other Phenylpropanoids

Apart from cinnamoyl esters, aromatic amino acids (see Chap. 5.1) and the alcohols corresponding to the common hydroxycinnamic acids, as well as some glycerolaryl compounds, are of interest in connection with the biosynthesis of lignin and other polycyclic phenolic compounds. 

Propiovanillone has been identified in Quercus rubra wood (152) and some phenylglycerol compounds are also found in various woody species. Thus, guaiacylglycerol (33) has been found in the sapwood of western hemlock (11) and the heartwood of Pinus resinosa (142). Further, the 1-O-glucoside and the 1-0-and 3-O-glucosides of p-hydroxyphenylglycerol have been reported from the inner bark of Larix leptolepis (105) and Picea glehnii (145), respectively, and an iso-prene derivative of the 3-(4-hydroxyphenyl)-propan-l-ol has been isolated from wood and bark of Zanthoxylum cuspidatum (86). 

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Phenylalanine Ammonia-Lyase. The building units of lignin are formed from carbohydrate via the shikimic acid pathway to give aromatic amino acids. Once the aromatic amino acids are formed, a key enzyme for the control of lignin precursor synthesis is phenylalanine ammonia-lyase (PAL) (1). This enzyme catalyzes the production of cinnamic acid from phenylalanine. It is very active in those tissues of the plant that become lignified and it is also a central enzyme for the production of other phenylpropanoid-derived compounds such as flavonoids and coumarins, which can occur in many parts of the plant and in many different organs (35). Radioactive phenylalanine and cinnamic acid are directly incorporated into lignin in vascular tissue (36). 

MYB, Papl or Pap2 Arabidopsis thaliana Anthocyanins and other phenylpropanoids increased 364... 

MYB, PI or P2 Zea mays cell lines 3-Deoxyflavonoids, C-glycosylflavones, other phenylpropanoids and fluorescent compounds increased 140, 317... 

Funk C, Brodelius P (1992) Phenylpropanoid metabolism in suspension cultures of Vanilla planifolia Andr. IV Induction of vanillinic acid formation. Plant Physiol 99 256-262 Funk C, Brodelius P (1994) Vanilla planifolia Andrews in vitro biosynthesis of vanillin and other phenylpropanoids derivatives. In Bajaj YPS (ed) Biotechnology in agriculture and forestry. Medicinal and aromatic plants VI, vol 26. Springer, Berlin Heidelberg New York, pp 377-402... 

The other phenylpropanoids tested, anoltiglate, isoeugenolisobutyrate and isoeugenol were completely ineffective. 

Ververidis F, Trantas E, Douglas C, Vollmer G, Kretzschmar G, Panopoulos N. 2007a. Biotechnology of flavonoids and other phenylpropanoids-derived natural products. Part I Chemical diversity impact, impa on plant biology and human health. Biotechnol J 2 1214-1234. 

Matern, U. (1991) Coumarins and other phenylpropanoid compounds in the defense response of plant cells. Planta Med., 57, S15-20. 

Ververidis, R, Trantas, E., Douglas, G., Vollmer, G., Kretzschmar, G., Panopoulos, N. (2007b) Biotechnology of flavonoids and other phenylpropanoid-derived natural products. Part II Reconstruction of multienzyme pathways in plants and microbes. Biotechnol.., 2,1235-49. 

Prokudina, E.A., Havlfdek, L., Al-Maharik, N., Lapcik, O., Stmad, M., and Gruz, J. 2012. Rapid UPLC-ESI-MS/MS method for the analysis of isoflavonoids and other phenylpropanoids. J. Food Compos. Anal. 26 36—42. 

While the results of the growth reversal experiments in the "supercomplex systems" described above had stimulated investigations at the level of "defined systems" (i.e. the examination of certain metabolic reactions in cell-free systems), no definitive answers as to the biochemical mode of action of glyphosate had been obtained. Based on our experience with inhibitors of phenylalanine ammonia-lyase (see below), we included the "complex system" level (i.e. the examination of a metabolic pathway jsi vivo) in our strategy in order to define the limits more closely. Hypocotyls from etiolated buckwheat seedlings provided a system in which the rapid synthesis of phenylalanine-derived products, such as anthocyanin and other phenylpropanoid compounds, can be very simply induced by illumination. Anthocyanins, in particular, can be conveniently extracted and quantified and, at least in buckwheat, are not subject to measurable turnover within... 

Other phenylpropanoids, so named due to their common phenylalanine 2 precursor, include hydroxycinnamic acids, cinnamic aldehydes and monoUgnols, coumarins, and stUbenoids 8. 

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