Phytochemicals lignins

A wide diversity of herbal remedies have purported abilities to stimulate defense functions. Complexes of carbohydrate and lignin, which are present in some herbs, modulate enteric immune functions (Kiyohara et al, 2000), and the changes in cytokine secretion (Matsumoto and Yamada, 2000) can trigger systemic responses. The polysaccharides present in other herbal medicines augment production of immunoglobulin (Ig) A by the Peyer s patches in the small intestine (Sakushima et al, 1997 Yu et al, 1998). The responses of the enteric immune system to lectins are variable (Pusztai 1993), and can elicit systemic responses (Lavelle et al, 2000). Other phytochemicals provide protection by inducing detoxification pathways in mucosal cells (Williamson et al, 1998). 

Nowadays there is scientific evidence that, besides plant polysaccharides and lignin, other indigestible compounds such as resistant starch, oligosaccharides, Maillard compounds, and phytochemicals—mainly polyphenols—can be considered DF constituents (Saura-Calixto and others 2000). Of these substances, resistant starch is a major constituent in cereals, whereas phytochemicals are the most important such substance in fruits and vegetables. Here, we address mainly polyphenols and carotenoids associated with DF in fruits and vegetables because of the important biological properties derived from them. 

STAFFORD, H.A., Possible multi-enzyme complexes regulating the formation of Cg-C3 phenolic compounds and lignins in higher plants, Rec. Adv. Phytochem., 1974, 8, 53-79. 

El-Basyouni, S.Z., A. C. Neish, andG. H. N. Towers The Phenolic Acids in Wlxeat III. Insoluble Derivatives of Phenolic Cinnamic Acids as Natural Intermediates in Lignin Biosynthesis. Phytochem. 3, 627—640 (1964). 

Boerjan W, Ralph J, Baucher M (2003) Lignin biosynthesis. Annu Rev Plant Biol 54 519-546 Dixon RA, Reddy MSS (2003) Biosynthesis of monolignols. Genomic and reverse genetic approaches. Phytochem Rev 2 289-306... 

Ralph J, Lundquist K, Brunow G et al (2004) Lignins natural polymers from oxidative coupling of 4-hydroxyphenylpropanoids. Phytochem Rev 3 29-60... 

Anterola, A. M., and Lewis, N. G., 2002, Trends in lignin modification a compehensive analysis of the effects of genetic manipulations/ mutations on lignification and vascular integrity, Phytochem. 61 221-294. 

McDougall, G. J., Stewart, D., and Morrison, I. M., 1996, Tyrosine residues enhance cross-linking of synthetic proteins into lignin dehydrogenation products, Phytochem. 41 43-47. 

Lignins natural polymers from oxidative coupling of 4-hydroxy-phenylpropanoids, Phytochem. 3 29-60. 

Phenolic compounds and flavonoids are a unique category of plant phytochemicals especially in terms of their vast po ential health-benefiting properties. They represent the most abundant and the most widely represented class of plant natural products. A substantial amount of research has been carried out over the past two decades yet large information gaps still exist. For example, the inventory of these compounds is still incomplete, although there is continuous effort to provide new structures. In addition the dissection of the metabolic pathways for certain phenolic compounds remains to be resolved. Recent reports underline that important questions that still need to be answered in the field of proanthocyanidin and tannin biosynthesis [Xie and Dixon, 2005], and even the exact nature of the biosynthetic pathway(s) leading to lignin monomers is not fully elucidated. 

Gross, G. G. Recent Advances in the Chemistry and Biochemistry of Lignins, Recent Adv. Phytochem. 1979, 12, 177-220 (Plenum Press). 

Marita, J. M., Ralph, J., Hatfield, R. D., Guo, D., Chen, R, and Dixon, R. A. (2003) Structural and compositional modifications in lignin of transgenic alfalfa down-regulated in caffeic acid 3-0-methyltransferase and caffeoyl coenzyme A 3-O-methyltransferase. Phytochem. 62(1), 53-65. 

Brunow, G., Kilpelainen, I., Lapierre, C., Lundquist, K., Simola, L. K., and Lemmetyinen, J. (1993) The chemical structure of extracellular lignin released by cultures of Picea abies. Phytochem. 32(4), 845-850. 

Peng, J., Lu, R, and Ralph, J. (1999) The DFRC method for lignin analysis. Part 5. Isochroman lignin trimers from DERC-degraded Pinus taeda. Phytochem. 50(4), 659-666. 

Scalbert, A., Monties, B., Lallemand, J. Y., Guittet, E., and Rolando, C. (1985) Ether linkage between phenolic acids and lignin fractions from wheat straw. Phytochem. 24(6), 1359-1362. 

Grisebach, H. Lignins. In The Biochemistry of Plants, Vol. 7, Secondary Plant Products (E. E. Conn, ed.), pp. 457-478. Academic Press, New York 1981 Grisebach, H., Hahlhrock, K. Enzymology and regulation of flavonoid and lignin biosynthesis in plants and plant cell suspension cultures. Rec. Adv. Phytochem. 5, 21-52 (1974)... 

Steelink, C. Biological oxidation of lignin phenols. Rec. Adv. Phytochem. 4, 240-271 (1972)... 

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