Terpenoids Terpenoid stress compound

The terpenoid stress compound phytuberin has been found in leaves of Nicotiana species. It has been produced in response to tobacco mosaic virus (TMV), tobacco necrosis virus (TNV) or the bacterium Pseudomanas lachrymans. Potato tubers inoculated29 with microorganisms accumulates the stress metabolite phytuberin, which is liquid antifugal sesquiterpene. It has been represented30 by the following structure ... 

When plants undergo various stresses, certain secondary metabolites, including defense compounds, accumulate. Several secondary metabolites such as terpenoid indole alkaloids, indole glucosinolate, nicotine alkaloids, and polyamines are known to accumulate through the induction of biosynthetic genes by jasmonates.898-900 MeJA also induces genes involved in the formation of tryptophan derivatives, terpenoid indole alkaloids.901 These compounds are known to be involved in defense response to pathogen attack as phytoalexins. 

The plant must be considered for example, the amount of compound in the tissues must be sufficient to produce a biological effect on the test insect. In the evaluation of this, it should be remembered that many plants have specialized tissues which contain high levels of secondary metabolites. For example, many conifer species contain specialized secretory structures, such as resin ducts, which contain high localized concentrations of terpenoids [82]. There may also be dynamic variations in the amounts of these compounds in the plant, resulting from seasonal fluxes or synthesis induced upon stress. 

Key Words Carotenoid chitosan methyl jasmonate phenolic compound salinity secondary metabolites stress response terpenoid. 

Other responses, such as formation of phytoalexins, are more specific (Chappell and Hahlbrock, 1984 Luckner, 1980). It has been shown that production of secondary compounds in cell cultures also can be enhanced by environmental stress. Treatment of cell cultures with fimgal, bacterial, or plant cell wall materials often results in the formation of a number of flavonoids, stilbenes, terpenoids, anthraquinones, rutacridone alkaloids, sanguinarine, and gossypol (Eilert, 1987 Heinstein 1985). In some cases, production of these metabolites is transient. Clearly, we need more information on the basic principles of the defensive response, such as structures and perception of defensive signals, transduction, and translation of these signals into a response (Luckner, 1980 Wink, 1987). 

Although phenolic compounds and terpenoids are very effective in cells as well as in animal models, human studies have not yet explored the hidden potential of these compounds. Many of the studies using phenolic compounds and terpenoids have used higher concentrations than can be obtained physiologically from dietary intake, suggesting a role of functional foods in prevention and treatment of diseases. In this chapter, we review the status of phenolic compounds and terpenoids as potential therapeutic agents, with an emphasis on the role of oxidative stress and the presence of redox-active plant compounds in diets. 

Plants produce primary and secondary metabolites with various functions. The primary metabolites - amino acids, simple sugars, nucleic acids and lipids - are compounds that are essential for their cellular processes. Secondary metabolites are compounds such as phenols, alkaloids, terpenoids and fiavonoids, which are produced in response to stress. 

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