Plant compounds

Although manual extraction of information from herbal texts is straightforward (Fig. 4.3A), the work is labor intense and requires many areas of expertise (Fig. 4.3B). Historians must provide context for the language. Botanists are necessary to update the names and correctly identify the plants discussed. Physicians and biomedical scientists are required to extrapolate the potential pharmacological function of the plant compounds used to treat a certain disorder in the text. Luckily, the use of bioinformatics to extract this information can be more efficient than manual extraction [7]. 

Gilbert ES, DE Crowley (1997) Plant compounds that induce polychlorinated biphenyl degradation by Arthro-bacter sp. strain BIB. Appl Environ Microbiol 63 1933-1938. 

Finally, in multipurpose plants compounds, which can be deposited in various places (e.g. corners, zones near sealings) in equipment, can contaminate products of the subsequent batch. Therefore, all equipment must be thoroughly cleaned before the next production campaign starts. Contaminants can be formed in the process, sometimes at ppm level, and be recycled with streams of solvents and/or reactants. Hence, the influence of recycling on process performance indices must be included in the program of laboratory studies, at least in their final stage. 

The Influence of Secondary Plant Compounds on the Associations of Soil Microorganisms and Plant Roots... 

Table II. Sources and Action of Secondary Plant Compounds on Root - Rhizosphere Interactions...

To facilitate in-plant compounding, most suppliers have developed systems which efficiently and repro-ducibly deliver a controlled additive package to a compound, using either a specialised concentrate or a masterbatch formulation. Some of the polymer manufacturers have also made available advanced additive delivery systems, which they have often developed originally for their own use (e.g. Eastman, Montell). 

In many studies it was not possible to separate the overall effects of the management practices of organic farming and so we include this section to describe the overall effects on important plant food components. We have tried to separate the effect for each plant compound when possible. 

Polyphenols, as one of the largest and most widespread class of plant compounds, are also present in saffron stigma. In the mass spectrum of the flavonoid fraction of the methanolic extract from saffron there were ions at m/z 611 and 633 which may be attributed to protonated and sodiated quasi-molecular ions of kaempferol diglycoside. [22] Flavonoids from the water extract can be isolated and concentrated... 

While poisonous plants on grazing lands have a significant impact on livestock production throughout the world, the natural toxins (secondary metabolites) in the plant may have multiple and diverse functions, not only for the plant world but also for the benefit of mankind. Many current pharmaceuticals have been chemically optimized from natural toxins of plant origin. New plant compounds and familiar compounds with renewed interest, e.g., nutraceuticals, herbal preparations, nutritional supplements, etc, are increasingly finding their value in human nutrition and health. 

There are numerous other examples of plants, insects, large herbivores, and other organisms playing synergistic roles in nature s balance. Multiple functions are typical of plant compounds and do not contradict in any way their main role as chemical-defense and signal-induction compounds. A trait that serves multiple functions in a given plant or animal is more likely to survive the rigors of natural selection. 

Numerous nitrogen-free toxins occur in plants. As discussed in the introduction to this Chapter, many of these compounds are believed to be for the protection of the plant from herbivory. However, because there is such a diversity in plant compounds, there are other functions they serve, e.g., insect attractants for pollination, and protection against environmental factors, such as UV light, low or high temperatures, drought, etc. 

Phytoestrogens are a diverse group of polyphenolic non-steroidal plant compounds that bind to human estrogen receptors (Cos et al., 2003). The best studied of these compounds are the isoflavones, the phytoestrogens present in soy and red clover. 

The list of tryptophan-derived molecules could be extended almost without end tryptophan is the parent molecule of the indole alkaloids, a large group of plant compounds. 

Herbivores select certain plant species or parts and reject others. Plant defenses determine food choices as much as nutritional value does. Plants can defend themselves mechanically as with thorns, hairs, waxes, or structural fibers, and chemically with secondary plant compounds. Mammals have had to cope with plant defenses since they adapted to an herbivorous lifestyle approximately 85-100 millions years ago (Archibald, 1996). 

Table 11.1 Classes of plant compound with antiherbivore defense functions...

Many thousands of secondary plant compounds have been identified and 400000 are suspected to exist. These numbers provide a great incentive for chemical prospecting (Eisner, 1989). The most prevalent, broad classes of plant secondary compound are phenolics, alkaloids, and terpenoids (Table 11.1). 

It has been suggested that metabolites resulting from detoxification of plant compounds such as ferulic acid, a detoxification by-product of coniferyl benzoate and analogous compounds, may interfere with reproduction. However, experiments have shown that coniferyl benzoate in the diet of Japanese quail [Coturnix coturnix) had no hormonal effects. Rather, costs of detoxication and reduced nutrient utilization deter wild birds such as ruffed grouse, Bonasa umbel-lus, from feeding (Jakubas etal, 1993). 

Some secondary plant compounds have proven carcinogenic in laboratory rodents. These include D-limonene in orange juice 5-8-methoxypsoralen in parsley and parsnips and caffeic acid in coffee, but also in smaller amounts in apples, apricots, broccoli, Brussels sprouts, cabbage, cherries, kale, peaches, pears, and plums (Ames and Gold, 1990 Ames etal., 1990). How dangerous these compounds can be to human health, is still being debated. 

FIGURE 11.17 Phototoxic effects of plant compounds on mammalian herbivores. 

Potential beneficial effects of secondary plant compounds... 

Secondary plant compounds, food preferences, and consumption... 

Herbivores biotransforms xenobiotics from natural or artificial sources to render them harmless. Disarming potentially toxic compounds is termed detoxication, while the term detoxification refers to correcting a state of toxicosis (Johns, 1990). Herbivores degrade secondary plant compounds in a variety of ways, starting in the mouth, and leading to excretion. 

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