Plant Substances

Many plant substances possess antivitamin D activity but the mode of action and in most cases the identity remain unknown. Rachitogenic factors have been observed in yeast. Because of the metaboHc interrelationships that exist between vitamin D, Ca, and P, it is sometimes difficult to differentiate between chelators of mineral elements and tme antivitamins. One reported vitamin D antagonist in oats was later identified as phytic acid (72). 

Sz. Nyiredy, Applicability of planar cliromatography in the analysis and isolation of plant substances , in Proceedings of Biokemia XV, pp. 146-151 (1991). 

Plant substances (juice, pulp, rind, and leaf) are homogenized with anhydrous sodium sulfate and methanol and fenothiocarb residue is extracted with acidic methanol [0.5 N hydrochloric acid-methanol (1 3, v/v)] by refluxing for soil. Fenothiocarb in the... 

As a first step, the authors built a database of the volatile terpenes for six olibanum samples with certified botanical origin and derived characteristic signatures associated with the botanical origin. In the second step they used these signatures to define the species of samples of different origin (commercial societies or markets from various countries of the Middle East) and to recognise the markers of olibanum in a mixture with other plants substances. 

Feeny PP (1976) Plant apparency and chemical defense. Res Adv Phytochem 10 1—40 Fraenkel GS (1959) The raison d etre of secondary plant substances. Science 129 1466-1470 Franklin LA, Yakovleva I, Karsten U, Liming K (1999) Synthesis of mycosporine-like amino acids in Chondrus crispus (Florideophyceae) and the consequences for sensitivity to ultraviolet B radiation. J Phycol 35 682-693... 

H. Schulz and M. Baranska, Identification and quantification of valuable plant substances by IR and Raman spectroscopy, Vib. Spectrosc., 43, 13-25 (2007). 

Eraenkel, G. S. (1959). The raison d etre of secondary plant substances. Science 129,1466-1470. 

Specific signals (e.g., an action potential or second messenger such as insPs or cAMP) can trigger a sudden increase in the cytoplasmic Ca "" level to 500-1000 nM by opening Ca "" channels in the plasma membrane or in the membranes of the endoplasmic or sarcoplasmic reticulum. Ryanodine, a plant substance, acts in this way on a specific channel in the ER. in the cytoplasm, the Ca "" level always only rises very briefly (Ca "" spikes ), as prolonged high concentrations in the cytoplasm have cytotoxic effects. 

Rotschild, M. 1973. Secondary plant substances and warning coloration in insects. In Insect-Plant Relationships (Van Emden, H. F., ed.), pp. 59-83. Oxford Oxford University Press. 

Fitzpatrick, F. K. Plant substances active against Mycobacterium tuberculosis. Antibiot Chemother 1954 4 528. Saha, J. C., E. C. Savini, and S. Kasinathan. Ecbolic properties of Indian medicinal plants. Part I. Indian J Med Res 1961 49 130-151. 

The nutritional requirements of insect species exhibiting different feeding habits like scavengers, parasites, predators and phytophagous insects, are similar in a qualitative sense (O. Each insect species needs, however, a particular quantitative composition of nutrients in its diet to complete development ( ). The presence of toxic substances in plants, secondary plant substances as they were formerly called by phytochemists, forms a barrier which phytophagous insects have overcome by specialization. Thus, an insect can tolerate or detoxify the secondary plant substances present in its host plants, while the majority of these substances being present in other plants still acts as toxins (J ). In this way phytophagous insects are adapted to the metabolic qualities of their host plants, i.e. a particular chemical composition of nutrients and secondary plant substances. 

In biting their food and by means of a relatively small number of gustatory receptor cells, the larvae are informed about the composition of nutrients and secondary plant substances. Taste perception, the integration of sensory information in the insect s central nervous system, is not merely a process of summation. Synergistic as well as antagonistic effects between individual compounds can be observed in the food uptake of larvae on artificial diets. 

Different insect species posses different gustatory receptor cells, their response spectra being adapted to the perception of chemical components distributed in their host plant species (9 ). Taste perception in P. brassicae larvae forms a representative example for phytophagous insects, which are able to discriminate a number of compounds like sugars, amino acids, salts, and secondary plant substances acting as feeding inhibitors or feeding incitants (3,6,, 10). 

Anthroposophists also take a unique approach to medicine. The body, they say, has three poles — cool, warm, and balancing. Illness arises from a disharmony of these poles, and we can restore the harmony with a variety of animal, mineral, and plant substances. We must take the time of day and planet constellations into consideration as we prepare these remedies, and we must never work on them between noon and three o clock in the afternoon because this is the least alive time of day. Anthroposophists frown upon vaccinations, but they approve of color therapy and a mistletoe preparation invented by Steiner. Sauerkraut they regard as a special food we require it for the health of our digestive tracts. 

Aromatic Amino Acids Are Precursors of Many Plant Substances... 

FIGURE 22-28 Biosynthesis of two plant substances from amino acids. 

The aromatic amino acids give rise to many plant substances. The PLP-dependent decarboxylation of some amino acids yields important biological amines, including neurotransmitters. 

These four classes of source materials have given rise to at least 13 coalified products that appear to be optically distinguishable. These 13 products may represent as many as nine separate sequences in which plant substances are altered to coal substances and in which the coal substances are further metamorphosed from one maceral to another. 

More than 400 chemical compounds have been identified in marijuana. Approximately 60 of these are unique to the cannabis plant, substances called cannabinoids. Of the cannabinoids, a group of isomers (chemically similar substances) called tetrahydro-cannabinols (THC) are thought to be the most psychoactive. These are Ai-THC (also called A9-THC) and A6-THC (also called A8-THC). Other cannabinoids include cannabidiolic acid (CBDA), cannabidiol (CBD), and cannabinol (CBN). Their role in marijuana intoxication is less well understood. The amount of THC produced depends on the strain of cannabis and on environmental factors such as growth, harvest, and storage conditions. 

In many instances, the materials or plant substances that prove to be allelopathic in laboratory or pot culture experiments may not elucidate similar magnitude of allelopathic response on aquatic weeds in aquatic environments, watersheds, or wetlands. Hence, it is imperative to confirm plant products for their allelopathic potential on weeds in their own natural habitat. A search was made on allelopathic plant products for use in water hyacinth control programs at Department of Agronomy, Annamalai University. Ten of 55 different plant products that showed allelopathic suppression of water hyacinth within 48 h of treatment were selected and tested for their efficacy in natural habitats. The field testing was done in a two tier model. First, the ten plant products were tested in microponds (simulated natural habitat). Second, the plant products that confirmed to be allelopathic in microponds were further evaluated in natural watersheds. 

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