Synthesis Of Plant Metabolites In Specialized Structures Or Tissues
Plants do not always produce their products in every cell of the organism. Often plants have developed tissue-specific locations for synthesis of certain compounds which not only accentuates the compound's specific function but perhaps avoids the toxic effects that the compound may have on the plant itself. Indeed, this is the case for all plant products within each cell of every plant, but the plant as a whole must have a system for dealing with potentially hazardous substances. The following...
Nitrogencontaining Compounds
4.6.1 Alkaloids from Plants that Are Used to Treat Malaria Quinine (Chinchona spp.) The bark of Chinchona trees is the source of the drug, quinine, which has been used to treat patients afflicted with malaria. Malaria is a disease in humans caused by the parasite, Plasmodium falciparum. The parasite is transmitted by the mosquito, Anopheles spp. Quinine, or more generally, the drug, chloroquine, since l986 in Brasil and Africa, has been shown to be no longer effective in treating malaria due to...
Collection Storage And Vouchering Of Plants
7.2.1 Collection of Plants in the Field Do's and Don'ts When collecting plants in the field for natural product extractions, it is important to be properly prepared. Based on our experience, we suggest that you do the following Wear field clothes (Figure 7.1) and cover yourself head to toe if collecting is to be in the cold of winter or when mosquitos or deer black flies are in abundance. FIGURE 7.1 Casey Lu (far right) and colleagues (from Humboldt State University Department of Biological...
References
Adler, Science News, SN149, 389, 1996. 2. Duke, J. A., Medicinal and industrial plants from arid lands. pp. 325-343, in Biotechnology for Aridland Plants, Mabry, T. J., Nguyn, H. T., Dixon, R. A., and Boness, M. S., Eds., IC2 Institute, The University of Texas at Austin, 1994, 369 pp. 3. Sydiskis, R. J., Owen, D. G., Lohr, J. L., Rosler, K. H., and Blomster, R. N., Inactivation of enveloped viruses by anthraquinones extracted from plants, Anti-microb. Agents Chemother., 35, 2463-2466, 1991. 4....
Transmembrane Signaling
We have examined ways in which plant molecules effect the synthetic capacity of cells and their ability to proliferate or complete their life cycle. Another important way that exogenous molecules interact with cells and their functions is by various types of transmembrane signaling. Two types of signaling, ligand gated ion channels and G-protein second messenger, are particularly relevant to the function of nerves and muscles. We will discuss these in detail and look at examples of how...
Cell Life Cycle And Cancer Treatment
Cancer is one of the predominant killers in the western world today. Despite much advancement in cancer therapy, many cancers are still ineffectively treated or become resistant or recur. In addition, the methods of treating cancer are often difficult for patients to tolerate due to the side effects. Thus, there continues to be great interest in the search for new and better treatments. Plant-based medicines have definitely found a role in this type of treatment and the mechanism of interaction...
Amines Amino Acids And Proteins
Compounds that contain nitrogen as part of a chain rather than being incorporated into a ring structure generally belong to this category of natural products. For the amines, this by definition imparts a basic nature to the molecule. For the amino acids this results in molecules that may be zwitterionic (forming a dipolar ion) depending on the pH of the environment. The common plant amines can be subdivided into aliphatic monoamines, aliphatic polyamines, and aromatic amines. Occasionally these...
Generalized View Of A Plant Cell And Its Subcellular Compartments
Before considering individual compartments within plant cells where plant metabolites are synthesized and stored, we must first examine how a typical plant cell is organized and how its various components are related to one another. For this purpose, we shall refer to the cell illustrated in Figure 2.2. The jacket that encloses this cell is the cell wall. This is the primary site for polymerization of cell wall polysaccharides (cellulose, hemicellulose, and pectic polysaccha-rides), lignin, and...
Terpenoids And Phenolics
4.5.1 Pokeweed (Phytolacca americana) Can Be Both Good and Bad Pokeweed (Figures 4.14, 4.15, and 4.16) is a common perennial garden weed with lush green shoots and bright red stems (due to presence of anthocyanin pigment). Leaves of its green shoots are harvested in the spring in Appalachia, boiled several times, each time pouring off the hot water. All parts of the plant except the above-ground leaves that grow in the spring contain toxic triterpene saponins (phytolaccigenin, jaligonic acid,...
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FIGURE 2.16 Examples of carotenoid and xanthophyll pigments from plants. P-carotene is the orange pigment in carrot roots, pumpkin fruits, leaves of deciduous trees, and some flower petals. Zeaxanthin and violaxantin are also found in autumn-colored leaves and flower petals and are responsible for the FIGURE 2.17 Carotenoid biosynthesis pathway in plants. (From Bartley, G. E. and Scolnik, P. A., The Cell Plant, 7, 1027-1028, 1995. With permission.) FIGURE 2.17 Carotenoid biosynthesis pathway in...
How And Where Some Of The Wellknown Plant Metabolites Are Synthesized In Plant Cells
2.4.1 Lipids, Proteins, and Nucleotides All living organisms produce three major categories of compounds (1) lipids, which make up both the plasma membrane and the membranes of all internal compartments and organelles (2) proteins, which make up both structural units of the cell such as microtubles and all the enzymes of every biochemical process and (3) nucleic acids and nucleotides, which code for all proteins, act as metabolic energy molecules such as ATP and biochemical regulators such as...
The History Of Herbal Medicine A Capsule Summary
Penelope Ody, in her book, The Complete Medicinal Herbal,1 has compiled a very nice summary on the origins of western herbalism, starting with ancient civilizations of Egypt, the Greeks, and Romans. She continues with Islamic influences from the Arab world, Ayurvedic medicine from ancient India (ajur meaning life and veda meaning knowledge, refers to knowledge of how to live and places emphasis on good health being the responsibility of the individual), and Tibetian herbalism. The legacy of...
Carbohydrate Metabolites
4.4.1 Human Uses of Starch from Plant Storage Organs Starch is a primary energy source for humans. We obtain it in abundance from cereal grains such as wheat (Triticum aestivum), rice (Oryza sativa), barley (Hordeum vulgare), oats (Avena sativa), rye (Secale cereale), and maize (Zea mays). It also occurs in abundance in tubers of potato (Solanum tuberosum), oxalis (Oxalis spp.) and tuberous roots of yam (Dioscorea spp.), yautia (Xan-thosoma brasiliense), sweet potato (Ipomoea batatus) (Figure...
Immunomodulation
The mammalian immune system consists of many cells and signal molecules which act in concert to protect the organism from that which is nonself. The chief cellular effectors are macrophages (big eaters) and white blood cells. Neutrophils and lymphocytes are the most important of the white blood cells. Some of the signal molecules are interleukin-1 (IL-1), tumor necrosis factor-a (TNF-a), and y-interferon (IF-y, also known as IL-6). Cells that come in contact with foreign organisms begin to...
Sulfurcontaining Compounds
4.7.1 Functions of Sulfur-Containing Compounds in Garlic in Medicine, Nutrition, and Pest Control 4.7.1.1 Natural History and Association with Humanity15 27 28 Garlic, Allium sativum (Liliaceae or lily family) has an ancient association with humans. It is so ancient that garlic is not found in nature and its exact origins are unknown. The earliest documented occurrence of garlic's use by humans is the fine clay sculptures of garlic cloves found at El Mahasna, Egypt which have been dated to 3750...
Adaptive Functions Of Metabolites In Plants
2.6.1 Sources of Metabolic Energy and Energy Transfer Without a source of metabolic energy or the ability to transfer the energy obtained from the environment through metabolic pathways, a living organism will die. This is why plants devote so much of their time and energy towards the production of pools of compounds that ultimately store the energy of the sun. Plants have several such sources of metabolic energy derived from stored metabolites or from ATP. The stored metabolites include starch...
Aloe Vera L NLBurm Liliaceae Mediterranean Aloe
Aloe contains several anthraquinone glycosides, e.g., aloin (barbaloin), isobar-baloin, and emodin. These anthraquinones share several activities, antiseptic, laxative, even viricidal. Some of the related sennosides have been proven synergistic as laxatives. Sydiskis et al.3 notes that anthraquinones can inactivate enveloped viruses. Are the anthraquinones synergistic or antagonistic as anti-virals Reflecting the natural tendency of investigators to modify natural chemical compounds, often...
Grinding And Extraction Protocols
7.3.1 General Extraction Protocols for Biologically Important Organic Compounds The primary ways for extraction of organic molecules of interest to biologists and medical investigators involve breaking open the cells of the organism under investigation. Cell rupturing is accomplished in a variety of ways. The method used depends on the type of organism being considered and the type of tissue used. For bacterial cells, one usually uses a French press so as to break open the cell walls. This...
Plant Seed Banks For Germplasm Preservation
9.5.1 Plant Introduction Stations in the U.S. Four regional plant-introduction stations in the U.S. are located in Pullman, WA Ames, IA Geneva, N.Y. and Griffin, GA. They are responsible for the management, regeneration, characterization, evaluation, and distribution of seeds of more than one-third of the accessions of the national system i.e., nearly 197,000 accessions of almost 4000 plant species . At Ames, IA, approximately 40,079 accessions are held the primary crops preserved include...
Growing Rare And Endangered Plants In Botanical Gardens And Arboreta How Is It Done
9.4.1 Involvement of Botanical Gardens and Arboreta According to The New York Botanical Garden, of approximately 250,000 species of flowering plants, it is estimated that some 60,000 of these may become extinct by the year 2050, and more than 19,000 species of plants are considered to be threatened or endangered around the world. More than 2000 species of plants native to the U.S. are threatened or endangered, with as many as 700 species becoming extinct in the next 10 years.15 The New York...
Case Studies With Medicinal Plants
8.2.1 Azadirachtin from the Neem Tree Azadirachta indica Neem, Azadiractica indica Juss , in the family Meliaceae, or mahogany family, has a long history of use in human civilization. As with many plant species long used by humanity, its exact origins are unknown. Some have suggested southern India and Burma as the region where neem originated, while others have suggested locations ranging from Indonesia to Iran.1 Neem grows well in dry tropical and subtropical regions, and has been introduced...
Case Studies With Plant Fragrances
Plant fragrances from flowers attract various kinds of pollinators, and other fragrances that come from both flowers and vegetative parts of plants deter predators see Chapter 2 . Many of these same fragrances from plants have utilitarian uses by humans, namely, perfumes, herbal teas, sachets, herbal wreaths, and insect repellents. We grow many fragrance herbs both commercially and in the home garden. Organic gardeners grow some of the insect-repelling herbs as companion plants with flowers and...
