Natural products from plants

FALL, R., BENSON, A.A., Leaf methanol - the simplest natural product from plants, Trends Plant Sci., 1996, 9,296-301. 

During the nineteenth century, chemists had a good deal of success in isolating and purifying natural products from plant sources. Morphine was isolated as a pure compound from crude opium in 1804. Quinine was isolated from the bark of the cinchona tree in 1820 and was initially employed as a fever reducer. However, its effectiveness against malaria was soon discovered and it found an alternative highly important medical use. Sodium salicylate was isolated from the bark of the willow tree in 1821 and was also shown to have analgesic, antipyretic, and antiinflammatory properties. It took an additional 76 years, until 1897, to synthesize the acetyl derivative, acetylsalicyclic acid, commonly known as aspirin. 

Natural products, from plants and foods to rocks and minerals, are complicated systems, but their analysis by Raman spectroscopy is a growing area. Most examples come from quality control laboratories, motivated to replace current time-consuming sample preparation and analysis steps with a less labor-intensive, faster technique but most authors anticipated the eventual application to process control. Often a method will be practiced in a trading house or customs facility to distinguish between items perceived to be of different qualities, and thus prices. 

Potential Anticancer Natural Products from Plant-Associated Fungi 473... 

Gunatilaka AAL, Natural products from plant-associated microorganisms Distribution, structural diversity, bioactivity, and implications of their occurrence, J AhrPwi/69 509—526, 2006. 

Fall, R., and A. A. Benson, Leaf Methanol—The Simplest Natural Product from Plants, Trends Plant Sci., 1, 296-301 (1996). 

Kaufman PB, Csele LJ, Warber S, Duke LA, Brielmann HL (1998) Natural Products from Plants. CRC, Boca Raton... 

Effect of Rotenone and Antimycin A on Electron Transfer Rotenone, a toxic natural product from plants, strongly inhibits NADH dehydrogenase of insect and fish mitochondria. Antimycin A, a toxic antibiotic, strongly inhibits the oxidation of ubiquinol. 

Natural products have been, and remain, a rich source of leads for the pharmaceutical industry and many marketed drugs are either natural products or are modifications of such substances. Hence, considerable effort is spent in isolating and characterising chemicals from natural sources which can be tested in a variety of biological screens. Often, it is necessary to carry out laborious extraction and purification steps and the advent of directly coupled HPLC-NMR has been explored as an alternative technique for natural product identification. The use of HPLC-NMR, and other hyphenated techniques such as HPLC-MS-MS, for identification of natural products from plant sources has been reviewed by Wolfender and co-workers [40,41],... 

Cholesterol is synthesized from acetyl-CoA in the liver. Cholesterol and a number of natural products from plants (including rubber) are isoprenoid compounds. The isoprenoid unit is a 5-carbon structure. 

There are examples in the literature for the application of LC-MS-NMR in the pharmaceutical industry. In the area of natural products, this technique has been applied as a rapid screening method of searching unknown marine natural products in chromatographic fractions [108] and for the separation and characterization of natural products from plant origin [109, 110]. Another application is in the area of combinatorial chemistry [111]. In the field of drug metabolism, LC-MS-NMR has been extensively applied for the identification of metabolites [112-120]. And finally, LC-MS-NMR has been used for areas such pharmaceutical research [35,121,122], drug discovery [123], degradation products [101], and food analysis [124,125]. 

Solvent extraction In hydrometallurgy to recover metals from ores In nuclear fuel reprocessing In waste water treatment To recover natural products from plants or from fermentation liquors In organic synthesis and analytical chemistry As a degreaser and cleaning agent... 

Gunatilaka AA. Natural products from plant-associated microorganisms distribution, structural diversity, bioactivity, and imph-cations of their occurrence. J. Nat. Prod. 2006 69 509-526. Porter JK. Ergot alkaloids and alkaloids from other endophytes, responsible for causing toxic syndrome in cattle after eating contaminated grass. Prikl. Biokhim. Mikrobiol. 1993 29 51-55. Porter JK. Analysis of endophyte toxins fescue and other grasses toxic to livestock. J. Anim. Sci. 1995 73 871-880. 

Finally, it may be worthwhile to point out that one of the most successful chemotherapeutic drugs provided by nature may be considered as a non-classical active-site-directed irreversible inhibitor This drug is penicillin (70). As a non-classical antimetabolite of D-alanyl-D-alanine, it first forms a reversible complex with the enzyme peptidoglycan transpeptidase, and then by a ringopening reaction of its p-lactam moiety, it forms a covalently linked penicil-loyl-enzyme complex97. However, the reaction involves the acylation of a sulfhydryl group in the active site of the enzyme in this respect, 70 resembles the classical-type endoalkylating antimetabolites, azaserine and DON (8 and 9, see Section 2.2.). Some of the more recently discovered antibiotics and natural products from plants with antitumor activity (e.g., camptothecin) are... 

The screening of natural products became highly popular following the discovery of penicillin from a mould. Plants, fungi, and bacterial strains were collected from all round the world in an effort to find other metabolites with useful biological activities. This led in particular to an impressive arsenal of antibacterial agents (Chapter 9). Screening of natural products from plant and microbial sources continues today in... 

NATURAL PRODUCTS FROM PLANT BIODIVERSITY AND THEIR USE IN... 

Natural Products from Plant Biodiversity and their Use 13... 

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