. Biochemistry of plants and animals, an introduction. Biochemistry. PLANT STRUCTURE AND COMPOSITION 197 imported from Central Europe. Like nicotine, atropine is also syn- thesized in the roots and later moved into the stems, leaves, and seeds. Space will not permit listing all the alkaloids of medical value. Many of the structures are extremely complex and therefore difficult to establish with certainty. The common medical compounds cocaine, codeine, quinine, strychnine, and morphine are alkaloids. Alkaloids have no known function in plants. The suggestion has been made that they represent ni
. Biochemistry of plants and animals, an introduction. Biochemistry. PLANT STRUCTURE AND COMPOSITION 197 imported from Central Europe. Like nicotine, atropine is also syn- thesized in the roots and later moved into the stems, leaves, and seeds. Space will not permit listing all the alkaloids of medical value. Many of the structures are extremely complex and therefore difficult to establish with certainty. The common medical compounds cocaine, codeine, quinine, strychnine, and morphine are alkaloids. Alkaloids have no known function in plants. The suggestion has been made that they represent nitrogen excretory products, or that they are by-products of nitrogen metabolism. Why these by-products should be formed in such quantities in the root and transported to the leaves for storage remains to be explained. Flower Pigments The numerous blue, purple, magenta, and nearly all the red flower, stem, fruit, and leaf pigments belong to a group of glycosides (page 72) designated as anthocyanins. The water-soluble yellow pigments in flowers, stems, and roots are generally flavones (anthoxanthins) and may occur as glycosides or uncombined as the free pigment. These pigments are usually freely soluble in the cell sap, although some occur in an amorphous or crystalline state, as in species of Delphinin. The chemistry of these compounds has been studied in considerable detail. Anthocyanins are all derivatives of 2-phenylbenzopyrylium salt. The. 2-phenylbenzopyrylium chloride principal difference between various members is the degree of hydroxyl- ation of the phenyl ring and the presence or absence of methyl esters. Pelargonidin, the pigment of scarlet pelargonium, orange-red dahlia, and red cornflower, contains a p-hydroxy group on the phenyl ring. Cyanidin pigments of the red rose, blue cornflower, and deep red dahlia contain two phenolic hydroxy groups, and delphinidin (blue delphinium) has three hydroxy groups. Both mono- and diglycosides. HO-. Please note that these images are
Size: 2453px × 1019px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookpublishernewyorkwiley, booksubjectbiochemis
