Papaver somniferum, alkaloid metabolism

Production can be increased by addition of precursors to the culture media, in which cases the precursors are not metabolized in the medium and, after uptake, appear in the right compartment of the plant cell. For C. roseus cultures, for example, it was found that increased indole alkaloid production was obtained after feeding with L-tryptophan, tryptamine, secologanin, loganin, loganic acid, or shikimic acid (20). Cell cultures have also been used for biotransformations, for example, the conversion of (-)-codeinone to (-)-codeine in Papaver somniferum cultures (100). For the tropane alkaloids a large number of precursor feeding and biotransformation studies with cultures of various solanaceous plants have been performed (see below). 

When morphine was fed to the stem below the developing capsules, 8% of the morphine was metabolized in a few days. Diurnal changes in the content of alkaloids in Papaver somniferum occur (Waller and Nowacki, 1978). The half-life of morphine in several species of poppies is 7.5 h. 

Laudanosine or Af-methyltetrahydropapaverine is a recognized metabolite of atracurium and cisatracurium. Laudanosine decreases the seizure threshold, and thus, it can induce seizures if present at sufficient threshold concentrations however, such concentrations are unlikely to be produced consequent to chemodegradable metabolism of clinically admiiustered doses of cisatracurium or atracurium. Laudanosine also occurs naturally in minute amounts (0.1 %) in opium, from which it was first isolated in 1871. Partial dehydrogenation of laudanosine will lead to papaverine, the alkaloid found in the opium poppy plant (Papaver somniferum). Laudanosine is a benzyltetrahydroisoquinoline alkaloid. It has been shown to interact with GABA receptors, opioid receptors, and ificotinic acetylcholine receptors, but not benzodiazepinergic or muscarinic receptors which are also involved in epilepsy and other types of seizures. 

Fairbairn JW, Wassel G (1964) The alkaloids of Papaver somniferum L. I. Evidence for a rapid turnover of the major alkaloids. Phytochemistry 3 253-258 Fairbairn JW, Hakim F, El-Kheir Y (1974) Alkaloid storage, metabolism and translocation in the vesicles of Papaver somniferum latex. Phytochemistry 13 1133-1139... 

Heydenreich K, Pfeifer S (1962) On the metabolism in Papaver somniferum L. V. Hourly variation in alkaloid content. Sci Pharm 30 164-173 Hodges CC, Rapoport H (1982) Enzymic conversion of reticuline to salutaridine by cell-free systems. Biochemistry 21 3729-3734... 

Coutts IGC, Hamblin MR, Tinley EJ (1979) The enzymatic oxidation of phenolic tetrahydroiso-quinoline-1-carboxylic acids. J Chem Soc Perkin Trans 1 2744-2750 Davis VE, Cashaw JL, McMurtrey KD, Ruchirawat S, Nimit Y (1982) Metabolism of tetrahydro-isoquinolines and related alkaloids. In Bloom F, Barchas J, Sandler M, Usdin E (eds) Beta-carbolines and tetrahydroisoquinolines. Liss, New York, p 99 Furuya T, Nakano M, Yoshikawa T (1978) Biotransformation of (RS)-reticuline and morphinan alkaloids by cell cultures of Papaver somniferum. Phytochemistry 17 891-893 Gates M (1953) Conversion of codeinone to codeine. J Am Chem Soc 75 4340-4341 Graves JMH, Smith WK (1967) Transformation of pregnenolone and progesterone by cultured plant cells. Nature (London) 214 124 8-1249... 

Roberts MF, McCarthay D, Kutchan TM, Coscia CJ (1983) Localization of enzymes and alkaloi-dal metabolites in Papaver latex. Arch Biochem Biophys 222 599-609 Schuchmann R, Wellmann E (1983) Somatic embryogenesis of tissue cultures of Papaver somniferum and Papaver orientate and its relationship to alkaloid and lipid metabolism. Plant Cell Rep 2 88-91... 

Fairbairn JW, Steele MJ (1981) Biosynthetic and metabolic activities of some organelles in Papaver somniferum latex. Phytochemistry 20 1031-1036 Fairbairn JW, Djote M, Paterson A (1968) The alkaloids of Papaver somniferum L.-VII. Biosynthetic activity of the isolated latex. Phytochemistry 7 2111-2116 Felklova M, Babkova K (1958) Latex tubes in Papaver somniferum during the vegetative period. Pharmazie 13 220... 

Roberts MF, Antoun MD (1978) The relationship between L-DOPA decarboxylase in the latex of Papaver somniferum and alkaloid formation. Ph3rtochemistry 17 1083-1087 Roberts MF, McCarthy D, Kutchan TM, Coscia CJ (1983) Localization of enzyme and alkaloidal metabolites in Papaver latex. Arch Biochem Biophys 222 599-609 Rueffer M, El-Shagi H, Nagakura N, Zenk MH (1981) (S)-Norlaudanosoline synthetase the first enzyme in the benzylisoquinoline biosynthetic pathway. FEBS Lett 129 5-9 Sasse F, Backs-Hiisemann D, Barz W (1979) Isolation and characterization of vacuoles from cell suspension cultures of Daucus carota. Z Naturforsch 34 848-853 Schuchmann R, Wellmann E (1983) Somatic embryogenesis of tissue cultures of Papaver somniferum and Papaver orientate and its relationship to alkaloid and lipid metabolism. Plant Cell Rep 2 88-91... 

Alkaloidal storage, metabolism, and translocation in the vesicles of P. somniferum have been reported (268, 298). The content of alkaloids in this plant of various ages (no statistical difference was found in the morphine content between the blue- and the white-seeded variety), the accumulation of morphine in several varieties of poppy in different climatic zones (326, 842), and the identification of opium-yielding Papavers have also been studied (843). The contents of morphine in dried capsules of P. 

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