Papaver somniferum biosynthesis

UNTERLINNER, B LENZ, R KUTCHAN, T.M., Molecular cloning and functional heterologous expression of codeinone reductase The penultimate enzyme in morphine biosynthesis in the opium poppy Papaver somniferum, Plant J., 1999,18,465-475. 

Grothe, T., Lenz, R. and Kutchan, T. M. 2001. Molecular characterization of the salu-taridinol 7-0-acetyltransferase involved in morphine biosynthesis in opium poppy Papaver somniferum. Journal of Biological Chemistry, 276(33) 30717-30 723. 

In the laboratory and associated greenhouse, we gave particular attention to the biosynthesis of the morphine alkaloids.12"14 At first we purchased Papaver somniferum seeds and grew splendid poppies, but they contained no morphine... 

Labelled reticuline was readily incorporated into thebaine 14, codeinone 15a, codeine 15b, and morphine 16 without scrambling of the labels. Salutaridine is not present in detectable quantities in Papaver somniferum. However, when appropriately labelled, it is well incorporated into morphine alkaloids. Salutaridine can be readily reduced to two stereo-isomeric allylic alcohols 17, both of which are converted by mild acid catalysis (17, see arrows) to give thebaine 14. The alkaloids 17, 14, 15a, and 15b were all shown to be precursors of morphine. This was of interest, because the earlier theory of Robinson suggested that unmethylated alkaloids were first assembled and methylation was a terminal stage of biosynthesis. 

Papaver Alkaloids.—Biosynthesis of morphine (36) occurs, in Papaver somniferum, through reticuline (33) by way of thebaine (35). The sequence from (35) to (36) involves, inter alia, two O-demethylations, with that at the methoxy-group at C-6 occurring first.1,2 Confirmation that the other methoxy-group is not demethylated first in this Papaver species obtains from the failure to detect oripavine (37), which is found in other Papaver species, as a natural constituent of P. somniferum. The experiment involved attempted isolation of radioactive (37), using inactive alkaloid as carrier, following a feeding experiment with radioactive reticuline (33).37... 

Figure 7.9 Intercellular and subcellular trafficking in alkaloid biosynthesis. A. Tropane alkaloid biosynthesis in Hyoscyamus muticus. B. Terpenoid indole alkaloid biosynthesis in Catharanthus roseus. C. Trafficking of the berberine bridge enzyme in Papaver somniferum cell cultures.

The benzylisoquinolines are formed from two molecules of fhe aromafic amino acid, tyrosine. In the past ten years, this pathway has been probed at the enzyme and gene level. The recent linking of the phloem-specific expression of tyrosine/Dopa decarboxylase (TYDC) genes with the bios)mthesis of the isoquinoline alkaloids in the opium poppy, Papaver somniferum (Facchini and De Luca, 1994, 1995, 2008 Liscombe and Facchini, 2008), and the association with alkaloid accumulation as part of the plant defence mechanism (Wink, 1993 Facchini et al, 1996) are of particular interest in furthering our knowledge of the location of alkaloid biosynthesis. 

Weid, M., Ziegler, J. and Kutchan, T.M. (2004) The role of latex and the vascular bundle in morphine biosynthesis in the opium poppy, Papaver somniferum. Proc. Natl. Acad. Sci. USA, 101,13957-4962. 

The isoquinoline alkaloids include the analgesics morphine and codeine as well as the antibiotic berberine (Fig. la). Morphine and codeine are two of the most important analgesics used in medicine, and plants remain the main commercial source of the alkaloids (8). Development of plant cell cultures of Eschscholzia califomica, Papaver somniferum, and Coptis japonica has aided in the isolation and cloning of many enzymes involved in the biosynthesis of isoquinoline alkaloids (9). 

Ounaroon A, Decker G, Schmidt J, Lottspeich F, Kutchan TM. (R,S)-reticuline 7-0-methyltransferase and (R,S)- norcoclaurine 6-O-methyltransferase of Papaver somniferum - cDNA cloning and characterization of methyl transfer enzymes of alkaloid biosynthesis in opium poppy. Plant J. 2003 36 808-819. 

Ziegler J, Diaz-Chavez ML, Kramell R, Ammer C, Kutchan TM. Comparative macroarray analysis of morphine containing Papaver somniferum and eight morphine free Papaver species identifies an O- methyltransferase involved in benzylisoquinoline 40. biosynthesis. Planta 2005 222 458-471. 

Lenz R, Zenk MH. Stereoselective reduction of codeinone, the penultimate enzymic step during morphine biosynthesis in Papaver somniferum Tetrahedron Lett. 1995 36 2449-2452. UnterUnner B, Lenz R, Kutchan TM. Molecular cloning and functional expression of codeinone reductase. Plant J. 1999 18 465-475. 

Narcotine.—Previous results had allowed the biosynthetic route to narcotine (83) to be traced as far as (-)-(5)-scoulerine (68). Further results show that isocorypalmine (82) and canadine (80) are effective precursors for (83) in Papaver somniferum. The biosynthesis of narcotine may thus be further defined as (68) -> (82) - (80) - (83). [It appears that aromatization of canadine (80) to give berberine (84) involves stereospecific removal of hydrogen from C-8 of (80).] As in... 

Brochmann-Hanssen, E. and Cheng, C. Y. (1984) Biosynthesis of a narcotic antagonist conversion of N-allylnorreticuline to n-allylnormorphine in Papaver somniferum. J. Nat. Prod. 47, 175,176. 

Morphinan Alkaloids.—Extensive research on the biosynthesis of morphine (51) and related alkaloids in Papaver somniferum has allowed a detailed description of the pathway from the amino-acid tyrosine through reticuline (44), thebaine (46), and codeine (50) to morphine (51) (Scheme The incorporation of (R)-... 

Pathak S, Mishra BK, Misra P, Misra P, Jodii VK, Shulda S, et al. High frequency somatic embryogenesis, regeneration and correlation of alkaloid biosynthesis with gene expression in Papaver somniferum. Plant Growth Regul 2012 68(l) 17-25. 

Fig. 2. Alkaloid biosynthetic pathways are associated with a diverse variety of cell types. The tissue-specific localization (shaded) of enzymes and/or gene transcripts are depicted for the biosynthesis of tropane alkaloids in Atropa belladonna and Hyoscyamus niger roots (A), monoterpenoid indole alkaloids in Catharanthus roseus leaves (B), pyrrolizidine alkaloids in Senecio vernalis roots (C), pyrrolizidine alkaloids in Eupatorium cannabinum roots (D), benzyl-isoquinoline alkaloids in Papaver somniferum vascular bundles (E), and protoberberine alkaloids in Thalictrwn flamtm roots (F).

Pienkny, S., et al., Fimctional characterization of a novel benzylisoquinoline O-methyltransferase suggests its involvement in papaverine biosynthesis in opium poppy (Papaver somniferum L). Plant J., 2009. 60(1) p. 56-67. 

Several studies have reported the production in microorganisms of plant enzymes that are involved in alkaloid biosynthesis [29, 99-102], In this sense, Unterlinner et al. [100] have cloned and expressed in Escherichia coli four cDNAs encoding for different isoforms of the Codeinone reductase NADPH-dependent enzyme isolated from Papaver somniferum. In this report has been investigated the substrate specificity of the enzyme and the structural analysis, being the first report about the cloning and expression of genes of the biosynthetic pathway of morphine [90],... 

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