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Biosynthetic studies on the tropane alkaloid hyoscyamine in Datura stramonium; hyoscyamine is stable to in vivo oxidation and is not derived from littorine via a vicinal interchange process.

Patterson S, O'Hagan D.

School of Chemistry, Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK.

The conversion of littorine to hyoscyamine has been investigated by feeding deuterium labelled (RS)-[2-(2)H]-, [3, 3-(2)H(2)]-, [2, 3, 3-(2)H(3)]- phenyllactic acids to transformed root cultures of Datura stramonium. Isolation and GC-MS analyses of the isotope incorporation into the resultant hyoscyamine does not support the involvement of a vicinal interchange process operating during the isomerisation of littorine to hyoscyamine. Additionally a metabolism study with [1'-13C, 3', 3'-(2)H(2)]-hyoscyamine has established that the alkaloid is metabolically stable at C-3' with no evidence for a reversible in vivo oxidation process to the corresponding aldehyde. The data do not support an S-adenosy-L-methionine (SAM 5)/co-enzyme-B(12) mediated process for the isomerisation of littorine to hyoscyamine.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12359518&dopt=Abstract hyoscyamine Levbid SL



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Effect of pmt gene overexpression on tropane alkaloid production in transformed root cultures of Datura metel and Hyoscyamus muticus.

Moyano E, Jouhikainen K, Tammela P, Palazon J, Cusido RM, Pinol MT, Teeri TH, Oksman-Caldentey KM.

Departament de Ciencies Experimentals i de la Salut, Universitat Pompeu Fabra, Avda Dr Aiguader 80, E-08003 Barcelona, Spain.

In order to increase the production of the pharmaceuticals hyoscyamine and scopolamine in hairy root cultures, a binary vector system was developed to introduce the T-DNA of the Ri plasmid together with the tobacco pmt gene under the control of CaMV 35S promoter, into the genome of Datura metel and Hyoscyamus muticus. This gene codes for putrescine:SAM N-methyltransferase (PMT; EC. 2.1.1.53), which catalyses the first committed step in the tropane alkaloid pathway. Hairy root cultures overexpressing the pmt gene aged faster and accumulated higher amounts of tropane alkaloids than control hairy roots. Both hyoscyamine and scopolamine production were improved in hairy root cultures of D. metel, whereas in H. muticus only hyoscyamine contents were increased by pmt gene overexpression. These roots have a high capacity to synthesize hyoscyamine, but their ability to convert it into scopolamine is very limited. The results indicate that the same biosynthetic pathway in two related plant species can be differently regulated, and overexpression of a given gene does not necessarily lead to a similar accumulation pattern of secondary metabolites.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12493848&dopt=Abstract hyoscyamine Levbid SL



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Preparation of a molecularly imprinted polymer for the solid-phase extraction of scopolamine with hyoscyamine as a dummy template molecule.

Theodoridis G, Kantifes A, Manesiotis P, Raikos N, Tsoukali-Papadopoulou H.

Department of Chemistry, Aristotle University Thessaloniki, 541 24 Thessaloniki, Greece. gtheodor chem.auth.gr

Molecularly imprinted polymers (MIPs) selective for scopolamine were produced using hyoscyamine (a close structural analogue) as template molecule. The produced polymers were used as media for solid-phase extraction, exhibiting selective binding properties for the analyte from biological samples. Human and calf urine and serum were processed on the MIP under various extraction protocols. The best performance was observed after loading the analyte in aqueous environment facilitating retention on the MIP by non-selective hydrophobic interactions. The MIPs were subsequently washed using an optimised solvent system to enable selective desorption of the analyte. Other related and non-related compounds were accessed to evaluate molecular recognition properties. Recoveries of up to 79% were achieved for the analyte of interest from biological samples.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12613802&dopt=Abstract hyoscyamine Levbid SL



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Alkaloid spectrum in diploid and tetraploid hairy root cultures of Datura stramonium.

Berkov S, Pavlov A, Kovatcheva P, Stanimirova P, Philipov S.

Institute of Botany, Bulgarian Academy Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria. berkov iph.bio.bas.bg

Hairy root cultures were obtained from diploid and induced tetraploid plants of Datura stramonium and analyzed by gas chromatography/mass spectrometry. Twenty alkaloids (19 for diploid and 9 for tetraploid hairy root cultures) were identified. A new tropane ester 3-tigloyloxy-6-propionyloxy-7-hydroxytropane was identified on the basis of mass spectral data. Hyoscyamine was the main alkaloid in both diploid and tetraploid cultures. In contrast to diploid hairy roots, the percentage contributions of the alkaloids, with exceptions for hyoscyamine and apoatropine, were higher in the total alkaloid mixture of tetraploid hairy roots.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12622224&dopt=Abstract hyoscyamine Levbid SL



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Tropane alkaloids in auxin-independent root cultures of Physochlaina physaloides.

Shimomura K, Hirose M, Natori S, Satake M, Yoshimatsu K, Ishimaru K.

Faculty of Life Science, Toyo University, 1-1-1 Izumino, Itakura-machi, Oura-gun, Gunma, 374-0193 Japan.

Adventitious and hairy root cultures of Physochlaina physaloides were established. These roots grew well and produced high amounts of tropane alkaloids (particularly hyoscyamine and 6 beta-hydroxyhyoscyamine) in auxin-free culture medium. The effects of basal media and temperature on the growth and alkaloid production of these roots were investigated. Both root cultures produced highest amount of tropane alkaloids in B5 medium though the optimum temperature for hairy roots were lower than that for adventitious roots.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12638187&dopt=Abstract hyoscyamine Levbid SL