Datura stramonium, alkaloid biosynthesis

Biosynthesis of tropan alkaloids hyosciamine and scopolamine by isomerization of alkaloid littorine in Datura. stramonium and related species 98CSR207. 

Robins, R. J., Parr, A. J. and Walton, N. J. 1991. Studies on the biosynthesis of tropane alkaloids in Datura stramonium L. transformed root cultures. 2. on the relative contributions of L-arginine and L-ornithine to the formation of the tropane ring. Planta, 183 196-201. 

The usefulness of GC-MS analysis for biosynthetic studies was demonstrated by Patterson and O Hagan [74] in their investigation of the conversion of littorine to hyoscyamine after feeding transformed root cultures of Datura stramonium with deuterium-labeled phenyllactic adds. This study complements previous investigations on the biosynthesis of the tropate ester moiety of hyoscyamine and scopolamine [75], where GC-MS played a key role. It also has general relevance in the biosynthetic pathway of tropane alkaloids in the entire plant kingdom [76]. 

Robins, R.J., Abraham, T., Parr, A.J., Eagles, J. and Walton, N.J. (1997) The biosynthesis of tropane alkaloids Datura stramonium the identity of the intermediate between N-methylpyrrolinium salt and tropinone.. Am. Chem. Soc., 119,10929-34. 

O Hagan D, Robins RJ, Wilson M, Wong CW, Berry M. Hu-orinated tropane alkaloids generated by directed biosynthesis in transformed root cultures of Datura stramonium. J. Chem Soc. Perkins Trans. 1. 1999 2117-2120. 

The A-methyl-A -pyrrolinium cation is the last common intermediate in both tropane alkaloid and nicotine biosynthesis (Scheme 3). A-Methyl-A -pyrrolinium cation formation begins with the decarboxylation of ornithine and arginine by ornithine decarboxylase (ODC) and arginine decarboxylase (ADQ, respectively. Putresdne is formed directly from ornithine by ODC, whereas agmatine and A-carbamoylputresdne serve as intermediates when putrescine is formed via ADC. An ODC cDNA isolated from Datura stramonium showed similarity to ADCs and other ODCs 127). ADC cDNAs have been isolated from oat and tomato 128,129). Arginine appears to supply most of the putrescine for alkaloid biosynthesis (l30). 

Robins RJ, Abraham TW, Parr AJ, Eagles J, Walton NJ (1997) The biosynthesis of tropane alkaloids in Datura stramonium the identity of the intermediates between N-methylp3nrolmium salt and tropinone. J Am Chem Soc 119(45) 10929-10934. doi 10.1021/ja964461p... 

Phenylalanine as a Precursor.— Tropic acid is found in Nature as the add moiety of the ester alkaloids hyoscyamine and hyosdne. A large amount of information, some conflicting, has been published in the past decade on the origin of this relatively simple molecule. We will review these data critically in the hope that it will aid work on the currently unsolved problem of its biosynthesis. It was discovered in 1960 that the administration of [3- C]phenylalanine to intact Datura stramonium plants yielded tropic acid having essentially all its activity at C-2. Later workers confirmed this result in D. stramonium (intact plants) and D. metel (sterile root cultures). It was then established that the other carbons of the phenylalanine side-chain were used for the production of the side-chain of tropic acid. The pattern of labelling found in the tropic... 

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