Abstract
The nortropane sulphur analogues 8-thiabicyclo[3.2.1] octan-3-one, 8-thiabicyclo[3.2.1]octan-3a-ol and 8-thiabicyclo[3.2.1]octan-3β-ol have been found to have differential effects in vitro on the activities of tropinone reductase I and tropinone reductase II from Datura stramonium L. It has been demonstrated that only tropinone reductase I is able to metabolise 8-thiabicyclo[3.2.1]octan-3-one and that only this enzyme is inhibited by 8-thiabicyclo[3.2.1]octan-3α-ol and 8-thiabicyclo[3.2.1]octan-3β-ol. A K m of 0.035 mM was determined for 8-thiabicyclo[3.2.1]octan-3-one and I50 values of 0.081 mM and 0.021 mM for 8-thiabicyclo[3.2.1]octan-3α-ol and 8-thiabicyclo[3.2.1]octan-3β-ol, respectively. The influence that these differential interactions might have on metabolism was investigated in transformed root cultures of D. stramonium. It was found that when these cultures were grown in the presence of either 8-thiabicyclo[3.2.1]octan-3-one or 8-thiabicyclo[3.2.1]octan-3β-ol the spectrum of alkaloids that accumulated was altered from that found in control roots in the manner predicted from the observed effects of these inhibitors on the isolated reductases. The effect could be mimicked by feeding pseudotropine, the product of tropinone reductase II. It is concluded that the relative levels of activity of the two tropinone reductases might play an important role in regulating the balance of tropan-3α-ols to tropan-3β-ols seen in the spectrum of tropane-alkaloid-producing plants.
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Abbreviations
- GC/MS:
-
gas chromatography/mass spectrometry;
- I50 :
-
concentration of inhibitor required to reduce the rate of reaction to half the maximal value;
- α-TBOL:
-
8-thiabicyclo[3.2.1]octan-3α-ol;
- β-TBOL:
-
8-thiabicyclo[3.2.1]octan-3β-ol;
- TBON:
-
8-thiabicyclo[3.2.1]octan-3-one;
- TR:
-
tropinone reductase
Referencess
Beresford, P.J., Woolley, J.G. (1974) Biosynthesis of tigloidine in Physalis peruviana. Phytochemistry 13, 2143–2144
Dräger B., Schaal, A. (1992) Pseudotropine formation and calystegins in Atropa belladonna root cultures. In: Phytochemistry and agriculture, p. 52, van Beek, T.A., ed. Proceedings of Phytochemical Society of Europe/Royal Netherlands Chemical Society meeting, Wageningen, April 1992
Dräger, B., Hashimoto, T., Yamada, Y. (1988) Purification and characterization of pseudotropine forming tropinone reductase from Hyoscyamus niger root cultures. Agric. Biol. Chem. 52, 2663–2667
Goldmann, A., Milat, M.-L., Ducrot, P.-H., Lallamand, J.-Y., Maille, M., Lepingle, A., Charpin, I., Tepfer, D. (1990) Tropane derivatives from Calystegia septum. Phytochemistry 29, 2125–2127
Lounasmaa, M. (1988) The tropane alkaloids. In: The alkaloids, vol.33, pp. 1–81, Brossi, A. ed Academic Press, Orlando
Nickon, A., Fieser, L.F. (1952) Configuration of tropine and pseudotropine. J. Am. Chem. Soc. 74, 5565–5570
Parr, A.J., Walton, N.J., Bensalem, S., McCabe, P., Routledge, W. (1991) 8-Thiabicyclo[3.2.1]octan-3-one as a biochemical tool in the study of tropane alkaloid biosynthesis. Phytochemistry 30, 2607–2609
Portsteffen, A., Dräger, B., Nahrstedt, A. (1992a) Two tropinone reducing enzymes from Datura stramonium transformed root cultures. Phytochemistry 31, 1135–1138
Portsteffen, A., Dräger, B., Nahrstedt, A. (1992b) Isolation and characterization of two tropinone reductases from Datura stramonium root cultures. In: Phytochemistry and agriculture, p. 63, van Beek, T.A., ed. Proceedings of Phytochemical Society of Europe/Royal Netherlands Chemical Society meeting, Wageningen, April 1992
Rabot, S., Robins, R.J. (1992) Pseudotropine:tiglyl-CoA acyl transferase: an ester-forming enzyme from Datura stramonium transformed root cultures. In: Phytochemistry and agriculture, p. 67, van Beek, T.A., ed. Proceedings of Phytochemical Society of Europe/Royal Netherlands Chemical Society meeting, Wageningen, April 1992
Robins, R.J., Walton, N.J. (1993) The biosynthesis of tropane alkaloids. In: The alkaloids, in press, Cordell, G.A. ed., Academic Press, Orlando
Robins, R.J., Parr, A.J., Payne, J., Walton, N.J., Rhodes, M.J.C. (1990) Factors regulating tropane alkaloid production in a transformed root culture of a Datura Candida x D. aurea hybrid. Planta 181, 414–422
Robins, R.J., Parr, A.J., Bent, E.G., Rhodes, M.J.C. (1991a) Studies on the biosynthesis of tropane alkaloids in Datura stramonium transformed root cultures. 1. The kinetics of alkaloid production and the influence of feeding intermediate metabolites. Planta 183, 185–195
Robins, R.J., Bachmann, P., Robinson, T., Rhodes, M.J.C., Yamada, Y. (1991b) The formation of 3 α -and 3 β -acetoxytropanes by Datura stramonium transformed root cultures involves two independent acetyl-CoA-dependent acyl transferases. FEBS Lett. 292, 293–297
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We are most grateful to J. Eagles (I.F.R., Norwich) for GC/MS analysis, to colleagues at I.P.B.P. and I.F.R. for helpful discussions, to the technical staff (Chemistry, Glasgow) and to W. Millar (Chemistry, Glasgow) for assistance with the reduction of TBON. This work was, in part, supported by a grant to B Dräger from the Deutsche Forschungsgemeinschaft (Dr227/I-I). The research reported here was supported by an Academic Research Collaboration Cooperative Award (project No. 215) from the British Council and the Deutscher Akademischer Austauschdienst to R.J. Robins and B. Dräger.
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Dräger, B., Portsteffen, A., Schaal, A. et al. Levels of tropinone-reductase activities influence the spectrum of tropane esters found in transformed root cultures of Datura stramonium L.. Planta 188, 581–586 (1992). https://doi.org/10.1007/BF00197052
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DOI: https://doi.org/10.1007/BF00197052