Display options
Cite
Ehmke A, von Borstel K, Hartmann T. Alkaloid N-oxides as transport and vacuolar storage compounds of pyrrolizidine alkaloids in Senecio vulgaris L. Planta. 1988;176(1):83-90doi: 10.1007/BF00392483.
Ehmke, A., von Borstel, K., & Hartmann, T. (1988). Alkaloid N-oxides as transport and vacuolar storage compounds of pyrrolizidine alkaloids in Senecio vulgaris L. Planta, 176(1), 83-90. https://doi.org/10.1007/BF00392483
Ehmke, A, et al. "Alkaloid N-oxides as transport and vacuolar storage compounds of pyrrolizidine alkaloids in Senecio vulgaris L." Planta vol. 176,1 (1988): 83-90. doi: https://doi.org/10.1007/BF00392483
Ehmke A, von Borstel K, Hartmann T. Alkaloid N-oxides as transport and vacuolar storage compounds of pyrrolizidine alkaloids in Senecio vulgaris L. Planta. 1988 Nov;176(1):83-90. doi: 10.1007/BF00392483. PMID: 24220738.
Copy Download .nbib Format: NLM
Share it on

Planta. 1988 Nov;176(1):83-90. doi: 10.1007/BF00392483.

Alkaloid N-oxides as transport and vacuolar storage compounds of pyrrolizidine alkaloids in Senecio vulgaris L.

Planta

A Ehmke, K von Borstel, T Hartmann

Affiliations

  1. Institut für Pharmazeutische Biologie der Technischen Universität Braunschweig, Mendelssohnstrasse 1, D-3300, Braunschweig, Federal Republic of Germany.

PMID: 24220738 DOI: 10.1007/BF00392483

Abstract

Cell-suspension cultures of pyrrolizidinealkaloid-producing species selectively take up and accumulate senecionine (sen) and its N-oxide (sen-Nox). Cultures established from non-alkaloid-producing species are unable to accumulate the alkaloids. The uptake and accumulation of (14)C-labelled alkaloids was studied using a Senecio vulgaris cell-suspension culture as well as protoplasts and vacuoles derived from it. The alkaloid uptake exhibits all characteristics of a carrier-mediated transport. The uptake of sen-Nox follows a multiphasic saturation kinetics. The Km-values for sen Nox of 53 μM and 310 μM are evaluated. Senecionine competitively inhibits sen-Nox uptake, indicating that the tertiary alkaloid and its N-oxide share the same membrane carrier. The N-oxide of sen shows a pH optimum below 5.5, whereas sen is taken up over a range from pH 4 to 8. Activation energies of 90 and 53 kJ·mol(-1) are calculated for sen-Nox and sen transport, respectively. At concentrations of 10 to 100 μM, sen-Nox is rapidly taken up by cells and protoplasts; within 2 h >90% of total N-oxide is within the cells. By contrast the uptake of sen is less efficient. Vacuoles isolated from protoplasts preloaded with sen-Nox totally retained the alkaloid N-oxide, whereas sen is rapidly lost during the procedure of vacuole preparation. N-oxidation converts the weak lipophilic tertiary base into a charged polar molecule which is excellently adapted to serve as the cellular transport and storage form of pyrrolizidine alkaloids.

References

  1. Lloydia. 1978 Sep-Oct;41(5):385-431 - PubMed
  2. J Org Chem. 1970 May;35(5):1721-2 - PubMed
  3. Xenobiotica. 1971 Jul-Oct;1(4):451-3 - PubMed
  4. Plant Cell Rep. 1987 Dec;6(6):466-9 - PubMed
  5. Plant Physiol. 1982 Nov;70(5):1335-40 - PubMed
  6. Plant Cell Rep. 1986 Feb;5(1):39-42 - PubMed
  7. Planta Med. 1986 Oct;(5):390-5 - PubMed
  8. Planta. 1986 Jan;167(1):44-53 - PubMed
  9. J Nat Prod. 1981 Mar-Apr;44(2):129-52 - PubMed
  10. Plant Physiol. 1985 Feb;77(2):398-402 - PubMed
  11. Stain Technol. 1972 Jul;47(4):189-94 - PubMed
  12. Fortschr Chem Org Naturst. 1982;41:115-203 - PubMed
  13. Plant Physiol. 1984 Jul;75(3):586-91 - PubMed
  14. Plant Physiol. 1980 Aug;66(2):261-6 - PubMed
  15. Plant Physiol. 1986 Feb;80(2):556-60 - PubMed
  16. Xenobiotica. 1971 Jul-Oct;1(4):419-47 - PubMed
  17. Plant Physiol. 1978 Dec;62(6):941-8 - PubMed
  18. Planta. 1984 Sep;162(3):250-60 - PubMed

Publication Types