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On the structure of endogenous ouabain

Open access
Kawamura, Akira, Guo, Jinsong, Itagaki, Yasuhiro, Bell, Charles, Wang, Yi, Haupert, Garner T., Magil, Sheila, Gallagher, Rex T., Berova, Nina, Nakanishi, Koji·1999·Proceedings of the National Academy of Sciences

Abstract

The ouabain-like sodium pump inhibitor in mammals (so-called “endogenous ouabain”) has been considered a subtle structural isomer of ouabain. Its structural investigation, however, has long been hindered by the paucity of sample material. Our recent purification of endogenous ouabain (3 μg) from bovine hypothalamus allowed the measurement of its 1 H-NMR. The obtained spectrum as well as reexamination of past microscale structural studies on endogenous ouabain led us to identify the purified material as ouabain in an unusual manner. It turned out that the structural analysis had been complicated by a facile ouabain–borate complexation in borosilicate glassware. In retrospect, it is not surprising that the polyhydroxylated ouabain molecule serves as a polydentate ligand to inorganic species. In its physiological environment, ouabain may exist as some unknown complex. The chemical species giving rise to the reported biological activities of hypothalamic inhibitory factor preparations remain to be clarified.

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Metadata

Authors
Kawamura, A., Guo, J., Itagaki, Y., Bell, C., Wang, Y., Haupert, G. T., Magil, S., Gallagher, R. T., Berova, N., & Nakanishi, K.
Venue
Proceedings of the National Academy of Sciences
Published
1999-06-08
Volume
96
Issue
12
Pages
6654-6659
ISSN
  • 0027-8424 (ISSN-L)
  • 1091-6490
OpenAlex
W1996613222
Cited by
198
References
0
FWCI
3.59
Type
journal article
Language
en
Open access
green

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CoChat. (2026). Citation check: On the structure of endogenous ouabain. https://app.cochat.ai/papers/10.1073/pnas.96.12.6654
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Kawamura, A., Guo, J., Itagaki, Y., Bell, C., Wang, Y., Haupert, G. T., Magil, S., Gallagher, R. T., Berova, N., & Nakanishi, K. (1999). On the structure of endogenous ouabain. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.96.12.6654

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