Chemical Forums
Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: Akutni on April 09, 2023, 08:34:17 AM
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This is the usual structure of biliverdin – https://commons.m.wikimedia.org/wiki/File:Biliverdin3.svg#mw-jump-to-license
But I've encountered this image – https://cs.m.wikipedia.org/wiki/Soubor:Biliverdin.png
Why is the structure different?
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The only structural difference that I have seen so far is the difference in protonation states. Is that what you mean?
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No idea how to understand the X in place of double bond - I think it potentially does make the other structure an isomer of the basic structure. Not that it makes much sense, it is a product of a heme metabolism, so I would expect it to retain the basic symmetrical structure..
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My eye passed over that. I have seen such an "X" once or twice before, and I assumed that it was a double bond. In other words, I assumed that the "X" was an anomaly of the drawing program, yet I am not 100% certain.
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The crosses in the double bonds usually mean either it doesn't matter; or that the double bond is defined but it is not known whether it is E or Z