[milansavic]

Greetings, good people, I am in need of *delete me* My girl has a tattoo and won't tell me what it is, so far i have narrowed it down to aminoacids, nitrocyclopenthane, I guess... I have absolutely no knowledge of chemistry and any kind of help is welcome. The link bellow is the pic. I apologize if this is not the right place to post such questions, but I am out of ideas. Thank you all in advance and best of luck in all your future endeavours.

Best regards,
Milan

[Borek]

Broadly speaking it is a peptide - you will need to determine each amino acid separately and then try to google for the systematic name (which will be basically a list of amino acids,something like Cys-Gly-His and so on). Chances are even googling for a partial name will give some leads.

[Corribus]

Based on residue search in BLAST database, it is the first (or last, depending on your perspective) 11 amino acids of corticoliberin. Basically a small part of a small protein.

https://pubchem.ncbi.nlm.nih.gov/compound/70678714

(The sequence shown in SEEPPISLDLT)

EDIT: It's a stress hormone. Maybe she's trying to tell you something.

[wildfyr]

Nice work Corribus!

OP, is she a biochemist or something like that? The tattoo is quite free of errors and isn't some mainstream science or psychedelic crap.

[Babcock_Hall]

Two minor nit picks.  The C-terminal threonine residue is in the form of an amide, but it needs a second hydrogen atom.  There is an extra proton on the side-chain of the aspartate residue.

[wildfyr]

Agh youre right. Still pretty good for such a complex structure when the tattoo artist has no idea what they are doing. The amide can be fixed, probably stuck with the extra proton on the O

[Corribus]

Two minor nit picks.  The C-terminal threonine residue is in the form of an amide, but it needs a second hydrogen atom.

Actually it just needs another bond trailing off to whatever, because the peptide keeps going (there's about 30 more residues - I guess she ran out of arm!). I agree though, the protonated carbonyl is going to have to be lived with.

[milansavic]

First of all, thank you for your feedback. She has a masters in pharmacy, and has had the tattoo for a couple of years before we met. I asked and it's not the stress hormone mentioned above. I asked a chemistry teacher in my local school and was told that the sequence is SEEPPISLELQ, hopefully that means something to you guys, but she can't tell me anything else without an "special organic chemistry book" that is impossible to find.  Don't really know what to do, I guess it's too much work to figure it out, so maybe I should accept that I'l never know! Again, thank you for replying me, best of everything to all of you!

[Borek]

Apparently there is whole family of hormones (not only in humans) that can start with SEEPPISL: Handbook of Stress and the Brain Part 1: The Neurobiology of Stress.

[Elric82]

I just saw this same picture over on ScienceMadness

[Arkcon]

People often go to multiple online places with a question.  Since that post has the exact same login name and question text, that's pretty likely.

You can also search our forums for "tattoo" -- its a common topic here as well.