[akuhl101]

Hi all,

Been struggling with this one and hoping an expert can assist me, appreciate any help I can get!

Alpha-Methyl-L-tyrosine vs Alpha-methyl-P-tyrosine. they have the same chemical formula but different CAS registry numbers: does that mean they are isomers and not identical molecules?

Alpha-methyl-p-tyrosine has CAS # 658-48-0 https://en.wikipedia.org/wiki/AMPT
α-Methyl-L-tyrosine has CAS # 672-87-7 https://www.sigmaaldrich.com/catalog/search?term=672-87-7&interface=CAS%20No.&N=0&mode=partialmax&lang=en&region=US&focus=product

Thank you again!
Andrew

[AWK]

AMPT is a racemate
cf. https://wiki2.org/en/Metirosine 

[sjb]

Based on the text of the wiki article for AMPT at this time alone (https://en.wikipedia.org/w/index.php?title=AMPT&oldid=765832635 ) I think AMPT is the racemate, and "AMLT" is a specific enantiomer. But two caveats -

• the fact that AMPT is in evaluation for its pharmacological effects makes me think this may also be a specific enantiomer (whether it is the same, I don't know at this time)
• you can have lots of CAS numbers for the same compound