InChi key question

According to
http://www.iupac.org/inchi/download/index.html

Caffeine has InChIKey=RYYVLZVUVIJVGH-UHFFFAOYAW
i.e., the flag character is "A".

Using the latest Marvin I got

InChIKey=RYYVLZVUVIJVGH-UHFFFAOYSA-N

Why is the difference? Thanks.

Okay, what JChem generated is Standard InChiKey, which is different from the InChi Key I got from IUPAC web site. Never mind then, I need to do some homework to understand the difference of the two.

Hi,

We have not reimplemented the InChIKey, we are just calling the original IUPAC software (with minor modification to be able to call via JNI) so it would be surprising if the result was different.

I've tried out caffeine with the original software, and Marvin too, the result in both cases:

InChIKey=RYYVLZVUVIJVGH-UHFFFAOYSA-N

I can not reproduce Your other result with any options.

Peter

Yes, both are correct. The short one is the "InChi Key", and the longer one is the "Standard InChi Key".