What does “sitagliptin free base SMILES” mean?
“SMILES” is a text string that encodes a chemical structure. “Sitagliptin free base” refers to sitagliptin in its un-salt form (as opposed to sitagliptin salts used in medicines, such as sitagliptin phosphate).
To provide the correct SMILES, I need the specific sitagliptin free-base structure identifier you’re using (for example, a database entry like PubChem/CAS, or a salt/base form reference). Different curated sources sometimes represent the same compound with different tautomer/protonation conventions, which changes the exact SMILES string.
Can you share the source you’re using (PubChem ID, CAS, or salt name)?
If you paste any of the following, I can return the matching sitagliptin free-base SMILES exactly as that source defines it:
- PubChem CID (or link)
- CAS number for the free base (not the salt)
- The exact chemical name from your supplier/spec sheet
- The salt form you’re converting from (e.g., “sitagliptin phosphate”), plus what “free base” SMILES format you need
If you’re converting from sitagliptin phosphate, what should you watch for?
When moving from a salt to the free base, the anion (for example, phosphate) is removed. The SMILES for the free base will therefore differ from the SMILES of sitagliptin phosphate, even though the sitagliptin cation/core is the same. The key edge case is whether the source SMILES encodes a particular protonation state (neutral vs. protonated), which can change the string.
Quick way to get the exact SMILES you need
Tell me which of these you want:
- Neutral sitagliptin (un-ionized) free base SMILES
- The structure as represented in PubChem for “sitagliptin” (which may or may not explicitly encode protonation)
- A supplier-specific SMILES (from your SDS/COA)
If you reply with the PubChem link/ID or CAS for the free base, I’ll produce the exact sitagliptin free-base SMILES string.