Reference Standard
| CAS Number | Not assigned |
| Formula | C₄₄H₆₇NO₁₂ |
| Molecular Weight | ~802 g/mol |
| Purity | ≥95% |
| Storage | Store at −20 °C; avoid light exposure |
A stereochemical and unsaturation-related impurity of tacrolimus involving epimerization at C-4 and diene formation.
Used as an impurity reference standard for stability and degradation studies of tacrolimus.
Analyzed by HPLC, LC-MS, NMR, and comparison with tacrolimus reference profiles.
