Description

(E/Z)-Fk-506 26,28-Allylic Ester Rearrangement Impurity is a critical process-related impurity encountered during the synthesis of the potent immunosuppressant Tacrolimus (FK-506). This compound is essential for pharmaceutical research and development, specifically for method development, stability studies, and ensuring the purity and safety of the final active pharmaceutical ingredient (API). It is primarily required by analytical laboratories, quality control units, and R&D departments within the pharmaceutical and biotechnology sectors for impurity identification, quantification, and regulatory compliance.

Application

• Pharmaceutical Reference Standard: Serves as a certified reference material (CRM) for the identification and quantification of this specific impurity in Tacrolimus (FK-506) API and drug products.
• Analytical Method Development & Validation: Used to develop, optimize, and validate sensitive HPLC, UPLC, or LC-MS/MS methods for impurity profiling.
• Stability Indicating Studies: Employed in forced degradation studies to understand the degradation pathways of Tacrolimus and to establish stability-indicating methods.
• Quality Control & Batch Release: Critical for setting impurity specifications and for the routine quality control testing of Tacrolimus batches to meet ICH, USP, or EP guidelines.
• Regulatory Submissions: Provides necessary data and impurity samples for regulatory filings (e.g., FDA, EMA) to demonstrate control over the manufacturing process.
• Process Chemistry Research: Used by chemists to study and optimize the synthesis pathway of Tacrolimus to minimize the formation of this rearrangement impurity.

Basic Information

Product Name	(E/Z)-Fk-506 26,28-Allylic Ester Rearrangement Impurity
CAS No.	131944-48-4
Molecular Formula	C44H69NO12
Molecular Weight	804.0 g/mol
Synonyms	FK-506 26,28-Allylic Ester Rearrangement Isomer; Tacrolimus Allylic Ester Impurity; (23E)-33-[(1R,2R,3S,4R)-3,4-Dihydroxy-2-[(1E,3R,4S)-4-hydroxy-3-methyl-1-octen-1-yl]-1-methoxycyclohexyl]-1,14,23-trihydroxy-2,16-dimethoxy-5,7,9,13-tetramethyl-29-oxa-5-azatricyclo[22.3.1.04,9]octacos-18-ene-3,15,17-trione; Tacrolimus Related Compound F (potential designation); 26,28-Allylic Ester Isomer of FK-506
EINECS	Contact for details

Quality Control

Every batch of (E/Z)-Fk-506 26,28-Allylic Ester Rearrangement Impurity is manufactured and analyzed under strict quality management systems. Our products undergo rigorous identity, purity, and impurity profile testing using advanced analytical techniques such as HPLC, LC-MS, and NMR to ensure compliance with pharmaceutical reference standard requirements. A comprehensive Certificate of Analysis (COA) detailing batch-specific results is provided with each shipment.

Storage

Preserve in a tightly closed container, protected from light. Store at controlled room temperature (15-25°C) or as indicated on the label. This compound is hygroscopic (moisture-sensitive) and should be handled in a dry environment to prevent degradation. For long-term storage, consider desiccation.

Specification

Item	Specification
Appearance	White to off-white solid
Identification (HPLC)	Retention time corresponds to reference standard
Identification (IR)	Spectrum matches reference spectrum
Purity (HPLC)	≥ 95.0% (Area Percent)
Related Substances (HPLC)	Individual unknown impurity ≤ 1.0% Total impurities ≤ 5.0%
Water Content (KF)	≤ 5.0% w/w
Residual Solvents (GC)	Complies with ICH Q3C guidelines

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.