Using UPLC-LTQ-Orbitrap-MS and HPLC-CAD to Identify Impurities in Cycloastragenol, Which Is a Pre-Clinical Candidate...

Area of Science:

• Pharmacology and Natural Products Chemistry
• Medicinal Chemistry
• Drug Development

Background:

• Chronic obstructive pulmonary disease (COPD) is a leading global cause of mortality.
• Cycloastragenol (CAG), derived from Astragali radix, is a promising pre-clinical candidate for COPD treatment.
• Efficient large-scale production and comprehensive impurity profiling are crucial for drug development.

Purpose of the Study:

• To establish an efficient large-scale synthesis of Cycloastragenol (CAG).
• To identify and characterize impurities present in CAG Active Pharmaceutical Ingredient (API).
• To evaluate the anti-inflammatory potential of novel impurities and propose degradation pathways.

Main Methods:

• Large-scale synthesis of CAG via Smith degradation from astragaloside IV (AS-IV).
• Impurity profiling using HPLC-CAD and UPLC-LTQ-Orbitrap-MS due to weak UV absorption.
• Isolation and structural elucidation of impurities using column chromatography, PTLC, and spectroscopic analysis.

Main Results:

• CAG was efficiently produced on a 2.5-kg scale.
• Fifteen impurities were identified from CAG API, with 6 fully elucidated and 9 putatively identified.
• Two novel 10,19-secocycloartane triterpenoids (compounds 9 and 14) exhibited anti-inflammatory activity.

Conclusions:

• The study provides a scalable method for CAG production and a comprehensive impurity profile.
• Identification of bioactive impurities aids in quality control and clinical safety assessment of CAG API.
• Proposed degradation pathways offer guidance for managing compounds with poor UV absorption characteristics.