Isolation and Structure Determination of Echinochrome A Oxidative Degradation Products.

Echinochrome A (Ech A, ) is one of the main pigments of several sea urchin species and is registered in the Russian pharmacopeia as an active drug substance (Histochrome), used in the fields of cardiology and ophthalmology. In this study, Ech A degradation products formed during oxidation by O in air-equilibrated aqueous solutions were identified, isolated, and structurally characterized. An HPLC method coupled with diode-array detection (DAD) and mass spectrometry (MS) was developed and validated to monitor the Ech A degradation process and identify the appearing compounds.