Synthesis and spectroscopic properties of carotenoid bis-phenylhydrazone astaxanthin : extending conjugation to a C=N group
We report on the synthesis and detailed spectroscopic characterization of bis-phenylhydrazone astaxanthin (BPH-Asx), a derivative of astaxanthin (Asx), in which the conjugated carbonyl group of Asx is replaced by a conjugated C N bond. BPH-Asx was successfully synthesized and characterized using various spectroscopic techniques, revealing subtle changes in absorption spectra and significant altera