Abstract
Little is known about the greening reaction of chlorogenic acid with amino acid in alkaline conditions. The isolation and characterization of the pigment were attempted by using ethyl caffeate and methylamine instead of chlorogenic acid and amino acid. The green compounds were purified by using Sephadex G-10 and thin layer chromatography, and were analyzed by ESR and C-13 MNR. The ESR spectrum of F3 (corresponding to purified pigment) in a liquid state showed that the structure of the C-OH moiety seemed to give either the quinone type or its polymerized form. The ESR spectrum of F3 in a solid state showed that the g-value of this fraction was 2.003. On the basis of the C-13 NMR spectrum, the signals assigned to two carbons (C1" and C-2") of the alcohol moiety of ethyl caffeate were observed clearly in F3. Considering the chemical shift of C-1 in ethyl caffeate, the C-1 in F3 could exist as -C=N-CH3. F3 seemed to be a precursor of the greening compound.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
