Background: The term chlorophyll c encompasses a small but heterogeneous
group of algal pigments, characterized for being porphyrins rather than chlorins. Chlorophylls
c are protochlorophyllide-type compounds that differ in their peripheral substituents.
Mass spectrometry has contributed to the structural elucidation of chlorophylls c,
often in parallel with the development of soft ionization techniques.
Objective: To provide comprehensive information on the structural characterization of
chlorophylls c by mass spectrometry.
Method: A detailed exam of the existing bibliography from both the chemical and marine
science literatures followed by the analysis of data on molecular masses and product ions.
Previous tandem mass spectra of chlorophyll c pigments are reproduced employing high resolution mass spectrometry.
Results: This article reviews the application of direct and tandem mass spectrometry techniques to the analysis
of acidic and esterified chlorophylls c, summarizes their fragmentation patterns and enumerates some experimental
fragmentation rules for their identification. The high resolution mass spectra of acidic and esterified
chlorophyll c compounds are shown as characteristic examples.
Conclusion: The combined information on the molecular mass and diagnostic fragmentation allows the unambiguous
characterization of the known acidic chlorophylls c, including the discrimination of isomeric pigments.
Tandem mass spectrometry is a technique of choice for the study of galactolipid-esterified chlorophylls
c, as the systematic fragmentation of successive parts in the molecules allows good tentative approaches to