Mass Spectrometry of Non-allomerized Chlorophylls a and b Derivatives from Plants

Background: Non-allomerized chlorophylls a and b are part of a great diversity of environments: senescent and ripened vegetal tissues, processed foods, sediments, fecal pellets, etc. Consequently, the articles characterizing their mass spectrometry behavior belong to a variety of disciplines. Objective: To compile in a single review all the information published related to mass spectrometry of 26 chlorophyll derivatives, including chlorophyllides, pheophorbides, pheophytins, and hydroxy-, lactone-, and pyro-chlorophyll derivatives. Method: A detailed and extensive bibliographic search through the Web of ScienceTM followed by a comprehensive and critic discussion. Results: This review gathers all the information concerning mass spectroscopic characteristics published for each non-allomerized chlorophyll of a and b series. This means that for each one of the 26 chlorophyll derivatives, it has been compiled the complete information published of mass (or exact mass), mass spectrometry technique and equipment (ionization method and mass analyzer), product ions, structural assignments and proposed mechanisms (if available), detailing the references. Conclusion: The evaluation of referenced data in literature has allowed to obtain common characteristics in the mass spectrometry behavior between the different chlorophyll derivatives. In addition, specific product ions have been reported, revealing specific structural modifications in the chlorophyll molecule, facilitating the structural characterization. This review embraces the application of predictive software tools, which improve accuracy of predictions and make straightforward the structural assignments.