Figure 5.
Structure Elucidation of the Maresin Conjugates in Tissue Regeneration: Evidence for MCTR1 and MCTR2. Using several lines of evidence to interrogate the physical properties of the bioactive structures isolated from self-resolving infectious exudates, that included the incorporation of radiolabeled DHA, deuterium incorporation and methyl-ester derivatives as well as Rainey Nickel desulfurization and UV chromophores we established that the molecules carried a DHA backbone with conjugated triene double bond systems that was allylic to a peptide containing an auxochrome such as sulfur. Using these lines of evidence the structures were assigned as 13R-glutathionyl, 14S-hydroxy-4Z,7Z,9E,11E,13R,14S,16Z,19Z-docosahexaenoic acid for MCTR1, and 13R-cysteinylglycinyl, 14S-hydroxy-4Z,7Z,9E,11E,13R,14S,16Z,19Z-docosahexaenoic acid for MCTR2. These mediators are evolutionary conserved and their production was established in organisms as diverse as planaria, mice and humans.