Identification and Total Synthesis of Two Previously Unreported Odd-Chain Bis-Methylene-Interrupted Fatty Acids with a Terminal Olefin that Activate Protein Phosphatase, Mg/Mn-Dependent 1A (PPM1A) in Ovaries of the Limpet .

Diverse non-methylene-interrupted (NMI) fatty acids (FAs) with odd-chain lengths have been recognized in triacylglycerols and polar lipids from the ovaries of the limpet , however their biological properties remain unclear. In this study, two previously unreported odd-chain NMI FAs, (12)-12,16-heptadecadienoic () and (14)-14,18-nonadecadienoic () acids, from the ovary lipids of were identified by a combination of equivalent chain length (ECL) values of their methyl esters and capillary gas chromatography-mass spectrometry (GC-MS) of their 3-pyridylcarbinol derivatives. On the basis of the experimental results, both and were synthesized to prove their structural assignments and to test their biological activity. The ECL values and electron impact-mass (EI-MS) spectra of naturally occurring and were in agreement with those of the synthesized and . In an in vitro assay, both and activated protein phosphatase, Mg/Mn-dependent 1A (PPM1A) up to 100 μM in a dose-dependent manner.