Pine nuts and other edible gymnosperm seeds contain unusual, bioactive polymethylene-interrupted polyunsaturated fatty acids (PMI-PUFAs), a subset of nonmethylene-interrupted PUFA with (-CH-) intervening between double bonds. Conventional methods for structure elucidation of PMI-PUFAs require special derivatization risking rearrangement artifacts. Here we introduce a facile solvent-mediated (SM) covalent adduct chemical ionization (CACI) system modified with a triple quadrupole MS, which distinguishes PMI-PUFAs from their analogues in direct methyl ester form. The prominent Δ5 desaturated PMI-PUFAs exhibit characteristic fragmentation at C to yield ω diagnostic ions and share their fragmentation pattern with normal methylene interrupted PUFAs for the α diagnostic ion. H transfer upon CID dissociation of PMI-PUFAs was found to be dependent on the relative position of isolated lone double bonds and cleavage points. Ginkgo and five species of pine nuts were characterized for their unique Δ5 fatty acid profile, without the need for chemical standards.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.analchem.0c00425 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Unusual polyunsaturated fatty acids in edible marine worms identified by covalent adduct chemical ionization mass spectrometry.
Food Chem
January 2025
School of Agriculture and Biotechnology, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China. Electronic address:
Non-traditional seafood, such as spoon worms (Urechis unicinctus) and peanut worms (Sipunculus nudus), serves as both delicacies and potential solutions to the global food insecurity crisis. Despite being consumed primarily in parts of China, Korea, and Japan, the nutritional values especially the complex fatty acid compositions of these marine worms are difficult to characterize. To overcome this obstacle, we employed covalent adduct chemical ionization (CACI) tandem mass spectrometry for the de novo identification of their unusual polyunsaturated fatty acids (PUFA).
View Article and Find Full Text PDFIdentification of Polymethylene-Interrupted Polyunsaturated Fatty Acids (PMI-PUFA) by Solvent-Mediated Covalent Adduct Chemical Ionization Triple Quadrupole Tandem Mass Spectrometry.
Anal Chem
June 2020
Dell Pediatric Research Institute, Depts of Pediatrics, of Chemistry, and of Nutrition, University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, Texas 78723, United States.
Pine nuts and other edible gymnosperm seeds contain unusual, bioactive polymethylene-interrupted polyunsaturated fatty acids (PMI-PUFAs), a subset of nonmethylene-interrupted PUFA with (-CH-) intervening between double bonds. Conventional methods for structure elucidation of PMI-PUFAs require special derivatization risking rearrangement artifacts. Here we introduce a facile solvent-mediated (SM) covalent adduct chemical ionization (CACI) system modified with a triple quadrupole MS, which distinguishes PMI-PUFAs from their analogues in direct methyl ester form.
View Article and Find Full Text PDFFractionated Antioxidant and Anti-inflammatory Kernel Oil from .
Molecules
September 2019
School of Advanced Agriculture and Bioengineering, Yangtze Normal University, Fuling 408100, Chongqing, China.
Polymethylene-interrupted polyunsaturated fatty acids (PMI-PUFAs) are emerging functional lipids with proven antioxidant and anti-inflammatory effects. In this study, a typical PMI-PUFA, sciadonic acid (C20:3, 5c 11c 14c), was enriched in the kernel oil of () by fractionation. Fractionated kernel oil of (containing 25% sciadonic acid) showed equal stability and similar radical scavenging ability compared with the non-fractionated oil.
View Article and Find Full Text PDFVariability of fatty acid profiles in ferns: Relation to fern taxonomy and seasonal development.
Phytochemistry
June 2019
Callaghan Innovation, PO Box 31310, Lower Hutt, 5040, New Zealand. Electronic address:
Ferns are known to contain long chain polyunsaturated fatty acids which may provide health benefits. The objective of this study was to investigate ferns of Pacific temperate regions (Far East of Russia and New Zealand) as sources of valuable fatty acids: arachidonic (20:4n-6) and eicosapentaenoic (20:5n-3). Fatty acids were analyzed in fronds of 23 fern species from 12 families.
View Article and Find Full Text PDFIsolation of two Δ5 polymethylene interrupted fatty acids from Podocarpus falcatus by countercurrent chromatography.
J Chromatogr A
May 2015
University of Hohenheim, Institute of Food Chemistry (170b), Stuttgart, Germany. Electronic address:
The lipids of gymnosperms frequently feature unusual polyunsaturated fatty acids (PUFAs) such as sciadonic acid (20:3Δ5,11,14) and juniperonic acid (20:4Δ5,11,14,17) showing a first double bond on C-5 which is separated from the next double bond by five methylene units. Compared to "classic" fatty acids, these fatty acids are not easily commercially available and their prices are quite high. For this reason, we wished to isolate those fatty acids from the seed oil of Podocarpus falcatus by countercurrent chromatography (CCC) after conversion of the fatty acids to methyl esters (FAMEs).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!