Trilinolenin, also known as glyceryl trilinolenate, is a highly polyunsaturated triacylglycerol (TAG) composed of three α-linolenic acid (ALA, C18:3 cis-9,12,15 n-3) chains esterified to a glycerol backbone. This lipid is characteristic of flaxseed, chia, and perilla oils, where it represents approximately 50–65% of total TAG content. As one of the most unsaturated TAG species, trilinolenin provides significant omega-3 biological potential but is highly susceptible to oxidative degradation.
Chemical Structure
Trilinolenin has the molecular formula C57H92O6 and a molecular weight of 873.34 g/mol. Each linolenoyl chain contains three cis double bonds located at Δ9,12,15, generating pronounced conformational kinks and increasing the number of bis-allylic sites. These structural features enhance membrane fluidity but also promote rapid autoxidation. Predicted collision cross section (CCS) values used in ion mobility spectrometry include 316.4 Ų for [M+Na]+ and 317.9 Ų for [M+NH4]+.
Physical Properties
Trilinolenin is typically a yellow, low-melting liquid with a melting point around −23°C. Its density is approximately 0.94 g/mL, and its boiling point is estimated near 814°C. It is insoluble in water but soluble in organic solvents such as chloroform and ethanol. Due to its extreme unsaturation and oxidative instability, storage under nitrogen atmosphere at −80°C is recommended.
Biological Functions
Upon hydrolysis by lipases, trilinolenin releases α-linolenic acid, which serves as a precursor for the biosynthesis of long-chain omega-3 fatty acids such as EPA and DHA, although conversion efficiency remains limited (~5–10%). Through downstream pathways, trilinolenin-derived metabolites contribute to resolvin production, supporting anti-inflammatory processes, membrane dynamics, and cardiovascular protection via LDL stabilization. However, its high peroxidation susceptibility may also increase ferroptosis-related oxidative stress under certain conditions.