α-Linolenic acid ethyl ester-d is intended for use as an internal standard for the quantification of α-linolenic acid ethyl ester by GC- or LC-MS. α-Linolenic acid ethyl ester is an esterified form of α-linolenic acid (). It increases cyclin E levels and the activity of Cdk2/cyclin E, ERK, and JNK in hepatic stellate cells when used at a concentration of 50 μM. α-Linolenic acid ethyl ester (25 μg/ml) inhibits the growth of S. mutans, C. albicans, and P. gingivalis by 98, 72, and 92%, respectively, in vitro. It has been found in biodiesel produced from castor oil using ethanol. α-Linolenic acid ethyl ester has been used as a substrate in lipid peroxidation assays for antioxidant activity.