Chemically speaking, this molecule is "midway" between Sorbitan Oleate and Sorbitan Trioleate, indicating that it's also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but in a ratio of two:3 that's why the "Sesqui" section from the molecule's title. It's also a potent antioxidant and