Chemically speaking, this molecule is "midway" involving Sorbitan Oleate and Sorbitan Trioleate, this means that it's also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but within a ratio of 2:three that's why the "Sesqui" component from the molecule's identify. A very multi-practica