Chemically speaking, this molecule is "halfway" in between Sorbitan Oleate and Sorbitan Trioleate, that means that it's also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but in the ratio of 2:three as a result the "Sesqui" portion in the molecule's name. It's also a potent antioxida