Chemically Talking, this molecule is "midway" between 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 two:three for this reason the "Sesqui" aspect inside the molecule's title.   It may operate as