The History of Skunk Defensive Secretion Research

Abstract

The striped skunk (Mephitis mephitis) is widely known for the highly odoriferous defensive secretion it uses to repel predators. Chemists have sporadically investigated the chemical composition of this secretion for many years. In this research, a number of chemicals have been incorrectly attributed to this secretion and the errors incorporated into the chemical literature. The major component in skunk spray was erroneously believed to be l-butanethiol, until it was later shown that the actual compound was (E)-2-butene-l-thiol. More recently, two studies identified the third major compound in the secretion as either (E)-2-butenyl methyl disulfide or (E)-2-butenyl propyl sulfide. These structural assignments were incorrect and the compound was later shown to be (E)-2-butenyl thioacetate. Two investigations have reported chemicals that could not be confirmed in a later study, so these compounds may have been artifacts produced during isolation or analysis. The striped skunk’s secretion is similar to, but different from, the defensive secretions of two other skunk species, the spotted skunk (Spilogale gracilis) and the hog-nosed skunk (Conepatus mesoleucus).

Folklore asserts that tomato juice will neutralize the odor of skunk spray, but human olfactory fatigue can explain the apparent disappearance of the odor on sprayed pets. The odoriferous thiols in skunk spray can easily be neutralized by oxidation to sulfonic acids.