Bombykol

Pheromones—hormonal substances that animals and some other organisms emit to attract or warn other members of their species—are well known today. But it has been only ≈60 years since they were first discovered and characterized. Bombykol, a sex pheromone released by female silkworm moths such as Bombyx mori and B. mandarina, was the first one to be studied thoroughly.

The pioneering work on bombykol was done by Adolf Butenandt and his co-workers at the Max Planck Institute of Biochemistry (Munich). He named the molecule after the silkworm genus, determined its structure, synthesized it, and demonstrated that its effects duplicated those of the natural product. Twenty years before his work on bombykol, he was awarded the 1939 Nobel Prize in Chemistry for his research on other sex hormones.¹

From Butenandt’s time until now, much research has been done on the biochemistry of bombykol:

• In 1987, Tetsu Ando and colleagues at the Tokyo University of Agriculture and Technology elucidated its biosynthetic pathway.
• In 1995, Shogo Matsumoto and co-workers at the Institute of Physical and Chemical Research (RIKEN) (Saitama, Japan) reported a biosynthesis of the compound outside of silkworm cells.
• In 1999, Jon Clardy and coauthors at Cornell University (Ithaca, NY) and the National Institute of Sericultural and Entomological Sciences (Tsukuba Science City, Japan) determined the structure of the protein in the male B. mori that binds bombykol emitted by the female.

Finally, in 2020, Jean-François Dufrêche and collaborators at the University of Montpellier Marcoule (Bagnols-sur-Cèze, France) and CNRS–University of Tours (France) proposed a theory for how pheromone molecules are transported in an atmosphere that contains aerosols—even though many pheromones are hydrophobic. They used bombykol as a model compound in their study.

1. Butenandt was affiliated with the Nazi party, which damaged his reputation in the years after World War II.