Researchers at John Innes Centre have shed light on how catnip produces nepetalactone, the terpene that sends cats into a state of wanton abandon. This simple, small molecule is part of an unusual chain of events, not previously seen by chemists, according to the team.
The researchers believe that understanding the production of these nepetalactones could help them recreate the way that plants synthesize other chemicals like vinblastine, which is used for chemotherapy. This could lead to the ability to create these useful medicines more efficiently and quickly than we are currently able to harvest them from nature.
In their paper published online this week in Nature Chemical Biology, the researchers report that in catnip, terpenes are formed in a two-step process; an enzyme activates a precursor compound which is then grabbed by a second enzyme to produce the substance of interest. This two-step process has previously never been observed, and the researchers also expect something similar is occurring in the synthesis of anti-cancer drugs vincristine and vinblastine from Madagascan periwinkle, Catharanthus roseus, and elsewhere in olive and snapdragon.
In the publication, the team described the process by which catmint produces nepetalactone in microscopic glands on the underside of its leaves. The study also identifies three new enzymes with unusual activity.
"We have made significant progress in understanding how catnip makes nepetalactones, the chemicals that sends cats crazy. Catnip is performing unusual and unique chemical processes, and we plan to use these to help us create useful compounds that can be used in treatment of diseases such as cancer. We are also working to understand the evolution of catnip to understand how it came to produce the cat-active chemicals," explained Benjamin Lichman, who conducted the work while a post-doc at John Innes Centre and who is now a lecturer at the University of York.
Image: Catnip’s intoxicating highs are caused by nepetalactone, a type of chemical called a terpene. Image courtesy of John Innes Centre.