anethole

Star anise

What do star anise and flu pandemics have in common?
Sit tight, and let’s find out.

Star anise is an 8-pointed seed pod that looks like … wait for it … a star. The “anise” part of the name comes from its flavour, similar to that of the anise plant. The two aren’t actually related; they just have a that licorice-y chemical compound in common. It’s a Chinese plant, and is one of the 5 ingredients of Chinese 5 Spice mix (along with cloves, cinnamon, fennel and Sichuan pepper).

The licorice flavour comes from a chemical called anethole, which is used to give flavour to liquors like Galliano, Ouzo, sambuca and absinthe. Much like myself, it loves alcohol. Its hydrophobic nature means it can’t be dissolved in water unless it’s first dissolved in alcohol. But when you add water, it creates a microemulsion (a mixture of two liquids that don’t want to mix, like oil and water). The resulting beverage is milky white, which you’ll be familiar with if you’ve ever added water to Ouzo.

If the thought of flaming sambuca shots makes your mouth water, don’t worry, you don’t need to get into a 12-step program. A drug commonly used to treat the dry mouth that patients experience while undergoing chemotherapy is derived from anethole.

So, back to the flu.
The other chemical compound that star anise is rife with is shikimic acid. It’s a very important compound that’s a precursor for a lot of other important biological compounds in nature; it’s an important building block. And it’s a huge building block for the drug company Roche, as the main ingredient in their anti-flu drug Tamiflu.

It’s so important to Tamiflu production that 90% of the Chinese star anise harvest goes to Roche, and that any shortage in star anise can actually cause a bottleneck in production. This was the case in the flu outbreaks in 2005 and 2009 as the world scrambled to stockpile doses (anyone remember swine flu?), and the price of star anise skyrocketed. It takes 13 g of star anise to make 1.3 g of shikimic acid, which can be turned into 10 Tamiflu capsules.

As a result of the worldwide shortages and panic over not having enough Tamiflu doses, scientists have uncovered a few alternative ways to extract shikimic acid from bacteria or pine needles. Necessity is the mother of invention, but the most efficient way is still to get it from star anise.

So there you have it!
I knew that mysterious little pod would have some delightful secrets to share, and it just so happens that they involve two of my favourite things: booze and drugs.