Star Anise – Tamiflu’s Vital Ingredient
Star anise, from China and Vietnam, has been known in the West for several centuries as a cooking spice and as an ingredient in anise-flavored liquors like Pernod. Now it has a new use – as the base for Roche’s bird flu drug Tamiflu.
In fact, star anise has a long history in Chinese herbal medicines, being used to treat such ailments as colic in babies, stomach aches and indigestion. When brewed as a tea it helps clear breathing passages. In women it has been prescribed to facilitate birth and increase lactation.
Unfortunately, the plant takes six years to flower, and it is difficult to cultivate. One estimate is that 10 years would be needed to produce sufficient quantities to treat just 20% of the world’s population.
An excellent article on Tamiflu and star anise is at the Common Dreams website:
The herb from which Tamiflu is made is grown in four provinces in China and "huge quantities" of its seeds are needed, according to the Swiss pharmaceutical manufacturer Roche. It is harvested by local farmers between March and May, purified and the shikimic acid extracted at the start of a 10-stage manufacturing process which takes a year. Only star anise grown in the four provinces of China is suitable for manufacture into Tamiflu and 90 per cent of the harvest is already used by Roche.
The article also details the production process:
Once shikimic acid is extracted from the seeds of star anise it is converted to epoxide in a process requiring three chemical steps carried out at low temperature on seven separate sites. The most dangerous part of the process involves the conversion of epoxide into azide in a reaction that produces highly explosive material. This is carried out by specialist companies that handle the material in small quantities to reduce the risk of explosion. Currently only one US company and two European companies are approved by the drug regulatory authorities in America and Europe to carry out the process. The final step involves the production of crystal strands of the active ingredient of Tamiflu, whose chemical name is oseltamivir, which are vacuum dried and converted to capsules.
Another useful article is at the Everything2.com website. It warns against trying to use star anise itself or products derived from the spice to combat bird flu.
Stocking up on Pernod as a remedy against the avian flu would be a grave mistake (pun intended)….The shikimic acid in your glass of Pernod may, together with its ethanol, calm you down and unrealistically allay your fears in the face of a flu pandemic, but it won't harm the H5N1 virus in the least. The extract it contains is just a distant raw material for the active drug itself.
October 25th, 2005