ABSTRACT
Illicium verum (Chinese star anise) and I. anisatum (Japanese star anise) are closely-related species whose star-shaped seeds contain shikimic acid, which was used in the synthesis of the anti-influenza medication oseltamivir. Illicium anisatum grows in the College Garden. Oseltamivir (Tamiflu) was approved by the US Food and Drug Administration for the treatment of influenza in adults in 1999, and by the European Medicines Agency in 2002. Oseltamivir phosphate is synthesised from oseltamivir epoxide which itself can be synthesised in a number of steps from either shikimic acid or quinic acid. Oseltamivir reduces replication of the influenza virus by inhibiting a viral enzyme, neuraminidase, which is necessary for the release of viral progeny from infected host cells. Oseltamivir phosphate is rapidly absorbed from the gastrointestinal tract and converted by liver enzymes (esterases) to the active metabolite.
