Oseltamivir total synthesis concerns the total synthesis of the antiinfluenza drug oseltamivir[1] marketed by Hoffmann-La Roche under the trade name Tamiflu. Its commercial production starts from the biomolecule shikimic acid harvested from Chinese star anise and from recombinant E. coli.[2][3] Control of stereochemistry is important: the molecule has three stereocenters and the sought-after isomer is only 1 of 8 stereoisomers.[citation needed]