Outline how oseltamivir (Tamiflu^®) works.

Oseltamivir was commercially produced from shikimic acid, a precursor which is a metabolite in micro-organisms and plants.

Outline how green chemistry was used to develop the precursor for oseltamivir in order to overcome a shortage of the drug during the flu season.

Suggest why the administration of antibiotics to humans and animals can affect the environment.

«drug» blocks/inhibits «viral» enzyme/neuraminidase/NA «activity»

prevents virus from leaving/escaping host cells «thus cannot infect other cells»

[2 marks]

ALTERNATIVE 1:
«using» genetically modified/GM E. Coli/bacteria/microorganisms

E. Coli/bacteria biosynthesis
OR
E. Coli/bacteria «overfed by glucose» undergo fermentation
OR
cells of the bacteria «are broken down to» form precursor/shikimic acid

ALTERNATIVE 2:
use readily available cyclic ester/lactone

forms «the correct stereoisomer of oseltamivir» in a shorter number of chemical steps

Do not accept “planting more Chinese star anise” or “other plant sources of shikimic acid”.

[2 marks]

«can develop antibiotic» resistance in bacteria/microorganisms
OR
changes in microbial/bacterial population

Accept secondary effects, such as reduced biodiversity of aquatic/soil ecosystems, denitrification of soil (due to decline in nitrogen-fixing bacteria). No mark for just stating “water contamination”.

No mark for just stating “failure of aquatic/marine environment”.

[1 mark]