Programmed cyclodextrin synthesis picks out specific molecule from 117,655 possibilities

Attaching a thioacetate orienting group to β-cyclodextrin has allowed chemists to attach seven different substituents to all seven of its identical sugar units, creating just one specific hepta-functionalised isomer out of the almost 200,000 possible.

Cyclodextrins are cyclic oligosaccharides made out of six (α), seven (β) or eight (γ) glucose subunits connected by glycosidic bonds. Despite being water-soluble, their centre is hydrophobic and big enough to host other hydrophobic molecules. This makes them popular in air fresheners like Febreeze, as they can trap foul-smelling molecules – once trapped in a cyclodextrin’s cavity, they can no longer be smelt. Cyclodextrins also help stabilise and solubilise drugs like hydrocortisone.