Of the several members in the GDCC host family , two have been used in several previous SAMPL challenges thanks to the Gibb group's participation. Those featured in previous SAMPL challenges include OctaAcid (OA) and tetra-endomethyl OctaAcid (TEMOA). A newer exo-OctaAcid (exo-OA) along with OA are part of the SAMPL7 host-guest blind challenge (Figure ). The guests for this system are diverse in their size and bulkiness, but typically have either a carboxylate or quaternary ammonium (Figure ). OA and exo-OA have a deep and hydrophobic basket-shaped pocket, and are fairly rigid . In total there are eight carboxylate groups in both OA and exo-OA. The propionate groups at the exterior site of the cavity are the same in both hosts.