Despite the same thermodynamic parameters of berberine and palmatine inclusion, the latter compound was encapsulated in and set free from CB7 much slower due to the more substantial steric hindrance.  The most rapid entry into CB7 and the most exothermic binding were found for epiberberine and coptisine, the alkaloids substituted with the less spacious dioxole ring on their isoquinoline moiety.
THERM