C. Parini et al., SOLID-STATE INTERACTION OF STEROIDS WITH CALIXARENES .1. A PRELIMINARY FTIR AND DSC STUDY ON 4-EN-3-KETO-STEROIDS, Journal of inclusion phenomena and molecular recognition in chemistry, 18(4), 1994, pp. 341-351
Both DSC and FTIR studies indicate that co-grinding and co-precipitati
on cause steroids to interact with calixarenes. This interaction leads
to breaking of the crystal lattice of the steroids, dispersion of the
steroidal carbonyls in a hydrophobic environment and formation of hyd
rogen bonds between steroidal and calixarene hydroxyls. This interacti
on seems to be specific, depending on the structure of the calixarene
and of the steroid involved. It is reasonable to assume that inclusion
complexes are formed.