Theoretical study of the complexation of amphotericin B with sterols.

The aim of this present work was the study of the intermolecular complexes between amphotericin B (AmB) and either cholesterol or ergosterol. In such complexes the intermolecular interaction energy mainly proceeds from both Van der Waals and H-bonding (via water molecules) forces. Our calculations have shown that the Van der Waals forces slightly favor the AmB-ergosterol complex. Several relative positions of the sterol with regard to AmB lead to energy minima: sterol may be either in contact with the AmB polar head or repelled towards the end of the macrolide ring. It appeared that the role played by some water molecules was to maintain the sterol close to the AmB polar head.