AnionicForm of Usnic Acid Promotes Lamellar to NonlamellarTransition in DPPC and DOPC Membranes.

Usnic acid is a secondary metabolitefound in several species oflichens, organisms resulting from the symbiosis between fungi andalgae. This compound has been extensively studied because of its pharmacologicalproperties. Despite its potential medicinal importance, it exhibitsa high degree of toxicity. The confinement of the usnic acid withinliposomes has been investigated as a possibility to reduce its toxicity.In this work, we characterize the interaction of usnic acid in itsneutral and anionic states (usniate) with DPPC and DOPC by means ofmolecular dynamics simulations. A lamellar to nonlamellar transitionis observed for both membranes upon contact with usniate within 100ns time scale. The transition suggests the formation of a liposome-likestructure encapsulating the metabolyte. Furthermore, such processoccurs at a significantly shorter time frame for DOPC. [ABSTRACT FROM AUTHOR]