The free energy profile in Fig. from our REUS calculation for absorption into an organic phase suggest that there is a ¡ 0.5 kcal mol -1 difference between the membrane bound state and organic phase. Moreover, the barrier to desorbing from the membrane is smaller in Fig. than it was in the equivalent desorption profile in Fig. , suggesting that perhaps sorgoleone could span the space between membrane and the organic phase above it.