Eq. 3 was used then to drive the diffusion of sorgoleone from membrane to organic phase. As before, the contacts number were calculated using non hydrogen atoms on sorgoleone and the heavy atoms in the head group and even carbons atoms of acyl tail of lipids. Equation 3 definition was applied using colvar module and utilized in SMD to move the sorgoleone molecule from membrane into the organic phase from 400 to -1000 contact number. Here 400 value represent sorgoleone in the membrane and the -1000 value represents sorgoleone complete absorption in the organic phase. In SMD simulation the sorgoleone was pulled with 0.01 kcal mol -1 contact -2 force constant over 15 ns. REUS simulations were performed using 96 replicas with force constant of 0.005 kcal mol -1 contact -2 to restraint sorgoleone on equally displace umbrellas from contact number -1000 to 400. Each replicate was run for 60 ns or 5.7µs in aggregate sampling.