X-Message-Number: 29872 Date: Mon, 1 Oct 2007 09:32:38 -0700 (PDT) From: Subject: membrane permeability to organic compounds J Drug Target. 1996;4(2):103-7. QSAR analysis of membrane permeability to organic compounds. Ren S, Das A, Lien EJ. University of Southern California, School of Pharmacy, Department of Pharmaceutical Sciences, Los Angeles 90033, USA. A general mathematical model involving partition coefficient, molecular weight and hydrogen bonding is used to correlate the structures and permeability of various organic compounds through the toad urinary bladder and human red blood cell (RBC) membranes. Log Per (permeability) is correlated with log Po/w (partition coefficient in olive oil/water, or ether/water), log MW (molecular weight) and Hb (hydrogen bonds). Log Po/w is the most important factor among three parameters examined. While increased MW always has a negative effect on the permeability, increased Hb can have either a slightly positive or a slightly negative effect depending on the solvent and membrane systems used. Systematic comparison of the QSAR's (quantitative structure activity relationship) of different biological membranes may serve as a useful guide in drug targeting to different tissues and cell types. PMID: 8894970 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=29872