Lipophilicity, molecular

Property-based descriptors, lipophilicity, molecular flexibility, PSA, and number of hydrogen-bond donors are the main parameters influencing the BBB permeability of compounds. 

Lipophilicity Molecular size Hydrogen bonding Ionization Melting point, crystal packing... 

Croizet, F., Langlois, M. H., Dubost, J. P., et al. (1990) Lipophilicity force field profile an expressive visualization of the lipophilicity molecular potential gradient.. /. Mol. Graph. 8, 149-53. 

In recent work within our laboratories, we have evaluated a number of unbonded silicas by CEC specifically for the separation of a range of pharmaceutically relevant basic analytes and mixtures. We purposefully chose strong basic analytes that comprised a wide range of lipophilicities, molecular weights and log P values to robustly test the separation systems. The basic analyte test mixture contained two AstraZeneca R D compounds, benzylamine, nortriptyline, diphenhydramine and procainamide. 

As permeability is a function of lipophilicity, molecular size, H-bonding capacity, and charge, and as charge is included in lipophilicity (log P) when the distribution... 

In summary, the equations of Tables II and III begin to sort out two general types of systems, each of which displays a different kind of nonspecific response to lipophilic molecular probes. 

There are, in addition to these simple functional group filters, a number of property-based filters that may be applied. These fdters take the form of calculated metrics, such as the Lipinski Rule of Five (LRoF Hydrogen-bond donors. Hydrogen-bond acceptors, Lipophilicity, Molecular weight). Solubility, total Polar Surface Area (tPS A), Blood-brain-barrier (BBB) Permeability, calculated metabolic filters (cADMET Absorption-Distribution-Metabolism-Excretion-Toxicity) and Bioavailability. 

Scientists at Bayer implemented traffic lights for the prioritization of molecules from the HTS hits. Their score is based on solubility, lipophilicity, molecular weight, Polar Surface Area (PSA), and number of rotatable bonds. 

In order to extend the CoMMA approach to account for the lipophilicity of the molecule, the - Leo-Hansch hydrophobic fragmental constants [Abraham and Leo, 1987] have been proposed as a set of atomic lipophilic weights for the calculation of lipophilic molecular multipole moments (hydropoles) [Burden and Winkler, 1999a]. 

Croizet, F., Langlois, M.H., Dubost, J.P., Braquet, P, Audry, E., Dallet, Ph. and Colleter, J.C. (1990). Lijwphilicity Force Field Profile An Expressive Visualization of the Lipophilicity Molecular Potential Gradient. J.Mol.Graphics, 8,153-155. 

Physicochemical drug properties, such as solubility, lipophilicity, molecular size and shape, charge and degree of ionisation, will affect the rate and route of permeation into the cornea. 

Lien EJ, Wang PH. Lipophilicity, molecular weight, and drug action reexamination of parabolic and bilinear models. J Pharm Sci 1980 69 648-650. 

FIG. 11 Schematic view of the designed photocatalytic systems with (a) transmembrane and (b) interfacial electron transfer, which is photosensitized by the CdS nanoparticles attached to the lipid membrane surface. Menaquinone (MQ) and heteropolyanions (HPA, SiWi20jo) are lipophilic molecular electron relays. Palladium particles are attached to CdS and operate as dark catalysts of hydrogen evolution from water. MV + methylviologen bication Gl glucose. 

Figure 6. The principal phase behavior of monotailed amphiphiles given by the clearing temperature T vs. the chain length n of the lipophilic molecular part. With increasing chain length liquid crystallinity appears (region A), reaches a maximum stability (plateau B), and vanishes (region C) in the case of very long substituents.

Distribution is the process by which an absorbed substance and/or its bio-transformation products circulate and partition within the body. The most important chemical characteristics that affect distribution are lipophilicity, molecular size and shape and degree of ionisation. Lipophilic, small, non-ionic molecules can diffuse readily across cellular membranes. Very low molecular, hydrophilic substances may diffuse through aqueous pores. A number of tissue parameters also affect tissue distribution, such as blood flow rate, the permeability of capillary and cell membranes and the nature of the extracellular fluid matrix. 

Physical-chemical properties of pesticides are fundamental in such dynamics, governing the processes of environment contamination, absorption, distribution, metabolism and finally excretion from the body. The most important parameters determining the fate of pesticides in the environment and the body are solubility, lipophilicity, molecular mass, charges and volatility. The reactivity to bind to proteins also influences the bioaccumulation process. 

In order to test for the role played by the lipophilic molecular moiety of ganglioside II%euAc-GgOsej -Cer, a number of derivatives were synthesized. They all carried the terminal Gal31- -3GalNAcBl ... 

M Hydrophilic molecular weight Mo Lipophilic molecular weight... 

---