Lipophilic properties

Knowledge of the spatial dimensions of a molecule is insufficient to imderstand the details of complex molecular interactions. In fact, molecular properties such as electrostatic potential, hydrophilic/lipophilic properties, and hydrogen bonding ability should be taken into account. These properties can be classified as scalar isosurfaces), vector field, and volumetric properties. 

Alcohol fractionation redistributes the phosphoHpids according to their respective hydrophilic and lipophilic properties (13). A process to produce fractionated phosphoHpids with a phosphatidylcholine (PC) content of more than 30% and a PC/PE (phosphatidylethanolamine) quotient of ca 4 has been developed. With this process it is possible to produce 1000 t per year. 

The acid dissociation constants (p/iT 2.7), equilibrium solubilities in several solvents (71JPS503) and lipophilicity properties (77JPS1675) for various penicillins have been summarized. 

Persistent or semi-persistent metabolites of compounds with lipophilic properties. 

Polyamide is available commercially as polyamide-6 (based on e-aminocapro-lactam, Macherey-Nagel) and as polyamide-11 (based on 11-aminoundecanoic acid, Merck). The lipophilic properties of these are different, thus altering their chromatographic selectivity. 

Amphiphilic (Section 19.5) Possessing both hydrophilic and lipophilic properties within the same species. 

By structural complementarity, dicationic l,4-diazabicyclo[2.2.2]octane (VII) provides an appropriate recognition site for phosphate ions and two stearyl side chains attached to the amines add lipophilic properties 59,60). Such a carrier model can selectively extract nucleotides from aqueous solution to chloroform solution via lipophilic salt formation. The order of nucleotide affinity is ATP > ADP > AMP. The selectivity ratios were 45 for ADP/AMP and 7500 for ATP/AMP at pH 3. The relative transport rate was ATP > ADP > AMP. The ratios were 60 for ATP/AMP and 51 for ADP/AMP. The modes of interaction of ADP and ATP are proposed to be as shown in Fig. 6. 

Adapalene (Table 1), a new highly stable naphtoic acid arotinoid with lipophilic properties, does not bind to CRABP, although it enhances its synthesis, and its rank-order of retinoid receptor affinity apears to be RAR(3 > RARy > > RARa. 

Mc2Sn(cap) and Et2Sn(cap) do not affect the embryonic development Bu2Sn(cap) and Bu2Sn(cap) exert toxic activity on C. intestinalis embryos in the early stages of development. This toxicity is concentration-dependent and is related to the lipophilic properties of the complexes. Cytotoxic... 

Ghose, A. K., Viswanadhan, V. N., Wendoloski,).). Prediction of hydrophobic (lipophilic) properties of small organic molecules using fragmental methods an analysis of... 

Neutral molecules show a range of retention properties between those of acids and bases. Progesterone membrane retention is very high in all cases. Griseofulvin and carbamazepine retention steeply increase with phospholipid content. The patterns of retention follow the lipophilicity properties of the molecules, as indicated by octanol-water apparent partition coefficients (Table 7.4). 

Schaper, K.-J., Simultaneous determination of electronic and lipophilic properties [pKa, P(ion), P(neutral)] for acids and bases by nonlinear regression analysis of pH-dependent partittion measurements, J. Chem. Res. (S) 357 (1979). 

In light of their high lipophilic properties, many OC compounds and some of their metabolites are detectable in adipose tissue however, this method cannot be applied to monitor occupationally exposed subjects on a routine basis because of the invasive nature of the sampling procedures. Because intact OC compounds and their metabolites are commonly found in blood and urine of the general population, comparison with appropriate reference groups or with individual pre-exposure values is recommended when surveying occupationally exposed workers. 

Due to their lipophilic properties, hormones tend to be divided up between the liquid and solid phases, making sorption an important parameter for hormone elimination from the liquid phase of sewage. In laboratory studies based on an... 

The patterns of retention follow the lipophilicity properties of the molecules, as indicated by octanol/water apparent partition coefficients. 

The incorporation of O-bridges or A-bridges into [n]polynorbomanes afforded molecules which had the potential to display unusual polarity since the top face that contained the heterobridges exhibited hydrophilic properties and the endo-i ce retained the lipophilic properties of the [n]polynorbomane. 

There are pharmacokinetic differences among /1-blockers in first-pass metabolism, serum half-lives, degree of lipophilicity, and route of elimination. Propranolol and metoprolol undergo extensive first-pass metabolism. Atenolol and nadolol have relatively long half-lives and are excreted renally the dosage may need to be reduced in patients with moderate to severe renal insufficiency. Even though the half-lives of the other /J-blockers are much shorter, once-daily administration still may be effective. /J-Blockers vary in their lipophilic properties and thus CNS penetration. 

The lipophilic properties of disulfoton suggest that the compound is likely to be absorbed readily by the lungs, gastrointestinal tract, and the skin. Toxicokinetic data in humans and animals show that disulfoton is readily and extensively absorbed by the gastrointestinal tract. Disulfoton and/or its... 

Analogous gel matrices of liquid crystalline lamellar phases can also be formed with nonionie mesogens, such as the combination of cetyl/stearyl alcohol and ethoxy-lated fatty alcohol, provided that the hydrophilic and lipophilic properties of the surfactant molecules are more or less balanced to favor the formation of lamellar structures. 

Hafkenscheid, T.L. and Tomlinson, E. Relationships between hydrophobic (lipophilic) properties ofbases and their retention in reversed-phase liquid chromatography using aqueous methanol mobile phases. J. Chromatogr. A, 292(2) 305-317, 1984. 

TBBPA concentrations in human plasma in the low ng/g lipids range have been reported (Table 2). Concentrations and detection frequency of TBBPA in adipose tissue are even lower due to the relatively low lipophilic properties of TBBPA ( ow = 5), and the metabolic fate of this BFR. 

Fig. 5.8 Analysis of marketed oral drugs and their lipophilic properties.

Analysis of the Hansch descriptors illustrates that increasing the lipophilicity property for this series of compounds will increase the bioactivity in a more dramatic fashion than increasing the Tafts steric parameter. Increasing the water accessible surface area (MOE descriptor) will increase the bioactivity of the compounds. But there is more than just adding lipophilicity and water accessible surface area to the molecules to increase binding affinity. A comparison of the substituents to the bioactivities illustrates that the bulkier X and Y groups increase bioactivity in conjunction with atomic partial charge distribution of the substituents. 

Especially in the case of high-molecular-weight surface-active substances (such as proteins), the period of change may be sufficiently prolonged to allow easy observation. This arises because proteins are surface active. All proteins behave as surface-active substances because of the presence of hydrophilic-lipophilic properties imparted from the different polar, such as glutamine and lysine, and apolar, such as alanine, valine, phenylalanine, isovaline, amino acids. Proteins have been extensively investigated as regards their polar-apolar characteristics as determined from surface activity. 

The plots of log k vs. log P w and the plots of log k (v) vs. log k (z) were studied for seven cephalosporins. A linear relationship was obtained in micellar solution and in microemulsion solution (Tables 3 and 4). The results obtained indicate that the capacity factor determined by EKC could be used both as parameter to characterize the partition behavior of drugs in ME and MC and as hydrophobic parameter instead of log Pow. k appears to be an evident parameter, and it shows a better diversification than P w. In the 1-octanol/water system, we did not found high values of the partition coefficients. In contrast, the ME systems used provide a better characterization of the drugs according to their hydrophilic/lipophilic properties. 

As In the case of the examples given in Tables I and III, the N-thiocarbamate derivatives were generally equal to the parent methylcarbamate in toxicity to house flies, particularly after taking into consideration Increase in molecular weights. Except for the methomyl and oxan l derivatives, substantial improvement in mosquito larvlcldal activity again appeare d to be a function of the lipophilic properties of the derivative. With the exception of the oxanyl derivatives, the data clearly indicate that the N-thiocarbamate derivatives are markedly less toxic to the white mouse than the parent methylcarbamate. Since... 

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