Lipophyllic molecules

Largely lipophyllic molecules of carotenoids are well miscible with lipids (Borel et al, 1996) and like lipids they are well soluble in most organic solvents (some carotenoids require special solvent mixtures to yield efficient solubilization with lipids). This property of both lipids and carotenoids is most frequently applied to prepare carotenoid-pigmented model lipid membranes. It involves the evaporation of a carotenoid lipid mixture followed by the hydration of a thin dry film. There are several different... 

The first step uses a 66 kDa albumin-like molecule as carrier (VNPr-U), from which the acidic conditions of the trank mucus (VNPr-D) will detach the urinary ligands. The carriers in the trank contents are additional OBPs which then preferentially bind the lipophylic ligands (L) released from their urinary vehicle. Once deposited at the VN-duct entrance, a third transporter (VNPr-D) completes the final movement into the organ (Rasmussen, pers. comm., 2001). 

As mentioned earlier, fullerene molecules can destroy the virions, but do not affect living cells. It is possible to suppose that the differences of the structures of virion envelope and cell membrane are the main reason for this phenomenon the outer side of virion envelope is enriched with protein molecules, whereas the outer side of cell membranes is more lipophylic. On the one hand, fullerene molecules can interact with proteins (Belgorodsky et al., 2006), and on the other hand, their penetration into a lipid bilayer does not destroy them (Ikeda et al., 2005 Piotrovsky, 2006). So it is not unlikely that the difference in the structure of outer side is the main driving force of the observed differences in the response of virions and cells in the presence of C60. 

The anti-inflammatory activity of curcumin and its derivatives is associated with the hydroxyl and phenol groups in the molecule, which are also essential for the inhibition of prostaglandins, PG synthetase and leucotriene synthesis (LT) (Kiuchi et al., 1982, 1992 Iwakami, et al, 1986). Claeson et al. (1993, 1996) suggested that the antiinflammatory action and the antiparasitic activity were associated with the (3-dicarbo-nylic system with conjugated double bonds (dienes) (Araujo et al., 1998, 1999). The better skin penetration and lipophylicity is attributed to the presence of a diene ketone system. Calebin-A, a novel curcuminoid isolated from turmeric, protects neuronal cells from (3-amyloid insult. The hydroxy group at para-position of this compound is most critical for the expression of biological activity (Kim et al., 2001). 

One method to gauge the lipophylic versus hydrophilic character of chemicals is to determine their relative solubility in a lipid-like medium (i.e., octanol) and water. Thus, the log P (if experimentally determined, it is referred to as the Mlog P if calculated, it is the Clog P) is the logarithm of the relative concentration of a molecule dissolved in an octanol versus water (logarithmically related to free energy). For example, a log P value of 0.5 indicates that in a separatory funnel containing 1 mole total of a substance, the ratio of concentrations in octanol... 

There is a universal desire in drug discovery to increase water solubility or, actually, to decrease hydrophobic ty. Many of the lead compounds produced, particularly by combi-chem, tend to be far too lipophylic. In fact, most small organic molecules are not very soluble in water. Nevertheless, many chemists think that because SFC mobile phases are nonaqueous, their compounds will not be soluble and SFC will not work for them. 

For most chemicals, exposure occurs primarily through ingestion, inhalation, or dermal contact. The entire amount of chemical exposure will not cross the membranes with 100% efficiency. Bioavailability is defined as the portion of the total quantity of concentration of a chemical that is available for biological action. If the availability of the molecule can be decreased, the amount of chemical at the site of action is thereby decreased, which leads to decreased toxicity. Bioavailability depends on the hydrophilic-lipophylic balance, its stability on exposure to alkali or acidic conditions, its stability in the presence of body enzymes, and so on. So knowledge of biochemistry and pharmacokinetics is essential in determining safety measures. 

Intercalation of amphiphilic molecules or polymers into the alkenyl chains of the stabilising ligands. This approach is based on hydrophobic forces that force the lipophylic (= hydrophobic) part(s) of the amphiphilic molecule or polymer into the hydrophobic monolayer on the nanoparticles. The hydrophilic parts then make these nanoparticles water dispersible. This method has been reported using PEG-oleate [25] and derivatised PM AO [poly (maleic anhydride-afi-octadecene)] [26-29]. 

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