Molecule properties affecting solubility

The use of highly fluorinated side-chain groups that are insulated from reaction centers in order to exploit their unique influence upon the solubility properties of the molecule without affecting the chemistry of the functional groups has spawned a new subfield of fluorine chemistry... 

Another property of proteins which is important in the understanding of the limits of their catalytic activity, as well as being useful in their recovery, is solubility. The solubility of globular proteins in aqueous solution is enhanced by weak ionic interactions, including hydrogen bonding between solute molecules and water. Therefore, any factor which interferes with this process must influence solubility. Electrostatic interactions between protein molecules will also affect solubility, since repulsive forces will hinder the formation of insoluble aggregates08. ... 

We found that the adsorbed PA molecules slightly affect the structure of silicon core. The PA adsorption does not change the optical properties of SiQDs, while it substantially decreases the ionization potentials in the excited state and results in some new active orbitals with adjacent energies around the Fermi energy level. Accordingly, the modified surface of SiQDs can serve as a reaction substrate to oxygen and solvent molecules, which is responsible for the increase in both PL stability and water solubility. 

Solubility enhancement by use of cyclodextrins is achieved for a number of drug substances, an approach of interest in formulation of drugs for topical, parenteral, and oral use (Stella and Rajewski, 1997 Loftsson and Masson, 2001 Qi and Sikorski, 2001). The solubilizing effect can be extensive even in low concentrations of cyclodextrin. The use of 0.1 M sulfobutyl-ether-P-cyclodextrin increases the solubility of prednisolone acetate and testosterone by a factor of 426 and 2020, respectively (Myrdal and Yalkowsky, 2002). Cyclodextrin encapsulation of a molecule will affect many of its physicochemical properties (Loftsson, 1995). As a result of complexation, solubility, pKa value, spectral properties, and the chemical reactivity of the included substance will change. The cyclodextrins are known to affect molecular orientation and to have an influence on rates and efficiency of electron transfer, excited state proton transfer, and rate of decomposition (Chattopadhyay, 1991 Fox, 1991 Sur et al., 2000). Cyclodextrins can also be used in combination with liposomes a cyclodextrin-liposome entity represents an even more complex environment to the drug molecule (Loukas et al., 1995). 

Thrombin, the two-chain derivative of the prothrombin molecule, has a molecular weight of approximately 37,000 daltons. Its proteolytic properties induce the conversion of fibrinogen to fibrin to produce the initial visible manifestation of coagulation, the soluble fibrin clot. In addition, thrombin influences the activity of Factors V, VIII, and XIII and plasmin. Thrombin affects platelet function by inducing viscous metamorphosis and the release reaction with subsequent aggregation. 

The forces between molecules are strongly affected by the presence of molecular dipoles. Two molecules that possess molecular dipoles tend to attract each other more strongly than do molecules without dipoles. One of the most important results of this is found in solvent properties. Table 17-IV shows some solubility data of... 

---