Solubilization basic side chain

Solubilization with basic side chains involves two essential strategies either direct binding of the amine function on a carbon atom of the parent molecule, or linking it to a function already present alcoholic or phenolic hydroxyl, carboxylic acid, amine or amide. 

In the search for water-soluble derivatives of the tranquillizer and anticonvulsant diazepam, scientists from Roche imagined an original solubilization approach, based on the attachment of a basic side chain to the ring-opened diazepam molecule (Figure 38.17). 

FIGURE 38.15 Solubilization by means of basic side chains. 

Animal glues are derived by the hydrolysis of the protein constituent collagen of animal hides and bones. Collagen in its natural state is water insoluble and must be conditioned to solubilize the protein. Collagen molecules are triple helices of amino acid sequences and contain both nonpolar and charged acidic and basic side chains. The conversion of... 

The size of the solubilizing chain is one of the selection parameters. The chains can be limited to the strict minimum and simply represent functional groups, or they can be made from larger residues containing several atoms (Table 36.2). The nature of the side chains is the second selection parameter. It has to be decided if they can be ionizable (acidic or basic) or non ionizable. 

The preparation and availability of suitable soluble polymer supports are basic requirements for the successful application of liquid-phase synthesis of peptides and nucleotides. Many parameters have to be considered when designing appropriate supports and the route of synthesis and the target product of synthesis must also be considered. Liquid-phase synthesis requires optimum solubility properties of the polymer supports and therefore the adaption of the functional capacity to the solubilizing power of the polymer backbone and side-chains is the determining step before synthesis. The main factors of evaluation are the solubility characteristics of the polypeptide or oligonucleotide to be synthesized. 

---