ZWITTERION

‘Zwitterion’ comes from the German word ‘zwitter,’ which means ‘hybrid’ or ‘hermaphrodite.’ An ion with both positive and negative electrical charges is known as a zwitterion. Because the net formal charge of zwitterions is usually zero, they are electrically neutral.

ZWITTERION:

A zwitterion is a molecule with both positive and negative charge areas. Zwitterions are amino acids that exist as dipolar ions in a solid state. The pH range must be supplied to determine whether or not a chemical is zwitterionic. This is because in the presence of sufficient alkaline solution, the zwitterion becomes an anion, and in the presence of sufficient acid solution, the zwitterion becomes a cation.

THEORETICAL STUDIES:

The findings of theoretical computations can provide insight into the equilibrium in solution. In aqueous solution, for example, pyridoxal phosphate, a type of vitamin B6, is projected to favour a tautomeric form in which a proton is transferred from the phenolic -OH group to the nitrogen atom.

Because tautomers are different molecules, their structures are sometimes distinct enough that they can be recognised separately in a combination. This enables the equilibrium to be tested experimentally.

CONJUGATED ZWITTERION:

Conjugated zwitterions (strongly polarised conjugated substances) are often very reactive, have a diradical nature, activate strong bonds and tiny molecules, and act as transient intermediates in catalysis.  Photochemistry (photoinduced electron transfer), organic electronics, switching, and sensing all make extensive use of donor-acceptor entities.

AMINO ACID AS ZWITTERION:

In living cells, amino acids are the building blocks of proteins. They’re substances with an amino group as well as a carboxyl group in them. Proteins include twenty distinct amino acids. They have the same structure, with R representing one of the 20 potential amino acid side chains.Amino acid structure general structure of an amino acid structure of an amino

The amino group (-NH3+)has a positive charge at neutral pH, while the carboxyl group (COO-)has a negative charge. The simplest amino acid, glycine, in its zwitterion state looks like this:

CHARACTERISTICS OF ZWITTERION:

The following are some of Zwitterions characteristics:

1.Ampholytes, for example, can create it because their molecules include both acid and basic groups.

2.The charged atoms in this sort of ion are usually kept together by one or more covalent bonds.

3.In Zwitterionic Compounds, the atoms have stable, distinct unit electrical charges.

4.Quaternary ammonium cations are present in these substances.

ISOELECTRIC POINT:

The isoelectric point of Zwitterion is represented by pI, pH (I), and IEP. The pH value at which the charge in molecules is neutral is this point. The pH of the surrounding environment has a significant impact on a molecule’s net charge .In an acidic medium, the molecules get more positively charged by receiving electrons, whereas in a basic medium, they become more negatively charged. The amino group is the most efficient proton receptor, while the carboxyl group is the most active proton supplier in amino acids. Furthermore, the Pl value influences a molecule’s solubility at a certain pH. At the determined isoelectric point, aqueous solutions would have less to nil solubility. As a result, the pH at which a molecule’s zwitterion is created is referred to as the molecule’s cell point. The isoelectric point has an impact on a variety of molecular structures, including dissolving solutions.

CALCULATION OF pH VALUE:

The pH value at the isoelectric point is computed using the Zwitterion’s equilibrium constants, such as acid and base. The formula is used to express it.

(pKa1 + pKa2)/ 2 = pl

Where,

pI = point of isoelectricity,

Ka1=The acid’s equilibrium constant .

Ka2 = the base’s equilibrium constant.

APPLICATION OF ZWITTERION:

A zwitterion is commonly utilised in the SDS PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) method for separating protein molecules. This is one of the most widely used molecular biology techniques. They have a lot of potential in a variety of medical and scientific disciplines.

1.Biomedical applications of zwitterionic bioceramic

2.Medical implants, medicine administration, blood-sensing nerves, dissecting membranes, and biopsies that help minimize bacterial adhesions and biofilm formation are all common applications.

3.Zwitterionic polymers are used in the marine industry to prevent aquatic organisms from growing algae or moss on boats and pillars.

CONCLUSION:

Zwitterions are sometimes referred to as “inner salts.” Dipolar substances aren’t usually thought of as zwitterions. The positive and negative marks on the amine oxide imply formal charges, which explains why. When working with acid, basic, or neutral leads, zwitterions are useful in medicinal chemistry design concerns.