A foldamer, is a discrete chain molecule

Molecule

A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

 or oligomer

Oligomer

In chemistry, an oligomer is a molecule that consists of a few monomer units , in contrast to a polymer that, at least in principle, consists of an unlimited number of monomers. Dimers, trimers, and tetramers are oligomers. Many oils are oligomeric, such as liquid paraffin...

 that adopts a secondary structure

Secondary structure

In biochemistry and structural biology, secondary structure is the general three-dimensional form of local segments of biopolymers such as proteins and nucleic acids...

 stabilized by noncovalent interactions

Noncovalent bonding

A noncovalent bond is a type of chemical bond, typically between macromolecules, that does not involve the sharing of pairs of electrons, but rather involves more dispersed variations of electromagnetic interactions. The noncovalent bond is the dominant type of bond between supermolecules in...

. They are artificial molecules that mimic the ability of protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, nucleic acid

Nucleic acid

Nucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...

s, and polysaccharide

Polysaccharide

Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...

s to fold

Folding (chemistry)

In chemistry, folding is the process by which a molecule assumes its shape or conformation. The process can also be described as intramolecular self-assembly where the molecule is directed to form a specific shape through noncovalent interactions, such as hydrogen bonding, metal coordination,...

 into well-defined conformations, such as helices and β-sheet

Beta sheet

The β sheet is the second form of regular secondary structure in proteins, only somewhat less common than the alpha helix. Beta sheets consist of beta strands connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet...

s. Foldamers have been demonstrated to display a number of interesting supramolecular properties including molecular self-assembly

Molecular self-assembly

Molecular self-assembly is the process by which molecules adopt a defined arrangement without guidance or management from an outside source. There are two types of self-assembly, intramolecular self-assembly and intermolecular self-assembly...

, molecular recognition

Molecular recognition

The term molecular recognition refers to the specific interaction between two or more molecules through noncovalent bonding such as hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, π-π interactions, electrostatic and/or electromagnetic effects...

, and host-guest chemistry

Host-guest chemistry

In supramolecular chemistry, host-guest chemistry describes complexes that are composed of two or more molecules or ions that are held together in unique structural relationships by forces other than those of full covalent bonds. Host-guest chemistry encompasses the idea of molecular recognition...

. They are studied as models of biological molecules and have been shown to display antimicrobial

Antimicrobial

An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...

 activity. They also have great potential application to the development of new functional materials.

Examples:

• m-Phenylene ethynylene oligomers are driven to fold into a helical conformation by solvophobic forces and aromatic stacking interactions.
• β-peptides
  Beta-peptide
  β-peptides consist of β amino acids, which have their amino group bonded to the β carbon rather than the α carbon as in the 20 standard biological amino acids. The only commonly naturally occurring β amino acid is β-alanine; although it is used as a component of larger bioactive molecules,...
  
   are composed of amino acid
  Amino acid
  Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
  
  s containing an additional methylene
  Methylene
  Methylene is a chemical species in which a carbon atom is bonded to two hydrogen atoms. Three different possibilities present themselves:* the -CH2- substituent group: e.g., dichloromethane ....
  
   unit between the amine
  Amine
  Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
  
   and carboxylic acid
  Carboxylic acid
  Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
  
  . They are more stable to enzymatic
  Enzyme
  Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
  
   degradation and have been demonstrated to have antimicrobial activity.
• Peptoid
  Peptoid
  Peptoids, or poly-N-substituted glycines, are a class of peptidomimetics whose side chains are appended to the nitrogen atom of the peptide backbone, rather than to the α-carbons .-Chemical structure and synthesis:...
  
  s are N-substituted polyglycines that utilize steric interactions to fold into polyproline type-I-like helical structures.
• Aedamers that fold in aqueous solutions driven by hydrophobic and aromatic stacking interactions.
• Aromatic Oligomide Foldamers These examples are some of the largest and best structurally characterized Foldamers.

Important reviews