In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...
, a moiety ( ) is a part of a
molecule
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...
that is given a name because it is identified as a part of other molecules as well.
Typically, the term is used to describe the larger and characteristic parts of organic molecules, and it should not be used to describe or name smaller
functional group
In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...
s
of atoms that
chemically react in similar ways in most molecules that contain them.
Occasionally, a moiety may contain smaller moieties and functional groups.
A moiety that acts as a branch extending from the backbone of a
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...
molecule is called a
substituent
In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule.
The suffix ''-yl'' is used when naming organic compounds that contain a single bond r ...
or
side chain
In organic chemistry and biochemistry, a side chain is a substituent, chemical group that is attached to a core part of the molecule called the "main chain" or backbone chain, backbone. The side chain is a hydrocarbon branching element of a mo ...
, which typically can be removed from the molecule and substituted with others.
The term is also used in
pharmacology
Pharmacology is the science of drugs and medications, including a substance's origin, composition, pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. More specifically, it is the study of the interactions that occur betwee ...
, where an
active moiety is the part of a molecule responsible for the
physiological or pharmacological action of a
drug
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...
.
Active moiety
In
pharmacology
Pharmacology is the science of drugs and medications, including a substance's origin, composition, pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. More specifically, it is the study of the interactions that occur betwee ...
, an active moiety is the part of a molecule or ion—excluding appended inactive portions—that is responsible for the
physiological or pharmacological action of a
drug substance. Inactive appended portions of the drug substance may include either the alcohol or acid moiety of an
ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...
, a
salt
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...
(including a salt with
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
or
coordination bonds), or other
noncovalent derivative (such as a
complex
Complex commonly refers to:
* Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
** Complex system, a system composed of many components which may interact with each ...
,
chelate, or
clathrate
A clathrate is a chemical substance consisting of a lattice (group), lattice that traps or contains molecules. The word ''clathrate'' is derived from the Latin language, Latin (), meaning 'with bars, Crystal structure, latticed'. Most clathrate ...
).
The parent drug may itself be an inactive
prodrug and only after the active moiety is released from the parent in free form does it become active.
See also
*
Moiety conservation
*
Moiety, each of the two kinship groups in some Indigenous societies
*
References
{{reflist, 30em
Organic chemistry