Small molecule

Small molecule

In pharmacology, a small molecule is a small organic compound that is biologically active (biomolecule) but is not a polymer. This term is very loosely used and it may or may not include monomers or primary metabolites, in fact it is generally used to denote molecules that are not protein which play a endogenous or exogenous biological role, such as cell signalling, are used as a tool in molecular biology or are a drug in medicine.

These compounds can be natural (such as secondary metabolites) or artificial (such as antiviral drugs); they may have a beneficial effect against a disease (such as FDA approved drugs) or may be detrimental (such as teratogens and carcinogens).


Most drugs are small molecules, although some drugs can be proteins, e.g. insulin. Many proteins are degraded if administered orally and most often cannot cross the cell membrane. This is often not the case for small molecules, some though of which are orally available as a Prodrug. Many dietary supplements are small molecules (but not herb extracts, such as ginkgo).

econdary metabolites

For organisms to produce small molecules they need one or more specialized enzymes (to create and destroy), which as a result are not that abundant in vertebrates (recent and small + slow population size), but very common in soil bacteria (such as streptomyces) and fungi, which in particular secrete antibiotics.

Plants also have several secondary metabolites, which play a role in cell signalling, pigmentation or in defence, several of which have also been used as drugs (medical and recreational).

*Nonribosomal peptides, such as actinomycin-D
*Terpenes, including steroids

Investigative tools

Enzymes and receptors are often activated or inhibited by endogenous protein, but can be also inhibited by endogenous or exogenous small molecule inhibitors or activators with can bind to the active site or on allosteric site.

An example is the teratogen and carcinogen phorbol 12-myristate 13-acetate which is a plant terpene which activates protein kinase C resulting in cancer, making it a very useful investigative tool. Voet and Voet (1995) Biochemistry, 2nd ed., John Wiley & Sons, Inc., New York, NY] There is also interest in creating small molecule artificial transcription factors to regulate gene expression, examples include wrenchnol (a wrench shaped molecule). [cite journal |author=Koh JT, Zheng J |title=The new biomimetic chemistry: artificial transcription factors |journal=ACS Chem. Biol. |volume=2 |issue=9 |pages=599–601 |year=2007 |month=September |pmid=17894442 |doi=10.1021/cb700183s |url=]

ee also

* Chemical compound microarray
* Chemogenomics
* Peptidomimetic


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • small molecule — Mit dem englischsprachigen Begriff small molecule (deutsch kleines Molekül, niedermolekulare Verbindung) wird in der Pharmakologie und Biochemie eine niedermolekulare Klasse von Wirkstoffen bezeichnet, deren Molekülmasse etwa… …   Deutsch Wikipedia

  • Small molecule anti-genomic therapeutics — Small molecule anti genomic therapeutics, or SMAT, refers to a biodefense technology that targets DNA signatures found in many biological warfare agents. SMATs are new, broad spectrum drugs that unify antibacterial, antiviral and anti malarial… …   Wikipedia

  • Discovery and development of small molecule c-Met inhibitors — The c Met (mesenchymal epithelial transition) tyrosine kinase stimulates cell scattering, invasion, protection from apoptosis and angiogenesis.[1] c Met is a receptor tyrosine kinase,[2] which can cause a wide variety of different cancers, such… …   Wikipedia

  • small molecule drug — noun A medicinal drug compound having a molecular weight of less than 1000 daltons, and typically between 300 and 700 daltons …   Wiktionary

  • Molecule (Brand) — Molecule is a brand of fabric care products manufactured by Molecule Labs in Benicia, California. Molecule Technical Fabric Care System is designed to clean, protect, and refresh Nomex and other technical fabrics. Nomex is a flame resistant… …   Wikipedia

  • Molecule — 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane A molecule (pronounced  …   Wikipedia

  • Molecule mining — This page describes mining for molecules. Since molecules may be represented by molecular graphs this is strongly related to graph mining and structured data mining. The main problem is how to represent molecules while discriminating the data… …   Wikipedia

  • Molecule Man — Promotional Artwork Publication information Publisher Marvel Comics …   Wikipedia

  • Small-angle neutron scattering — (SANS) is a laboratory technique, similar to the often complementary techniques of small angle X ray scattering (SAXS) and light scattering. These are particularly useful because of the dramatic increase in forward scattering that occurs at phase …   Wikipedia

  • Small interfering RNA — (siRNA), sometimes known as short interfering RNA or silencing RNA, is a class of 20 25 nucleotide long double stranded RNA molecules that play a variety of roles in biology. Most notably, siRNA is involved in the RNA interference (RNAi) pathway …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”