Enediyne
Encyclopedia
Enediynes are a class of bacterial natural product
s characterized by either nine- and ten-membered rings containing two triple bond
s separated by a double bond
. Many of these compounds are capable of undergoing Bergman cyclization
. The resulting diradical
, a 1,4-dehydrobenzene derivative, is capable of abstracting hydrogen atoms from the sugar backbone of DNA which results in strand scission. This high reactivity with DNA makes the substances toxic. They are being researched as antitumor agents. Several of the naturally occurring enediynes have entered clinical trials against cancer and in Japan neocarzinostatin
is used clinically.
Three classes of enediynes exist:
The enediyne group in those compounds is often called a warhead.
Natural product
A natural product is a chemical compound or substance produced by a living organism - found in nature that usually has a pharmacological or biological activity for use in pharmaceutical drug discovery and drug design...
s characterized by either nine- and ten-membered rings containing two triple bond
Triple bond
A triple bond in chemistry is a chemical bond between two chemical elements involving six bonding electrons instead of the usual two in a covalent single bond. The most common triple bond, that between two carbon atoms, can be found in alkynes. Other functional groups containing a triple bond are...
s separated by a double bond
Double bond
A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electrons instead of the usual two. The most common double bond, that between two carbon atoms, can be found in alkenes. Many types of double bonds between two different elements exist, for example in...
. Many of these compounds are capable of undergoing Bergman cyclization
Bergman cyclization
The Bergman cyclization or Bergman reaction or Bergman cycloaromatization is an organic reaction and more specifically a rearrangement reaction taking place when an enediyne is heated in presence of a suitable hydrogen donor . It is named for the American chemist Robert George Bergman...
. The resulting diradical
Radical (chemistry)
Radicals are atoms, molecules, or ions with unpaired electrons on an open shell configuration. Free radicals may have positive, negative, or zero charge...
, a 1,4-dehydrobenzene derivative, is capable of abstracting hydrogen atoms from the sugar backbone of DNA which results in strand scission. This high reactivity with DNA makes the substances toxic. They are being researched as antitumor agents. Several of the naturally occurring enediynes have entered clinical trials against cancer and in Japan neocarzinostatin
Neocarzinostatin
Neocarzinostatin is a macromolecular chromoprotein enediyne antibiotic with anti-tumoral activity secreted by Streptomyces macromomyceticus....
is used clinically.
Three classes of enediynes exist:
- CalicheamicinCalicheamicinThe calicheamicins are a class of enediyne antibiotics derived from the bacterium Micromonospora echinospora, with calicheamicin γ1 being the most notable. It was isolated originally from a rock collected by a Scripps Research Institute chemist while hiking in Waco, Texas. It is extremely toxic to...
/esperamicinEsperamicinThe esperamicins are a class of bacteria-derived chromoprotein enediyne antibiotics, of which esperamicin A1 is the most well studied. Esperamcin A1 and the related enediyne calicheamicin are the two most potent antitumor agents known. The esperamicins are extremely toxic DNA splicing... - Dynemicin Dynemicin ADynemicin A is an anti-cancer enediyne drug. It displays properties which illustrate promise for innovative cancer treatments, but still requires further research.-History and background:...
- ChromoproteinChromoproteinChromoprotein: A conjugated protein, sulch as hemoglobin, that contains a pigmented prosthetic group, such as hem in hemoglobin . Other examples of chromoprotein are: myoglobin, cytochromes and flavoproteins.In hemoglobin:...
types
The enediyne group in those compounds is often called a warhead.