Aplidine
Encyclopedia
Aplidine, also known as dihydrodidemnin B, is a chemical compound
extracted from the ascidian
Aplidium albicans. It is currently undergoing clinical trial testing. It is a member of the class of compounds known as didemnins.
, meaning it is a cyclic peptide
in which there is one or more ester
bond in place of one or more of a peptide bond. Its chemical structure is very close to that of didemnin B, the only difference being that the lactate
residue in didemnin B is present in the oxidized pyruvate version.
and immunosuppressive
activities. It shows promise in shrinking tumors in pancreatic, stomach, bladder, and prostate cancers. As of 2007, it was undergoing multicenter phase II clinical trials. In July 2003, aplidine was granted orphan drug
status by the European Medicines Agency
for treating acute lymphoblastic leukemia
.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
extracted from the ascidian
Ascidiacea
Ascidiacea is a class in the Tunicata subphylum of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of the polysaccharide tunicin, as compared to other tunicates which are less rigid.Ascidians are found all over the world, usually in shallow...
Aplidium albicans. It is currently undergoing clinical trial testing. It is a member of the class of compounds known as didemnins.
Chemical structure
Aplidine is a cyclic depsipeptideDepsipeptide
A depsipeptide is a peptide in which one or more of the amide bonds are replaced by ester bonds.Depsipeptides have often been used in research to probe the importance of hydrogen bond networks in protein folding kinetics and thermodynamics. They are also found in nature as natural products...
, meaning it is a cyclic peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
in which there is one or more ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
bond in place of one or more of a peptide bond. Its chemical structure is very close to that of didemnin B, the only difference being that the lactate
Lactic acid
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...
residue in didemnin B is present in the oxidized pyruvate version.
Pharmacological activity
Like all didemnin compounds, it exhibits antitumor, antiviralAntiviral drug
Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...
and immunosuppressive
Immunosuppression
Immunosuppression involves an act that reduces the activation or efficacy of the immune system. Some portions of the immune system itself have immuno-suppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reaction to treatment of other...
activities. It shows promise in shrinking tumors in pancreatic, stomach, bladder, and prostate cancers. As of 2007, it was undergoing multicenter phase II clinical trials. In July 2003, aplidine was granted orphan drug
Orphan drug
An orphan drug is a pharmaceutical agent that has been developed specifically to treat a rare medical condition, the condition itself being referred to as an orphan disease...
status by the European Medicines Agency
European Medicines Agency
The European Medicines Agency is a European agency for the evaluation of medicinal products. From 1995 to 2004, the European Medicines Agency was known as European Agency for the Evaluation of Medicinal Products.Roughly parallel to the U.S...
for treating acute lymphoblastic leukemia
Acute lymphoblastic leukemia
Acute lymphoblastic leukemia is a form of leukemia, or cancer of the white blood cells characterized by excess lymphoblasts.Malignant, immature white blood cells continuously multiply and are overproduced in the bone marrow. ALL causes damage and death by crowding out normal cells in the bone...
.