Cyclochlorotine is a secondary metabolite of the fungus Penicillium islandicum that causes hepatic necrosis and has carcinogenic properties. It is listed as an IARC Group 3 carcinogen.

Chemically, it is a chlorinated

Chlorine

Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

 macrocyclic

Macrocycle

A macrocycle is, as defined by IUPAC, "a cyclic macromolecule or a macromolecular cyclic portion of a molecule." In the chemical literature, organic chemists may consider any molecule containing a ring of nine or more atoms to be a macrocycle...

 pentapeptide derived from the amino acids 3-phenyl-β-alanine, serine

Serine

Serine is an amino acid with the formula HO2CCHCH2OH. It is one of the proteinogenic amino acids. By virtue of the hydroxyl group, serine is classified as a polar amino acid.-Occurrence and biosynthesis:...

, dichloroproline, and aminobutyric acid

Aminobutyric acid

Aminobutyric acid may refer to any of three isomeric chemical compounds:* α-Aminobutyric acid* β-Aminobutyric acid* γ-Aminobutyric acid...

.

Although tributyltin

Tributyltin

Tributyltin compounds are a group of compounds containing the 3Sn moiety, such as tributyltin hydride or tributyltin oxide. They are the main active ingredients in certain biocides used to control a broad spectrum of organisms...

(TBT) was recently found to induce apoptosis in different immune cells.