Omacetaxine mepesuccinate (Molecule of the Month for April 2013)
Omacetaxine mepesuccinate is an alkaloid from Cephalotaxus harringtonia that is indicated for treatment of Chronic Myelogenous Leukemia. Cephalotaxus harringtonia, commonly known as Cowtail Pine or Japanese Plum Yew, is a coniferous bush or small tree in the plum yew family. It is native to Japan, but is occasionally utilised in western gardens and several cultivars exist for these purposes. Japanese plum yew has been in cultivation in Europe since 1829, many modern horticulturists are familiar with the Japanese species Cephalotaxus harringtonia, named in honor of the Earl of Harrington, one of the first to grow the plant in a European garden. An Australian company, ChemGenex Pharmaceuticals Ltd., is developing a leukemia therapy called Omacetaxine derived from the leaves of this yew species.
It was approved by the USFDA on 26th October 2012 for the treatment of adult patients with chronic myeloid leukemia (CML) with resistance and/or intolerance to two or more tyrosine kinase inhibitors (TKIs)
Omacetaxine is a protein translation inhibitor. It inhibits protein translation by preventing the initial elongation step of protein synthesis. It interacts with the ribosomal A-site and prevents the correct positioning of amino acid side chains of incoming aminoacyl-tRNAs. Omacetaxine acts only on the initial step of protein translation and does not inhibit protein synthesis from mRNAs that have already commenced translation
Formal Chemical Name (IUPAC)
1-((1S,3aR,14bS)-2-Methoxy-1,5,6,8,9,14b-hexahydro-4H-cyclopenta(a)(1,3)dioxolo(4,5-h)pyrrolo(2,1-b)(3)benzazepin-1-yl) 4-methyl (2R)-2-hydroxy-2-(4-hydroxy-4-methylpentyl)butanedioate
Update by Karl Harrison
(Molecule of the Month for April 2013 )