Jul 1, 1976

Inversion of optical configuration of alpha-methylfluorene-2-acetic acid (cicloprofen) in rats and monkeys

Drug Metabolism and Disposition : the Biological Fate of Chemicals
S J LanE C Schreiber


A simple and sensitive radiometric method to determine the individual enantiomers of cicloprofen has been developed. 14C-Cicloprofen was converted to its L-leucine diastereoisomers, which were separated by thin-layer chromatography and quantified by measuring the radioactivity in the area corresponding to each individual diastereoisomer. This technique has also been used to measure the enantiomers of unlabeled cicloprofen by condensing with 14C-labeled L-leucine. By using the radiometric method, a unique biotransformation process, the inversion of the (-)-enantiomer of alpha-methylfluorene-2-acetic acid to its (+)-enantiomer, has been demonstrated in the rat and monkey. The rate of (-)- to (+)-inversion was found to be faster in the rat than in the monkey. After single or repeated oral adminstration of the racemic modification or the (-)-enantiomer of cicloprofen to both species, the ratio of (+)- to (-)-enantiomers of cicloprofen in plasma, urine, or bile increased with time. At 5, 22, and 48 hr after oral administration of a single 50-mg/kg dose of the (-)-enantiomer, 14C-cicloprofen in rat plasma contained 20, 50, and 79%, respectively, of the (+)-enantiomer. After receiving the same dose of (-)-enantiomer, monkey plasma con...Continue Reading

  • References
  • Citations


  • We're still populating references for this paper, please check back later.
  • References
  • Citations


  • This paper may not have been cited yet.

Mentioned in this Paper

Molecular Stereochemistry
Inversion Mutation Abnormality
Mass Spectrometry
Spectrophotometry, Ultraviolet

About this Paper

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Bone Marrow Neoplasms

Bone Marrow Neoplasms are cancers that occur in the bone marrow. Discover the latest research on Bone Marrow Neoplasms here.

IGA Glomerulonephritis

IgA glomerulonephritis is a chronic form of glomerulonephritis characterized by deposits of predominantly Iimmunoglobin A in the mesangial area. Discover the latest research on IgA glomerulonephritis here.

Cryogenic Electron Microscopy

Cryogenic electron microscopy (Cryo-EM) allows the determination of biological macromolecules and their assemblies at a near-atomic resolution. Here is the latest research.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

LRRK2 & Immunity During Infection

Mutations in the LRRK2 gene are a risk-factor for developing Parkinson’s disease. However, LRRK2 has been shown to function as a central regulator of vesicular trafficking, infection, immunity, and inflammation. Here is the latest research on the role of this kinase on immunity during infection.

Antiphospholipid Syndrome

Antiphospholipid syndrome or antiphospholipid antibody syndrome (APS or APLS), is an autoimmune, hypercoagulable state caused by the presence of antibodies directed against phospholipids.

Meningococcal Myelitis

Meningococcal myelitis is characterized by inflammation and myelin damage to the meninges and spinal cord. Discover the latest research on meningococcal myelitis here.

Alzheimer's Disease: MS4A

Variants within membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease by recent genome-wide association studies. Here is the latest research.