Omeprazole Chirality, Stereopair Viewing
From WikidChem
Isolating one enantiomer of a chiral compound is important to the drug industry because our chiral bodies react differently to the right handed and left handed versions of a molecule.
H3 Pain Relievers
The pain reliever Advil has three basic components: isobutyl (the root "but-" indicates four carbons), a phenol group , and propionic acid (the root "prop-" indicates three carbons). When the underlined parts of each component's name are put together, they form the molecule's common name, Ibuprofen. The carbon marked with a blue star is the stereogenic center, or asymmetric carbon, responsible for the two enantiomers of ibuprofen. The right handed R molecule is the actual pain reliever, while the left handed L one is an inactive compound. Advil is sold as a combination of the two enantiomers probably because it takes too much time and effort to separate the two when the nonessential molecule isn't even harmful.
H3 Sedative
Thalidomide is another chiral compound. Once again the blue star marks the asymmetric carbon. Here the left handed enantiomer is responsible for the sedative effects, while the right handed one (teratogen, or monster making) causes birth defects in pregnant women. When thalidomide was sold as a racemate in Europe, many babies were born with major defects as a result of the R-thalidomide. The FDA never approved Thalidomide for use in the US. However, because it is useful for treating leprosy, there is still talk today of using Thalidomide. Another problem with thalidomide is that the S molecule will racemize in the human body at the rate of.12 parts per hour, so resolving the enantiomers is not helpful. The rates of conversion for the other shown reactions are listed as well.
The rate of elimination (excretion or degradation) of the R molecule is much greater than that of the S molecule --since this is the one that elicits a sedative effect, and thus--. One might wonder whether it is used up by the R-factors in the body that the molecule binds to effect the response.
H3 Omeprazole
The long and complicated formal name for the compound shown on this slide is shown at the top. The Main group is imidazole, the first circled pentagon with nitrogen. The 1 H refers to the position of the Nitrogen which bears an H, and thus no double bond. The hexagonal group attached to imidazole is benzene, hence 1 H benzimidazole. The other parts of the molecule and their systematic names and shown with the red underline and corresponding red circles.
The common name of this compound is Omeprazole, or Prilosec. It is used to inhibit proton pumps in the digestive system to alleviate acid reflux. Here the Sulfur is the stereogenic molecule, because its lone pair of electrons makes it a tetrahedral asymmetric atom. The right handed enantiomer is omeprazole, while the left handed version is esomeprazole (S), commonly called Nexium. It is advertised as a souped up drug for acid reflux.
With the 3D glasses, you can see the 3D structure of the molecule (for a better image see [Jmol]). One eye sees the compound in red, the other in blue, so that the combined system has depth. Unless your eyes have different prescriptions, in which case it is especially difficult to see 3D.
The next slide is another 3D molecule.
