Valliappan Kannappan – Page 7

Fischer Projection: hassle free way to depict a stereoformula in 2D projection

2 Comments / Chirality / By Valliappan Kannappan / #chirality, #chiralpedia, #fischer_projection, #naming_system

One of the major problems in organic chemistry is the representation of three-dimensional structures in a two-dimensional media (viz. sheet of paper, blackboard, etc.). Chemists sometimes represent structures for chiral molecules with two-dimensional formulas called Fischer projection formulas. These two-dimensional formulas are a quick way to show three dimensions without the hassle of having to draw 3-D. The Fischer projection, devised by the carbohydrate chemist Emil Fischer in 1891. This projection formula is a technique …

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Naming enantiomers: the left-(or right-) handed?

1 Comment / Chirality / By Valliappan Kannappan / #chiral_center, #CIP_rule, #naming_system, #stereogenic_center

Enantiomers are pair of molecules that exist in two forms that are mirror images of one another but cannot be superimposed one upon the other. They are also referred to by chemists as chiral twins or handed molecules. Each twin is called an enantiomer. Naming of enantiomers is important to understand ‘which structure refers to which enantiomer?’. The chirality of organic molecules is described by the Cahn-Ingold-Prelog (CIP) system. This system is also referred to as the R/S convention …

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Thalidomide tragedy: the story and lessons …

2 Comments / Chirality / By Valliappan Kannappan / #chiral_drug, #chirality, #toxicity

In the 1940s and early 1950s, pregnant women throughout the world who experienced morning sickness and other anxieties associated with the first term of pregnancy were given barbiturate sedatives for relief. The issue with these barbiturates, like most sedatives, was the fact that they were highly toxic in large doses. In 1957, Chemie Grunenthal of Germany launched thalidomide as a safer alternative to barbiturate sedatives. Thalidomide, as a new sedative, was a very “attractive” drug …

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Separating mirrored molecules

1 Comment / Chiral separation and analysis / By Valliappan Kannappan / #chiral_chromatography, #chiral_membranes, #chiral_separation, #chiral_sieves, #chirality, #mirrored_molecules

In nature, most chiral molecules only appear in one specific enantiomeric form. [Read more @ the blog – “The handed world“, https://chiralpedia.com/blog/the-handed-world/]. Moreover, the handedness of the enantiomer can have a powerful effect on how that molecule behaves. The chiral difference between two molecules often plays a huge role in pharmacology and physiology, even though the two seem nearly identical but are not really in a bioenvironment, which is chiral. [Read more @ the blog …

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