Search Results for: thalidomide

The Thalidomide Paradox

Synopsis The thalidomide tragedy is one of the most infamous episodes in pharmaceutical history—yet its stereochemical secrets are still being unraveled. A fascinating article by Tokunaga E, Yamamoto T, Ito E, and Shibata N., published in Scientific Reports (Nature Research, 2018; https://www.nature.com/articles/s41598-018-35457-6), sheds new light on the phenomenon through the lens of the self-disproportionation of enantiomers, the physical chemistry of chirality. Thalidomide’s tragic past is linked to its two “mirror-image” forms. One form, the S-enantiomer, …

The Thalidomide Paradox Read More »

Thalidomide

Thalidomide was a racemic therapeutic and prescribed to pregnant women to control nausea and vomiting. The drug was withdrawn from world market when it became evident that the use in pregnancy causes phocomelia (clinical conditions where babies are born with deformed hand and limbs). Later in late 1970s, the thalidomide enantiomers were separated and enantioselective studies indicated that the (R)- enantiomer, the good partner, is an effective sedative, the (S)-enantiomer, the evil partner, harbors teratogenic …

Thalidomide Read More »

Thalidomide tragedy: the story and lessons …

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 …

Thalidomide tragedy: the story and lessons … Read More »

The Hidden Chirality in Drug Metabolites: A metabolic blind spot

“Chirality isn’t hidden — we just stopped looking closely enough” The Unseen Journey After the Dose: 💊 When a patient swallows a drug, the journey is far from over. Sometimes, the real chiral story begins after the dose. The drug molecule meets a series of enzymes — oxidases, reductases, transferases — each capable of transforming it into one or more metabolites. We often assume these are simply inactive breakdown products, but chemistry rarely plays it …

The Hidden Chirality in Drug Metabolites: A metabolic blind spot Read More »

When Drug Labels Miss the Twist: The regulatory bind spot

“When chemistry tells two stories, the label should tell both” Drug labels tell us what’s inside — but not always how the molecule twists. And sometimes, that subtle twist changes everything: how a drug acts, how it’s regulated, and even whether it’s safe or addictive. Chirality — the property of handedness in molecules — has always shaped pharmacology. One mirror image of a molecule (an enantiomer) can save lives, while its twin may do little …

When Drug Labels Miss the Twist: The regulatory bind spot Read More »

Part 9: Stereochemistry in Drug Discovery and Development

“From hit to lead to medicine – where stereochemistry shapes every stage of discovery” Introduction Stereochemistry is not only crucial in the final stages of drug production – it plays a significant role right from the discovery and lead optimization phases. In this part, we consider how medicinal chemists account for chirality when designing compounds and how structure-activity relationships (SAR) can depend on stereochemistry. We also look at how screening libraries incorporate stereochemical diversity, and …

Part 9: Stereochemistry in Drug Discovery and Development Read More »

Part 8: Stereochemistry in Biologics and Natural Products

“Nature’s stereochemists – chirality in biologics, peptides, and natural products” Introduction Stereochemistry is inherent in biological macromolecules and natural products. This part explores chirality beyond small synthetic drugs – specifically, in biologics (peptides, proteins, nucleic acids) and in natural product-derived drugs. We examine how nature’s biosynthetic machinery imparts stereochemistry with high fidelity (e.g., enzymes produce single enantiomers of amino acids, sugars, complex polyketides). We discuss examples of drugs that are derived from natural chirality (like …

Part 8: Stereochemistry in Biologics and Natural Products Read More »

Part 7: Analytical Techniques for Stereochemistry

“Measuring handedness – tools and techniques that bring chirality into focus” Introduction Ensuring the correct stereochemistry and measuring stereochemical purity is a crucial aspect of pharmaceutical quality control and research. This part covers the major analytical techniques used to distinguish and quantify enantiomers and diastereomers in drug substances and products. Key techniques include: We’ll discuss how these techniques are applied in practice: e.g., during process development, a chiral HPLC method is developed to monitor enantiomeric …

Part 7: Analytical Techniques for Stereochemistry Read More »

Part 6: Resolution of Enantiomers

“Separating the inseparable: how chemists resolve mirror-image molecules.” Introduction Despite advances in asymmetric synthesis (Part 5), sometimes we still end up with a racemic mixture of enantiomers. When direct stereoselective routes are impractical, chemists must separate the enantiomers – a process known as resolution. This part examines classical and modern methods for resolving enantiomers, their pros and cons, and how they are applied in pharmaceutical contexts. We will cover: We’ll also discuss the racemic mixture …

Part 6: Resolution of Enantiomers Read More »

Part 4: Stereochemistry in Drug Action and Pharmacology

“Why one enantiomer heals while the other may harm – the pharmacology of chirality” Introduction Chirality doesn’t just influence drug properties in theory – it has very real consequences in pharmacology. In this section, we explore how stereochemistry affects drug action at multiple levels: pharmacodynamics (drug-receptor interactions) and pharmacokinetics (absorption, distribution, metabolism, excretion). We will define terms like eutomer (the more active enantiomer) and distomer (the less active one) and introduce the concept of the …

Part 4: Stereochemistry in Drug Action and Pharmacology Read More »