Valliappan Kannappan

Part 5: Stereoselective and Stereospecific Synthesis

Leave a Comment / Stereochemistry / By / , , / June 2, 2026

“Crafting molecules with precision – the art of stereochemical synthesis” Introduction Having seen why the correct stereochemistry is crucial for drug efficacy and safety, the next challenge is how to obtain the desired stereoisomer. This part covers strategies and methods in stereoselective and stereospecific synthesis. We clarify the terminology: a stereoselective reaction preferentially yields one …

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Part 4: Stereochemistry in Drug Action and Pharmacology

Leave a Comment / Stereochemistry / By / , / June 2, 2026

“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 …

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Part 3: Nomenclature and Configuration

Leave a Comment / Stereochemistry / By / , , / June 2, 2026

“Decoding the rules: how chemists name and navigate molecular twists.” Introduction Correctly describing the stereochemistry of a molecule is as important as understanding it. In this part, we focus on the Cahn–Ingold–Prelog (CIP) system, which provides the rules for unambiguous assignment of absolute configuration at stereocenters (R/S) and for double bond geometry (E/Z) system. We …

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Part 2: Fundamental Concepts of Chirality

Leave a Comment / Stereochemistry / By / / June 2, 2026

“From left- and right-handedness to life’s molecular signatures—chirality explained” Introduction Building on the overview of chirality, this section delves into core concepts: symmetry elements in molecules, the definitions of enantiomers and diastereomers, and the phenomenon of optical activity. Understanding these fundamentals is essential for grasping how stereochemistry manifests and is measured. We will also explore …

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Part 1: Introduction to Stereochemistry

Leave a Comment / Chirality, Stereochemistry / By / , , / June 2, 2026

“The 3D language of molecules – why stereochemistry is the hidden key in drug science.” Introduction Stereochemistry is the branch of chemistry concerned with the three-dimensional arrangement of atoms in molecules and how this spatial arrangement influences chemical behavior. The term “chirality” (from the Greek cheir meaning hand) describes the property of an object or …

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Mapping Stereochemical Nomenclature: A Chiralpedia Guide

Leave a Comment / Chiral science / By / , , / August 21, 2025

Stereochemistry, the study of spatial arrangements of atoms in molecules, demands a precise and universally accepted nomenclature system. Unlike simple chemical formulas, which only indicate connectivity, stereochemical nomenclature conveys three-dimensional information essential for understanding molecular behavior, biological interactions, and pharmaceutical effects. Several systems have been developed to capture these subtle but critical differences. 🔬✨ Stereochemical …

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The Thalidomide Paradox

Leave a Comment / Chirality / By / , , / August 14, 2025

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 …

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Episode 10: Future Reflections: How the Story of Chiral Drug Regulation Continues

Leave a Comment / Chiral science, Chirality, Regulatory Affairs / By / , / June 2, 2026

“Approval is not the end of a molecule’s journey – the mirror must be watched, studied, and questioned throughout its life.” Introduction The development and approval of chiral drugs, especially single-enantiomer entities, marked a new chapter in pharmaceutical science. However, approval is only the beginning. Ensuring that a chiral drug continues to behave safely and …

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Episode 9: Challenges on the Horizon: Complex Chirality and Emerging Scientific Questions

Leave a Comment / Chiral science, Chirality, Regulatory Affairs / By / , / June 2, 2026

“As the molecular world grows more intricate, so do the challenges in regulating and understanding chirality.” Introduction While the 1990s and 2000s solidified regulatory frameworks for simple chiral drugs -classic single stereocenter, stable enantiomers –science has since moved into more complex territory. Today, pharmaceutical innovation increasingly deals with molecules featuring multiple stereocenters, dynamic chirality, axial …

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Episode 8: Beyond the Approval: Ethical and Economic Dimensions of Chiral Drugs

Leave a Comment / Chiral science, Chirality, Regulatory Affairs / By / , / June 2, 2026

“Approving a drug is only half the journey. The true story unfolds where science, ethics, commerce, and access collide.” Introduction Chirality reshaped regulatory science and drug development -but its impact extends far beyond the laboratory and approval desk. The commercialization of single-enantiomer drugs, especially through chiral switches, has raised important ethical and economic debates about …

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