The stereochemistry of a molecule can have a drastic impact on its efficacy and toxicity. This activity provides instructors with homework and discussion questions for use within organic chemistry courses to discuss the importance of understanding the toxicity of stereoisomers using common pharmaceuticals and drugs.
By understanding how the structure of a molecule impacts its function, such as ability to degrade in the environment, chemists can design chemical products that have reduced impacts on humans and the environment. These brief lessons introduce design rules for biodegradability and provide instructors discussion questions that link toxicology concepts directly to organic chemistry concepts, such as alkanes and carbon branching, and electrophilic aromatic substitution.
The toxicity of xenobiotic (a substance foreign to the body, typically a chemical substance) electrophiles are related to their ability to bind to proteins in the body. There are about 50 specific reactive protein binding mechanisms known, with 6 being the most common reaction mechanisms: SN1, SN2, Acylation, Schiff Base formation, Michael Addition and SNAr. This unit provides a brief introduction to electrophilic-nucleophilic reactions in the body, along with some discussion questions for instructors.
Understanding what makes a molecule hazardous to the environment or toxic to humans is a key piece to green chemistry design. However, what do we mean when we use the terms “hazardous” or “toxic”? There are many toxicological and environmental endpoints that determine whether or not a molecule will have human an environmental impact. This activity helps students to understand more about the various endpoints and how to assess whether or not a molecule poses human and environmental risks.
In this lab, a bioassay is performed on salts that are used for road de-icing. The lab demonstrates the concept of LD50, or the lethal dose of a chemical that kills 50% of a particular organism when 100% of the organisms are exposed. Concepts: bioassays, toxicology, LD50
Developed by Beyond Benign
The Global Warming and Greenhouse Effect laboratory exercise was developed to demonstrate global warming for introductory chemistry courses for both majors and non-majors. The experiment was created for general chemistry or environmental science courses and tested at the Siena College workshop.
Students assess the toxicity of methanol, ethanol and isopropanol by examining the effect these substances have on germination of lettuce seeds. The procedure introduces students to the concepts of toxicity measurements, while using standard equipment and common techniques such as serial dilution and volumetric measurement. Concepts: ecotoxicity, serial dilution, volumetric measurement
Developed by Irv Levy (Gordon College)
This module allows students to explore the link between pKa and skin irritation. pKa appears highly predictive of acute skin irritation for acids and bases in man.
Toxicity testing of chemical mixtures are extremely important for avoiding regrettable substitution, however, they are very expensive and can take a long time to perform. Research has developed computational modeling tools for pKa determination, with some report correlations as high as 0.90 for toxicity experiments (Voutchkova et al. 2012). The pKa of a chemical can be a promising indicator of penetration for human skin in vitro and correlate with erythema, edema, and color meter readings.