quinine Structure Determination

Summary

This presentation delves into alkaloids, organic bases found in plants, excluding amino acids and peptides. It focuses on quinine, an alkaloid used as an anti-malarial drug and muscle relaxant. The script outlines quinine's extraction process from the bark of the Cinchona tree, its physical properties, and chemical structure elucidation. The talk also covers the identification of functional groups and the structure confirmation through oxidation and reduction reactions, ultimately revealing quinine's molecular formula and structure.

Takeaways

• 🌿 Alkaloids are organic bases found in plants, often used in medicine despite their poisonous nature.
• 💊 Alkaloids have various applications including as anti-malarial drugs, muscle relaxants, and non-narcotic energizers.
• 🔬 The structure of alkaloids can be elucidated through chemical reactions and analysis of their properties.
• 🧪 The presence of certain groups in alkaloids, such as methoxy, secondary alcohol, and olefinic linkages, can be confirmed through specific chemical tests.
• 🌱 Cinchona alkaloids, like quinine, are extracted from the bark of the Cinchona tree and have significant medicinal value.
• 📈 The process of extracting quinine involves blanching the bark, precipitation, washing, and drying.
• 🔍 Physical properties of quinine, such as being a white, crystalline powder that is soluble in water and has a melting point of 17 degrees Celsius, are important for its identification.
• 🧬 The molecular formula of quinine is C20H24N2O2, and it contains two nitrogen atoms.
• 🔬 The structure of quinine is confirmed through oxidation reactions that yield specific acids and other products.
• 🧪 The position of functional groups in quinine is determined through a series of chemical reactions and tests.
• 🔎 The final structure of quinine is confirmed by extensive spectroscopic analysis.

Q & A

What are alkaloids?

Alkaloids are a group of naturally occurring organic bases that are often found in plants. They are typically bitter-tasting and can have various pharmacological effects, including being poisonous in some cases.

What are some common sources of alkaloids?

Alkaloids are commonly found in the seeds, roots, bark, and stems of plants. They can also be sourced from various plant acids like acetic acid or malic acid.

What is the significance of alkaloids in medicine?

Alkaloids are significant in medicine because they can be used in small quantities for their medicinal properties. They are used as anti-malarial drugs, muscle relaxants, and non-narcotic energizers.

Who first isolated quinine, and when?

Quinine was first isolated in 1850 by Pelletier and Caventou.

What is the process of extracting quinine from the bark of the Cinchona tree?

Quinine is extracted from the bark of the Cinchona tree by blanching, which results in a form that can be further studied and analyzed.

What are the properties of quinine?

Quinine is a white, crystalline powder that is readily soluble in water, melts at 17 degrees Celsius, and is optically active.

How is the presence of a secondary alcoholic group in quinine confirmed?

The presence of a secondary alcoholic group in quinine is confirmed by its ability to form monacetates and Mulligan's weights.

What confirms the presence of a methoxy group in quinine?

The presence of a methoxy group in quinine is confirmed by its reaction with SPM for methyl iodide.

How is the structure of quinoline acids confirmed?

The structure of quinoline acids is confirmed by treating them with soda lime, which results in decarboxylation, and then further reactions that reveal the presence of specific groups.

What is the molecular formula of quinoline?

The molecular formula of quinoline is C9H7N.

How is the final structure of quinine elucidated?

The final structure of quinine is elucidated through a series of chemical reactions and analyses, including oxidation and treatment with various reagents, which confirm the presence of different functional groups and the overall structure.