Question

Many plants contain interesting compounds that sometimes have medicinal properties. Some of these compounds are listed below with the chemical composition given after each name. Write the formulas for these compounds. (a) Aescin from horse chestnuts has anti-inflammatory properties ( 55 carbons, 86 hydrogens, and 24 oxygens). (b) Proanthocyanidins found in cranberries help to prevent urinary tract infections. Proanthocyanidins are polymers composed of epicatechin units (15 carbons, 14 hydrogens, and 6 oxygens). (c) Betulinic acid found in the common birch tree is an antimalarial drug ( 30 carbons, 48 hydrogens, and 3 oxygens).

Short answer

Aescin: \(C_{55}H_{86}O_{24}\); Proanthocyanidins (one unit): \(C_{15}H_{14}O_{6}\); Betulinic acid: \(C_{30}H_{48}O_{3}\).

Step-by-step solution

- Identify the composition of each compound

Determine the number of carbon (C), hydrogen (H), and oxygen (O) atoms in each compound. This can be achieved by carefully reading the information provided for each compound.

- Write the empirical formula

Based on the identified number of each type of atom, write the chemical formula using subscripts to show the number of each atom. For instance, if a compound has 10 carbons, 12 hydrogens, and 5 oxygens, the formula would be \({C}_{10}H_{12}O_{5}\).

- Apply Step 2 to Aescin

Aescin has 55 carbons, 86 hydrogens, and 24 oxygens, so the formula is \(C_{55}H_{86}O_{24}\).

- Apply Step 2 to Proanthocyanidins

Proanthocyanidins are composed of epicatechin units, each with 15 carbons, 14 hydrogens, and 6 oxygens. The formula for one unit is \(C_{15}H_{14}O_{6}\).

- Apply Step 2 to Betulinic acid

Betulinic acid has 30 carbons, 48 hydrogens, and 3 oxygens, so the formula is \(C_{30}H_{48}O_{3}\).

Key concepts

chemical composition

Chemical composition refers to the types and quantities of atoms that make up a specific compound. Understanding chemical composition helps to identify the elements in a substance and their ratios. For instance, in the exercise above, the chemical composition of aescin includes 55 carbon atoms, 86 hydrogen atoms, and 24 oxygen atoms. Knowing these details is essential as it allows scientists to write the correct chemical formula for the compound. This is crucial in fields like medicinal chemistry where precise formulas determine how substances interact.

empirical formula

The empirical formula represents the simplest ratio of the elements in a compound. It's not necessarily the actual number of atoms but rather the smallest whole number ratio. For example, a compounding exercise showed that proanthocyanidins have a chemical formula based on their units, where each unit is composed of 15 carbons, 14 hydrogens, and 6 oxygens, written as \(C_{15}H_{14}O_{6}\). Writing the empirical formula is a fundamental step in chemistry to understand the basic composition and properties of compounds. By mastering this, you can easily convert the information from a compound's chemical composition into its correct formula.

medicinal chemistry

Medicinal chemistry is the branch of chemistry focused on the design, synthesis, and development of pharmaceutical agents. Compounds like aescin and betulinic acid, mentioned in the exercise, show how the chemical composition directly relates to medicinal properties. Aescin with its \(C_{55}H_{86}O_{24}\) formula is known for anti-inflammatory properties, while betulinic acid \(C_{30}H_{48}O_{3}\) is recognized for its antimalarial effects. Understanding their chemical formulas helps researchers develop better drug formulations and understand the mechanism by which these compounds work in the body.

organic compounds

Organic compounds are molecules primarily composed of carbon atoms in combination with other elements such as hydrogen, oxygen, nitrogen, and more. The plant compounds in the exercise, like aescin, proanthocyanidins, and betulinic acid, are all organic compounds. Their compositions, shown as \(C_{55}H_{86}O_{24}\), \(C_{15}H_{14}O_{6}\), and \(C_{30}H_{48}O_{3}\) respectively, illustrate complex structures that define organic chemistry. Organic compounds form the basis of life and are integral in numerous biochemical processes.

polymer chemistry

Polymer chemistry deals with the study of large, chain-like molecules called polymers, which can have repeating units. In the exercise, proanthocyanidins are described as polymers composed of epicatechin units. Each epicatechin unit has a formula of \(C_{15}H_{14}O_{6}\). Proanthocyanidins illustrate how polymer chemistry is essential in understanding the structure and function of natural compounds, which can have significant health benefits like preventing urinary tract infections. Recognizing the polymeric nature of compounds helps in grasping how macromolecules function and are applied, especially in materials science and medicinal chemistry.