1. In allergy sufferers, histamine causes runny noses, red eyes, and other symptoms. Here is its structural formula.

a. Give the chemical formula for this compound.

Ans: C5H9N3

b. Circle the amine functional groups in histamine.

Ans: 

c. Which part (or parts) of the molecule make the compound water-soluble?

Ans: 

2. Antihistamines are widely used drugs for treating symptoms of allergies caused by reactions to histamine compounds. This class of drug competes with histamine, occupying receptor sites on cells normally occupied by histamine. Here is the structure for a particular antihistamine.

a. Give the chemical formula for this compound.

Ans: C16H21N3

b. What similarities do you see between this structure and that of histamine (shown in the previous question) that would allow the antihistamine to compete with histamine?

Ans:

The two-carbon chain with a nitrogen at the end (marked in red) and a three-atom sequence of N-C-N (marked in blue), as well as the spatial placement of these pieces are similar. The flat 5-ring of histamine is also relatively similar to the flat 6-ring of the antihistamine.

The antihistamine would bind to the histamine receptor sites on cells more tightly than histamine itself, thus block the histamine actions.

3. Consider this statement. “Drugs can be broadly classed into two groups: those that produce a physiological response in the body and those that inhibit the growth of substances that cause infections.” Into which class does each of these drugs fall?

Antibiotic (Keflex) & Penicillin inhibit the growth of substance that cause infection. Aspirin, Morphine, Estrogen and Amphetamine produce a physiological response in the body.

4.Herbal or alternative medicines are not regulated in the same way as prescription or OTC medicines. In particular, the issues of concern are identification and quantification of the active ingredient, quality control in manufacture, and side effects when the herbal remedy is used in conjunction with another alternative or prescription medicine.

a. What do you think is the evidence from herbal supplement manufacturers that address these issues?

Ans: Products such as herbs can sometimes be tainted with pesticides, germs, or toxic heavy metals. Ingredients and its amount listed on labels are sometimes misrepresented — some supplements do not contain what’s listed on the label, contain more or less than the amount, or are not listed on the label at all. In 2013, researchers in Toronto published a report in which they sampled and analyzed 44 herbal supplements and found that 48% of the supplements contained any of the herb listed on the label. More than half of the supplements contained something that wasn’t on the label.

Some herbal suppliers (those who grow, harvest, or sell the crops) may practice unethical behaviours, by mixing or even substituting their crops with less expensive or more readily available plants. Accidental contamination is also an issue, when one plant grows in with others, as well as cases of mistaken identity (when one plant looks like another). These problems can make it harder for a company to be sure that what they thought they were buying to make supplements is actually the herb they wanted.

b. Do you know anything about Singapore’s legislation on this topic?

Ans: Health supplements are currently not subjected to premarket approvals or licensing for their importation, manufacture and sales in Singapore. However, dealers have the obligation to make sure that such products are safe to consume and they conform to quality standards and safety.