Questions for CM8001-AE 9
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.
C5H9N3
b. Circle the amine functional group in histamine.
c. Which part (or parts) of the molecule make the compound water-soluble?
Amine group , -NH group and double bond make the compound soluble in water.
2.Antihistamine are widely used drugs for treating symptoms of allergirs caused by reactions to histamine compounds. This class of drug competes with histamine, occupying receptor sites on cells noramlly occupied by histamine. Here is the structure for a particular antihistamine.
a. Give the chemical formula for this compound.
C16H21N3
b. What similarities do you see between this structure and that of histamine (shown in the previous question 1) that would allow the antihistamine to compete with histamine?
Histamine and antihistamine are compounds that have opposite effects on the human body. Histamines trigger an allergic response while antihistamines calm it. The human body is able to create both of these chemical messengers on its own, though they can also be introduced into the body from outside sources. Since a histamine and an antihistamine compete for the same receptors, an antihistamine can block the effect of the histamine.
The similarities in the two structures are a two-carbon chain with a nitrogen at the end , and a three-atom sequence of N-C-N. Given the similarities in structure, we might guess that the antihistamine would bind to histamine receptor sites on cells more tightly than histamine itself, thus blocking histamine action. And also, when histamine and antihistamine are both present at the same time, antihistamine cancels the effects of histamine. This is because once antihistamine binds to the receptor site, it blocks the effects of histamine as histamine is unable to bind to the receptor site. No chemical messengers would be produced by histamine.
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?
a. aspirin
Aspirin is classified as a drug that produces a physiological response in the body. Aspirin binds to COX-1 enzymes that are involve in the production of prostagalandins and prevent the conversion of arachidonic acid to prostagalandin. Prostagladins are messenger molecules that call for swelling, fever, increase pain, inhibit dilation of blood vessels, regulate production of acid and mucus in the stomach and assist kidney functions. Thus, the physiological response of aspirin is the inhibition of prostagladin activity.
b. morphine
Morphine is classified as a drug that produces a physiological response in the body. Morphine binds to opiate receptors in the brain and releases chemicals that binds to the GABA receptor. The binding of these chemicals inhibits the activity of GABA which is to shut down the release of dopamine. As such, Dopamine can be released into the synapatic cleft, allowing it to bind to dopamine receptor on the post-synaptic membrane to signal for pleasure. Thus, the physiological response of morphine is the pleasure that is felt.
c. (Keflex) antibiotic
Keflex is classified as a drug that inhibit the growth of substances that cause infections. Keflex is a bactericidal agent that acts by the inhibition of bacterial cell-wall synthesis. As such, this prevents the growth and development of bacteria in the body. Without bacteria growth and propagation, bacteria cannot initiate a sizable effect on the body to cause an infection.
d. estrogen
Estrogen is classified as a drug that produces a physiological response in the body. It mimics the effects of the natural hormone and is responsible for the development and regulation of the female reproductive system and secondary sex characteristics. Estrogen is used as medication as part of some oral contraceptive, in hormone replacement therapy for postmenopausal, hypogonadal, and transgender women, and in the treatment of certain hormone-sensitive cancers like prostate cancer and breast cancer.
e. amphetamine
Amphetamine is classified as a drug that produces a physiological response in the body. It is a central nervous system stimulant that affects chemicals in the brain and nerves that contribute to hyperactivity and impulse control. It is used to treat attention deficit hyperactivity disorder (ADHD), narcolepsy and obesity.
f. penicillin
Penicillin is classified as a drug that inhibit the growth of substances that cause infections. It is a group of antibiotics which include penicillin G (intravenous use), penicillin V (use by mouth), procaine penicillin, and benzathine penicillin (intramuscular use). It fights bacteria in your body and is used to treat many different types of infections caused by bacteria, such as ear infections. Specific structural requirements are equated to constructing the perfect ‘trap’ for catching targeted bacteria.
4. Herbal or alternative medicine are not regulated in the same way as prescription or OTC medicines. In particular, this 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?
Some herbal supplements do contain harmful bacteria, pesticides or substantial amount of toxic heavy metals. Manufacturers omit some of the ingredients when listing on the labels. This was investigated by Food and Drug Administration (FDA) of the United States in 1994, as herbal products became more popular then.
Furthermore, manufacturers do mix or substitute the ingredients just to reduce cost or for convenience. This causes complication which such products. Contamination is also prone as plants growing together may cause some form of confusion when identifying them. Crops being mad in such way give rise to integrity issues which are faced by the buyer as they are not sure if they will be able to get the right product or herb.
In much recent 2013, 44 herbal supplements were sampled by researchers from Toronto, and the results shown that more than half contains other ingredients that are not listed on their labels. Majority were contaminated. The research was don using DNA bar coding analysis, where 48% of the supplement contains what was listed on the label.
b. Do you know anything about Singapore’s legislation on the topic?
Chinese Proprietary Medicine (CPM) used in Traditional Chinese medicine (TCM) are medicinal products often associate with herbs. This products are usually in tablets, capsule and liquid forms, and are regulated by the Health Science Authority (HSA). A set of safety and quality compliance regulations must be met before these products can be marketed in Singapore. These sellers of such products have to receive license authorised by HSA in order to sell their products in Singapore.
Reference:
Health Science Authority. 2016. Use of Chinese Proprietary Medicines. Retrieved from: http://www.hsa.gov.sg/content/hsa/en/Health_Products_Regulation/Consumer_Information/Consumer_Guides/Complementary_Health_Products/Use_of_Chinese_Proprietary_Medicine.html