Download 10.6 Chiral molecules have 4 different groups attached to a central

Chiral molecules have 4 different groups
attached to a central atom.
A chiral molecule and its nonsuperimposable mirror image are a special
kind of isomer called enantiomers.
Enantiomers have identical physical
properties.
The only way we can tell them apart is by
seeing their effect on plane polarized light.
10.6
However, the body can tell them apart. These two
enantiomers may have very different actions in the
human body.
One enantiomer fits into a receptor site, while the other does not. The
molecule on the right will have (possibly) no affect on the human body.
10.6
Consider the two enantiomers above.
Dextromethorphan is a safe cough suppressant.
Levomethorphan is an addictive opiate.
10.6
Steroids perform many functions in the body:
Function
Regulation of secondary
sexual characteristics
Reproduction and control of
the reproductive cycle
Examples
Estradiol (an estrogen); testosterone
(an androgen)
Progesterone and the gestagens
Regulation of metabolism
Digestion of fat
Cell membrane component
Cortisol; cortisone derivatives
Cholic acid; bile salts
Cholesterol
C
A
D
This is the basic carbon
skeleton for all steroids.
B
10.7
Functional groups in some common steroids
alcohols
carboxylic acid
ketones
Can you identify
the functional
groups
in the other
examples?
10.7
RU-486, The Abortion Pill
Controversial: how about a
class discussion on the topic?
RU-486 acts as an antagonist – a drug that fits into a receptor
site, but does not have the customary effect as does another
drug; in this case the other drug is progesterone.
Getting a New Drug to Market
On average, the process takes about 12 years and
over
$500 million.
10.9
Animals and Drug Testing
Is it morally ethical to test newly developed drugs on animals?
What does the LD50 standard mean?
Provide pros and cons for both sides of the issue of animal testing.
10.9
Prescription, Generic, and Over-the-Counter
Medicines
A generic drug is chemically equivalent to the pioneer drug, but cannot be
marketed until the patent protection on the pioneer drug has run out after
20 years.
The lower priced drug commonly marketed under its generic name, in this
case alprazolam instead of Xanax.
10.10
Herbal Remedies
10.11
Ephedra – used safely for thousands of years as herbal remedy
known as Ma Huang.
In 2003, several deaths related to the ingredients led the
FDA (in 2004) to ban ephedra products. At this time, there
are ongoing discussions to make the product available again.
10.11
Ephedra
The herb contains the amphetamine-like
alkaloids – ephedrine and the less active
pseudoephedrine.
Pseudoephedrene is used as a decongestant
Ephedrine is a bronchodilator (opens the airways), and a stimulant
10.14
Drugs of Abuse
10.12
OxyContin contains oxycodone
Oxycodone has been used
safely for many years.
But this formulation includes a time-released mechanism for long-lasting
treatment of chronic pain.
Drug abusers quickly determined how to get around the time-release
and were able to rapidly ingest large amounts of oxycodone. The effects
were said to be similar to heroin.
Over-prescribed in the Appalachian areas in late 1990s and early 2000s.
Many became addicted.
10.12
Marijuana – Cannabis sativa
THC, or delta-9-tetrahydrocannabinol is the active drug in
marijuana.
Medical uses continue to be argued, the Federal Government is
opposed.
10.12
MDMA or Ecstasy
3,4-methylenedioxy-n-methylamphetamine
Schedule I drug, yet clinical therapists are continuing to argue
its potential benefits as a therapeutic agent.
10.12