Lecture 3 Concept Notes

Question 1

What do drugs in similar pharmacologic classes share?

Answer 1

Usually share the same structural features

Question 2

Examples of similar features?

Answer 2

Basic nitrogen
Aromatic ring
Esters
Phenols
Aliphatic Carbons or alicyclic moieties

Question 3

What does stereochemistry permit a molecule to do?

Answer 3

Orient itself in a unique position

Question 4

Pharmacophore

Answer 4

Steric & electronic features that is necessary to ensure optimal interactions with a specific target to reach a desired biological response

Question 5

Chirality in the body

Answer 5

Biological targets are often also chiral, as well as amino acids, carbohydrates & phospholipid

Question 6

Chirality is important in drug discovery. Why?

Answer 6

It can affect the whether or not the drug is active, and some enantiomers of drugs can be toxic or tetratogenic

Question 7

+ Epinephrine is less active than (-). Why?

Answer 7

On the + enantiomer, the OH group is pointing away from the receptor and the drug will not occupy it. On the - enantiomer, the OH group is pointing towards the receptor and it will be occupied

Question 8

Constitutional isomers

Answer 8

Same atoms different connectivity

Question 9

Stereoisomers

Answer 9

Same atoms, same connectivity, different stereochemistry

Question 10

Conformational isomers

Answer 10

Changes are made about a single bond rotations

Question 11

Geometric Isomers

Answer 11

Changes are made around a double bond

Question 12

Optical Isomers

Answer 12

isomers that can rotate polarized plane light.
Diastereomers & enantiomers

Question 13

enantiomers

Answer 13

non superimposable mirror images of one another
sp3 chiral carbons

Question 14

Properties of an aneantiomer

Answer 14

physical and chemical properties are idenitcal

Question 15

Enantionmers can differ how in binding

Answer 15

One enantiomer of a drug may be inactive or less active

Question 16

How can enantiomers be useful?

Answer 16

Useful in accessing chiral precursors for organic synthesis

Question 17

How were enantiomers discovered

Answer 17

When two of the same drug were placed in front of a polarizing filter and it was realized that they were rotating the plane of light in different ways

Question 18

D/L Designation

Answer 18

D= Right
L = Left

Do problems on slides

Question 19

Cahn-Ingold Prelog Rule

Answer 19

S= counter clockwise
R= clockwise
IF lowest priority is on a wedge, change the S-R and vise versa

Question 20

Increasing priority

Answer 20

-H
-CH3
- N
-O
- SH
-Cl
-Br
-I

Question 21

How to determine if two molecules are enantiomers of eachother

Answer 21

Check the configuration on the chiral carbons. If BOTH chiral carbons change, then they are enantiomers

(R)(R) –> (S)(S)

Question 22

How to determine if two molecules are diasteromers of eachother?

Answer 22

Check the configuration on the chiral carbons. If ONLY ONE chiral carbons change, then they are diasteromers

(R)(R) –> (S)(R)

Question 23

Diasteromers

Answer 23

Can have different physical and chemical properties
Not mirror images
Non-super imposable

Question 24

Erythro

Answer 24

Two groups that are adjacent to eachother the are on the same side

Question 25

Threo

Answer 25

Two groups that are adjacent to eachother that areon the opposite sides

Question 26

Meso Compounds

Answer 26

Optically inactive. Molecule has a plane of symmetry. achiral diasteromer due to an internal plane of symmetry

Question 27

How to determine how many stereoisomers a chiral drug will have?

Answer 27

Count the stereogenic centers. Use the formula 2^n to determine