Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Med Chem Midterm > Lecture 3 cont > Flashcards

Lecture 3 cont Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

Neutral fats make up ____-____% of body weight

A

20-50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

the more lipophilic the drug, the ____ likely it will deposit in neutral fats

A

MORE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the mechanisms in which lipophilic drugs deposit in neutral fats?

A

either:

  1. Direct physical dissolution
  2. primary deposition into membranes, follows by slow redistribution into fatty tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

give an example of drugs that get deposited into neutral fats.
what is the effect of this?

A

ultra short acting barbiturates (such as thiopental)

thus, these drugs have a VERY SHORT DURATION OF ACTION because they are deposited into these neutral fats, thus decreasing its plasma concentration below therapeutic levels.

this could be intentional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

does sulfur increase or decrease lipophilicity

A

in organic molecules, sulfur INCREASES lipophilicity (except when bound to hydrogen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is thiopental

A

a sulfur containing, ultra short acting barbiturate that gets deposited into neutral fats, thus having a very short duration of action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does QSAR stand for

A

quantitative structure-activity relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

QSAR studies were originally performed by whom and when

A

Hansch in the 1960s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

true or false

QSAR studies began in the 1960s and are still evolving

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Hansch performed studies to correlate what?

A

he wanted to correlate the CHEMICAL STRUCTURE and PHYSICAL PROPERTIES of the drug to its biological activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is THF

A

Tetrahydrofuran – an organic solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does LD50 mean

A

the dose at which 50% of the test sample is killed. Lethal dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is ED50

A

effective dose – the dose at which 50% of the population gets treated effectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

give the formula for the rate of the drug response, according to QSAR

A

Rate of response = d[Response]/dt = ACkx

A = probability of molecule reaching the site of action
C = extracellular drug concentration
Kx = rate (or equilibrium) constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

in QSAR, what are the 3 parameters used to correlate the chemical structure, physical properties, and biological activities of a drug?

A

-lipophilic parameter (pi)
-electronic parameter (sigma)
-steric parameter (Es)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does the lipophilic parameter (pi) of QSAR indicate?

A

the relative lipid solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

a positive p value in QSAR indicates what?

A

a positive p value means that the substituent will cause an increase in lipid solubility

18
Q

give the equation of QSAR

A

Log 1/C (A) = -k(pi) squared + k’pi + p sigma + k”

A= probability of the molecule reaching the site of action
C = extracellular drug concentration
pi = lipophilic parameter
sigma = electronic parameter

19
Q

in the QSAR formula:

log1/C (A) = -kpi^2 + k’pi + psigma + k”

which are variables?
which are constants?

A

constants = k, k’, k”, p
variables = pi, sigma

20
Q

Hansch proposed his equations to measure the ___, ____, and ___ contributions when a molecule is…..

this is helpful for what?

A

Hansch proposed his equations to measure the LIPOPHILIC, ELECTRONIC, AND STERIC contributions when a molecule is SUBSTITUTED BY VARIOUS GROUPS.

this is helpful in drug design

21
Q

Alkyl (–R) and Alkoxy (R–O) are typically electron withdrawing or donating?

A

donating

22
Q

what is a nitrile group

are they electron donating or withdrawing?

A

R-C triple bond N

the most electron withdrawing group

23
Q

are halogens electron donating or withdrawing?

name the halogens

A

withdrawing

fluorine
chlorine
bromine
iodine
astatine
teenessine

24
Q

what is an alkoxy group?

are they electron donating or withdrawing?

A

donating

alkyl with a single bond to oxygen

25
Q

amine groups are electron donating or withdrawing?

A

donating, as long as it doesnt become protonated in aliphatic/aprotic conditions

26
Q

the lipophilic parameter gives what?

A

the relative lipid solubility

27
Q

what is the rate limiting condition for a drug to reach the site of action?

A

movement through a series of membranes

28
Q

since the rate limiting conditions for reaching the site of action involves movement through a series of membranes, _______ has become the most important physiochemical measurement for QSAR studies

A

PARTITION COEFFICIENT

29
Q

what value is the “relative lipid solubility profile”

A

partition coefficient

30
Q

p substituent=…….

a positive p value means what?

A

p substituent = log PC (substituent molecule) - log PC (parent molecule)

a positive p value means the substituent will cause in INCREASE IN LIPID SOLUBILITY

31
Q

True or false

when added as substituents, halogens cause a decrease in lipophilicity

A

FALSE

they actually contribute to lipophilicity a pretty substantial amount

32
Q

is carboxamide a polar or nonpolar substituent?

will in cause an increase or decrease in PC?

A

polar substituent. will cause a decrease in PC

33
Q

will COCH3 group cause increase or decrease in PC

A

decrease

COCH3 = acetyl

34
Q

will nitrile group cause increase or decrease in PC

A

decrease

CN

hydrophiliv

35
Q

will alkyl groups cause an increase or decrease in PC

A

increase

36
Q

true or false

the more carbons in an alkyl group, the more it will contribute to an increase in PC

A

true

37
Q

the lower the pi, the _____ hydrophilic

A

more

38
Q

the higher the sigma value, the more electron _____ it is

A

withdrawing

39
Q

the higher the ES, the ____ it is

A

larger

40
Q

when looking at QSAR and multiple formulas are generated with relatively the same correlation coefficients (r squared), which equation should you pick?

A

the shortest variable containing equation

41
Q

to obtain maximal activity……

A

maximize log A. use small, potent dose

42
Q
A

Med Chem Midterm (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions