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Question 1

What value does the regression coefficient have for a perfect fit?

a) 0.1

b) 1

c) 10

d) 100

Question 2

What does the symbol P represent in a QSAR equation?

a) pH

b) plasma concentration

c) partition coefficient

d) prodrug

Question 3

What is the symbol π in a QSAR equation?

a) The hydrophobicity of the molecule.

b) The electronic effect of a substituent.

c) The substituent hydrophobicity constant.

d) A measure of the steric properties for a substituent.

Question 4

Calculate the logP value for the structure shown; logP for benzene = 2.13; π(OH) -0.67; π(CH₃) 0.52.

a) 3.32

b) 0.94

c) 1.98

d) 2.13

Question 5

What does MR represent in a QSAR equation?

a) Molar refractivity is a steric factor.

b) Molar refractivity is an electronic factor.

c) Molar refractivity is a hydrophobic factor.

d) Molar refractivity is a stereoelectronic factor.

Question 6

What software programme is used to determine the Verloop steric parameter?

a) Alchemy

b) Chem3D

c) Sterimol

d) ChemDraw

Question 7

What does a negative value of σ signify for a substituent?

a) It is electron donating.

b) It is electron withdrawing.

c) It is neutral.

d) It is hydrophobic.

Question 8

The QSAR equation relating the insecticidal activity of a series of diethyl phenylphosphonates versus σ is shown below.

What does r represent?

a) The regression or correlation coefficient.

b) The number of compounds tested.

c) The standard deviation.

d) The F test.

Question 9

The QSAR equation relating the insecticidal activity of a series of diethyl phenylphosphonates versus σ is shown below.

What does s represent?

a) The regression or correlation coefficient.

b) The number of compounds tested.

c) The standard deviation.

d) The F test.

Question 10

A series of 102 phenanthrene aminocarbinols (see structure below) were tested for antimalarial activity and found to fit the following Hansch equation:

(n=102, r=0.913, r²=0.834, s=0.258) What is the significance of -0.015(π_sum)² + 0.14π_sum in the equation? (π_sum indicates the sum of the π constants for all the substituents in the molecule)?

a) It indicates that activity falls to a minimum value as π_sum increases to an optimum value, then rises again as π_sum increases beyond that value.

b) It indicates that activity falls to a minimum value as π_sum decreases to a certain value, then rises again as π_sum increases beyond that value.

c) It indicates that activity rises to a maximum value as π_sum increases to an optimum value, then falls again as sum increases beyond that value.

d) It indicates that activity rises to a maximum value as π_sum decreases to a certain value, then falls again as π_sum decreases beyond that value.

Question 11

A series of 102 phenanthrene aminocarbinols (see structure below) were tested for antimalarial activity and found to fit the following Hansch equation:

(n=102, r=0.913, r²=0.834, s=0.258) What does the term Σπ_X represent in the equation?

a) The sum of the hydrophobic factors corresponding to the substituent X present in the molecule.

b) The sum of the electronic factors corresponding to the substituent X present in the molecule.

c) The largest hydrophobic factor of the substituent X present in the molecule.

d) The smallest hydrophobic factor of the substituent X present in the molecule.

Question 12

A series of 102 phenanthrene aminocarbinols (see structure below) were tested for antimalarial activity and found to fit the following Hansch equation:

(n=102, r=0.913, r²=0.834, s=0.258) What does the term Σσ_X signify in the equation?

a) The sum of the hydrophobic factors corresponding to the substituent X present in the molecule.

b) The sum of the electronic factors corresponding to the substituent X present in the molecule.

c) The sum of the steric factors of the substituent X present in the molecule.

d) None of the above.

Question 13

A series of 102 phenanthrene aminocarbinols (see structure below) were tested for antimalarial activity and found to fit the following Hansch equation:

(n=102, r=0.913, r²=0.834, s=0.258) What do the terms Σσ_X and Σσ_Y signify in the equation?

a) Hydrophilic groups on rings X and Y are good for activity.

b) Hydrophobic groups on rings X and Y are good for activity.

c) Electron withdrawing groups on rings X and Y are good for activity.

d) Electron donating groups on rings X and Y are good for activity.

Question 14

A Hansch analysis is being carried out in order to relate biological activity to σ and π. Which of the following substituents would best suit the study?

a) SO₂NH₂, CONH₂, CH₃SO₂, CH₃CO, CN

b) NH₂, OH, F, Cl CF₃

c) NO₂, CO₂H, F, OCH₃, NMe₂

d) SO₂NH₂, Br, NMe₂, NH₂, CF₃SO₂

Question 15

Which of the following statements is false when comparing 3D QSAR with conventional QSAR?

a) Only drugs of the same structural class should be studied by 3D QSAR or QSAR.

b) 3D QSAR has a predictive quality unlike QSAR.

c) Experimental parameters are not required by 3D QSAR, but are for QSAR.

d) Results can be shown graphically in 3D QSAR, but not with QSAR.

Oxford University Press, Online Resource Centre, Chapter 18.

Chapter 18

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