Pharmaceutical Chemistry Test Bank
QUESTION AND SOLUTION
Q2) You are given the following data set for the activity of N, N-dimethyl-α-
bromophenethylamine derivatives as adrenergic antagonists against norepinephrine (see
the data for epinephrine in this module as a guide)
You are tasked to calculate the logvalues as well as the actual inhibitory concentrations for
both the observed and calculated values based on the following Hansch equation:
The sum (Σ) of the contributions of the lipophilicity parameter, π, and the electronic effect
parameter, σ, are listed in the table. The first task is to calculate the log logfor each
derivative (calculated column) and then calculate the observed and calculated C for each of
the values as well (see equations provided in the lesson notes).
Finally, draw a scatter plot graph in Microsoft Excel that shows the relation between
calculated and observed values for log.
Explain in your response what the values for n, r, and s represent in the above Hansch
equation. Which derivative would you consider to be the most potent for its antagonist
activity against norepinephrine at adrenergic receptors? [20 points)
Solution:
To calculate the log-values and actual inhibitory concentrations for the given data set, we will use the
Hansch equation:
log = 1.2631 - 1.6200π + 7.845σ
The values for n, r, and s in the equation represent the following:
n: The number of data points used in the analysis (in this case, n=22).
r: The correlation coefficient, which measures the strength and direction of the linear relationship
between the observed and calculated values. In this case, r=0.911, indicating a strong positive
correlation.
s: The standard error of estimate, which measures the accuracy of the calculated values. A smaller
value of s indicates a better fit between the observed and calculated values. In this case, s=0.257.
Calculation of the log-values and actual inhibitory concentrations for each derivative using the
provided data:
QUESTION AND SOLUTION
Q2) You are given the following data set for the activity of N, N-dimethyl-α-
bromophenethylamine derivatives as adrenergic antagonists against norepinephrine (see
the data for epinephrine in this module as a guide)
You are tasked to calculate the logvalues as well as the actual inhibitory concentrations for
both the observed and calculated values based on the following Hansch equation:
The sum (Σ) of the contributions of the lipophilicity parameter, π, and the electronic effect
parameter, σ, are listed in the table. The first task is to calculate the log logfor each
derivative (calculated column) and then calculate the observed and calculated C for each of
the values as well (see equations provided in the lesson notes).
Finally, draw a scatter plot graph in Microsoft Excel that shows the relation between
calculated and observed values for log.
Explain in your response what the values for n, r, and s represent in the above Hansch
equation. Which derivative would you consider to be the most potent for its antagonist
activity against norepinephrine at adrenergic receptors? [20 points)
Solution:
To calculate the log-values and actual inhibitory concentrations for the given data set, we will use the
Hansch equation:
log = 1.2631 - 1.6200π + 7.845σ
The values for n, r, and s in the equation represent the following:
n: The number of data points used in the analysis (in this case, n=22).
r: The correlation coefficient, which measures the strength and direction of the linear relationship
between the observed and calculated values. In this case, r=0.911, indicating a strong positive
correlation.
s: The standard error of estimate, which measures the accuracy of the calculated values. A smaller
value of s indicates a better fit between the observed and calculated values. In this case, s=0.257.
Calculation of the log-values and actual inhibitory concentrations for each derivative using the
provided data:
