L20 + L21 QSAR Analysis DB

Question 1

The number of parameters in the equation for over determination should not exceed.

e.g so if there are 40 compounds

Answer 1

The number of coumpounds/5

so if there are 20 compounds… 40/5 = 8 so 8 is the maximum number of terms in an equation.

Question 2

How does Free wilson analysis differ to Hansch?

Answer 2

It’s different to Hansch Analysis as equation is derived relating structure to activity using biological data alone.

It allows simultaneous combinations of subsitituents on molecules.

However Hansch analysis derives more reliable equations compared to free wilsons

Question 3

What are the similarities between Hansch and Free Wilson

Answer 3

Both use linear regression
Both require biological data
Both judge the reliability of P value
Both provide a Tool where you can predict activity

Question 4

what makes free wilson inferior to hansch?

Answer 4

the level of overdetermination is less than Hansch analysis, and when you want to change substituents in more than one position.

Question 5

How do you calculate a compounds activity?

Answer 5

Add up the higest activities on each position on the compound. + the mean activity.

e,g 1.3 + 1.3 + 2.5 + mean activity (which could be 6.6) = compound activity

Question 6

How to calculate the degree of overdetermination

Answer 6

total number of compounds + number of restricting equations divided by number of unknowns

e.g 17 compounds, three restricting equations = 20 parameters.

9 unknown substituent points

20/9 = 2.2