theory test Flashcards
physiological PH
7.4
% ionise acid equation
%A = 100 / 1+ 10 [pKa-pH]
% ionised base equation
%B = 100 / 1+1- [pH-pKa]
weak acid graph
high ph S shape
strong base graph
backwards s high pH
what is the most electron donating group
Et - ethyl
summary pKa chart
left is Pka below 5
right is pKa above 5
top left is strong acids
- carboxylic acid CO2H
top right is weak acids
- phenol
- B-lactam
bottom left is weak bases
- aromatic amine
bottom right is strong bases
- amine
- guanidine
summary of no bases and no acid groups
no N atom = no basic groups
no Oh, NH, SH = no acidic groups
cis
same side
trans
opposite sides
highest and lowest priority
4 = lowest priority = lowest atomic number
E and Z
E opposite
Z same
R
clockwise
S
anticlockwise
if H has filled in wedge
needs to have other wedge so swap from R-S or S-R
what is hydrolysis
reaction with water
molecules most prone to hydrolysis
- esters
- amides
- lactams
- carbamate
- lactones
how to change hydrolysis reaction time
- increase pH = increase in hydrolysis
- metal ions increase hydrolysis
- increase in temp = increase in hydrolysis
what is oxidation
reaction with oxygen or reversible e loss
molecules most prone to oxidation
- phenol
- alcohol
- aldehyde
- amine
- thioether
oxidation without oxygen
double phenol
= catechol
oxidation preventatives
chelating agent - trap metal ions so they cant catalyse
antioxidants - eg vit C
racemisation
transformation from R-S or S-R
- need H and C=O attached to the stereocenter
- can be less active, more active or toxic
epimerisation
same as racemisation but it is when only one centre can racemise when there is numerous other stereocenters
H20 solubility and lipid solubility
has H2O solubility increases lipid solubility decreases and vice versa
H bonds and H2O solubility
as H bonds increase H2O solubility increases
lipinskis rule of 5
- all for passive transport
1. molecular weight under 500
2. log p under 5
3. not more then 5 H donors (OH, NH groups)
4. not more then 10 H acceptors (N+O atoms)
exceptions to lipinskis rule of 5 `
- antibiotics
- antifungals
- vitamins
- cardiac glucosides
- these require active transport
equation for P
drug in organic solvent / drug in aqueous solvent
what does the P value mean
high p = prefers organic phase
low p = prefers aqueous phase
what does the log P mean
if log p is greater then 0.5 = water insoluble
if log p is less then 0.5 = water soluble
h2o bonds formed with OH
3
h2o bonds formed with o
2
h2o bonds formed with =O
2
h2o bonds formed with NH2
3
h2o bonds formed with NH
2
h2o bonds formed with N
1
h2o bonds formed with S
2
h2o bonds formed with N if attached to benzene ring
0
h2o bonds formed with NH it attached to benzene ring
1
h20 bonds formed with NH2 if attached to benzene ring
2
gastric absorption of drug in an empty stomach
empty stomach
- drug needs to exist in most lipophilic phase in order to get absorbed therefore needs to have the lowest
