Metabolism 1 Flashcards
What is epoxidation?
epoxies normally unstable intermediates, but maybe stable enough to be isolated from polycyclic compounds
What are the 3 oxidations involving of CYP450 that are dealkylations?
N, O, S
What is oxidative deamination?
formation of ketone and release of ammonium ions
What is N - oxidation?
N-oxides formed by CYP450 or by N-oxidates
What is phosphothionate oxidation?
replacement of phosphothionate sulfur atom with oxygen
What are the 6 oxidation metabolism reactions which are not catalysed by CYP450?
alcohol dehydrogenase aldehyde dehydrogenase Xanthine oxidase amine oxidase aromatases alkylhydrazine oxidase
What are the 9 oxidation metabolism reactions involving CYP450?
Aromatic hydroxylation aliphatic hydroxylation Epoxidation Dealkylations N,O,S oxidative deamination dehalgonation N-oxidation S-oxidation Phosphothionate oxidation
What are the two hydrolysis reactions?
ester
amide
What is glucuronidation?
conjugation with D-glucuronic acid, bypassing requirement for phase 1 metabolism
Where does O- glucrondation form and where are they excreted?
O-glucoronides form from phenols, alcohols and COOH
excreted in bile released into gut
Where are N-glucuronides formed?
amines, amides, and sulphonamides may also form spontaneously
What is sulfonation? What is the enzyme involved?
conjugation pathway for phenols, alcohols, amines and some thiols
Sulfotranferase
which conc does sulphate conjugation and glucuronide conjugation occur and why?
sulphate - low substrate conc
glue - high conc due to limited supply of PAPs (co factor in sulfation)
What is acetylation common for? what co factor is needed? and where does it take place?
aromatic amines & sulfonamides
acetyl CoA - c-factor
liver (kupffer cells) , RES (reticuloendothelial system) organs:spleen,lung, gut
What is amino acid conjugation?
COOH drugs can be conjugated with AAs
