Biotransformation Flashcards
Where does metabolism take place?
intestines, liver, lungs, kidneys, blood, placenta
What happens in phase I reactions and which types are there?
Change of functional group suitable for conjugation.
- Oxidation
- Hydrolysis
- Reduction
What are phase 1 enzymes?
CYP p450. Cytochrome p450
What is oxidation?
Reactions resulting in the addition of oxygen and/or the
removal of hydrogen
What are hydroxylation, S-oxidation, N-O-de-alkylation and Epoxidation?
hydroxylation: addition of O to form OH
S-oxidation: add O to S group
N-O-de-alkylation: deletion of CH to form OH
Epoxidation: ontstaat een bruggetje met O ertussen
What is aromatic hydroxylation?
additiion of OH to aromatic ring
What types of Oxidation are there?
dehydrogenases: hydrogen is removed
monoamine oxidase: break down neurotransmitters
peroxidase: in ER
How does metabolism of alcohol work?
Oxidation of alcohol –> acetaldehyde, followed by further oxidation of the
acetaldehyde –> acetate
What is hydrolysis?
A reaction with water that often involves splitting of the
molecule
What enzymes are involved in hydrolysis?
-esterases –> esters
-peptidases
-amidases
-cholinesterase –> acetylcholinesterase
What is reduction?
reaction resulting in addition of hydrogen AND/OR removal of oxygen
What are examples of reduction?
– R-OH ⇒ R-H (de-hydroxylation)
– R-C=O ⇒ R-C-OH (hydrogenation)
– R-COOH ⇒ R-C=O (decarboxylation)
– R-NO2⇒ R-NH2 (amination)
– R-C-H ⇒ R-CH3 (methylation)
What are enzymes involved in reduction reactions?
reductases
What is the goal of conjugation reactions?
-make polar group
-increase water solubility
-excretion
What are phase II reactions?
Conjugation reactions
