Steroids Flashcards
What do steroids have in common?
‘Gonane’ nucleus
20 carbon atoms, 4 rings
Uses of steroids
- Pill - contraception
- Strength-building
- Asthma treatments
- Cripple arthritic patient
Describe Cortisone
Produced naturally to stress (w/ adrenaline)
Suppresses immune system
Increases blood sugar
Anti-inflammatory
What part of the gonane structure is always trans?
BC
What part of the gonane structure is either Cis or Trans
AB
Name a steroid which is AB Cis
Coprostane
Name a steroid which is AB trans
Colestane
Physical properties of steroids
White crystalline solids
100-150 degree melting point
Poorly soluble in water
OK in ethanol + organic solvents
What is the precursor of all steroids?
Cholesterol
Formation of Pregneolone from Cholesterol
What are Leukotrienes?
Fatty compounds which cause inflammation + bronchitis
Two main mechanism of clinical effects to Leukotrienes
1) Leukotriene antagonist (montelukast, leukast)
2) Inhibitor of leukotriene synthesis (zileuton)
Wittig Reaction
Reaction of an aldehyde or ketone with a triphenyl phosphonium ylide to give an alkene and triphenylphosphine oxide.
Name a leukotriene antagonist
Montelukast
Name suppressors of leukotriene synthesis
Zileuton
Theophylline
Function of Zileuton
- A 5-LOX inhibitor = inhibits lipoxygenase, suppressing leukotriene synthesis
- Used for management of asthma (not relief)
Function of Theophylline
- member of xanthine family, inhibits leukotriene synthesis
- non-selective adenosine receptor antagonist
- interacts with other drugs (cimetidine, phenytoin)
- narrow therapeautic window
Aminophylline
Made up of theophylline + ethylenediamine
- ethylenediamine improves solubility
- found as dihydrate
Function of a Muscarinic antagonist
Blocks activity of muscarinic acetylcholine receptor
Examples of muscarinic antagonist + use
Ipratropium Bromide
Tiotropium Bromide (M3 receptor)
Both used in COPD, asthma
They both block acetylcholine
