D. Chemistry Flashcards
Adrenaline
R-stereoisomer
heart rate, blood vessels, air passage, metabolism
catecholamine family
Noradrenaline greater potency to a adrenoceptors rather than Beta
Adrenaline both
B1 (heart)- isoprenaline not selective
B2 selective (bronchi) - salbutamol
bigger R group near N favours selectivity to B2 over a receptors and duration
R stereoisomer is most effective
look at SAR relationships of adrenoceptor molecules
steroids
gonane nucleus: 19/20 carbon atoms
ABCD fused rings (3 6-membered….1 5-membered)
types of steroids
sex hormones
cholesterol
corticosteroids (glucocorticoids: metabolism and immune)
mineralocorticoids (renal and blood functions)
cortisone
response to stress
suppress immune system
anti inflammatory
increase blood sugar
corticosteroids (hydrocortisone) for arthritis
systemic or injoint cortisol flare (recrystallisation)
steroids for asthma
inhaled (fluticasone, beclometasone)
tablets prednisolone
wedged bond in structure-Beta bond
dotted bond- alpha bond
all four rings are chair conformation
B-C junction trans
C-D junction mostly trans
A-B trans or cis
Physical properties of steroids
White crystalline
100-250 C melt
poor soluble in water
cholesterol
precursor for all steroid hormones, bile acids, vitamin
cholesterol to pregnenolone
oxidised then oxidative cleavage
ketone side chain and isocarproic acid side product
pregnenolone to progesterone
oxidation of alcohol to ketone
then isomerisation to give a-B unsaturated system
