Lecture 22 - Introduction to Steroids/Pulmonary

alpha face

side of steroid ring system away from you (behind plane defined by the page) —> denoted with dashed line

beta face

side of steroid ring system toward you (in front of plane defined by the page) —> denoted with solid line

A and B rings in…

alpha

C and D rings in…

beta

substituent on C-17 face

typically on B face

C-18 methyl face

typically on B face

C-19 methyl face

typically on B face

cis ring junction

both substituents at the ring junction (including H) are on the same face

trans rung junctions

the substituents at the ring junction (including H) are on opposite faces

estrane

18 carbon atoms; C-19 methyl group is replaced by H

androstane

19 carbon atoms

pregnane

21 carbon atoms with a 17 side chain (C-20 and C-21)

-ene meaning

double bond

-ol meaning

alcohol

-one meaning

ketone

what interactions is alpha face involved in

hydrophobic

what disturbs alpha face interactions

hydrophilic and/or bulky substituents

trans or cis for binding

trans (want flat)

what interactions is beta face involved in

H-bonding

what will enhance beta face interactions

polar.hydrophilic substituents

Location and type of functional group at position 3

Alcohol (OH) or ketone (C=O) are typically present

Location and type(s) of functional group(s) on the D-ring

2 carbon side chain at C-17 or C-21

how does C. Unsaturation at positions 1 (delta1) and 4 (delta4) changes the geometry of the A ring

increases glucocorticoid activity 3-4x and decreases mineralo if 1,4 diene; still increases if just 1-ene or 4-ene

biochemical roles for cholesterol

Conversion to glucocorticoid adrenal hormones (cortisol, hydrocortisone)

ketol

ketone + alcohol

common placement of ketol

17B