Lecture 13: Chemistry of Potency of Steroids Flashcards

1
Q

What are adrenocorticosteroids produced by?

A

Adrenal cortex

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2
Q

What are the three types of adrenocorticosteroids?

A
  • Glucocorticoids
  • Mineralocorticoid
  • Sex hormones
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3
Q

What are the glucocorticoids?

A
  • Cortisol
  • corticosterone
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4
Q

What are the mineralocorticoids?

A

Aldosterone

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5
Q

What are the functions of glucocorticoids?

A
  • Regulating glucose metabolism
  • Suppressing inflammation and immune response
  • Maintaining cardiovascular function
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6
Q

What three structures make up steroids?

A
  • Cyclopentano
  • Phenanthrene
  • Perhydrophenanthrene
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7
Q

What is the steroid backbone called?

A

Cyclopentanoperhydrophenanthrenes

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8
Q

What is the steroid backbone made up of?

A

Four rings A-D with 2 methyl groups, the methyl groups have solid wedged bonds

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9
Q

What is alpha and beta notation?

A

Relates to the plane within which different functional groups occupy

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10
Q

Why do steroids have different enantiomers?

A

Enantiomers differ in their interactions with enzymes, proteins, receptors and other chiral molecules. These differences in interactions lead to different biological properties, different pharmacokinetics

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11
Q

How many chiral centres do steroids have?

A

6

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12
Q

What is the purpose of wedge and dotted bonds in steroids?

A

Dictates the plane in which the functional groups and atoms are attached to the backbone. Wedge bonds stick out, dotted stick in.

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13
Q

What does beta notation mean?

A

Substituents coming out towards us - shown as a solid line

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14
Q

What does alpha notation mean?

A

Substituents going back the way - shown as a broken line

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15
Q

What notation does c17 uaully have?

A

Beta notation

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16
Q

Why is C17 important?

A

Usually a tail that is part of a steroid molecule that is functionalized and changed in order to change their efficacy and gives the clinical effect of the steroid

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17
Q

What are fusion bonds?

A

Link the two ring systems

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18
Q

What conformation can fusion bonds have?

A
  • Cis
  • Trans
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19
Q

What is a trans bond?

A

when two groups that are added across the bond and one is in alpha and one is in beta conformation

20
Q

What is a cis bond?

A

When both groups are in the same conformation

21
Q

Do natural steroids have cys type geometry?

A

No

22
Q

What do sex hormones interact with?

A

vertebrate androgen or estrogen receptors.

23
Q

What is the function of mineralocorticoids

A

Influence Salt balance and water retention

24
Q

What is the starting point for the biosynthesis of steroids?

A

Cholesterol

25
Q

What are glucocorticoids used for?

A

Treatment of rheumatoid diseases, symptomatic relief from asthma and allergic reaction and topical application for dermatologic disorders and cancer therapy (by preventing phospholipid release amongst other mechanisms)

25
Q

What are glucocorticoids used for?

A
  • Treatment of rheumatoid diseases
  • symptomatic relief from asthma and allergic reaction
  • topical application for dermatologic disorders
  • cancer therapy (by preventing phospholipid release amongst other mechanisms)
26
Q

What are the two types of glucocorticoids?

A
  • Natural
  • Synthetic
27
Q

GIve examples of natural steroids

A
  • Hydrocortisone
  • Cortisone
28
Q

Name synthetic hormones

A
  • Prednisone
  • Beclomethasone
  • Dexamathasone
  • Fluocilonone
  • Prednisolone
  • Budesonide
  • Betamethasone
  • Fluticasone
29
Q

What are the requirements for biologically active adrenocorticoids?

A
  • 3 keto group
  • 4,5 unsaturation
30
Q

What does 4,5 unsaturation mean?

A

Means a double bond is present

31
Q

What is the name of 4,5 unsaturated bond?

A

Delta 4 steroid

32
Q

Why does the A ring require 3 keto group and 4,5 unsaturation?

A

The double bond locks the ring in shape since you cant twist a double bond

33
Q

How can glucocorticoid activity be increased?

A
  • By introducing a double bond between C1 and C2 (anti-inflammatory effect enhances)
  • By introducing an 11 β-hydroxyl (OH) group
34
Q

How does adding double bonds increase activity of steroids?

A

Makes the ring planer so more likely to bind in the receptor pocket

35
Q

What is found at C17 of glucocorticoids?

A

alpha hydroxyl group

36
Q

What do mineralocorticoids have that give them thier activity?

A

Hydroxyl group on 21st position on ring D

37
Q

What are sex hormones usually like?

A

position c17 has a short ring- usllauy only 3/4 carbons

38
Q

Where are natural sex steroids made?

A
  • by the gonads
  • by adrenal glands
  • by conversion from other sex steroids
39
Q

What is the requirement of steroids to reach target receptors in cell nuclei

A

Require significant lipophilicity

40
Q

How can clearance from the lungs be reduced?

A

By increasing lipophilicity

41
Q

Why is it often impossible to avoid off target effects and longer twerm toxicity with steroids?

A

They have strong sequence homology - amino acids sequence are almost identical, very similar active sites

42
Q

What are the routes of administration for steroids?

A
  • Topical
  • Inhaled
  • Oral
  • Systemic
43
Q

What are inhaled steroids used for

A

use to treat the nasal mucosa, sinuses, bronchi, and lungs – such as beclomethasone and fluticasone.

44
Q

Name oral forms of steroids?

A
  • Prednisone
  • Prednisolone
45
Q

Name systemic forms of steroids

A
  • Hydrocortsone
  • Methylprednisolone