Chemistry of Potency of Steroids

What are components of the steroid backbone structure?

What is the name of the steroid backbone?

• 3 6-membered rings, 1 5-membered ring

• cyclopentanoperhydrophenanthrenes

What gives the steroid backbone a 3D shape?

• the 2 methyl groups

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How are the 4 rings in steroid backbone named?

What ring is 1st?

• A-D (D always the 5 membered ring, A always furthest from 5 ring)

• A ring (so carbon 1 is on A ring)

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What is numbering system of steroid backbone?

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• note: numbers snake around c and d

Is triangle away or towards you (chirality)?

Is dashed line away or towards you (chirality)?

Which should the H be on a chiral centre?

• towards

• away

• away

Does steroid backbone have chiral centres?

Why is this important?

• yes many

• can make lots of diff molecules for diff functions

What is alpha notation?

What is beta notation?

Which notation is C17 assumed to be?

• alpha is away from you (think dashing alpha)

• beta is towards you (think triangle - beta squad AJ)

• C17 assumed beta facing (so towards)

Are natural steroids, cis or trans?

What does this mean for the structure?

• trans

• due to being trans, molecules are as far away from eachother as possible, good as is low energy and prevents ring strain

If steroid ring was cis-trans-trans, what would happen to it?

• the ring would start to dip down

What does cortisol do?

• primary stress hormone

• increases glucose in the bloodstream (why not being stressed important for diabetics - also checking cortisol levels)

• enhances brains use of glucose and increases substances that repair tissue

How long does it take for cortisol to integrate with its receptor and evoke response?

• 20 minutes

• dampens inflammation

What part of steroid is modified to change function of molecule?

• changes at C17 (the tail of the steroid molecule)

What part of steroid is important in anchoring molecule to active site?

What part of steroid is important in indicating functionality of the molecule?

• backbone

• tail

What are the 3 classes of adrenocorticoids?

• glucocorticoids

• mineralocorticoids (aldosterone)

• sex hormones

What are structural requirements of a glucocorticoid?

• 3-keto group (ketone on C3)

• and 4,5 unsaturation (double bond between C3 and C4)

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If a double bond is added between C1 and C2, what changes are made in functionality of steroid?

What steroid has this double bond?

What is the drawback?

• increased inflammatory effect

• prednisolone

• increases effect, but also increase in S/E

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What can be added to C11 of steroid to increase glucocorticoid activity?

• an OH group

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What are structural requirements of mineralocorticoids?

• 3-keto (C3 ketone)

• 4,5 unsaturation (double bond between C4 and C5)

• OH on C21 (for mineralocorticoid activity- sodium and water retention)

For sex hormone steroids, what is usually absent on steroid molecule?

• C20 and C21 usually absent (so sex hormones have shorter tail)

Why is short half-life good for steroids?

• prevents hyperactivation of the immune system (effect doesnt last a super long time)