20 Steroid Hormones: Medicinal Chemistry Duncan

Question 1

How many carbons are in the basic steroid structure?

Answer 1

17

Question 2

Which position is this carbon in?

Answer 2

1

Question 3

Which position is this carbon in?

Answer 3

5

Question 4

Which position is this carbon in?

Answer 4

6

Question 5

Which position is this carbon in?

Answer 5

10

Question 6

Which position is this carbon in?

Answer 6

11

Question 7

Which position is this carbon in?

Answer 7

14

Question 8

Which position is this carbon in?

Answer 8

15

Question 9

Which position is this carbon in?

Answer 9

17

Question 10

Which position is this carbon in?

Answer 10

21

Question 11

Which position is this carbon in?

Answer 11

19

Question 12

Which position is this carbon in?

Answer 12

18

Question 13

Which position is this carbon in?

Answer 13

20

Question 14

Beta or Alpha?

Answer 14

Alpha

Question 15

Beta or Alpha?

Answer 15

Beta

Question 16

Which form is this structure in?

Answer 16

Allo Form

Question 17

Which form is this structure in?

Answer 17

Normal form

Question 18

Which form is commonly found in the human body?

Answer 18

Allo form

Question 19

Cis or Trans?

Answer 19

Trans (up/down)

Question 20

Cis or Trans?

Answer 20

Trans (up/down)

Question 21

Cis or Trans?

Answer 21

Cis (down/down)

Question 22

What is the double bond nomenclature?

Answer 22

Delta symbol or “-ene-“

Question 23

What are the three main classes of steroid hormones?

Answer 23

Estranes, Androstanes, Pregnanes (glucocorticoids/Progestins)

Question 24

How many carbons are found in main Androstane structure?

Answer 24

19

Question 25

How many carbons are found in main Estrane structure?

Answer 25

18

Question 26

How many carbons are found in main Pregnane (Glucocorticoids/Progestins) structure?

Answer 26

21

Question 27

What class of steroid is this?

Answer 27

Androstane (Androgen)

Question 28

What class of steroid is this?

Answer 28

Estrane (Estrogen)

Question 29

What class of steroid is this?

Answer 29

Pregnane (Adrenocorticosteroid). Requires the -OH group on the 21 carbon to be in the adrenocorticoid family

Question 30

What class of steroid is this?

Answer 30

Pregnane (Progesterone)

Question 31

What is the first thing to be named in a structure?

Answer 31

The side chains

Question 32

What is the second thing to be named in a structure?

Answer 32

Structural class

Question 33

What is the third thing to be named in a structure?

Answer 33

The double bonds and ketos

Question 34

What is the chief precursor for all the steroid hormones?

Answer 34

Cholesterol

Question 35

What is the rate limiting step is the production of cholesterol?

Answer 35

The formation of mevalonic acid catalyzed by HMG-CoA reductase (target of statins)

Question 36

What needs to happen for Pregnenolone to make Progesterone?

Answer 36

The double bond is in the wrong place (C5=C6), needs to be moved to C4=C5

Question 37

What are the main things that need to happen to Pregnenolone for it to have high ACH activity?

Answer 37

Needs the double bond to be moved to C4=C5 and REQUIRES the addition of C17 OH group (missing in corticosterone)

Question 38

How does the biosynthesis of Androgens and Estrogens occur?

Answer 38

Pregnenolone (made from cholesterol) and/or progesterone are converted first to androgenic compounds. These can be further converted into the estrogens. Note: Tissues making lots of estrogens must first make lots of androgens, since these are the starting material (tissues that synthesize large amounts of androgens can have a small amount of estrogens "leak out")

Question 39

What needs to happen in the basic steps of steroid catabolism?

Answer 39

Steroids are hydrophobic in large part. To aid in their excretion, they need to be rendered more water soluble. Thus, a major late step in catabolism is linking hydrophilic molecules such as glucuronic acid or sulfate

Question 40

What happens in the catabolism of ACSs?

Answer 40

Removal of C4=C5 double bond, then the C3 =O; and also the C17-beta side chain (-COCH2OH)

Question 41

What happens in the catabolism of Estrogens?

Answer 41

Converted to either estriol (addition of C16 -OH) or a C2 methoxy, C17 keto metabolite

Question 42

What happens in the catabolism of Androgens (i.e. testosterone)?

Answer 42

C4=C5 double bond and the C3 keto are reduced. 17 hydroxy is reveresed

Question 43

How can the use of tests determine if someone is taking exogenous testosterone?

Answer 43

There is typically a 1:1 ratio of testosterone to its metabolite epitestosterone in the urine. Using exogenous testosterone-generating steroids increases testosterone, but has not effect on epitestosterone. A ratio of T:epi of greater than 1 is indicative of steroid use, a ratio of \> 4:1 is taken as evidence of abuse, illegal