Estrogen

Question 1

What is the most potent naturally occurring estrogen?

Answer 1

17 B-estradiol

Question 2

What is special about the phenolic ring?

Answer 2

responsible for selective, high affinity binding

Question 3

Conjugated Estrogens

Answer 3

extracted from urine of pregnant mares. consists of multiple types of conjugated estrogen metabolites

Question 4

Ethinyl Estradiol

Answer 4

orally active due to addition of ethinyl group upon carbon 17 of the estrane nucleus

Question 5

Mestranol

Answer 5

prodrug converted to ethinyl estradiol

Question 6

Tamoxifen

Answer 6

agonist at bone & endometrium
antagonist in breast
Used to breast cancer with estrogen receptor positive tumors
Tamoxifen is a pure trans isomer

Question 7

Raloxifene

Answer 7

agonist at bone
antagonist in breast & endometrium
treatment of osteoporosis in postmenopausal women
SE: for postmenopausal women with coronary heart disease, may also cause DVTs and blood clots

Question 8

Ospemifene

Answer 8

used to treat painful intercourse

can cause endometrial cancer

Question 9

Clomiphene

Answer 9

binds to estrogen receptor and prevents the binding of estrogen.
blocks feedback effect of estrogen on pituitary on gonadotropin release to increase FSH, LH.
Used for infertility
May show ovarian hyper stimulation, increased incidence of multiple births, ovarian cysts

Question 10

Fulvestrant

Answer 10

Pure antiestrogen
prevents binding of estrogen to the receptor
Alters the receptor structure so that the receptor is targeted for proteosomal degradation
ER down regulated and abolishes ER mediated transcription of estrogen dependent genes

Question 11

Anastrazole

Answer 11

Selective aromastase inhibitor

Question 12

Exemestane

Answer 12

Aromatase inactivator
Exemestane is an irreversible, steroidal aromatase inactivation, structurally related to the natural substrate androstenedione. It acts as a false substrate for the aromatase enzyme.