5α-Dihydrolevonorgestrel

5α-Dihydrolevonorgestrel

Clinical data
Other names	5α-Dihydrolevonorgestrel; 5α-DHLNG; 5α-LNG
Identifiers
IUPAC name (5S,8R,9R,10S,13S,14S,17R)-13-Ethyl-17-ethynyl-17-hydroxy-1,2,4,5,6,7,8,9,10,11,12,14,15,16-tetradecahydrocyclopenta[a]phenanthren-3-one
CAS Number	78088-19-4
PubChem CID	9995794
ChemSpider	8171375
UNII	7Z4S6960I5
Chemical and physical data
Formula	C21H30O2
Molar mass	314.469 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@]2(C#C)O)CC[C@@H]4[C@@H]3CCC(=O)C4
InChI InChI=1S/C21H30O2/c1-3-20-11-9-17-16-8-6-15(22)13-14(16)5-7-18(17)19(20)10-12-21(20,23)4-2/h2,14,16-19,23H,3,5-13H2,1H3/t14-,16-,17+,18+,19-,20-,21-/m0/s1 Key:BMVIRDJAPBCAPQ-WQGSDSCCSA-N

5α-Dihydrolevonorgestrel (5α-DHLNG) is an active metabolite of the progestin levonorgestrel which is formed by 5α-reductase. It has about one-third of the affinity of levonorgestrel for the progesterone receptor. In contrast to levonorgestrel, the compound has both progestogenic and antiprogestogenic activity, and hence has a selective progesterone receptor modulator-like profile of activity. This is analogous to the case of norethisterone and 5α-dihydronorethisterone. In addition to the progesterone receptor, 5α-DHLNG interacts with the androgen receptor. It has similar affinity for the androgen receptor relative to levonorgestrel (34.3% of that of metribolone for levonorgestrel and 38.0% of that of metribolone for 5α-DHLNG), and has androgenic effects similarly to levonorgestrel and testosterone. 5α-DHLNG is further transformed into 3α,5α- and 3β,5α-THLNG, which bind weakly to the estrogen receptor (0.4 to 2.4% of the RBA of E2) and have weak estrogenic activity. These metabolites are considered to be responsible for the weak estrogenic activity of high doses of levonorgestrel.

See also

• 5α-Dihydronorethisterone
• 5α-Dihydroethisterone
• 5α-Dihydronandrolone
• 5α-Dihydronormethandrone