Cyclotriol

Cyclotriol (developmental code name ZK-136295; also known as 14α,17α-ethanoestriol) is a synthetic estrogen which was studied in the 1990s and was never marketed.[2][1][3][4] It is a derivative of estriol with a bridge between the C14α and C17α positions.[2][1][3][5] The drug has 40% of the relative binding affinity of estradiol for the human ERα.[2] It showed an absolute bioavailability of 40% with high interindividual variability and an elimination half-life of 12.3 hours in pharmacokinetic studies in women.[1]

Cyclotriol

Clinical data
Other names	ZK-136295; Cycloestriol; 14α,17α-Ethanoestriol; 14α,17α-Ethanoestra-1,3,5(10)-triene-3,16α,17β-triol; 14,21-Cyclo-19-norpregna-1,3,5(10)-triene-3,16α,17α-triol
Routes of administration	By mouth[1]
Drug class	Estrogen
Pharmacokinetic data
Bioavailability	40%[1]
Elimination half-life	12.3 hours[1]
Identifiers
IUPAC name (8R,9S,13S,14S,16R,17R)-13-Methyl-7,8,9,11,12,13,15,16-octahydro-14,17-ethanocyclopenta[a]phenanthrene-3,16,17(6H)-triol
CAS Number	135768-83-1
PubChem CID	15967764
ChemSpider	8601225
UNII	743NA857FA
CompTox Dashboard (EPA)	DTXSID00929146
Chemical and physical data
Formula	C20H26O3
Molar mass	314.425 g·mol^−1
3D model (JSmol)	Interactive image
SMILES C[C@]12CC[C@H]3[C@H]([C@@]14CC[C@@]2([C@@H](C4)O)O)CCC5=C3C=CC(=C5)O
InChI InChI=1S/C20H26O3/c1-18-7-6-15-14-4-3-13(21)10-12(14)2-5-16(15)19(18)8-9-20(18,23)17(22)11-19/h3-4,10,15-17,21-23H,2,5-9,11H2,1H3/t15-,16-,17-,18+,19+,20+/m1/s1 Key:PAMNOUDFJQSYMD-MUJBESKKSA-N

See also

• List of estrogens § Estriol derivatives
• Cyclodiol

References

1. Baumann A, Fuhrmeister A, Brudny-Klöppel M, Draeger C, Bunte T, Kuhnz W (October 1996). "Comparative pharmacokinetics of two new steroidal estrogens and ethinylestradiol in postmenopausal women". Contraception. 54 (4): 235–42. doi:10.1016/S0010-7824(96)00194-1. PMID 8922877.
2. Michael Oettel; Ekkehard Schillinger (6 December 2012). Estrogens and Antiestrogens II: Pharmacology and Clinical Application of Estrogens and Antiestrogen. Springer Science & Business Media. pp. 10, 15, 76, 331–332. ISBN 978-3-642-60107-1.
3. Lang, Rainer; Reimann, Roland (1993). "Studies for a genotoxic potential of some endogenous and exogenous sex steroids. I. Communication: Examination for the induction of gene mutations using the ames salmonella/microsome test and the HGPRT test in V79 cells". Environmental and Molecular Mutagenesis. 21 (3): 272–304. doi:10.1002/em.2850210311. ISSN 0893-6692. PMID 8462531. S2CID 39049586.
4. Reimann R, Kalweit S, Lang R (1996). "Studies for a genotoxic potential of some endogenous and exogenous sex steroids. II. Communication: examination for the induction of cytogenetic damage using the chromosomal aberration assay on human lymphocytes in vitro and the mouse bone marrow micronucleus test in vivo". Environ. Mol. Mutagen. 28 (2): 133–44. doi:10.1002/(SICI)1098-2280(1996)28:2<133::AID-EM10>3.0.CO;2-G. PMID 8844995.
5. Hundal BS, Dhillon VS, Sidhu IS (March 1997). "Genotoxic potential of estrogens". Mutat. Res. 389 (2–3): 173–81. doi:10.1016/S1383-5718(96)00144-1. PMID 9093381.