1-Keto-1,2,3,4-tetrahydrophenanthrene

1-Keto-1,2,3,4-tetrahydrophenanthrene
Clinical data
Other names	THP-1; 1,2,3,4-Tetrahydrophenanthren-1-one
Identifiers
	IUPAC name 3,4-Dihydro-2H-phenanthren-1-one;
CAS Number	573-22-8 ;
PubChem CID	225683;
ChemSpider	196209;
UNII	RAN6R458LN;
ChEMBL	ChEMBL88130;
CompTox Dashboard (EPA)	DTXSID50280072 ;
Chemical and physical data
Formula	C14H12O
Molar mass	196.249 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES C1CC2=C(C=CC3=CC=CC=C23)C(=O)C1;
	InChI InChI=1S/C14H12O/c15-14-7-3-6-12-11-5-2-1-4-10(11)8-9-13(12)14/h1-2,4-5,8-9H,3,6-7H2; Key:KBARGPSSEIXDQU-UHFFFAOYSA-N;

1-Keto-1,2,3,4-tetrahydrophenanthrene (THP-1), or 1,2,3,4-tetrahydrophenanthren-1-one, is a synthetic steroid-like compound which was reported to be the first synthetic estrogen, or the first synthetic compound identified with estrogenic activity.^[1]^[2] It was first synthesized in 1933 by Cook et al. and was tested due to its similarity to the presumed chemical structure of estrone.^[1]^[2] Upon reassessment many decades later, the compound was found to bind only weakly to the estrogen receptors, and, unexpectedly, did not actually have functional activity as an estrogen or antiestrogen in vitro or in vivo.^[2] It did, however, show some androgenic and antiandrogenic activity in vitro.^[2]