sc-8109 sc-8109 sc-8109 is a steroidal antimineralocorticoid of the spirolactone group which was never marketed. it is a potent antagonist of the mineralocorticoid receptor and is more potent than the related drug sc-5233 (of which sc-8109 is the 19-nor analogue). however, sc-8109 was found to have relatively low oral bioavailability and potency, though it nonetheless produced a mild diuretic effect in patients with congestive heart failure. spironolactone (sc-9420; aldactone), another spirolactone, followed and had both good oral bioavailability and potency, and was the first antimineralocorticoid to be marketed. sc-8109clinical dataother names19-norspirolactone; 19-nor-17α-(2-carboxyethyl)testosterone γ-lactone; 3-oxo-17β-hydroxyestr-4-ene-17-propanoic acid lactone; 17-hydroxy-3-oxo-19-nor-17α-pregn-4-ene-21-carboxylic acid γ-lactoneidentifiers iupac name (8r,9s,10r,13s,14s,17r)-13-methylspirophenanthrene-17,5'-oxolane]-2',3-dione cas number1722-54-9pubchem cid168943chemspider147774chemical and physical dataformulac21h28o3molar mass328.452 g·mol−13d model (jsmol)interactive image smiles c12cc3(1cc24ccc(=o)o4)ccc5=cc(=o)cc35 inchi inchi=1s/c21h28o3/c1-20-9-6-16-15-5-3-14(22)12-13(15)2-4-17(16)18(20)7-10-21(20)11-8-19(23)24-21/h12,15-18h,2-11h2,1h3/t15-,16+,17+,18-,20-,21+/m0/s1key:cxxaioqmcgjvht-xujomzstsa-n in addition to its antimineralocorticoid activity, sc-8109 shows potent progestogenic activity, with similar potency relative to that of progesterone. its analogue, sc-5233, possesses similar but less potent progestogenic activity. in addition, sc-5233 has been assessed and found to possess some antiandrogenic activity, antagonizing the effects of testosterone in animals, and sc-8109 may as well. relative affinities (%) of sc-8109 and related steroids compoundprarergrmrshbgcbg progesterone1003–10<1<13–10 ? ? sc-810919125–50<1<115–25 ? ? values are percentages (%). reference ligands (100%) were progesterone for the pr, testosterone for the ar, estradiol for the er, dexa for the gr, and aldosterone for the mr.