prebediolone acetate prebediolone acetate prebediolone acetate (brand names acetoxanon, acetoxanone, acetoxy-prenolon, artisone, artivis, pregnartrone, sterosone), also known as 21-hydroxypregnenolone 21-acetate or 21-acetoxypregnenolone (a.o.p.), as well as 3β,21-dihydroxypregn-5-en-20-one 21-acetate, is a synthetic pregnane steroid which is described as a glucocorticoid and has been used in the treatment of rheumatoid arthritis. it is the c21 acetate ester of prebediolone (21-hydroxypregnenolone), the c21 hydroxylated derivative of pregnenolone. prebediolone acetate has been known since at least 1950. the compound is also an intermediate in a synthesis of deoxycorticosterone acetate (21-acetoxyprogesterone). prebediolone acetateclinical datatrade namesacetoxanon, acetoxanone, acetoxy-prenolon, artisone, artivis, pregnartrone, sterosoneother names21-hydroxypregnenolone 21-acetate; pregnenolone 21-acetate; 21-acetoxypregnenolone; a.o.p.; 3β,21-dihydroxypregn-5-en-20-one 21-acetate; pregn-5-en-3β,21-diol-20-one 21-acetateidentifiers iupac name phenanthren-17-yl]-2-oxoethyl] acetate cas number566-78-9pubchem cid248856chemspider217884uniidx3xod2s6bchemblchembl1328310comptox dashboard (epa)dtxsid60878641 echa infocard100.008.454 chemical and physical dataformulac23h34o4molar mass374.521 g·mol−13d model (jsmol)interactive image smiles cc(=o)occ(=o)1cc21(cc32cc=c43(cc(c4)o)c)c inchi inchi=1s/c23h34o4/c1-14(24)27-13-21(26)20-7-6-18-17-5-4-15-12-16(25)8-10-22(15,2)19(17)9-11-23(18,20)3/h4,16-20,25h,5-13h2,1-3h3/t16-,17-,18-,19-,20+,22-,23-/m0/s1key:mdjrzsnphzemjh-mtmzyosnsa-n