(1alpha,11alpha)-11-(Acetyloxy)-1-(methoxymethyl)-2-oxaandrosta-5,8-dieno(6,5,4-bc)furan-3,7,17-trione 19545-26-7 4-19-00-03134 (Beilstein Handbook Reference) Antibiotic SL-2052 BRN 0067676 NSC 627609 SL-2052 Wartmannin Wortmannin