Task: Please answer the following question about the molecule with SMILES C#C[C@]1(O)CC[C@H]2[C@@H]3CCc4cc(OC)ccc4[C@H]3CC[C@@]21C.
Request: Which USAN substem can this drug or clinical candidate name be matched with?
Completion: -estr-
Task: Please answer the following question about the molecule with {SMILES__description} {SMILES#}.
{#Description|Question|Request!}: {quest#}
{#Result|Answer|Completion!}: {answ#}
C#C[C@]1(O)CC[C@H]2[C@@H]3CCc4cc(OC)ccc4[C@H]3CC[C@@]21C
C#C[C@]1(O)CC[C@H]2[C@@H]3CCc4cc(OC)ccc4[C@H]3CC[C@@]21C
(8R,9S,13S,14S,17R)-17-ethynyl-3-methoxy-13-methyl-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-17-ol
Which USAN substem can this drug or clinical candidate name be matched with?