This molecule comprises three fused rings: Ring A, Ring B, and Ring C.
1. Ring A is a 1,3-diazine (an aromatic ring containing four carbons and two nitrogens arranged in a meta position).
2. Ring B, positioned centrally within the fused system, is a thiophene ring consisting of one sulfur atom and four carbon atoms.
3. Ring C is a five-membered carboncycle, with three carbons not shared with Ring B exhibiting sp3 hybridization.

Number the atoms of Ring A sequentially in a clockwise direction as N1, C2, N3, C4, C5, and C6. Rings A and B share the atoms C5 and C6, while the other two carbon atoms of Ring B are shared with Ring C.

At the C4 position of Ring A, a substituent (-S-CH2-C(O)=N-) is attached in the following sequence: a sulfur atom bonded to a methylene group (-CH2-), followed by an imine carbonyl group (-C(O)=N-) in which the imine carbon also carries a hydroxyl group.
The imine nitrogen is further bonded directly to a six-membered aliphatic cyclohexane that contains three consecutive stereocenters. This cyclohexane ring is numbered counterclockwise from C-1a to C-6a:
1. The ring carbon (C-1a) bonded to the imine is R-configured.
2. The next two ring carbons (C-2a and C-3a) are both S-configured.
3. Both C-2a and C-3a bear a methyl substituent.