The molecule is based on a 1,2-dihydroquinolines system (a six-membered benzene ring A fused to a six-membered ring B containing one NH). Number the ring B as N1-C2-C3-C4-C5-C6 and ring A as C5-C6-C7-C8-C9-C10. In ring B, C3 is double-bonded to C4. C2 is double-bonded to an external nitrogen. That external nitrogen bears an isopropyl group (-CH(CH3)2) as its other substituent. The indole nitrogen (position 1) is unsubstituted and carries one hydrogen. In Ring A, a methyl group is attached at C9.