RESIDUE 290 17 CONECT C4 3 C5 N3 N9 CONECT C5 3 C4 C6 N7 CONECT C6 3 C5 N1 C61 CONECT C8 3 N9 N7 H8 CONECT N1 2 C6 C2 CONECT N3 3 C4 C2 HN3 CONECT O2 1 C2 CONECT C2 3 N1 N3 O2 CONECT C61 4 C6 H61 H61A H61B CONECT N9 3 C4 C8 HN9 CONECT N7 2 C5 C8 CONECT H8 1 C8 CONECT HN3 1 N3 CONECT H61 1 C61 CONECT H61A 1 C61 CONECT H61B 1 C61 CONECT HN9 1 N9 END HET 290 17 HETNAM 290 6-methyl-3,9-dihydro-2H-purin-2-one FORMUL 290 C6 H6 N4 O1