RESIDUE 4HC 18 CONECT CA 3 CA2 CA6 HA CONECT CA2 3 CA OA2 OA3 CONECT CA4 3 CA5 CD1 OA3 CONECT CA5 3 CA4 CA6 CD4 CONECT CA6 3 CA CA5 OA6 CONECT CD1 3 CA4 CD2 HD1 CONECT CD2 3 CD1 CD3 HD2 CONECT CD3 3 CD2 CD4 HD3 CONECT CD4 3 CA5 CD3 HD4 CONECT OA2 1 CA2 CONECT OA3 2 CA2 CA4 CONECT OA6 2 CA6 HA6 CONECT HA 1 CA CONECT HD1 1 CD1 CONECT HD2 1 CD2 CONECT HD3 1 CD3 CONECT HD4 1 CD4 CONECT HA6 1 OA6 END HET 4HC 18 HETSYN 4HC 4-HYDROXY-1-BENZOPYRAN-2-ONE; 4-HYDROXYCOUMARIN HETNAM 4HC 4-HYDROXY-2H-CHROMEN-2-ONE FORMUL 4HC C9 H6 O3