A compound having the following Chemical Formula 1a or 1b, an optical isomer thereof, or a pharmaceutically acceptable salt thereof: wherein, A1, A2, A3, A4 and A5 are each independently C; Q is O; R1 and R6 are each independently H or an unsubstituted or substituted alkyl, or R1 and R6 together with the nitrogen atom to which they are attached form an unsubstituted or substituted 5- to 7-membered heterocyclic ring; R3 and R4 are each independently H, halo or an unsubstituted or substituted alkyl; and R5 is amidine or guanidine; wherein, A1, A2, A3, A4, A5, A6, A7 and A8 are each independently C; Q is O; R1 and R6 are each independently H, an unsubstituted or substituted alkyl, or R1 and R6 together with the nitrogen atom to which they are attached form an unsubstituted or substituted 5- to 7-membered heterocyclic ring; R2 is H or an unsubstituted or substituted alkyl; R3 and R4 are each independently H, halo or an unsubstituted or substituted alkyl; and R5 is amidine or guanidine; the dotted line represents the presence or absence of a bond, and when the bond is present, either a double bond forms between S and N in the 5-membered heterocycle and the exocyclic nitrogen atom N of NR1R6 becomes an amino group as a substituent for the 5- membered hetero ring and R2 is not present, or a double bond forms between the carbon atom between S and N in the 5-membered heterocycle and the exocyclic nitrogen atom, so that the exocyclic nitrogen atom becomes an imino group and R6 is not present; wherein the substituent in any of formula 1a and 1b is one to three selected from the group consisting of -(CR a 2) n R b, -C OR a, -(CH 2) n -C OR a, -(CH 2) n -C NR a R b,-C NR a R b, and -NR a C R b, where R a and R b are each independently hydrogen, halo,-C OR c, C1-C4 alkyl or phenyl, n is an integer from 1 to 4, the C1-C4 alkyl or phenyl is unsubstituted or substituted with one or two -C OR c, or C1-C4 alkoxy, and R c is hydrogen, C1-C4 alkyl or benzyl. A1, A2, A3, A4 and A5 are each independently C; Q is O; R1 and R6 are each independently H or an unsubstituted or substituted alkyl, or R1 and R6 together with the nitrogen atom to which they are attached form an unsubstituted or substituted 5- to 7-membered heterocyclic ring; R3 and R4 are each independently H, halo or an unsubstituted or substituted alkyl; and R5 is amidine or guanidine; wherein, A1, A2, A3, A4, A5, A6, A7 and A8 are each independently C; Q is O; R1 and R6 are each independently H, an unsubstituted or substituted alkyl, or R1 and R6 together with the nitrogen atom to which they are attached form an unsubstituted or substituted 5- to 7-membered heterocyclic ring; R2 is H or an unsubstituted or substituted alkyl; R3 and R4 are each independently H, halo or an unsubstituted or substituted alkyl; and R5 is amidine or guanidine; the dotted line represents the presence or absence of a bond, and when the bond is present, either a double bond forms between S and N in the 5-membered heterocycle and the exocyclic nitrogen atom N of NR1R6 becomes an amino group as a substituent for the 5- membered hetero ring and R2 is not present, or a double bond forms between the carbon atom between S and N in the 5-membered heterocycle and the exocyclic nitrogen atom, so that the exocyclic nitrogen atom becomes an imino group and R6 is not present; A1, A2, A3, A4, A5, A6, A7 and A8 are each independently C; Q is O; R1 and R6 are each independently H, an unsubstituted or substituted alkyl, or R1 and R6 together with the nitrogen atom to which they are attached form an unsubstituted or substituted 5- to 7-membered heterocyclic ring; R2 is H or an unsubstituted or substituted alkyl; R3 and R4 are each independently H, halo or an unsubstituted or substituted alkyl; and R5 is amidine or guanidine; the dotted line represents the presence or absence of a bond, and when the bond is present, either a double bond forms between S and N in the 5-membered heterocycle and the exocyclic nitrogen atom N of NR1R6 becomes an amino group as a substituent for the 5- membered hetero ring and R2 is not present, or a double bond forms between the carbon atom between S and N in the 5-membered heterocycle and the exocyclic nitrogen atom, so that the exocyclic nitrogen atom becomes an imino group and R6 is not present; wherein the substituent in any of formula 1a and 1b is one to three selected from the group consisting of -(CR a 2) n R b, -C OR a, -(CH 2) n -C OR a, -(CH 2) n -C NR a R b,-C NR a R b, and -NR a C R b, where R a and R b are each independently hydrogen, halo,-C OR c, C1-C4 alkyl or phenyl, n is an integer from 1 to 4, the C1-C4 alkyl or phenyl is unsubstituted or substituted with one or two -C OR c, or C1-C4 alkoxy, and R c is hydrogen, C1-C4 alkyl or benzyl.