Galactoside derivative as galectin-3 inhibitor

A compound of Formula (I) below, a stereoisomer, or a pharmaceutically acceptable salt thereof:

• wherein Sp is an unsaturated or saturated C3-15 monocyclic or polycyclic carbocycle or 3- to 15-membered heterocycle, and Sp has or does not have 1 to 3 substituents selected from among halogen, CN, NO2, OH, oxo, Rx and Ry;
• A1 is H, halogen, CN, NO2, OH, Rx, or Ry;
• B1 is halogen, CN, NO2, Rx, or Ry;
• R1 and R2 are each independently H or a metabolizable group in the body;
• Rx is H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-14 cycloalkyl, 4- to 14-membered heterocycloalkyl, C6-10 aryl, 5- to 14-membered heteroaryl, C3-14 cycloalkyl-C1-6 alkyl-, (4- to 14-membered heterocycloalkyl)-C1-6 alkyl-, C6-10 aryl-C1-6 alkyl-, C6-10 aryl-C3-6 cycloalkyl-, (5- to 14-membered heteroaryl)-C1-6 alkyl-, C6-10 aryl-C6-10 aryl-, C6-10 aryl-C6-10 aryl-C1-6 alkyl, C6-10 aryloxy-C6-10 aryl-, C6-10 aryl-(5- to 14-membered heteroaryl)-, or (5- to 14-membered heteroaryl)-C6-10 aryl-C1-6 alkyl-;
• Ry's are each independently —ORx, —SRx, —NHORx, —N(OH)Rx, —C(O)Rx, —C(O)NRxRx, —C(O)ORx, —OC(O)Rx, —OC(RxRx)-C(O)Rx, —OC(RxRx)-C(O)ORx, —OC(O)NRxRx, —OC(RxRx)-C(O)NRxRx, —NRxRx, —NRxC(O)Rx, —NRxC(O)ORx, —NRxC(O)NRxRx, —C(═NRx)Rx, —C(═NRx)NRxRx, —NRxC(═NRx)NRxRx, —N═CRxRx, —NRxS(O)Rx, —NRxS(O)2Rx, —NRxS(O)2NRxRx, —S(O)Rx, —S(O)NRxRx, —S(O)2Rx, —S(O)2NRxRx, —OS(O)2Rx, —PRxRx, —P(O)RxRx, —OP(O)RxRx, —OP(O)(ORx)2, or —P(O)2RxRx;
• the C1-6 alkyl moiety has or does not have 1 to 3 substituents selected from halogen;
• the C3-14 cycloalkyl moiety, the 4- to 14-membered heterocycloalkyl moiety, the C6-10 aryl moiety and the 5- to 14-membered heteroaryl moiety each independently include a monocyclic or polycyclic ring, and have or do not have 1 to 3 substituents selected from the group consisting of halogen, OH, CN, NO2, oxo, C1-6 alkylamido, C1-6 alkoxycarbonyl, C1-6 alkyl, haloC1-6 alkyl, C1-6 alkoxy, and haloC1-6 alkoxy;
• and
• the C3-14 cycloalkyl moiety and the 4- to 14-membered heterocycloalkyl moiety are each independently saturated or unsaturated within a range having no aromaticity.