The present invention relates to novel compounds having a histone deacetylase 6 (HDAC6) inhibitory activity, optical isomers thereof or pharmaceutically acceptable salts thereof, a pharmaceutical use thereof, and a method for preparing the same. According to the present invention, the novel compounds, optical isomers thereof or pharmaceutically acceptable salts thereof have the histone deacetylase 6 (HDAC6) inhibitory activity, and are effective in preventing or treating HDAC6-related diseases, comprising infectious diseases； neoplasm； internal secretion； nutritional and metabolic diseases； mental and behavioral disorders； neurological diseases； eye and ocular adnexal diseases； circulatory diseases； respiratory diseases； digestive diseases； skin and subcutaneous tissue diseases； musculoskeletal system and connective tissue diseases； and teratosis or deformities, and chromosomal aberration.本發明係關於具有組蛋白去乙醯酶6 (HDAC6)抑制活性之新穎化合物、其光學異構體或其醫藥學上可接受之鹽、其醫藥用途及其製備方法。根據本發明，該等新穎化合物、其光學異構體或其醫藥學上可接受之鹽具有組蛋白去乙醯酶6 (HDAC6)抑制活性，且可有效預防或治療HDAC6相關疾病，包含傳染病；贅瘤；內分泌；營養及代謝疾病；精神及行為障礙；神經疾病；眼及眼附件疾病；循環系統疾病；呼吸道疾病；消化系統疾病；皮膚及皮下組織疾病；肌肉骨胳系統及結締組織疾病；及畸形或變形，及染色體畸變。
