The present invention provides compounds having mPGES-1 inhibiting activity and being useful in the prophylactic and/or treatment of pain, rheumatism, arthritis deformans, fever, Alzheimer’s disease, multiple sclerosis, arteriosclerosis, glaucoma, hypertonic oculi, Ischemic retinopathy, systemic scleroderma and/or malignant tumor mainly on colon cancer.The present invention is related to compounds represented by formula [I-a], [I-b] or [I-c], or pharmaceutical acceptable salt thereof.[Each symbol shown in the formula has the same meanings as it is disclosed in the specification.]本發明是提供具有mPGES-1抑制活性，對疼痛、風濕性關節炎、變形性關節症、發燒、阿茲海默氏症、多發性硬化症、動脈硬化、青光眼、高眼壓症、缺血性視網膜疾病、全身性硬皮症及/或大腸癌為首的惡性腫瘍的預防或治療的之目的而有用的化合物。本發明是關於式[I-a]、[I-b]或[I-c]的化合物，或其在藥學上可容許的鹽。[式中的各代號是與說明書所述的代號同義。]
