The present invention relates to a novel compound inhibiting Hsp 90 and to a pharmaceutical composition including same as an active ingredient. Compounds of formula 1 and formula 2 according to the present invention inhibit the accumulation of HIF-1± protein, which is an Hsp90 client protein, by suppressing Hsp90 expression, and effectively inhibit the activity of vascular endothelial growth factor (VEGF). Furthermore, said compounds have low cytotoxicity and can thus be used as an active ingredient for the treatment of diabetic retinopathy and arthritis.