The present invention provides a compound having a glucosylceramide synthase inhibitory action, which is expected to be useful as an agent for the prophylaxis or treatment of lysosomal storage diseases (e.g., Gaucher's disease, Fabry's disease, GM1-gangliosidosis, GM2 activator deficiency, Tay-Sachs disease, Sandhoffs disease), neurodegenerative diseases (e.g., Parkinson's disease, Lewy body dementia, multiple-system atrophy) and the like.
The present invention relates to a compound represented by the formula (I): wherein each symbol is as described in the description, or a salt thereof.