The present invention relates to a compound of the general formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each a hydrogen or an acyl, a pharmaceutically acceptable acid addition salt thereof or a hydrate thereof; a pharmaceutical comprising this compound; a pharmaceutical composition comprising this compound and a pharmaceutically acceptable carrier; and 2-amino-2-(2-(4-(1-hydroxy-5-phenylpentyl)phenyl)ethyl)propane-1,3-diol or 2-amino-2-(2-(4-formylphenyl)ethyl)propane-1,3-diol, the derivatives of the two compounds whose amino group and/or hydroxy group are(is) protected or a salt thereof. The compound of the present invention shows superior immunosuppressive action with less toxicity and higher safety, and is useful as a drug for prevention or suppression of rejection of organs or bone marrow transplantation, or as a drug for prevention or treatment of various autoimmune diseases or allergic diseases.