A novel compound represented by the following formula (1) or a salt thereof: ##STR00001## wherein symbol "A" represents a saturated heterocyclic group, a 5-membered heteroaromatic group having two heteroatoms in the ring, a group represented by the formula A1 (R.sup.2, R.sup.3, and R.sup.4 represent hydrogen atom, hydroxyl group, etc.), etc., B represents a group represented by the formula B1 (R.sup.11 represents hydrogen atom, hydroxyl group, etc.), etc., R.sup.1 represents an alkyl group, and symbol "n" represents an integer of 2 to 6, which has a parathyroid hormone depressing action and showing low toxicity, and a medicament containing the compound or salt thereof as an active ingredient.