Abstract: The present invention provides a technology which enables introduction of an active ingredient (e.g. nucleic acids) into various cells with a high efficiency, and compounds used therefor. The present invention provides a compound represented by the formula: [wherein, each symbol is as defined in the present description] or a salt thereof.

Abstract: The present invention provides a heterocyclic compound having an orexin type 2 receptor agonist activity. A compound represented by the formula (I): wherein each symbol is as described in the specification, or a salt thereof, is useful as an agent for the prophylaxis or treatment of narcolepsy.

Abstract: The present invention provides a technology which enables introduction of an active ingredient (e.g. nucleic acids) into various cells with a high efficiency, and compounds used therefor. The present invention provides a compound represented by the formula: [wherein, each symbol is as defined in the present description] or a salt thereof.

Abstract: The present invention provides a heterocycle derivative having a superior amyloid ? production inhibitory activity and/or a superior ?-secretase modulation activity, and use thereof. A compound represented by the formula (I): wherein each symbol is as defined in the present specification, or a salt thereof.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a heterocycle derivative having a superior amyloid ? production inhibitory activity and/or a superior ?-secretase modulation activity, and use thereof. A compound represented by the formula (I): wherein each symbol is as defined in the present specification, or a salt thereof.

Abstract: There is provided a compound of the formula (I?): wherein x is a nitrogen or CRx, Rx is a hydrogen, etc., R1 is an optionally substituted hydrocarbon group, etc., R2 is an optionally substituted hydrocarbon group, etc., ring A is 5- to 8-membered heterocyclic ring, etc., and each of Y1, Y2 and Y3 is an optionally substituted carbon or a nitrogen, etc.; or a salt thereof or a prodrug thereof, which have CRF receptor antagonistic activity and use thereof.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a heterocycle derivative having a superior amyloid ? production inhibitory activity and/or a superior ?-secretase modulation activity, and use thereof. A compound represented by the formula (I): wherein each symbol is as defined in the present specification, or a salt thereof.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a compound represented by the formula wherein R1 is a hydrocarbon group optionally having substituent(s), amino optionally having substituent(s), hydroxy optionally having a substituent or a heterocyclic group optionally having substituent(s), R2 is a hydrogen atom or a hydrocarbon group optionally having substituent(s), R3 is a hydrogen atom, a halogen atom, a hydrocarbon group optionally having substituent(s), amino optionally having substituent(s), hydroxy optionally having a substituent or mercapto optionally having a substituent, Xa to Xe are each a carbon atom or a nitrogen atom, m is 0 to 2, and ring A to ring C are each a ring optionally having substituent(s), or a salt thereof, which is useful as an agent for the prophylaxis or treatment of a disease relating to an action of melatonin, and the like.

Abstract: The present invention provides a compound represented by the formula wherein R1 is a hydrocarbon group optionally having substituent(s), amino optionally having substituent(s), hydroxy optionally having a substituent or a heterocyclic group optionally having substituent(s), R2 is a hydrogen atom or a hydrocarbon group optionally having substituent(s), R3 is a hydrogen atom, a halogen atom, a hydrocarbon group optionally having substituent(s), amino optionally having substituent(s), hydroxy optionally having a substituent or mercapto optionally having a substituent, Xa, Xb, Xc and Xd are each a carbon atom or a nitrogen atom, provided that any one or two of Xa, Xb, Xc and Xd is/are nitrogen atom(s), m is 0 to 2, and rings A to C are each a ring optionally having substituent(s), or a salt thereof, which is useful as an agent for the prophylaxis or treatment of a disease relating to an action of melatonin, and the like.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a heterocycle derivative having a superior amyloid ? production inhibitory activity and use thereof. The present invention relates to a compound represented by the formula (I): wherein each symbol is as defined in the present specification, or a salt thereof.

Abstract: The present invention provides a heterocycle derivative having a superior amyloid ? production inhibitory activity and/or a superior ?-secretase modulation activity, and use thereof. A compound represented by the formula (I): wherein each symbol is as defined in the present specification, or a salt thereof.

Abstract: The present invention provides a compound represented by the formula wherein R1 is a hydrocarbon group optionally having substituent(s), amino optionally having substituent(s), hydroxy optionally having a substituent or a heterocyclic group optionally having substituent(s); R2 is a hydrogen atom or a hydrocarbon group optionally having substituent(s); Xa and Xb are each C, N, O or S; Xc and Xd are each C or N; m is 0-2; n is 1-3; ring A is a 5-membered ring optionally having substituent(s); ring B is a 6-membered ring optionally having substituent(s); and ring C is a 3- to 5-membered ring optionally having substituent(s), provided that when Xa, Xc and Xd are each C, then Xb is N or S, or a salt thereof, which is useful as an agent for the prophylaxis or treatment of a disease relating to an action of melatonin, and the like.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.

Abstract: The present invention provides a compound represented by the formula which is useful as an agent for the prophylaxis or treatment of diseases related to the action of melatonin, or a salt thereof and the like.