Abstract: A pharmaceutical composition comprising as an active ingredient, an aromatic heterocyclic compound represented by the formula (I): [wherein Q1 represents CR2 (wherein R2 represents a hydrogen atom or the like) or the like; Q2 represents CR3 (wherein R3 represents a hydrogen atom or the like) or the like; Q3 represents a nitrogen atom or the like; R1 represents —C(?O)OR16 (wherein R16 represents a hydrogen atom or the like) or the like; R5 represents a hydrogen atom or the like; R6 represents optionally substituted cycloalkyl or the like; X and Y may be the same or different and each represent CH in which H may be substituted with a substituent or the like; and Z represents a nitrogen atom or the like] or the like is provided.

Abstract: The present invention provides 2-aminoquinazoline derivatives represented by formula (I): wherein R1 and R2 may be the same or different and each represents a hydrogen atom, substituted or unsubstituted lower alkyl, and the like; X represents a bond or CR7aR7b wherein R7a and R7b may be the same or different and each represents a hydrogen atom, and the like; when X is a bond, R3 represents substituted or unsubstituted aryl or a substituted or unsubstituted aromatic heterocyclic group; when X is CR7aR7b wherein R7a and R7b have the same meanings as defined above, respectively, R3 represents substituted or unsubstituted lower alkoxy, substituted or unsubstituted aryl, and the like; R4 represents a hydrogen atom, hydroxy, substituted or unsubstituted lower alkoxy, and the like; and R5 represents a hydrogen atom, substituted or unsubstituted aryl, and the like, or a pharmaceutically acceptable salt thereof.

Abstract: The present invention provides 2-aminoquinazoline derivatives represented by formula (I): wherein R1 and R2 may be the same or different and each represents a hydrogen atom, substituted or unsubstituted lower alkyl, and the like; X represents a bond or CR7aR7b wherein R7a and R7b may be the same or different and each represents a hydrogen atom, and the like; when X is a bond, R3 represents substituted or unsubstituted aryl or a substituted or unsubstituted aromatic heterocyclic group; when X is CR7aR7b wherein R7a and R7b have the same meanings as defined above, respectively, R3 represents substituted or unsubstituted lower alkoxy, substituted or unsubstituted aryl, and the like; R4 represents a hydrogen atom, hydroxy, substituted or unsubstituted lower alkoxy, and the like; and R5 represents a hydrogen atom, substituted or unsubstituted aryl, and the like, or a pharmaceutically acceptable salt thereof.

Abstract: The invention relates to an endothelin antagonistic peptide of the formula (I): X-A-Trp-B-Gly-Thr-E-G-Y   (I) SEQ ID NO: 2 wherein represents Asn or Asp; B represents His or Lys; E represents Ala or Ser; G represents Ala or Pro; X represents X1-Gly or  and Y represents hydroxy, lower alkoxy, amino, wherein X1, X3, Y1, Y2 and Z are further defined, or a pharmaceutically acceptable salt thereof.

Abstract: Disclosed in a peptide represented by the following formula (I):

Abstract: The invention relates to biologically pure cultures of Streptomyces sp. RE-701 (FERM BP-3624) and Streptomyces sp. RE-629 (FERM BP-4126) that produce endothelin antagonistic peptides.

Abstract: Peptides represented by the following formula (I): ##STR1## wherein A represents Asn or Asp; B represents His or Lys; and E represents Ala or Ser;(1) X.sup.1 and Y.sup.1 are combined together to form a single bond as X.sup.1 --Y1, or (2) X.sup.1 represents hydrogen and Y.sup.1 represents hydroxy;and Z represents, in case of (1),Trp-Phe-Phe-Asn-Tyr-Tyr-7Hyt-Z.sup.1Trp-Val-Tyr-Phe-Ala-His-Leu-Asp-Ile-Ile-Trp-Z.sup.1,Trp-Val-Tyr-Tyr-Ala-His-Leu-Asp-Ile-Ile-Trp-Z.sup.1,Trp-Leu-Tyr-Phe-Ala-His-Gln-Asp-Val-Ile-Trp-Z.sup.1,Trp-Phe-Phe-Asn-Tyr-R-T-Z.sup.1wherein Z.sup.1 is an organic moiety,wherein R is Tyr or a covalent bond,T is Trp, Ala, Phe, Tyr, Trp-Trp, Asn-Tyr-Tyr-Trp, Trp-Asn-Tyr-Tyr-Trp, Trp-Val-Tyr-Phe-Ala-His-Leu-Asp-Ile-Ile-Trp,or in case of (2), Z representsTrp-Val-Tyr-Phe-Ala-His-Leu-Asp-Ile-Ile-Trp-Z.sup.1Trp-Val-Tyr-Tyr-Ala-His-Leu-Asp-Ile-Ile-Trp-Z.sup.1Trp-Leu-Tyr-Phe-Ala-His-Gln-Asp-Val-Ile-Trp-Z.sup.1.