Abstract: The present invention relates to phopholipase C-inhibiting peptides which are represented by formula (I): ##STR1## wherein J.sup.1 and J.sup.2 are each hydrogen or combined together to form a single bond; W is hydrogen, a substituted or unsubstituted alkanoyl, a substituted or unsubstituted aroyl or coumaryl; X is a single bond, -Leu- or -Ser-Leu-Val-Glu-Leu-Val-Ser-Tyr-Tyr-Glu-Lys-His-Ala-Leu- (at least one of the N-terminal 14 amino acid residues may be deleted); Y is a single bond or -Pro-Val-; and Z is hydroxy or amino.

Abstract: The present invention relates to phospholipase C-inhibiting peptides which are represented by formula (I): ##STR1## wherein n represents 0 or 1; each J.sup.1 and J.sup.2 is a hydrogen atom, or J.sup.1 and J.sup.2 are combined together to form a single bond; W represents a hydrogen atom, a substituted or unsubstituted alkanoyl group, a substituted or unsubstituted aroyl group or coumaryl group; X represents a single bond, -Leu-, or -Ser-Leu-Val-Glu-Leu-Val-Ser-Tyr-Tyr-Glu-Lys-His-Ala-Leu- (wherein at least one amino acid residue may be deleted, inserted or substituted); Y represents a single bond or -Pro-Val-; R.sup.1 represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; and R.sup.2 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

Abstract: The present invention relates to a peptide which has phospholipase C-inhibiting activity and which has the amino acid sequence defined in Sequence Listing by SEQ ID: No. 1; or a modified peptide in which one or more of the amino acid residues of the above mentioned peptide are deleted, or in which one or more amino acid residues are added to the above mentioned peptide, and/or in which one or more of the amino acid residues are substituted with other amino acid residues or modified amino acid residues.