Compositions and methods of use of peptides in combination with biocides and/or germicides

An antimicrobial composition comprising at least one chemically-modified peptide and a second antimicrobial compound wherein said chemically-modified peptide is represented by Formula II:

• 6
• wherein:
• X is any natural or non-natural, modified or unmodified amino acid except glutamate or aspartate;
• n=1 to 10;
• (a) when said chemically-modified peptide is 1-3 amino acids, at least one amino acid is a cationic amino acid, the net charge of said peptide at neutral pH is at least +1, and said chemically-modified peptide does not contain glutamate or aspartate;
• (b) when said chemically-modified peptide is 4-5 amino acids, at least two of the amino acids are cationic amino acids, the net charge of said peptide at neutral pH is at least +2, and said chemically-modified peptide does not contain glutamate or aspartate;
• (c) when said chemically-modified peptide is 6-8 amino acids, at least three of the amino acids are cationic amino acids, the net charge of the peptide at neutral pH is preferably at least +3, and said chemically-modified peptide does not contain glutamate or aspartate;
• and
• (d) when said chemically-modified peptide is 9-10 amino acids, at least four of the amino acids are cationic amino acids, the net charge of the peptide at neutral pH is preferably at least +4, and said chemically-modified peptide does not contain glutamate or aspartate;
• wherein:
• R1 is C1-C20 alkyl;
• C3-C6 cycloalkyl;
• C4-C20 alkenyl;
• C4-C20 alkynyl;
• C1-C20 haloalkyl;
• C3-C20 haloalkenyl;
• C3-C20 haloalkynyl;
• C2-C20 alkoxyalkyl;
• C2-C20 alkylthioalkyl;
• C2-C20 alkylsulfinylalkyl;
• C2-C20 alkylsulfonylalkyl;
• C5-C20 cycloalkylalkyl;
• C4-C20 alkenyloxyalkyl;
• C4-C20 alkynyloxyalkyl;
• C4-C20 (cycloalkyl) oxyalkyl;
• C4-C20 alkenylthioalkyl;
• C4-C20 alkynylthioalkyl;
• C6-C20 (cycloalkyl) thioalkyl;
• C2-C20 haloalkoxyalkyl;
• C4-C20 haloalkenyloxyalkyl;
• C4-C20 haloalkynyloxyalkyl;
• C4-C20 alkoxylalkenyl;
• C4-C20 alkoxyalkynyl;
• C4-C20 alkylthioalkenyl;
• C4-C20 alkylthioalkynyl;
• C4-C20 trialkylsilylalkyl;
• C1- C20 alkyl substituted with NR3R4, nitro, cyano, or phenyl optionally substituted with R5, R6, and R7;
• C1-C20 alkoxy;
• C1-C20 haloalkoxy;
• C1-C20 alkylthio;
• C1-C20 haloalkylthio;
• NR3R4;
• or phenyl, benzyl, pyridyl, furanyl, thienyl, naphthyl, pyrimidinyl, benzofuranyl, benzothienyl, or quinolinyl each optionally substituted with R5, R6 or R7;
• R2 is C1-C20 alkyl;
• C3-C6 cycloalkyl;
• C4-C20 alkenyl;
• C4-C20 alkynyl;
• C1-C20 haloalkyl;
• C3-C20 haloalkenyl;
• C3-C20 haloalkynyl;
• C2-C20 alkoxyalkyl;
• C2-C20 alkylthioalkyl;
• C2-C20 alkylsulfinylalkyl;
• C2-C20 alkylsulfonylalkyl;
• C5-C20 cycloalkylalkyl;
• C4-C20 alkenyloxyalkyl;
• C4-C20 alkynyloxyalkyl;
• C4-C20 (cycloalkyl) oxyalkyl;
• C4-C20 alkenylthioalkyl;
• C4-C20 alkynylthioalkyl;
• C6-C20 (cycloalkyl) thioalkyl;
• C2-C20 haloalkoxyalkyl;
• C4-C20 haloalkenyloxyalkyl;
• C4-C20 haloalkynyloxyalkyl;
• C4-C20 alkoxylalkenyl;
• C4-C20 alkoxyalkynyl;
• C4-C20 alkylthioalkenyl;
• C4-C20 alkylthioalkynyl;
• C4-C20 trialkylsilylalkyl;
• C1-C20 alkyl substituted with NR3R4, nitro, cyano, or phenyl optionally substituted with R5, R6, and R7;
• C1-C20 alkoxy;
• C1-C20 haloalkoxy;
• C1-C20 alkylthio;
• C1-C20 haloalkylthio;
• NR3R4;
• or phenyl, benzyl, pyridyl, furanyl, thienyl, naphthyl, pyrimidinyl, benzofuranyl, benzothienyl, or quinolinyl each optionally substituted with R5, R6 or R7;
• R3 is independently hydrogen;
• C1-C4 alkyl;
• or phenyl optionally substituted with at least one R8;
• R4 is independently hydrogen;
• C1-C8 alkyl;
• or phenyl optionally substituted with at least one R8;
• R5 is independently C1-C6 alkyl;
• C1-C6 alkoxy;
• C1-C6 haloalkyl;
• halogen;
• C2-C8 alkynyl;
• C1-C6 thioalkyl;
• phenyl or phenoxy each optionally substituted with at least one R8;
• cyano;
• nitro;
• C1-C6 haloalkoxy;
• C1-C6 haloalkythio;
• C2-C6 alkenyl;
• C2-C6 haloalkenyl;
• acetyl;
• CO2CH3;
• or N(C1-C2 alkyl)2;
• R6 is independently methyl;
• ethyl;
• methoxy;
• methylthio;
• halogen;
• or trifluoromethyl;
• R7 is independently halogen;
• R8 is independently halogen;
• C1-C4 alkyl;
• C1-C4 alkoxy;
• C1-C4 haloalkyl;
• nitro;
• or cyano;
• and
• wherein:
• said second antimicrobial compound is a compound selected from the group consisting of a biocide, a biodispersant, a germicide, a preservative, an antibacterial agent, an antiviral agent, an antifungal agent and an antiparasitic agent.