Antibiotic compounds, formulations and methods of use

A compound of formula (IV):

• wherein:
• RA;
• RB;
• RC;
• RD;
• RE;
• and RF each individually represents the side chain of a natural or non-natural α-amino acid in which any functional groups may be protected, preferably wherein RA;
• RB;
• RC;
• RD;
• RE;
• and RF each individually represents hydrogen, branched or linear chain C1-C4 alkyl, optionally substituted with a hydroxyl, suflhydryl, alkyl thiol ether, carboxyl, in particular a β-carboxyl or a γ-carboxyl, an aromatic or heteroaromatic substituent, in particular benzyl, guanidinium or imidazolium, and/or an amino group, preferably ε-NH3+;
• R1 represents an optionally substituted alkyl moiety, an optionally substituted benzyl moiety;
• R2 represents hydrogen, hydroxymethyl, aminoethyl, aminomethyl, or 5-(2-amino)pentanoic acid;
• R3 represents —NH2 or —N(H)—COCH2NH2;
• R4 represents an optionally substituted alkyl moiety, an optionally substituted cycloalkyl moiety;
• or an optionally substituted aryl moiety;
• and
• R5 and R6 each independently represent hydrogen or an optionally substituted alkyl moiety;
• or a pharmaceutically acceptable salt, stereoisomer, solvate, or prodrug thereof.

A compound of:

• formula (V):
• wherein:
• RA;
• RB;
• RC;
• RD;
• RE;
• and RF each individually represents the side chain of a natural or non-natural α-amino acid in which any functional groups may be protected, preferably wherein RA;
• RB;
• RC;
• RD;
• RE;
• and RF each individually represents hydrogen, branched or linear chain C1-C4 alkyl, optionally substituted with a hydroxyl, suflhydryl, alkyl thiol ether, carboxyl, in particular a β-carboxyl or a γ-carboxyl, an aromatic or heteroaromatic substituent, in particular benzyl, guanidinium or imidazolium, and/or an amino group, preferably ε-NH3+;
• R1 represents an optionally substituted alkyl moiety, an optionally substituted benzyl moiety;
• R2 represents hydrogen, hydroxymethyl, aminoethyl, aminomethyl, or 5-(2-amino)pentanoic acid;
• R4 represents an optionally substituted alkyl moiety, an optionally substituted cycloalkyl moiety;
• or
• an optionally substituted aryl moiety;
• or a pharmaceutically acceptable salt, stereoisomer, solvate, or prodrug thereof;
• or
• formula (VI):
• wherein:
• RA;
• RB;
• RC;
• RD;
• RE;
• and RF each individually represents the side chain of a natural or non-natural α-amino acid in which any functional groups may be protected, preferably wherein RA;
• RB;
• RC;
• RD;
• RE;
• and RF each individually represents hydrogen, branched or linear chain C1-C4 alkyl, optionally substituted with a hydroxyl, suflhydryl, alkyl thiol ether, carboxyl, in particular a β-carboxyl or a γ-carboxyl, an aromatic or heteroaromatic substituent, in particular benzyl, guanidinium or imidazolium, and/or an amino group, preferably ε-NH3+;
• R1 represents an optionally substituted alkyl moiety, an optionally substituted benzyl moiety;
• R2 represents hydrogen, hydroxymethyl, aminoethyl, aminomethyl, or 5-(2-amino)pentanoic acid;
• R4 represents an optionally substituted alkyl moiety, an optionally substituted cycloalkyl moiety;
• or
• an optionally substituted aryl moiety;
• or a pharmaceutically acceptable salt, stereoisomer, solvate, or prodrug thereof.