Chlorophyll and bacteriochlorophyll esters, their preparation and pharmaceutical compositions comprising them

A chlorophyll (Chl) or bacteriochlorophyll (Bchl) compound of the formula I:

• 5
• and pyro-derivatives thereof wherein the radical COXR1 at position 132 is absent,
• wherein
• X is O, S or NH;
• M is a central metal atom or represents two H atoms;
• R3 and R5 are each, independently, acetyl, vinyl, ethyl 1-hydroxyethyl or an ether or ester of said 1-hydroxyethyl radical;
• R4 is methyl or formyl;
• the dotted line at positions 7-8 represents an optional double bond;
• and
• R1 and R2, the same or different, are selected from the group consisting of:
• (i) a C1-C25 hydrocarbyl radical that may be straight or branched, saturated or unsaturated, optionally substituted by one or more radicals selected from halogen, oxo (═O), OH, CHO, COOH or NH2, or interrupted by one or more heteroatoms selected from O, S and NH, or by carbocyclic or heterocyclic moieties;
• (ii) a residue of an amino acid, an oligopeptide or a polypeptide containing a hydroxy group or of a derivative thereof selected from the group consisting of esters and N-protected derivatives, wherein said hydroxylated amino acid or derivative thereof is linked to the COO− residue of the Chl or BChl derivative through said hydroxy group;
• (iii) a residue of a peptide as defined in (ii) linked to the COO residue via a C1-C25 hydrocarbyl as defined in (i) wherein said C1-C25 saturated or unsaturated hydrocarbyl residue optionally substituted by one or more radicals selected from halogen, oxo (═O), OH, CHO, COOH or NH2, or such a residue interrupted by one or more heteroatoms selected from O, S and NH, or by a phenyl ring is further substituted by an end functional group selected from OH, COOH, or NH2;
• (iv) a residue of a cell- or tissue-specific ligand selected from an oligo-peptide and a protein directly linked to the COO− residue or via a C1-C25 hydrocarbyl as defined in (i) wherein said C1-C25 saturated or unsaturated hydrocarbyl residue optionally substituted by one or more radicals selected from halogen, oxo (═O), OH, CHO, COOH or NH2, or such a residue interrupted by one or more heteroatoms selected from O, S and NH, or by a phenyl ring, is further substituted by an end functional group selected from OH, COOH, or NH2;
• and
• (v) a residue of a mono-, oligo- or polysaccharide or from polyoxyethylene directly linked to the COO− residue or via a C1-C25 hydrocarbyl as defined in (i) wherein said C1-C25 saturated or unsaturated hydrocarbyl residue optionally substituted by one or more radicals selected from halogen, oxo (═O), OH, CHO, COOH or NH2, or such a residue interrupted by one or more heteroatoms selected from O, S and NH, or by a phenyl ring, is further substituted by an end functional group selected from OH, COOH, or NH2;
• with the proviso that R1 is not methyl when R2 is ethyl, phytyl, geranylgeranyl or the residue of an amino acid, a peptide or a protein or of derivatives thereof.