Radioprotectors

A method of cancer radiotherapy which comprises administering to a subject in need of such therapy an amount effective to protect biological material of the subject from ionizing radiation damage of a compound of formula (I) effective to minimise damage to non-tumour cells and tissues, and subjecting the locus of a tumour in the subject to an ionizing radiation source:

• wherein
• X is optionally substituted alkylamino;
• Y and Z may be the same or different and are selected from N, O, S and C(R′) wherein R′ is hydrogen or optionally substituted alkyl;
• {overscore (---)} is a double bond unless the attached Y or Z group is O or S in which case it is a single bond;
• is a single bond unless the attached {overscore (---)} is a single bond in which case is a double bond and adjacent (H) is absent;
• and R1 to R11 may be the same or different and are selected from hydrogen, a sterically hindering group and an electron donating group;
• or any two of R1 to R11, Y, Z, NH and R′ may together with the carbon atoms to which they are attached form an optionally substituted ring which may contain heteroatoms provided that at least one of R1 to R11 is an electron donating group and that when X is NCH3, Y and Z are N and R1, R2 and R4 to R11 are hydrogen, then R3 is not OH or OCH2CH3;
• wherein sterically hindering groups are selected from optionally substituted alkyl, optionally substituted alkenyl, and optionally substituted ring which may contain heteroatoms, NHR, N(R)2 or OR where R is hydrogen or optionally substituted alkyl and wherein electron donating groups are selected from optionally substituted alkyl, optionally substituted alkenyl, NHR, N(R)2 or OR where R is as defined above;
• and pharmaceutically acceptable salts, hydrates, solvates and/or tautomers thereof.

A method of protecting biological materials from effects of exposure to an ionizing radiation source which comprises contacting the biological material with a compound of formula (I) for a time sufficient to allow association of the compound with DNA in the biological material:

• wherein
• X is optionally substituted alkylamino;
• Y and Z may be the same or different and are selected from N, O, S and C(R′) wherein R′ is hydrogen or optionally substituted alkyl;
• {overscore (---)} is a double bond unless the attached Y or Z group is O or S in which case it is a single bond;
• is a single bond unless the attached {overscore (---)} is a single bond in which case is a double bond and adjacent (H) is absent;
• and R1 to R11 may be the same or different and are selected from hydrogen, a sterically hindering group and an electron donating group;
• or any two of R1 to R11, Y, Z, NH and R′ may together with the carbon atoms to which they are attached form an optionally substituted ring which may contain heteroatoms provided that at least one of R1 to R11, is an electron donating group and that when X is NCH3, Y and Z are N and R1, R2 and R4 to RI11 are hydrogen, then R3 is not OH or OCH2CH3;
• wherein sterically hindering groups are selected from optionally substituted alkyl, optionally substituted alkenyl, and optionally substituted ring which may contain heteroatoms, NHR, N(R)2 or OR where R is hydrogen or optionally substituted alkyl and wherein electron donating groups are selected from optionally substituted alkyl, optionally substituted alkenyl, NHR, N(R)2 or OR where R is as defined above;
• and pharmaceutically acceptable salts, hydrates, solvates and/or tautomers thereof.

A method of protecting DNA from damage by chemotherapeutic agents which comprises administering a protective amount of a compound of formula (I) to a patient in need thereof:

• wherein
• X is optionally substituted alkylamino;
• Y and Z may be the same or different and are selected from N, O, S and C(R′) wherein R′ is hydrogen or optionally substituted alkyl;
• {overscore (---)} is a double bond unless the attached Y or Z group is O or S in which case it is a single bond, is a single bond unless the attached {overscore (---)} is a single bond in which case is a double bond and adjacent (H) is absent;
• and R1 to R11 may be the same or different and are selected from hydrogen, a sterically hindering group and an electron donating group;
• or any two of R1 to R11, Y, Z, NH and R′ may together with the carbon atoms to which they are attached form an optionally substituted ring which may contain heteroatoms provided that at least one of R1 to R11 is an electron donating group and that when X is NCH3, Y and Z are N and R1, R2 and R4 to R11 are hydrogen, then R3 is not OH or OCH2CH3;
• wherein sterically hindering groups are selected from optionally substituted alkyl, optionally substituted alkenyl, and optionally substituted ring which may contain heteroatoms, NHR, N(R)2 or OR where R is hydrogen or optionally substituted alkyl and wherein electron donating groups are selected from optionally substituted alkyl, optionally substituted alkenyl, NHR, N(R)2 or OR where R is as defined above;
• and pharmaceutically acceptable salts, hydrates, solvates and/or tautomers thereof.