Glutathione peroxidase mimetics and uses thereof

A compound of formula 1:

• wherein,
• the compound of formula 1 is a ring;
• and X is O or NH
• M is Se or Te
• n is 0 or 1
• R1 is:
• oxygen and forms an oxo complex with M;
• oxygen and forms together with the metal, a 4-7 membered ring, which optionally is substituted by an oxo or amino group;
• or
• oxygen and forms together with the metal, a first 4-7 membered ring, which is optionally substituted by an oxo or amino group, wherein said first ring is fused with a second 4-7 membered ring, wherein said second 4-7 membered ring is optionally substituted by alkyl, alkoxy, nitro, aryl, cyano, hydroxy, amino, halogen, oxo, carboxy, thio, thioallcyl, or —NH(C═O)RA, —C(═O)NRARB, —NRARB or —SO2R where RA and RB are independently H, alkyl or aryl;
• R2, R3 and R4 are independently hydrogen, alkyl, alkoxy, nitro, aryl, cyano, hydroxy, amino, halogen, carboxy, thio, thioalkyl, or —NH(C═O)RA, —C(═O)NRARB, —NRARB or —SO2R where RA and RB are independently H, alkyl or aryl;
• or R2, R3 or R4 together, with the organometallic ring to which two of the substituents are attached, form a fused 4-7 membered ring system wherein said 4-7 membered ring is optionally substituted by alkyl, alkoxy, nitro, aryl, cyano, hydroxy, amino, halogen, oxo, carboxy, thio, thioallcyl, or —NH(C═O)RA, —C(═O)NRARB, —NRARB or —SO2R where RA and RB are independently H, alkyl or aryl;
• wherein R4 is not an alkyl;
• wherein if R2, R3 and R4 are hydrogens and R1 forms an oxo complex with M, n is 0 then M is Te;
• or
• if R2, R3 and R4 are hydrogens and R1 is an oxygen that forms together with the metal an unsubstituted, saturated, 5 membered ring, n is 0 then M is Te;
• or
• if R1 is an oxo group, and n is 0, R2 and R3 form together with the organometallic ring a fused benzene ring, R4 is hydrogen, then M is Se;
• or
• if R4 is an oxo group, and R2 and R3 form together with the organometallic ring a fused benzene ring, R1 is oxygen, n is 0 and forms together with the metal a first 5 membered ring, substituted by an oxo group a to R1, and said ring is fused to a second benzene ring, then M is Te.