Methoxatin derivatives

A compound of Formula I, or a salt thereof:

• wherein
• R1 and R2 are independently selected from the group consisting of H, —CH3, —C2H5, —CH2Ph, Ph, t-Bu, —CH2CH2Si(CH3)3, —CH2CCl3, —CH2═CHCH2, and —CH2CH2CN;
• X and Y are the same and are selected from the group consisting of:
• —OH, —OCH3, —OC2H5, or —OCH2Ph, or
• X and Y are taken together to form a cyclic group of —OCH2CH2O— or —OCH2CH2CH2O—, or
• X and Y are taken together to form an oxo group (═O);
• Z is H, R3-T- or R4—S—S-T-:
• T is selected from the group consisting of:
• —(CH2)n—, —(CH2)n—(OCH2CH2)m—, —(CH2)n—(OCH2CH2CH2)m—, —CH2C(═O)NHO—(CH2)n—, —CH2C(═O)NHO—(CH2)n—(OCH2CH2)m—, —CH2C(═O)NHO—(CH2)n—(OCH2CH2CH2)m—, —(CH2C(═O)NH)m—(CH2)n—, —(CH2CH2C(═O)NH)m—(CH2)n—, —(CH2)n—(NHC(═O)CH2)m—, —(CH2)n—(OCH2CH2)m—CH2NHC(O)—, and
• —(NHC(═O)CH2CH2)m—, wherein n is an integer from 2 to 12, m is an integer from 1 to 6;
• R3 is selected from the group consisting of:
• H2C═CH—,
• H2C═CHCH2O—
• HOCH2CH(OH)—, HOCH2CH(OH)CH2O—, HC≡C—, HC≡CCH2O—, (Ph)3CS—, HS—, Tr-S—, (HO)2B—, (PhO)2B—, (CH3O)2B—, CF3(CF2)f(CH2)g—, and —N3, wherein f is an integer from 1 to 11, g is 0 or an is an integer from 1 to 3;
• and
• R4 is selected from the group consisting of:
• pyridine-2-yl, 5-nitropyridin-2-yl, N3-T-, HC≡C-T-, HC≡CCH2O-T-, CF3(CF2)f(CH2)g-T-, (HO)2B-T- and