The present invention relates to compounds of the formula (I) wherein X1 and X2 independently represent O, NH or S, R1 and R2 are independently selected from the group consisting of a C1-C30 hydrocarbyl group, an amino acid bonded via an amide bond or a peptide bonded via an amide bond each having up to 200 amino acids, the conjugated residue X1 or X2 in this case being NH, and hydrogen, both radicals R1 and R2 preferably not being H, wherein R3 is a residue selected from group consisting of —S—R6, wherein R6 is a C1-C30 hydrocarbyl group, at least one of R1 and R2 not being H when X1 and X2 are oxygen, —S—CH2—CH(NH2)(COOH) (cysteine-S-yl), a homologue or derivative (e.g. N-acetyl cysteine-S-yl) thereof, a peptide having up to 200 amino acids which contains at least one amino acid radical with a thiol group, preferably a cysteine radical, and is bonded via the thio sulfur, preferably via the cysteine sulfur (peptide-S-yl), coenzyme A which is bonded via a thiol group or fragments thereof, acyl carrier protein bonded via a thiol group, and dihydrolipoic acid bonded via a thiol group, and pharmaceutically acceptable salts thereof. The present invention also relates to the use of these compounds for preparing a drug and drugs containing the same.