Disclosed are novel conjugates and methods for the preparation thereof. One of the methods for the preparation of a conjugate comprises a step of: acting a compound of formula (I), with a thiol-containing molecule of formula (II), wherein represents an amino acid, a peptide, a protein, an antibody, a nucleotide, an oligonucleotide, a saccharide, a polysaccharide, a polymer, a small molecule, an optionally substituted C.sub.1-C.sub.8-alkyl, an optionally substituted phenyl, or an optionally substituted aromatic 5- or 6-membered heterocyclic system; resulting in a compound of formula (III).

Compounds and embodiments of a method for treating and/or preventing autoimmune diseases are disclosed. The method includes administering to a subject having an autoimmune disease, such as an inflammatory bowel disease, a therapeutically effective amount of a compound according to formula I

##STR00001##

wherein X and Y independently are O or NR.sup.1; each R.sup.1 is independently H or C.sub.1-C.sub.6 alkyl; ring A is aryl; each R.sup.2 independently is H, alkyl, alkoxy, amide, cyano, halo, haloalkyl, hydroxyalkyl, heteroalkyl, heterocyclyl, sulfonyl, sulfonamide, or two R.sup.2 groups, taken together with the atom or atoms to which they are attached, combine to form a 4-10 membered ring system; p is 0, 1, 2, 3, or 4; R.sup.3 and R.sup.4 independently are H or C.sub.1-C.sub.6 alkyl; and R.sup.5 is halo, cyano, or C.sub.1-C.sub.6 alkyl.

Compounds and embodiments of a method for treating and/or preventing autoimmune diseases are disclosed. The method includes administering to a subject having an autoimmune disease, such as an inflammatory bowel disease, a therapeutically effective amount of a compound according to formula I ##STR00001##
wherein X and Y independently are O or NR.sup.1; each R.sup.1 is independently H or C.sub.1-C.sub.6 alkyl; ring A is aryl; each R.sup.2 independently is H, alkyl, alkoxy, amide, cyano, halo, haloalkyl, hydroxyalkyl, heteroalkyl, heterocyclyl, sulfonyl, sulfonamide, or two R.sup.2 groups, taken together with the atom or atoms to which they are attached, combine to form a 4-10 membered ring system; p is 0, 1, 2, 3, or 4; R.sup.3 and R.sup.4 independently are H or C.sub.1-C.sub.6 alkyl; and R.sup.5 is halo, cyano, or C.sub.1-C.sub.6 alkyl.