The present invention relates to new compounds of formula I and pharmaceutically acceptable salts and/or co-crystals thereof. The present invention also relates to pharmaceutical compositions comprising these compounds and to their use as medicaments for the prevention, prophylaxis of progression, and/or treatment of a disease in which modulation of extracellular (chemotactic) cytokines and/or TNF-alpha and or nuclear factor kappa B (NFKB) and/or inflammatory cells is beneficial, such as autoimmune diseases, like rheumatoid arthritis, oligoarthritis, spondyloarthropathy, psoriatic arthritis, psoriasis and inflammatory bowel diseases, such as Crohns' disease and ulcerative colitis.