Degenerative disorders, like rheumatoid arthritis (RA) are generally associated with proteolytic enzymes responsible for cartilage destruction and bone damage. Thus, development of therapeutic approaches against arthritis may include protease inhibition. The present report expresses assessing of trypsin inhibition by purpurin identified by in-silico method and assessed by wet-lab experiments. Purpurin is a pharmacologically active anthraquinone, present in Ayurvedic massaging oils, prescribed for inflammatory conditions like rheumatoid arthritis, joint aches etc. Isothermal titration calorimetry experiments identified multiple-sites protein-binding free energies of purpurin. From the present study, it could be concluded that purpurin is capable of inhibiting a serine protease, trypsin that could be of therapeutic value for rheumatoid arthritis treatment.