The present invention provides compositions comprising lanthionine ketimine derivatives and thiomorpholine dicarboxylic acid derivatives, as well as processes for the preparation of such compounds. The invention also concerns the use of lanthionine, lanthionine ketimine (LK), LK derivatives, thiomorpholine dicarboxylic acid (TMDCA), and TMDCA derivatives. It concerns the use of these compounds for the treatment and/or prevention diseases, including diseases affecting the central nervous system. The invention provides for compounds and methods having anti-oxidant, anti-neuroinflammatory and neuroprotective activities. It also provides for compounds having the ability to pass through and/or be transported through cellular membranes, such the blood-brain barrier.