Salicylic acid (SA) derivatives are widely used for treatment of various diseases. Acetylsalicylic acid represents the most widely used drug in the world, 4-Aminosalicylic acid (4-ASA) was historically used as a systemic antituberculosis drug as well as diflunisal is a strong pain killer and antipyretic. 5-Aminosalicylic acid (5-ASA) which had been synthesized at the end of 19th century and employed first for the production of azo dyes, was then identified as a very valuable medicinal agent as well as part of many biologically active agents. 5-ASA is not metabolized to salicylic acid for pharmacological activity. It is not considered a true salicylate. In contrary to other salicylates, 5-ASA doesn’t induce upper gastrointestinal (GI) side effects. Moreover, It was found, especially, useful for treatment of inflammatory bowel diseases (IBD). It is unique among salicylates and has a broad specrum of biological activities including, anti-inflammatory, analgesic, neuroprotective and antitumor. Since we are interested in this compound and its derivatives, we prepared this review to give insight into its chemistry, anti-inflammatory activity, in particular, for treatment of IBD. Different approaches for colonic targeting of 5-ASA w ill be covered with emphasis on chemical methods as well as its proposed mechanisms of action.

In this study, hexahydro-6H-indolo[2,3-b]quinoxaline (1) was synthesized by condensation of isatin with 1,2- diaminocyclohexane. It was then reacted with methyl bromoacetate, hydrazine and finally condensed with selected carbonyl compounds to give the hydrazones 4-23. The new compounds have been characterized, screened for biological activity. Some of them showed significant antibacterial and anti-inflammatory activities. In particular, compound 20 showed interesting activities as anti-inflammtory and antibacterial.