Synthesis and Bioactivity of Nitric Oxide Donor and Antioxidant Drug Hybrid

Purpose: In ischemic stroke or peripheral artery disease, there is a blockage of the arteries that results in increased free radicals and cell death. Our goal was to synthesize a hybrid compound SA-9-01 and assess the NO releasing and reactive oxygen species (ROS) scavenging ability using chemical assays. We hypothesize that the hybrid compound will prevent cell death by improving blood circulation and neutralizing ROS. Methods: SA-9-01 was synthesized using a synthetic procedure similar to a previously designed analog SA-2 and structure was verified by 1HNMR. The NO releasing activity was determined using the Griess assay by measuring the total nitrite formation. The xanthine oxidase assay was used to measure the ROS scavenging activity. Results: Compound SA-9 (25 mM) released NO at concentrations between 1.35-1.40 µM at t=90 mins sufficient to provide therapeutic activity, while a known NO donor SIN-1 released between 2-15 µM at same concentration and time point. From the xanthine oxidase assay, the scavenging ratio for SA-9-01 (250 µM) was about 20-25% at t=100 mins and comparable to previously described compound SA-2 and Baicalein (the positive control). Conclusion: Compound SA-9-01 was synthesized successfully with the correct chemical structure and was found to be a tautomer of the first batch SA-9. The Griess assay demonstrated that SA-9 releases physiological level of NO. SA-9-01 also demonstrated ROS scavenging activity. The testing of SA-9-01 in cells is under progress.