Neuroprotective carbazole alkaloids from Streptomyces sp. HS-NF-1322 by inhibition of ferroptosis

Three rare new carbazole alkaloids, antiostatin A7 (1), ( ± )-morindolestatin B (2) and morindolestatin C (3), were obtained from a fermentation broth of the soil-derived Streptomyces sp. HS-NF-1322 strain. Their structures were assigned by various spectroscopic techniques including HR-ESI-MS and 2D NMR. These new isolates, together with ( ± )-morindolestatin (4), were assayed for their neuroprotective effects on erastin-induced ferroptosis on the PC12 and HT-22 cell lines. All of these alkaloids significantly improved cell viability, and reduced ROS production of these neuronal cells. Notably, compound 1 dramatically protected PC12 cells from ferroptosis with a higher viability than the positive drug deferoxamine at 10 μM.