Aims: Morus alba is a plant that is well known for its medicinal properties. In Asian countries, it is traditionally used for anti-inflammatory, hypoglycemic, hypolipidemic and antioxidant applications. The aim of this study was to evaluate the antiulcer and antioxidant activity of a new steroid from M. alba. Main methods: Column chromatography was employed to isolate different compounds from M. alba. The molecular structures of the compounds were characterized via IR, UV, H-1 NMR, C-13 NMR and mass spectroscopic methods. A newly isolated compound was tested for antiulcer activity in pylorus-ligation- and ethanol-induced ulcer models and biochemically estimated for SOD, CAT, GR, GPx, GSH and LPO levels. Key findings: Five new compounds were isolated: one of these was a new steroid named albosteroid. This new compound exhibits significant (P<0.05, P<0.01 and P<0.001) antiulcer activity in pylorus-ligation- and ethanol-induced ulcer models. Furthermore, this compound showed significant dose-dependent reversal of ethanol-diminished activity in antioxidant enzymes, such as SOD, CAT, GPx and GSH, and reduced the ethanol-elevated levels of GR and LPO. Significance: The present study clearly demonstrates the anti-ulcer and antioxidant potential of compound 1, which was supported by macroscopic and histopathological studies of stomach wall tissues of differently treated groups of rats. (C) 2012 Elsevier Inc. All rights reserved.