Industrial Crops and Products 58 (2014) 125–132 Contents lists available at ScienceDirect Industrial Crops and Products jo ur nal home p age: www.elsevier.com/locate/indcrop New constituents from the roots of Oenothera biennis and their free radical scavenging and ferric reducing activity Ateeque Ahmad a,1 , Dhananjay Kumar Singh b,1 , Kaneez Fatima b , Sudeep Tandon a , Suaib Luqman b,c,∗ a Process Chemistry and Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India b Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India c Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India a r t i c l e i n f o Article history: Received 7 January 2014 Received in revised form 3 April 2014 Accepted 8 April 2014 Keywords: Oenothera biennis Evening primrose Antioxidant DPPH NO scavenging FRAP a b s t r a c t In an effort to discover biologically active molecules from plants, the present study reports isolation of two new compounds [dihydroxyprenyl xanthone acetylated (1) and cetoleilyl diglucoside (2)] along with four known compounds [oenotheralanosterol A (3) and B (4), oenotheraphenoxylactone (5), and oenotheraphytyllactone (6)] from the roots of Oenothera biennis and their free radical scavenging and ferric reducing activity. The structures of the new compounds (1–2) were elucidated by 1D and 2D NMR spectral methods, viz.: COSY, HSQC, HMBC, and DEPT aided by FABMS, ESIMS, IR spectroscopy, and elemental analysis. Compounds 1–6 along with mixture of oenotheralanosterol A and B (7) and dihy- droxyprenyl xanthone (8) were evaluated for both scavenging and reducing potential using an array of in vitro assay system. Compound 7 displayed 69.83% inhibition of DPPH free radical formation whereas the ferric reducing antioxidant power of compound 5 was found maximum which showed significant relation with the presence of high phenolics and NO scavenging. Highest flavonoid content was observed in compound 8 which also scavenges NO radical formation maximally whereas compound 3 exhibit better total antioxidant capacity. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The genus Oenothera is typically an under shrub distributed in the temperate and tropical parts of the world native to Amer- ica. It belongs to the family Onagraceae commonly known as evening primrose or evening star (Anon, 1966). A variety of con- stituents were described from Oenothera species including steroids, terpenoids, fatty acids, flavonoids, and tannins (Srivastava et al., 1998). O. biennis seeds are rich dietary source of -linoleic acid (Becker, 1983) which is important for the formation of hormones. The seeds are reported to possess fatty acids (Hudson, 1984) and sterols (Fedeli et al., 1976) while the leaves contain flavonoids (Kagan, 1967; Kowalewski et al., 1968) and oenothin (Yoshida et al., 1991). Antiarthritic (Delbarre and De Grey, 1980), antitumor, and antithrombic (Yoshida et al., 1991; Gao et al., 1982) properties have been reported from this plant. The chemical constituents and its ∗ Corresponding author at: Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India. E-mail address: s.luqman@cimap.res.in (S. Luqman). 1 These authors contributed equally to this work. antimicrobial activity from O. biennis roots and its related analogues have also been reported (Shukla et al., 1999a,b, 2000; Srivastava et al., 2007). In continuation of our previous work, in this paper the isolation and structure elucidation of two new compounds, dihydroxyprenyl xanthone acetylated (1) and cetoleilyl diglucoside (2) from the roots of O. biennis is being reported. Four constituents oenotheralanos- terol A (3), oenotheralanosterol B (4), oenotheraphenoxylactone (5) oenotheraphytyllactone (6) reported previously (Ahmad et al., 2010, 2012), and some known compounds such as -sitosterol, oleanolic acid, -sitosterol-3-O--d-glucoside were also isolated and identified on the basis of 1 H, and 13 C NMR, DEPT spectroscopic studies, including 2D-NMR, COSY, HETCOR, HSQC, and chemical reactions. To the best of our knowledge and understanding, this is the first report on the isolation of two new compounds (1–2) along with four known compounds (3–6) from the roots of O. biennis. In a recent publication, the anti-inflammatory activity of O. biennis root compounds and its traditional use in arthritis management has also been reported (Singh et al., 2012). Due to the significant therapeu- tic use and medicinal value of natural products from this plant, and in an effort to discover new biologically active molecules, two new compounds (1–2) along with four known compounds (3–6) and http://dx.doi.org/10.1016/j.indcrop.2014.04.008 0926-6690/© 2014 Elsevier B.V. All rights reserved.