Anthraquinone glycosides from Cassia roxburghii and evaluation of its free radical scavenging activity

• Published in: Carbohydrate research Vol. 360; pp. 47 - 51
• Main Authors: El-Toumy, Sayed A., El Souda, Sahar S., Mohamed, Tahia K., Brouard, Iñaki, Bermejo, Jame
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.10.2012; Elsevier
• Subjects: Anthraquinones; Anthraquinones - chemistry; Anthraquinones - isolation & purification; Anthraquinones - pharmacology; antioxidant activity; Biochemistry & Molecular Biology; Cassia; Cassia - chemistry; Cassia roxburghii; Chemistry; Chemistry, Applied; Chemistry, Organic; emodin; flavonoids; free radical scavengers; Free Radical Scavengers - chemistry; Free Radical Scavengers - isolation & purification; Free Radical Scavengers - pharmacology; Free radicals scavenging activity; glycosides; Glycosides - chemistry; Glycosides - isolation & purification; Glycosides - pharmacology; leaf extracts; leaves; Life Sciences & Biomedicine; Molecular Structure; nuclear magnetic resonance spectroscopy; Physical Sciences; Plant Leaves - chemistry; Science & Technology; Cassia roxburghii; Anthraquinones; Free radicals scavenging activity; ANTIOXIDANT ACTIVITY; SEED; FISTULA L; FLOWERS
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2012.07.020

Two new anthraquinone glycosides, namely emodin 1-O-β-glucoside (2→1) glucopyranoside (1) and aloemodin 8-O-β-glucoside (6→1) glucopyranoside (2) have been isolated from Cassia roxburghii. [Display omitted] ► Two new anthraquinone glycosides. ► NMR of the isolated compounds. ►Free radicals scavenging activity. The methanolic extract of the leaves of Cassia roxburghii DC., was investigated for its anthraquinone glycosides and antioxidant activity. Two new anthraquinone glycosides named emodin 1-O-β-d-glucopyranosyl-(1→2)-glucopyranoside (1) and aloemodin 8-O-β-d-glucopyranosyl-(1→6)-glucopyranoside (2) along with aloemodin 8-O-β-d-glucopyranoside (3), emodin (4), aloemodin (5) and one flavonoid, quercetin-3-O-α-l-rhamnopyranoside, were isolated from the leaves of C. roxburghii. Structures of the isolated compounds were established by UV, HRESI-MS, and 1D/2D 1H/13C NMR spectroscopy. The total extract and some isolated compounds were determined against DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazinyl radical, for their free radical scavenging activity, the total alcoholic extract showed strong antioxidant activity while the two new compounds showed weak antioxidant activity.