Two New Antioxidant Phenylpropanoids from Lindelofia stylosa

• Published in: Chemistry & biodiversity 2008-12, Vol.5 (12), p.2676-2683
• Main Authors: Choudhary, M. Iqbal, Begum, Afshan, Abbaskhan, Ahmed, Musharraf, Syed Ghulam, Ejaz, Asma, Atta-ur-Rahman
• Format: Article
• Language: English
• Subjects: Anion-scavenging activity; Antioxidant activity; Antioxidants - chemistry; Antioxidants - isolation & purification; Antioxidants - pharmacology; Benzamides - chemistry; Boraginaceae - chemistry; Free Radical Scavengers - chemistry; Free Radical Scavengers - isolation & purification; Free Radical Scavengers - pharmacology; Glycosides; Inhibitory Concentration 50; Lindelofia stylosa; Naphthalene glycosides; Phenylpropanoids; Phenylpropionates - chemistry; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plants, Medicinal; Radical-scavenging activity; Superoxides
• ISSN: 1612-1872; 1612-1880
• DOI: 10.1002/cbdv.200890221

Two new phenylpropanoids were isolated from Lindelofia stylosa (Kar. and Kir.) and characterized as 4‐hydroxy‐N‐{4‐[(E)‐3‐(4‐hydroxy‐3‐methoxyphenyl)prop‐2‐enamido]butyl}benzamide (1) and 2‐[3‐hydroxy‐4‐(4‐hydroxyphenoxy)phenyl]‐1‐(methoxycarbonyl)ethyl (E)‐3‐(3,4‐dihydroxyphenyl)prop‐2‐enoate (2). Four known compounds, i.e. two phenylpropanoids, p‐coumaric acid (=(E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoic acid; 3) and ferulic acid (=(E)‐3‐(4‐hydroxy‐3‐methoxyphenyl)prop‐2‐enoic acid; 4), and two naphthalene glycosides, 8‐O‐β‐D‐glucopyranosyltorachrysone (5) and 8‐O‐β‐D‐glucopyranosyl‐6‐demethoxytorachrysone (6), were also isolated for the first time from the plant. Compounds 1–6 were subjected to various antioxidant assays, including DPPH radical‐ and superoxide anion‐scavenging, and Fe2+‐chelation assays. Compound 2 was found to be most active in all assays with potency nearly similar to that of propyl gallate. Besides 2, compounds 1 and 5 were also found to be active in DPPH radical‐scavenging standard assay.