Polyphenolic profile and bioactivity study of Oenothera speciosa Nutt. aerial parts.
Two new flavonol glycosides, myricetin 4'-O-alpha-L-rhamnopyranoside (1) and quercetin 3'-O-alpha-L-rhamnopyranoside (2), together with a novel biflavonol compound, speciin (3), as well as eleven phenolic metabolites, namely myricitrin (4), europetin 3-O-alpha-L-(1)C(4)-rhamnopyranoside (5), quercitrin (6), hyperin (7), rhamnetin 3-O-beta-galacto-pyranoside (8), caffeic acid (9), caffeic acid methyl ester (10), chlorogenic acid (11), chlorogenic acid methyl ester (12), gallic acid (13) and gallic acid methyl ester (14), were identified from the 80 % methanol extract of the aerial parts (leaves and stems) of Oenothera speciosa Nutt. (Onagraceae). In addition myricetin (15), quercetin (16) and ellagic acid (17) were identified from the chloroform extract. The structures were established depending on their chemical and physical analyses (UV, HR-ESIMS, 1D and 2D NMR). It was found that 80 % aqueous methanol extract of O. speciosa is non-toxic to mice up to 5 g kg(-1)b wt. The investigated extract exhibited significant antihyperglycaemic and anti-inflammatory activities in a dose dependant manner. Also, the 80 % methanol extract, myricitrin(4) and hyperin(7) showed potent antioxidant activity in vitro using 1,1-diphenyl 2-picryl hydrazyl (DPPH) radical assay.
Marzouk
Mohamed S
MS
Natural Products Group, Centre of Scientific Excellence, National Research Center, Cairo, Egypt. msmarzouk@yahoo.co.uk
Moharram
Fatma A
FA
El Dib
Rabab A
RA
El-Shenawy
Siham M
SM
Tawfike
Ahmed F
AF
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D001786:Blood Glucose / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry* / Q000494:pharmacology; D008297:Male; D000432:Methanol / Q000737:chemistry; D051379:Mice; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D031664:Oenothera / Q000033:anatomy & histology / Q000737:chemistry; D010636:Phenols / Q000737:chemistry* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols; D051381:Rats; D017207:Rats, Sprague-Dawley
D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D001786:Blood Glucose; D005419:Flavonoids; D016166:Free Radical Scavengers; D006027:Glycosides; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D000432:Methanol