Antioxidant constituents of Nymphaea caerulea flowers
- 作者：Vijai K. Agnihotri ; Hala N. ElSohly ; Shabana I. Khan ; Troy J. Smillie ; Ikhlas A. Khan ; Larry A. Walker
- 关键词：Nymphaea caerulea ; Nymphaeaceae ; Antioxidant activity ; 2S 3S ; 4S-trihydroxypentanoic acid ; Myricetin 3-O-(3″ ; -O-acetyl)-
//www.sciencedirect.com/scidirimg/entities/204e.gif" alt="greek small let
- 刊名：Phytochemistry
- 出版年：2008
- 期刊代码：85_00319422
- 类别：ch
- 出版时间：July 2008
- 卷：69
- 期：10
- 页码：2061-2066
- 文件大小：214 K
摘要
As part of an ongoing search for antioxidants from medicinal plants, 20 constituents were isolated from the Nymphaea caerulea flowers, including two 2S,3S,4S-trihydroxypentanoic acid (1), and myricetin 3-O-(3′′-O-acetyl)-
-l-rhamnoside (2), along with the known myricetin 3-O--l-rhamnoside (3), myricetin 3-O-β-d-glucoside (4), quercetin 3-O-(3′′-O-acetyl)--l-rhamnoside (5), quercetin 3-O--l-rhamnoside (6), quercetin 3-O-β-d-glucoside (7), kaempferol 3-O-(3′′-O-acetyl)--l-rhamnoside (8), kaempferol 3-O-β-d-glucoside (9), naringenin (10), (S)-naringenin 5-O-β-d-glucoside (11), isosalipurposide (12), β-sitosterol (13), β-sitosterol palmitate (14), 24-methylenecholesterol palmitate (15), 4-methyl-5-ergosta-7,24(28)-diene-3β,4β-diol (16), ethyl gallate (17), gallic acid (18), p-coumaric acid (19), and 4-methoxybenzoic acid (20). The structures were determined by spectroscopic means. Compounds were tested for antioxidant activity and nine compounds 2–7, 11, 12 and 18 were considered active with IC50 of 1.16, 4.1, 0.75, 1.7, 1.0, 0.34, 11.0, 1.7 and 0.95 μg/ml, respectively, while 1 was marginally active (IC50 > 31.25 μg/ml). The most promising activity was found in the EtOAc fraction (IC50 0.2 μg/ml). This can be attributed to the synergistic effect of the compounds present in it.
-l-rhamnoside (2), along with the known myricetin 3-O--l-rhamnoside (3), myricetin 3-O-β-d-glucoside (4), quercetin 3-O-(3′′-O-acetyl)--l-rhamnoside (5), quercetin 3-O--l-rhamnoside (6), quercetin 3-O-β-d-glucoside (7), kaempferol 3-O-(3′′-O-acetyl)--l-rhamnoside (8), kaempferol 3-O-β-d-glucoside (9), naringenin (10), (S)-naringenin 5-O-β-d-glucoside (11), isosalipurposide (12), β-sitosterol (13), β-sitosterol palmitate (14), 24-methylenecholesterol palmitate (15), 4-methyl-5-ergosta-7,24(28)-diene-3β,4β-diol (16), ethyl gallate (17), gallic acid (18), p-coumaric acid (19), and 4-methoxybenzoic acid (20). The structures were determined by spectroscopic means. Compounds were tested for antioxidant activity and nine compounds 2–7, 11, 12 and 18 were considered active with IC50 of 1.16, 4.1, 0.75, 1.7, 1.0, 0.34, 11.0, 1.7 and 0.95 μg/ml, respectively, while 1 was marginally active (IC50 > 31.25 μg/ml). The most promising activity was found in the EtOAc fraction (IC50 0.2 μg/ml). This can be attributed to the synergistic effect of the compounds present in it.