► The crude tea polysaccharides (TPS) showed stronger antioxidant abilities than that of TPS fractions. ► EGCG causes a synergistic increase in the antioxidant activities of TPS fractions. ► Tea ...polysaccharides are not good antioxidants and the same as dextrans in the antioxidant activities.
The crude polysaccharides from tea leaves (TPS) looks like have good antioxidant activities. However, whether or not the antioxidant abilities of crude TPS depend on tea polyphenols in the crude TPS is not understand. Herein, TPS fractions were isolated from crude TPS and their antioxidant activities were compared. The crude TPS showed stronger antioxidant activities than that of TPS fractions. However, EGCG (6.15μg/mL) significantly enhanced DPPH radical scavenging potential of TPS fractions for each dose. Moreover, EGCG (8.0μg/mL) significantly improved the reducing power of TPS fractions. EGCG causes a synergistic increase in the antioxidant activities of TPS fractions. The antioxidant activities of dextrans in the absence and presence of EGCG were investigated to illustrate that the antioxidant activities of TPS is similar to dextrans. These results illustrated that TPS fractions hardly exhibited antioxidant activities and tea polyphenols are the major antioxidant in the crude TPS. TPS as food antioxidants is an old woman’s tale.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
HPLC chromatograms at 254nm and 280nm of flavonoids extract from D. boryanum (Willd.) Ching. Display omitted
► Characterization of flavonoids from Dryoathyrium boryanum. ► Evaluation of bioactivities ...of flavonoids from D. boryanum. ► Ferns with higher flavonoid content showed more anticancer activity.
The profiles and bioactivities of flavonoids extracted from Dryoathyrium boryanum (Willd.) Ching were investigated. The total flavonoids content in extract from D. boryanum is about 145.8mg/g. By means of HPLC–DAD–ESI–MS, the main flavonoids in D. boryanum were tentatively identified as 3-hydroxyphloretin 6′-O-hexoside, quercetin-7-hexoside, apigenin7-O-glucoside, luteolin 7-O-glucoside, apigenin 7-O-galactoside, acacetin 7-O-(α-D-apio-furanosyl) (1→6)-β-d-glucoside, 3-hydroxy phloretin 6-O-hexoside, luteolin-6-C-glucoside. 0.21mg/ml flavonoids extract from D. boryanum showed very strong superoxide anion radical scavenging potential, which is higher than that of rutin (0.25mg/ml). The extract (0.21mg/ml of flavonoids) from D. boryanum exhibited similar DPPH scavenging potential with that of rutin (0.25mg/ml). However, rutin (0.25mg/ml) showed a significantly higher reducing power and ABTS scavenging potential than that of 0.21mg/ml flavonoids extract from D. boryanum. It had no effect on acetylcholinesterase. D. boryanum can be considered as a medicinal plant and the flavonoids from D. boryanum are excellent antioxidants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Seven homoisoflavonoids and one stilbenoid, 3-(4′-methoxybenzyl)-6,7-dihydroxy-5-methoxychroman-4-one (1) which is new; 3-(4′-methoxybenzyl)-6-hydroxy-5,7-dimethoxychroman-4-one (2); ...3-(4′-methoxybenzyl)-5,7-dimethoxychroman-4-one (3); 3-(3′-hydroxy-4′-methoxybenzyl)-5,7-dimethoxychroman-4-one (4); 3-(4′-methoxybenzylidene)-5,7-dihydroxy-6-methoxychroman-4-one (5); 3-(4′-hydroxybenzylidene)-5,7-dihydroxy-6-methoxychroman-4-one (6); 3-(4′-hydroxybenzylidene)-5,7-dihydroxychroman-4-one (7) and 4,3′,5′-trihydroxy-3-methoxystilbene (8), were isolated from the yellow inter-bulb deposits from Scilla nervosa. The structures of these compounds were elucidated by 1D- and 2D-NMR and mass spectrometry. A number of extracts, fractions and compounds tested displayed bacterostatic activity with MICs ranging between 0.156 and 1.250mg/ml. Two extracts displayed significant α-glucosidase inhibitory activity and a number of extracts, fractions and compounds showed strong antioxidant activity with, compounds 1, 2 and 8 displaying lower MECs than the positive control ascorbic acid (0.0156mg/ml).
•Εthylacetate fraction of Scilla nervosa was subjected to chromatographic separation.•One new homoisoflavonoid was isolated and characterized using NMR and MS.•Εxtracts and compounds of the plant were subjected to biological assays.•Yellow deposit had broader antimicrobial spectrum than the washed bulbs.•Stilbenoid from the yellow deposit is more potent than ascorbic acid.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The crude polysaccharides from tea leaves (TPS) looks like have good antioxidant activities. However, whether or not the antioxidant abilities of crude TPS depend on tea polyphenols in the crude TPS ...is not understand. Herein, TPS fractions were isolated from crude TPS and their antioxidant activities were compared. The crude TPS showed stronger antioxidant activities than that of TPS fractions. However, EGCG (6.15 mu g/mL) significantly enhanced DPPH radical scavenging potential of TPS fractions for each dose. Moreover, EGCG (8.0 mu g/mL) significantly improved the reducing power of TPS fractions. EGCG causes a synergistic increase in the antioxidant activities of TPS fractions. The antioxidant activities of dextrans in the absence and presence of EGCG were investigated to illustrate that the antioxidant activities of TPS is similar to dextrans. These results illustrated that TPS fractions hardly exhibited antioxidant activities and tea polyphenols are the major antioxidant in the crude TPS. TPS as food antioxidants is an old womanas tale.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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