Polyphenols and antioxidant capacity of Bulgarian medicinal plants

Extracts of 21 plants used in Bulgarian phytotherapy for the treatment of respiratory, gastrointestinal and other inflammatory disorders were screened in vitro for antioxidant activity and phenolic compounds content. Plant extracts were prepared as herbal teas following the ethnic use. The water-phase TEAC (Trolox equivalent antioxidant capacity) of the teas were compared to that of the famous tea-like beverages mate, rooibos and honeybush, and to that of green and black tea, well known for their high antioxidant potential. The content of total phenolics in the teas was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as quercetin equivalents (QE). Seven Bulgarian medicinal plants were with high phenolics content and antioxidant properties: Pulmonaria officinalis L. (Boraginaceae) (TEAC 2.02+/-0.14 mM/QE 673.39+/-9.92 microM), Hypericum perforatum L. (Hypericaceae) (TEAC 3.75+/-0.14 mM/QE 881.93+/-6.68 microM), Agrimonia eupatoria L. (Rosaceae) (TEAC 3.76+/-0.5mM/QE 702.29+/-6.82 microM), Origanum vulgare L. (Lamiaceae) (TEAC 5.87+/-0.2mM/QE 1653.61+/-11.52 microM), Melissa officinalis L. (Lamiaceae) (TEAC 4.06+/-0.31 mM/QE 1370.09+/-41.38 microM), Rubus sp. diversa (Rosaceae) (TEAC 4.23+/-0,12 mM/QE 608.95+/-5.95 microM), Cotinus coggygria Scop. (Anacardiaceae) (TEAC 7.05+/-0.19 mM/QE 923.33+/-14.19 microM). Therefore, Bulgarian herbs can be considered to be a rich source of water-soluble antioxidants and/or phenolic compounds as compared to studied foreign plants.     

Isolation and characterization of a new hispolone derivative from antioxidant extracts of Pistacia atlantica

The quantification of the total phenolic compounds of Pistacia atlantica showed that the different parts of the tree are rich in natural phenolic compounds. The antioxidant tests proved that the phenolic extracts have a strong antioxidant activity. The positive correlation between the Trolox equivalent antioxidant capacity (TEAC) and the amount of phenolic compounds confirms their contribution to the antioxidant activity. Among the various phenolic compounds isolated and characterized by spectroscopic methods, a new natural antioxidant 1 (methyl 5‐(3,4‐dihydroxyphenyl)‐3‐hydroxypenta‐2,4‐dienoate) derived from hispolone 2 has been isolated from the mushroom Inonotus hispidus growing on Pistacia atlantica. Hispolone 2 (6‐(3,4‐dihydroxyphenyl)‐4‐hydroxyhexa‐3,5‐dien‐2‐one) and hispidin 3 (6‐(2‐(3,4‐dihydroxyphenyl)vinyl)‐4‐hydroxy‐2H‐pyran‐2‐one) have been also identified using spectroscopic methods, including 2D‐NMR and EI‐MS. Copyright © 2009 John Wiley & Sons, Ltd.     

Comparison of antioxidant activity and phenolic content of three lichen species

The antioxidant activities (AA), reducing powers (RP) and total phenolic contents (TPC) of methanol and water extracts of three lichen species, Usnea longissima Ach., Usnea florida (L.) Weber ex Wigg. and Lobaria pulmonaria (L.) Hoffm. were determined in vitro. Of the extracts tested, the methanol extracts of Lobaria pulmonaria and Usnea longissima showed potent antioxidant activities. The methanol extract of L. pulmonaria also had the highest total phenolic contents (87.9 mg/g lyophylisate). For the methanol extract of this species, there was also a strong correlation between antioxidant activity and total phenolic contents. However, a similar correlation was not observed for U. longissima. Although the methanol extract of U. longissima had a lower phenolic content (38.6 mg/g lyophylisate), it exhibited potent antioxidant activity. On the other hand, there was a strong correlation between the reducing powers and the total phenolic contents of the extracts. The highest reducing power was determined for the methanol extract of L. pulmonaria.     

In vitro antiproliferative and antioxidant activities of the extracts of Muntingia calabura leaves

The in vitro antiproliferative and antioxidant activities of the aqueous, chloroform and methanol extracts of Muntingia calabura leaves were determined in the present study. Assessed using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, the aqueous and methanol extracts of M. calabura inhibited the proliferation of MCF-7, HeLa, HT-29, HL-60 and K-562 cancer cells while the chloroform extract only inhibited the proliferation of MCF-7, HeLa, HL-60 and K-562 cancer cells. Interestingly, all extracts of M. calabura, which failed to inhibit the MDA-MB-231 cells proliferation, did not inhibit the proliferation of 3T3 (normal) cells, indicating its safety. All extracts (20, 100 and 500 μg/ml) were found to possess antioxidant activity when tested using the DPPH radical scavenging and superoxide scavenging assays with the methanol, followed by the aqueous and chloroform, extract exhibiting the highest antioxidant activity in both assays. The total phenolic content for the aqueous, methanol and chloroform extracts were 2970.4 ± 6.6, 1279.9 ± 6.1 and 2978.1 ± 4.3 mg/100 g gallic acid, respectively. In conclusion, the M. calabura leaves possess potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds, and thus, needs to be further explored.     

Evaluation of the antioxidant activity of wheatgrass (Triticum aestivum L.) as a function of growth under different conditions

The antioxidant activity of wheatgrass, which is consumed as a dietary supplement, was estimated at different levels. The methods employed include FRAP (ferric reducing antioxidant power), ABTS (2,2'-azobis-3-ethylbenzthiazoline-6-sulfonic acid) and DPPH (1,1'-diphenyl-2-picrylhydrazyl) assays. Aqueous and ethanol extracts of wheatgrass grown under different conditions over a period of 6, 7, 8, 10 and 15 days were used. Lipid peroxidation and oxygen radical absorbance capacity (ORAC) were determined and utilized to check the potency of a few selected extracts. Different conditions used for growth were (1) tap water, (2) tap water with nutrients, (3) soil and tap water, and (4) soil with nutrients. For comparison, a commercially available wheatgrass tablet was analysed. To explain the reasons behind the observed differences, the total phenolic and flavonoid contents of the extracts were measured. These contents increased with growth under all the conditions. The ethanol extracts were found to have a higher phenolic and flavonoid content than the aqueous extracts. The highest FRAP values occurred on day 15 of growth under condition 4, the values being 0.463 and 0.573 mmol of ascorbic acid and Trolox equivalents/100 g fresh wheatgrass for aqueous and ethanol extracts, respectively. In the aqueous extracts no specific trend was observed with the DPPH assay for the different conditions nor for the growth period. In the case of ethanol extracts, however, it increased with the growth period and the wheatgrass grown in condition 4 was found to be the most effective. These extracts were also found to inhibit significantly ascorbate-Fe2+ induced lipid peroxidation in rat liver mitochondria. The ORAC values of aqueous and ethanol extracts of day 10 with condition 4 were found to be 39.9 and 48.2, respectively, being higher than those reported for many natural extracts or vegetables.     

In vitro antiproliferative and antioxidant activities and total phenolic contents of the extracts of Melastoma malabathricum leaves

The present study aims to determine the in vitro antiproliferative and antioxidant activities of various extracts from the leaves of Melastoma malabathricum using various established in vitro assays. The aqueous extract inhibited the proliferation of Caov-3 and HL-60 cell lines, while the chloroform extract exhibited antiproliferative activity against the Caov-3, HL-60, and CEM-SS cell lines. The methanol extract demonstrated antiproliferative activity against more cell lines, including the MCF-7, HeLa, Caov-3, HL-60, CEM-SS, and MDA-MB-231 cancer cell lines. Interestingly, all extracts did not inhibit the proliferation of 3T3 cells, thus indicating their noncytotoxic properties. Unlike the chloroform extracts, the aqueous and methanol extracts of M malabathricum (20, 100, and 500 μg/ml) produced high antioxidant activity for the superoxide scavenging assay with only the 500 μg/ml aqueous and methanol extracts exhibited high activity for the 2,2-diphenyl -1-picrylhydrazyl radical scavenging assay. The total phenolic content recorded for the aqueous, methanol, and chloroform extracts were 3344.2 ± 19.1, 3055.1 ± 8.7, and 92.5 ± 7.3 mg/100 g of gallic acid, respectively. The M malabathricum leaves possessed potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds.     

Chemical compositions, anti-inflammatory, antiproliferative and radical-scavenging activities of Actinidia callosa var. ephippioides

Oxidative stress and inflammation are related to several chronic diseases including cancer. Actinidia callosa var. ephippioides (ACE) is a special folk medicinal plant from Taiwan. The aim of this study is to evaluate the antioxidant, anti-inflammatory, and antiproliferative activities of the methanol extract and fractions from the stem of ACE. Trolox Equivalent Antioxidant Capacity (TEAC), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, total phenolic content, flavonoid content, inhibition on nitric oxide (NO) productions by LPS-induced RAW264.7 cell, and on lung cancer cell proliferation were employed. Among all fractions, ethyl-acetate fraction (EA-ACE) showed higher TEAC, DPPH radical scavenging activities, polyphenol and flavonoid contents, respectively. EA-ACE also decreased the LPS-induced NO production and expressions of inducible nitric-oxide synthase (iNOS) in RAW264.7 cells. EA-ACE had the highest antiproliferative activity with an IC(50) (The concentrations required for inhibition of 50% of cell viability) of 469.17 ± 3.59 μg/mL. Catechin also had good effects in the antioxidant and anti-inflammatory activities. Catechin might be an important bioactive compound in the stem of ACE. The above experimental data indicated that the stem of ACE is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.     

Antioxidant, anti-inflammatory, and antiproliferative activities of Taxillus sutchuenensis

Inflammation is related to several chronic diseases, including cancer and atherosclerosis. Taxillus sutchuenensis (Lecomte) Danser is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antiproliferative activities of the aqueous-thanol extract from T. sutchuenensis (AETS) and its fractions. TEAC, DPPH radicals, total phenolic compounds, total flavonoid content, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were tested. Among all fractions, the ethyl-acetate (EA) fraction showed the highest TEAC and DPPH radical scavenging activities. The EA fraction also had the highest polyphenol and flavonoid content. The EA fractions also decreased LPS-induced NO production and the expression of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the aqueous/ethanol extract and fractions were studied in vitro using A549 cells, and the results were consistent with their antioxidant capacities. EA fractions had the highest antiproliferative activity with an IC(50) of 454.38 ± 1.48 μg/ml. Quercetin also had antioxidant, anti-inflammatory, and antiproliferative activities. Quercetin might be an important bioactive compound in T. sutchuenensis. The experimental data indicated that T. sutchuenensis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.     

锁阳中粗多酚和粗多糖抗氧化活性的比较△

目的:比较锁阳粗多酚和粗多糖的抗氧化活性,为锁阳入药提供依据.方法:100 g锁阳粉末提取粗多酚和粗多糖.采用超声波辅助乙醇法提取粗多酚,依次用石油醚、三氯甲烷、醋酸乙酯和正丁醇进行萃取.同时用水提醇沉法提取粗多糖.用DPPH·法和ABTS+法进行锁阳粗多酚和粗多糖的抗氧化活性检测.结果:多酚粗提物中的总酚含量达到了922.9 mgGAE·g-1(没食子酸当量),而多糖粗提物中的多糖含量为366.6 mg·g-1(葡萄糖当量).DPPH.法检测锁阳粗多酚和粗多糖的IC50值分别为79.3 μg· mL-1和145.6 μg· mL-1.经ABTS+法检测,二者的TEAC值分别为2.12 mmol·g-1和0.69 mmol·g-1.结论:锁阳粗多酚的抗氧化活性远高于锁阳粗多糖.     

异叶蛇葡萄和蛇葡萄提取物抑制黄嘌呤氧化酶和脂质氧化酶的活性研究

蛇葡萄和异叶葡萄是湖北地区应用的具有抗病毒作用的药用植物,它们的抗氧化活性用酶的和非酶的体外抗氧化测定方法进行研究.实验结果显示,两种植物的提取物具有抑制黄嘌呤氧化酶和脂质氧化酶的活性;用Trolox等价抗氧化能力(TEAC)方法测定,显示两种提取物是ABTS· 自由基离子的清除剂,与葡萄种子提取物相比较,显示具有较强的抗氧化能力.     

Bioavailability of Bioactive Molecules from Olive Leaf Extracts and its Functional Value

Olive leaves are an important low‐cost source of bioactive compounds. The present study aimed to examine the effect of in vitro digestibility of an olive leaf aqueous extract so as to prove the availability of its phenolic compounds as well as its antioxidant, antimicrobial, and anticancer activity after a simulated digestion process. The total phenolic content was significantly higher in the pure lyophilized extract. Phenolic compounds, however, decreased by 60% and 90% in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), respectively. Regarding antioxidant activity, it was reduced by 10% and 50% after gastric and intestinal digestion, respectively; despite this fact, high antioxidant capacity was found in both SGF and SIF. Moreover, the olive leaf extract showed an unusual combined antimicrobial action at low concentration, which suggested their great potential as nutraceuticals, particularly as a source of phenolic compounds. Finally, olive leaf extracts produced a general dose‐dependent cytotoxic effect against U937 cells. To sum up, these findings suggest that the olive leaf aqueous extract maintains its beneficial properties after a simulated digestion process, and therefore its regular consumption could be helpful in the management and the prevention of oxidative stress‐related chronic disease, bacterial infection, or even cancer. Copyright © 2016 John Wiley & Sons, Ltd.     

In vitro antioxidant and antimicrobial activity of extracts from Morus alba L. leaves, stems and fruits

In this study, the aqueous and ethanolic extracts (leaves, stems and fruits) from Morus alba L., a traditional Chinese medicine, were evaluated for their antioxidant and antimicrobial properties. Ethanolic extracts showed higher contents of both total phenolics and flavonoids than aqueous extracts. The total phenolic content was in the order of: leaf extracts > fruit extracts > stem extracts, whereas the total flavonoids was: leaf extracts > stem extracts > fruit extracts. Using DPPH assays, the concentrations providing 50% inhibition (IC(50)) values of aqueous extracts from leaves, stems and fruits were 7.11 ± 1.45 mg/ml, 86.78 ± 3.21 mg/ml and 14.38 ± 2.83 mg/ml, respectively, whereas the IC(50) values of ethanolic extracts were 3.11 ± 0.86 mg/ml, 14.62 ± 2.45 mg/ml and 12.42 ± 2.76 mg/ml, respectively. In sum, the antioxidant activities of ethanolic extracts from M. alba L. were stronger than the aqueous extracts, and in the order of: leaf extracts > fruit extracts > stem extracts. The ethanolic extracts exhibited moderate antimicrobial activities, whereas the aqueous extracts showed poor antimicrobial properties in our test system. This study validated the medicinal potential of M. alba L.     

Studies on antioxidant,hepatoprotective, and vasculoprotective potential of Viola odorata and Wrightia tinctoria

We have reported the antidyslipidemic, antihypertensive, and Ca⁺⁺ channel blocking activities of Viola odorata (VO) and Wrightia tinctoria (WT). This study extends our understanding of their therapeutic potential by exploring the effects on biomarkers of hepatic and vascular dysfunction together with phytochemical standardization and antioxidant potential. Total phenolic compounds, total flavonoids content, and proanthocyanins of the methanolic extracts were identified using HPLC. Antioxidant capacity was measured using the in vitro assays. Two studies of 6‐week duration were conducted on a high‐fat diet rat model to test the leaves and seed extracts of VO and WT (300 and 600 mg/kg) for their effect on biomarkers for hepatic and vascular dysfunction. The HPLC analysis showed high contents of total phenolic compounds, total flavonoids content, and proanthocyanins along with distinctive phenolic composition. Both extracts exhibited significant antioxidant potential in 1,1‐diphenyl‐2‐picrylhydrazyl, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid), fluorescence recovery after photobleaching, and total antioxidant capacity (TAC) assays, comparable with synthetic standard antioxidants. The in vivo studies indicated a significant reduction in the high‐fat‐diet‐induced rise in serum uric acid, phosphorus, aspartate aminotransferase, alanine aminotransferase, and gamma‐glutamyl transferase. This study indicates the potential of VO and WT to protect from vascular and hepatic damage and an antioxidant effect, thus making these herbs strong candidates for managing cardiometabolic disorders.     

Hepatoprotective effects of lychee (Litchi chinensis Sonn.): a combination of antioxidant and anti-apoptotic activities

Aim of the study

Gimjeng and Chakapat lychee (Litchi chinensis Sonn.) were evaluated for hepatoprotective activity on CCl₄-induced hepatotoxicity in rats.

Materials and methods

Fruit pulp extracts of the lychees were examined for vitamin C, phenolic contents, anti-lipid peroxidation activity and hepatoprotective effect. Male Wistar albino rats were intraperitoneally injected (ip) with CCl₄ (2 ml/kg), then were orally administered (po) with silymarin (100 mg/kg), and Gimjeng or Chakapat extracts (100 and 500 mg/kg). After ten days, the rats were sacrificed and their livers were examined histopathologically and immunohistochemically. Their serum glutamate-pyruvate transaminase, glutamate-oxalate transaminase, and alkaline phosphatase activities were analyzed. Apoptotic activity of the livers was assessed quantitatively.

Results

The Gimjeng and Chakapat extracts showed the contents of vitamin C (1.2 ± 0.6 and 4.3 ± 0.1 mg/100 g) and phenolics like trans-cinnamic acid and pelargonidin-3-O-glucoside (9.80 ± 0.21 and 19.56 ± 0.4 mg GAE/g extract, respectively), and trolox equivalent antioxidant capacity (TEAC) values (11.64 and 9.09 g/mg trolox), respectively. The Gimjeng as compared to the Chakapat demonstrated a better antioxidant activity as revealed by anti-lipid peroxidation activity with the TEAC values. Administration of CCl₄ in rats elevated the serum GPT, GOT, and ALP level whereas silymarin, Gimjeng and Chakapat extracts prevented these increases significantly. Significant decrease of apoptotic cells together with restoration of morphological changes confirmed the hepatoprotective effect in the CCl₄-induced rats pretreated with the extracts.

Conclusion

Antioxidant properties of the Gimjeng and Chakapat lychees as evidenced by the vitamin C and phenolic compounds, anti-lipid peroxidation and anti-apoptosis could explain the hepatoprotective effects in CCl₄-induced hepatotoxicity.     

印度蜂蜜提取物中的酚类化合物的抗氧化活性及α淀粉酶抑制活性研究(英文)

AIM:To evaluate the antioxidant and α-amylase inhibition potential of phenolic compounds in the extracts of Indian honey.METHODS:Phenolic compounds were extracted from Indian honey through column chromatography.The antioxidant poten-tial of extracted phenolic compounds was measured by two different biochemical assays:ferric reducing antioxidant power(FRAP) assay and scavenging activity on 2,2-diphenyl-1-picrylhydrazyl(DPPH) radicals.Moreover,α-amylase inhibition assay of phenolic compounds of honey was also evaluated.RESULTS:The scavenging inhibition rate varied from 86.8% to 78.6% from the highest(6 mg·mL-1) to the lowest(1.5 mg·mL-1) concentration,whereas,reducing power assay varied from 0.89 Abs to 0.19 Abs from the highest to the lowest concentration.Butylated hydroxytoluene(BHT) was used as reference compound for antioxidant assays.α-amylase inhi-bition assay is reported from the phenolic honey extracts for the first time.The inhibition rate for α-amylase varied from 88.8% to 30.5% from the highest(20 μg·mL-1) to the lowest concentration(4 μg·mL-1).CONCLUSION:Honey phenolic extract possessed antioxidant and α-amylase inhibition activity,thus increasing its potential therapeutic property.     

Antioxidant and anticholinesterase constituents from the petroleum ether and chloroform extracts of Iris suaveolens

The aim of this study was to investigate the phytochemical, antioxidant and anticholinesterase activities of Iris suaveolens. After determining total phenolic and flavonoid contents of the petroleum ether, chloroform and methanol extracts prepared from the rhizomes, the antioxidant capacity of the extracts was established using β‐carotene–linoleic acid and CUPRAC methods. The chloroform extract which was rich in phenolic content exhibited the highest inhibition of lipid peroxidation in the β‐carotene–linoleic acid system, and the best cupric reducing antioxidant capacity among the tested extracts. The petroleum ether extract indicated moderate anticholinesterase activity while the chloroform extract revealed significant butyrylcholinesterase inhibitory activity (75.03 ± 1.29%). Spectroscopic methods were used for the structural elucidation of the compounds (1–13) isolated from the petroleum ether and chloroform extracts. Coniferaldehyde (6), having the highest antioxidant activity in the β‐carotene–linoleic acid assay at 25 and 50 µg/mL, demonstrated also the best effect in the CUPRAC method among the tested compounds (1–12). 3‐Hydroxyirisquinone (10) showed the best anticholinesterase activity among the tested compounds (1–4, 6–12), and coniferaldehyde exhibited almost the same butyrylcholinesterase inhibitory activity (82.60 ± 2.33%) as galantamine (86.26 ± 0.66%). Copyright © 2010 John Wiley & Sons, Ltd.     

Antioxidant principles from Bauhinia tarapotensis

A new cyclohexenone (1) and a new caffeoyl ester derivative (2), together with the known compounds (-)-isolariciresinol 3-alpha-O-beta-D-glucopyranoside (3), (+)-1-hydroxypinoresinol 1-O-beta-D-glucopyranoside (4), isoacteoside (5), luteolin 4'-O-beta-D-glucopyranoside (6), and indole-3-carboxylic acid (7), were isolated from the leaves of Bauhinia tarapotensis. The structures of these new compounds were determined by spectroscopic data analysis. The antioxidant activities of 1-7 were determined by measuring their free radical scavenging effects, using the 1,1-diphenyl-2-dipicrylhydrazyl free radical (DPPH) and Trolox equivalent antioxidant activity (TEAC) methods, and the coupled oxidation of beta-carotene and linoleic acid. Compounds 3-5 showed good activities in the DPPH and TEAC tests, while compounds 1 and 2 were active in the coupled oxidation of beta-carotene and linoleic acid bioassay.     

锁阳中粗多酚和粗多糖抗氧化活性的比较

目的：比较锁阳粗多酚和粗多糖的抗氧化活性,为锁阳入药提供依据。方法：100g锁阳粉末提取粗多酚和粗多糖。采用超声波辅助乙醇法提取粗多酚,依次用石油醚、三氯甲烷、醋酸乙酯和正丁醇进行萃取。同时用水提醇沉法提取粗多糖。用DPPH·法和ABTS＋法进行锁阳粗多酚和粗多糖的抗氧化活性检测。结果：多酚粗提物中的总酚含量达到了922．9mgGAE·g-1（没食子酸当量）,而多糖粗提物中的多糖含量为366．6mg·g-1（葡萄糖当量）。DPPH·法检测锁阳粗多酚和粗多糖的IC50值分别为79．3μg·mL-1和145．6p,g·mL-1。经ABTS’法检测,二者的TEAC值分别为2．12mmol·g-1和0．69mmol·g-1。结论：锁阳粗多酚的抗氧化活性远高于锁阳粗多糖。     

管花肉苁蓉提取物的抗氧化活性研究

目的研究管花肉苁蓉甲醇提取物和乙醇提取物的抗氧化活性，并对这两种提取物进行比较以确定能获得更高药效的提取剂。方法采用测定总酚含量、总黄酮含量、清除DPPH自由基能力及其总抗氧化能力一氧自由基吸收量（ORAC）和抗氧化当量（TEAC）来研究管花肉苁蓉的抗氧化活性。结果甲醇和乙醇提取物中含有一定量的总酚[（32．65±6．22）mgGA／g和（31．45±3．54）mgGA／g]，总黄酮含量较高[（65．33±6．71）mgRE／g和（62．70±8．56）mgRE／g]；两种提取物均可以有效清除DPPH自由基，半数清除浓度分别为（141．50±3．50）μg/ml和（174．82±31．85）μg／ml；乙醇提取物的ORAC和TEAC值分别为（438．59±24．14）仙molTE／g和（137．18±2．47）μmol TE／g，均高于甲醇提取物[（368．34±25．64）μmolTE／g和（114．42±1．42）μmol TE／g]，其中TEAC值的差异显著（P〈0．05）。结论两种提取物均有较高的抗氧化活性，建议选择70％的乙醇作为提取剂可以获得具有较高抗氧化活性的管花肉苁蓉提取物。     

高效液相色谱-二苯基三硝基苯肼在线检测葡萄酒中抗氧化活性成分

目的: 建立高效液相色谱-二苯基三硝基苯肼(HPLC-DPPH)在线法评价葡萄酒清除自由基的活性,研究其抗氧化活性物质基础。 方法: 葡萄酒样品经HPLC分离,在柱后与DPPH工作液在三通处混合,于PEEK管中充分反应后,流经检测器记录反应信号,以水溶性维生素E类似物(Trolox)为标准计算活性成分的抗氧化当量(TEAC),比较7种不同地区葡萄酒总抗氧化能力及活性成分差异。 结果: 通过定性分析得出葡萄酒样品中没食子酸、原儿茶酸、原花青素二聚体B₁、龙胆酸、儿茶素、咖啡酸和没食子酸乙酯对DPPH自由基具有清除活性,但原花青素二聚体B₂、香草酸、丁香酸和对香豆酸没有清除活性。不同地区葡萄酒总抗氧化能力不同,所含抗氧化活性成分也有较大差异,共有活性成分有7种,其中原花青素二聚体B₁与没食子酸活性最强,其次是儿茶素和未知物1,活性较弱的是咖啡酸、原儿茶酸和没食子酸乙酯。 结论: 葡萄酒中含有多种抗氧化活性物质;该法能够实现对天然产物抗氧化活性的分析,具有在线、无损、高通量筛选、快速分析的特点。