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1.
Three fractions (peel, pulp and aril) of gac fruit (Momordica cochinchinensis Spreng) were investigated for their phytochemicals (lycopene, beta-carotene, lutein and phenolic compounds) and their antioxidant activity. The results showed that the aril had the highest contents for both lycopene and beta-carotene, whilst peel (yellow) contained the highest amount of lutein. Two major phenolic acid groups: hydroxybenzoic acids and hydroxycinnamic were identified and quantified. Gallic acid and p-hydroxybenzoic acid were found in all fractions. Ferulic acid and p-hydroxybenzoic acid were most evident in pulp. Myricetin was the only flavonoid found in all fractions. Apigenin was the most predominant flavonoid in pulp (red), whereas rutin and luteolin gave the highest content in aril. The extracts of different fractions exhibited different levels of antioxidant activity in the systems tested. The aril extract showed the highest FRAP value. The greatest antioxidant activities of peel and pulp extracts were at immature stage, whereas those in the seed extracts increased from mature stage to ripe stage. The contents of total phenolic and total flavonoid in peel and pulp decreased during the fruit development stage (immature > ripe fruit) and subsequently displayed lower antioxidant capacity, except for the seed.  相似文献   

2.
A simple HPLC method with good separation efficiency was developed to determine all-trans and cis forms of carotenoids in Dunaliella salina cultivated in Taiwan. The analysis used a C30 column (250 × 4.6 mm, 5 μm) and an isocratic solvent system (flow rate = 1 mL/min) mixing methanol–acetonitrile–water (84/14/2, v/v/v) and methylene chloride, (75/25, v/v). Carotenoids were detected at 450 nm. Moreover, the antioxidant capacities of the algal carotenoid extract were also evaluated with Trolox equivalent antioxidant capacity (TEAC) assay, reducing power and 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging assay. Results showed that 7 carotenoids in the algal extract could be separated simultaneously within 30 min and the total amount of them was 290.77 mg/g algae. The contents of all-trans-β-carotene and 9- or 9′-cis-β-carotene, the major carotenoids in the algae, were 138.25 and 124.65 mg/g algae, respectively. The contents of all-trans-lutein, all-trans-zeaxanthin, 13- or 13′-cis-β-carotene, all-trans-α-carotene and 9- or 9′-cis-α-carotene were 6.55, 11.27, 4.95, 2.69, and 2.41 mg/g algae, respectively. The algal carotenoid extract had significantly higher antioxidant activity than all-trans forms of α-carotene, β-carotene, lutein and zeaxanthin in all antioxidant assays. The cis forms of carotenoids, especially 9- or 9′-cis-β-carotene, might play crucial roles for the antioxidant capacities of the algal extract.  相似文献   

3.
The composition of phenolic acids in various parts of mangosteen fruit (Garcinia mangostana) was determined by GC and MS. The total content of phenolic acids, identified by GC-FID ranged from 265.7 ± 12.7 (aril) to 5027.7 ± 188.0 (peel) mg per kg of dry matter of sample. Ten phenolic acids were identified in mangosteen fruit. Of these, protocatechuic acid was the major phenolic acid in the peel and rind, while p-hydroxybenzoic acid was the predominant phenolic acid in the aril. m-Hydroxybenzoic acid was detected only in the peel, while 3,4-dihydroxymandelic was present only in the rind. The phenolic acids liberated from esters and glycosidic bonds were the major fractions of phenolic acids in mangosteen fruit.  相似文献   

4.
The antioxidant potentials of buntan pumelo (Citrus grandis Osbeck) and its fermented products were determined. The essential oil from peel had higher total phenolic (214 mM) and flavonoid (134 mg QE/g of dried material) contents than those of different solvent extracts from fruit pulp. In addition, DPPH free radical-scavenging activity and ferric-reducing antioxidant power values determined for the essential oil were 26.1 ± 1.2% and 2.3 ± 0.3 mM, respectively, which were significantly higher than those of various fruit pulp extracts. The ethanol-fermented products of pumelo juice had higher total phenolic and flavonoid contents than those of fresh juice. For maintenance of the substantial antioxidant properties of pumelo products, ethanol-fermented juice rather than fresh or acetate-fermented juice is recommended. Through correlation analysis, the phenolic compounds in the fermented pumelo products were found to be the major contributors to the free radical-scavenging activity and ferric-reducing power.  相似文献   

5.
Polyphenols and anthocyanins were extracted from Kadsura coccinea fruit. The contents of total phenolics and anthocyanins, influences of pH and temperature on anthocyanins, and antioxidant activities of extracts were further analyzed. The results showed that the total phenolic content of peel extracts was superior to that of pulp extracts. The total anthocyanin content of peel extracts was 180 ± 2.91 mg/100 g of fresh peel tissues. K. coccinea anthocyanins were stable below pH 4, whilst high temperature and extended heating time induced their degradation. Metal-chelating capacity (MCC) assay indicated that no ortho-dihydroxy aromatic moiety existed in the B-ring of the anthocyanin molecules, but there might be a catechol group in the B-ring of the polyphenol molecules. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and reducing power of extracts decreased in the following order: peel polyphenol extracts > anthocyanin extracts > pulp polyphenol extracts. It would be worthwhile to introduce this rare fruit into more countries.  相似文献   

6.
Ether, methanolic and aqueous extracts of lyophilized rambutan (Nephelium lappaceum L.) peels and seeds were evaluated for phenolic contents, antioxidant and antibacterial activities. High amounts of phenolic compounds were found in the peel extracts and the highest content was in the methanolic fraction (542.2 mg/g dry extract). Several potential antioxidant activities, including reducing power, β-carotene bleaching, linoleic peroxidation and free radical scavenging activity, were evaluated. The peel extracts exhibited higher antioxidant activity than the seed extracts in all methods determined (P < 0.05). The methanolic fraction was found to be the most active antioxidant as shown by their 50% DPPH inhibition concentration, 4.94 μg/mL. The results indicated this fraction exhibited greater DPPH radical scavenging activity than BHT and ascorbic acid (0.32 g dry extract/g BHT or ascorbic acid). Antibacterial activity against eight bacterial strains was assessed by disc diffusion and broth macrodilution methods. All peel extracts exhibited antibacterial activity against five pathogenic bacteria. The most sensitive strain, Staphylococcus epidermidis, was inhibited by the methanolic extract (MIC 2.0 mg/mL).  相似文献   

7.
The nutritional and antioxidant properties of peels, pulp and seeds of kembayau (Dacryodes rostrata) fruits were evaluated. Kembayau seeds and pulp were rich in fat, while peels had the highest ash contents. Potassium was the most prevalent mineral in peels (380.72-1112.00 mg/100 g). In kembayau fruits, total flavonoid content (1012.74-28,022.28 mg rutin equivalent/100 g) was higher than total phenolic and total monomeric anthocyanin contents. Kembayau seeds exhibited high flavonoid and phenolic contents compared to the contents in peels and pulp. Antioxidant capacities were also higher in seeds as typified by trolox equivalent antioxidant capacity assay (51.39-74.59 mmol TE/100 g), ferric reducing antioxidant power assay (530.05-556.98 mmol Fe2+/100 g) and by 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity (92.18-92.19%) when compared to peels and pulp. Pulp and peels of kembayau fruit may be an important source of energy and minerals for human consumption, while seeds have a good potential as antioxidants.  相似文献   

8.
The antioxidant potential of different fractions of Lawsonia inermis (Lythraceae) was investigated. The n-butanolic fraction showed the highest yield of extraction; it also exhibited a strong antioxidant activity in the DPPH assay and a potent capacity in preventing linoleic acid oxidation. Five phenolic glycosides were identified in this fraction. The structure of a new compound was established as 1,2,4-trihydroxynaphthalene-1-Ο-β-d-glucopyranoside. In addition, the known 2,4,6-trihydroxyacetophenone-2-Ο-β-d-glucopyranoside was described for the first time in this species. The three other compounds, lalioside (2,3,4,6-tetrahydroxyacetophenone-2-Ο-β-d-glucopyranoside), lawsoniaside (1,2,4-trihydroxynaphthalene-1,4-di-Ο-β-d-glucopyranoside) and luteolin-7-Ο-β-d-glucopyranoside, have been previously reported in L. inermis. The antioxidant activity of these glycosides was evaluated by DPPH and β-carotene assays, and compared to those of commercial standards. 1,2,4-Trihydroxynaphthalene-1-Ο-β-d-glucopyranoside was the most active in the DPPH free-radical scavenging test (EC50 = 6.5 μg/ml) and showed a moderate inhibition in the β-carotene bleaching assay. Chemical components of L. inermis have good antioxidant capacities and this species could be used as a potential source of new natural antioxidants.  相似文献   

9.
Total phenolic content, proanthocyanidins, gallotannins, flavonoids, and antioxidant activities of Sclerocarya birrea and Harpephyllum caffrum methanolic extracts were evaluated using in vitro assays. S. birrea young stem extract contained the highest levels of total phenolic content (14.15 ± 0.03 mg GAE/g), flavonoids (1.21 ± 0.01 mg CE/g) and gallotannins (0.24 ± 0.00 mg GAE/g). H. caffrum stem bark extract had the highest content of proanthocyanidins (1.47%). The EC50 values of the extracts in the DPPH free radical scavenging assay ranged from 4.26 to 6.92 μg/ml, compared to 6.86 μg/ml for ascorbic acid. A dose-dependent linear curve was obtained for all extracts in the ferric-reducing power assay. Dichloromethane and methanol extracts exhibited dose-dependent acetylcholinesterase inhibitory activity. Similarly, all extracts exhibited high antioxidant activity comparable to butylated hydroxytoluene based on the rate of β-carotene bleaching (84.1–93.9%). The two Anacardiaceae species provide a source of natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial to the health of consumers.  相似文献   

10.
Citrus sulcata was subjected to ultrasound, high-pressure, and Soxhlet extractions. The antioxidant and anti-inflammatory activities of the extracts were evaluated qualitatively and quantitatively. The antioxidant content of the peel extract was twice that of the fruit extract. The quantitative analysis showed that the narirutin and hesperidin contents in the peel extracts were 8.8 and 7.5 mg/100 g, respectively. These extracts had a total phenolic content of 112.22 ± 2.89 gallic acid equivalent (GAE) mg/100 g, a total flavonoid content of 54.09 ± 1.01 rutin equivalent (RE) mg/100 g, DPPH radical scavenging activity of 46%, and antioxidant activity of 213.25 ± 2.82 μM of Trolox equivalents (TEAC). C. sulcata extracts could prevent hydrogen peroxide (H2O2)-induced oxidative stress, reduce expression of the inflammatory markers nuclear Factor kappa B (NFκB) and phosphorylated IκBα (p-IκBα) in A549 human lung carcinoma cells, and inhibit Lipopolysaccharide (LPS)-induced THP-1 monocyte differentiation to an extent of 85%.  相似文献   

11.
Açai fruit are native to the Amazon region of South America and two predominant species are commercially exported as fruit pulps for use in food and beverage applications. Detailed characterisation of the polyphenolic compounds present in the de-seeded fruits of Euterpe oleracea and Euterpe precatoria species were conducted by HPLC–ESI–MSn analyses and their thermal stability and overall influence on antioxidant capacity were determined. Anthocyanins were the predominant polyphenolics in both E. oleracea (2247 ± 23 mg/kg) and E. precatoria (3,458 ± 16 mg/kg) species, and accounted for nearly 90% of the trolox equivalent antioxidant capacity in both E. oleracea (87.4 ± 4.4 μmol TE/g) and E. precatoria (114 ± 6.9 μmol TE/g) fruits. Various flavones, including homoorientin, orientin, taxifolin deoxyhexose and isovitexin; various flavanol derivatives, including (+)-catechin, (−)-epicatechin, procyanidin dimers and trimers, and phenolic acids, including protocatechuic, p-hydroxybenzoic, vanillic, syringic and ferulic acids, were also present in both species. Thermal stability of these compounds was evaluated, following a thermal holding cycle (80 °C for up to 60 min) in the presence and absence of oxygen. Both species experienced only minor changes (<5%) in non-anthocyanin polyphenolic contents during all thermal processes whereas 34 ± 2.3% of anthocyanins in E. oleracea and 10.3 ± 1.1% of anthocyanins in E. precatoria were lost under these conditions, regardless of the presence of oxygen. Proportional decreases (10–25%) in antioxidant capacity accompanied the anthocyanin changes. Results suggest that both açai species are characterised by similar polyphenolic profiles, comparable antioxidant capacities, yet only moderate phytochemical stability during heating.  相似文献   

12.
Four underutilized Georgia-grown fruit crops, namely loquat (Eriobotrya japonica), mayhaw (Crataegus sp.), fig (Ficus carica), and pawpaw (Asimina triloba), and their leaves were analysed for total polyphenols by Folin–Ciocalteau method, and antioxidant capacity by ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) assays. Organic acids and phenolic compounds were identified by RP-HPLC. For lipid profile, fruits were separated into two fractions – seed and fruit (i.e., without seed); lipid was extracted using the Folch method and analysed for fatty acids, phytosterols, tocopherols, and phospholipids. The major organic acid identified in all samples was malic acid (177–1918 mg/100 g FW). The predominant phenolic acids in all the fruits were gallic (1.5–6.4 mg/100 g FW) and ellagic (0.2–33.8 mg/100 g FW), and the most abundant flavonoid was catechin (12.2–37.8 mg/100 g FW). Total lipid content varied from 0.1% in mayhaw fruit to 21.5% in pawpaw seed. Linoleic acid was the predominant fatty acid in all of the samples (28.2–55.7%).  相似文献   

13.
In this work, we have investigated about the presence of several natural stilbenes in 12 samples of pistachios harvested from 10 different farms of Sicily (Bronte and Agrigento). At the same time, we have evaluated the relation between the stilbenes synthesis and the possible contamination of mycotoxin produced by Aspergillus flavus and Aspergillus parasiticus. We have found two types of stilbenes in the samples of pistachios examined: trans-resveratrol and trans-resveratrol-3-O-β-glucoside (trans-piceid). Their concentration ranged from 0.07 to 0.18 mg/kg (av. = 0.12 ± 0.03 mg/kg) for trans-resveratrol, from 6.20 to 8.15 mg/kg (av. = 6.97 ± 0.55 mg/kg) for trans-piceid and from 6.38 to 8.27 mg/kg (av. = 7.09 ± 0.54 mg/kg) for total resveratrol.  相似文献   

14.
Aqueous extract, proanthocyanidin rich extract, and organic extracts of Cymbopogon schoenanthus L. Spreng (lemon grass) shoots from three different locations in South Tunisia were screened for their antioxidant, acetylcholinesterase and antimicrobial activities. In addition to the evaluation of these activities, the contents of flavonoids and total phenolic compounds were determined.Antioxidant activity measured by DPPH assay showed that the proanthocyanidin extract exhibited higher antioxidant activity than the aqueous extract. Extract concentration providing 50% inhibition (IC50) ranged from 16.4 ± 6.8 μg/mL to 26.4 ± 6.8 μg/mL. The antioxidant activity was also determined using the β-carotene/linoleic acid bleaching test. The best results (IC50 = 0.11 ± 0.10 mg/mL) were obtained with the proanthocyanidin extract of the plants collected from the desert region (Dhibat).The greatest acetylcholinesterase inhibitory activity (IC50 = 0.23 ± 0.04 mg/mL) was exhibited by the ethyl acetate and methanol extracts of the plants collected from the mountainous region. It seems that extracts obtained with more polar solvents gave better results.The proanthocyanidin extracts showed a good antimicrobial activity against Streptococcus sobrinus at low concentration (MIC = 4 mg/mL). Therefore, these extracts could be used to prevent carious lesions by inhibiting S. sobrinus growth.  相似文献   

15.
Fatty acids (FA), phytosterols, tocopherols, phenolic compounds, total carotenoids and hydrophilic and lipophilic ORAC antioxidant capacities were evaluated in 16 cultivars of Sacha inchi (SI) seeds with the aim to valorise them and offer more information on the functional properties of SI seeds. A high α linolenic (α-Ln) fatty acid content was found in all cultivars (ω3, 12.8–16.0 g/100 g seed), followed by linoleic (L) fatty acid (ω6, 12.4–14.1 g/100 g seed). The ratio ω6/ω3 was within the 0.83–1.09 range. γ- and δ-tocopherols were the most important tocopherols, whereas the most representative phytosterols were β-sitosterol and stigmasterol. Contents of total phenolics, total carotenoids and hydrophilic and lipophilic antioxidant capacities ranged from 64.6 to 80 mg of gallic acid equivalent/100 g seed; from 0.07 to 0.09 mg of β-carotene equivalent/100 g of seed; from 4.3 to 7.3 and, from 1.0 to 2.8 μmol of Trolox equivalent/g of seed, respectively, among the evaluated SI cultivars. Results showed significant differences (p < 0.05) among the evaluated SI cultivars in the contents of ω3, ω6, antioxidant capacities and other evaluated phytochemicals. SI seeds should be considered as an important dietary source of health promoting phytochemicals.  相似文献   

16.
Gundelia tournefortii L. is an important food source and a well-known medicinal plant in Eastern Anatolia. Therapeutic effects of medicinal plants are known to be closely related to their antioxidant capacities. Antioxidant activities of G. tournefortii, both for the aerial parts and seeds, were investigated by using both 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation inhibition methods. The seeds were found to have higher antioxidant potential than the aerial, with IC50 values of 0.073 mg/mL for DPPH scavenging and 0.146 mg/mL for lipid peroxidation inhibition capacities. In addition, total phenolic contents of the Gundelia tournefortii L. extracts, especially the seed extracts correlates to its high antioxidant activity with 105.1 ± 8.7 μg gallic acid equivalents (GAEs) per mg of seed extract. Plant extracts with high phenolics content are known to have important effects on various enzymes, as well as glutathione-S-transferases, which are important detoxification enzymes in phase II systems with an important role in developing multi-drug resistance to chemotherapy in tumour cells. Consequently, the effects of G. tournefortii extracts on crude cytosolic glutathione-S-transferase was also studied and the seed extracts have shown effective inhibition of cytosolic GST activity, with an IC50 of 97.51 μg/mL.  相似文献   

17.
Three unknown dihydroflavanol glycosides: 2R,3R-4′O-methyl dihydrokaempferol 7-O-[3″-O-acetyl]-β-d-glucopyranoside (1), 2R,3R-4′-O-methyl dihydrokaempferol 7-O-β-d-β-l-xylopyranosyl-(1″′ → 6″)-[3″-O-acetyl]-β-d-glucopyranoside (2), 2R,3R-4′-O-methyl dihydrokaempferol 3-O-β-d-β-l-xylopyranosyl-(1″′ → 6″)-[3″-O-acetyl]-β-d-glucopyranoside (3), together with gallic acid (4) were isolated from the n-butanol fraction of Pouteria obovata fruit flour by chromatographic methods and their structures were elucidated on the basis of CD, UV, MS, monodimensional NMR (1H and 13C) and bidimensional NMR (COSY, HSQC and HMBC). The quantitative analysis of flavonoids and phenols were also reported. Total phenolic amount (51.1 ± 14.1 mg GAE/1000 g; p < 0.0006) and flavonoid content (153.2 ± 3.5 mg CE/100 g; p < 0.004) were detected spectrophotometrically.  相似文献   

18.
Pornpimon Mayachiew 《LWT》2008,41(7):1153-1159
The antimicrobial and antioxidant activities of Indian gooseberry (Phyllanthus emblica Linn.) and galangal (Alpinia galanga) extracts were investigated. Two different methods (disc diffusion and agar dilution methods) were employed to evaluate the antimicrobial activities of plant extracts against Staphylococcus aureus. The minimum inhibitory concentration (MIC) values of Indian gooseberry and galangal extracts were found to be 13.97 and 0.78 mg/ml and the minimum biocidal concentration (MBC) values were 13.97 and 2.34 mg/ml, respectively. The antioxidant activities of Indian gooseberry and galangal extracts, which were evaluated by the β-carotene bleaching method, were 86.4% and 70.3%, respectively. The total phenolic contents of Indian gooseberry and galangal extracts, as determined by the Folin-Ciocalteu method, were 290.4±0.7 and 40.9±0.2 mg/g plant extract (in GAE), respectively. The GC-MS analysis showed that the main compounds of galangal extract are 1,8-cineole (20.95%), β-bisabolene (13.16%), β-caryophyllene (17.95%) and β-selinene (10.56%). On the other hand, the use of high-performance liquid chromatography (HPLC) with UV detection indicated many compounds within the Indian gooseberry extract.  相似文献   

19.
Nitraria tangutorun Bobr., a unique kind of fruit, widely spreads in the Qinghai-Tibet Plateau. In the present study, nine anthocyanins were identified in two variations (purple fruit and red fruit) of N. tangutorun by HPLC/DAD-ESI/MS. Cyanidin-3-O-(trans-p-coumaroyl)-diglucoside (215.76 ± 22.91 mg of Mv3G5G equivalent per 100 g of fresh weight) and pelargonidin-3-O-(p-coumaroyl)-diglucoside (5.13 ± 0.35 mg of Mv3G5G equivalent per 100 g of fresh weight) were the main anthocyanins in the purple and red fruits respectively. In addition, most of the anthocyanins were acylated by coumaric acid, and the rare anthocyanins that naturally presented a coumaric acid in both cis and trans configurations have been detected. Furthermore, the extract of the two variations showed significantly different antioxidant activity (p < 0.01) according to DPPH, ABTS and FRAP assay. Purple fruit possessed higher antioxidant activity than red fruit. There were significant correlations between antioxidant activity and both the total polyphenol content and anthocyanins content. This work is valuable for elucidation of anthocyanins composition in N. tangutorun and for further utilization as a functional food and medicine material.  相似文献   

20.
This study reports the essential oil composition, antioxidant and antimicrobial activity of the essential oil and methanol extract of aerial parts of Semenovia tragioides. GC and GC/MS analysis identified 17 compounds representing 99.4% of the oil. The main components comprising 61.9% of the oil were lavandulyl acetate (25.5%), geranyl acetate (12.5%), trans-β-ocimene (8.8%), p-cymene (7.7%) and γ-terpinene (7.4%). The samples were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and β-carotene/linoleic acid assay methods. None of the plant samples showed appreciable antioxidant activity in DPPH test. However, methanol extract exhibited considerable linoleic acid oxidation inhibition (77.4%) in the β-carotene/linoleic acid test, a value near to that of butylated hydroxytoluene (BHT, 95.6%). Total phenolic content of the plant extract as gallic acid equivalents was 7.5 μg/mg. The essential oil exhibited strong antimicrobial activity against all but one of the tested microorganisms while the plant extract only inhibited two of them weakly.  相似文献   

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