Thai plants from Doi Tung: brine shrimp lethality, antioxidative activity and combination effect with L-ascorbic acid

Methanolic extracts of 18 Thai plants from Doi Tung, the north of Thailand, were examined for brine shrimp lethality and antioxidative activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. In brine shrimp lethality, the highly toxic plant extracts were Mitrephora wangii (LC(50) 14.8?μg?mL(-1)) and Hydrocotyle javanica (LC(50) 13.3?μg?mL(-1)). The extracts of Sageretia cordifolia, Ulmus lancaefolia and Acer chiangdaoense exhibited highly antioxidative activities with IC(50) values of 6.7, 8.1 and 9.8?μg?mL(-1), respectively. Moreover, the extracts of S. cordifolia, U. lancaefolia and A. chiangdaoense have shown slightly synergistic effects (combination index; CI?相似文献   

Antioxidant and anticancer activity of fresh corm extract from Romulea tempskyana (Iridaceae)

The antioxidant and anticancer properties of a medicinal plant, Romulea tempskyana (R. tempskyana) (Iridaceae) were investigated. The fresh corm water extract of R. tempskyana significantly increased cell viability against H(2)O(2) cytotoxicity(.) The extract also showed high inhibition of the lipid peroxidation activity (78.20%), reducing power (IC(50) 64.99?μg?mL(-1)) activity and hydroxyl (IC(50) 38.66?μg?mL(-1)), superoxide (IC(50) 25.99?μg?ml(-1)) and DPPH (IC(50) 19.88?μg?mL(-1)) radical scavenging activity. On the other hand, treatment of the cells with higher extract concentration showed the anticancer activity inducing cytotoxicity. The extract significantly affected Hepatoma G2 and H1299 cell proliferation (IC(50); 103.79 and 88.15?μg?mL(-1)). The amount of MDA (2-fold and 2.5-fold) and activities of several cellular antioxidant enzymes, including Se-GSPx (30%, 15%), non-Se-GSH-Px (11%, 16%) and GST (17%, 23%) increased in Hepatoma G2 and H1299 cells treated with IC(50) concentrations of extract, respectively. These findings suggest that R. tempskyana extract exhibits antioxidant and carcinogenesis-reducing potential.     

Turmerin, the antioxidant protein from turmeric (Curcuma longa) exhibits antihyperglycaemic effects

A wide range of proteinaceous inhibitors are present in plants to protect themselves from hydrolytic enzymes. In this study, turmerin, a water-soluble peptide in turmeric rhizomes, was evaluated for its inhibitory potential against glucosidase and its antioxidant (AO) capacity. Turmerin inhibited α-amylase and α-glucosidase activities with IC?? values 31 and 192?μg?mL?1, respectively. Under the experimental conditions, those values for a standard glucosidase inhibitor, acarbose, were 81 and 296?μg?mL?1, respectively. The AO capacity of turmerin was evaluated using in vitro assay systems. Turmerin showed good DPPH (IC???=?29?μg?mL?1) and superoxide (IC???=?48?μg?mL?1) and moderate ABTS (IC???=?83?μg?mL?1) radical scavenging and Fe(II) chelation (IC???=?101?μg?mL?1) capacities. The inhibitory potential showed by turmerin against enzymes linked to type 2 diabetes, as well as its moderate AO capacity, could rationalise the traditional usage of turmeric rhizome preparations against diabetes.     

Antioxidant and antibacterial activities of bark extracts from Commiphora berryi and Commiphora caudata

This study investigates the in vitro antioxidant and antimicrobial activities of eight extracts obtained from the dried barks of Commiphora berryi and Commiphora caudata (Burseraceae). The radical scavenging activity was assessed by 1,1-diphenyl-2-picryl hydrazyl (DPPH) and nitric oxide assays. The methanolic extracts of C. berryi and C. caudata showed significant DPPH radical scavenging activity, with IC?? values of 26.92 and 21.16?μg?mL?1, respectively, and low radical scavenging activity against the nitric oxide assay. The antimicrobial activity of the plants was tested against the Gram-positive and Gram-negative bacteria. The ethyl acetate, chloroform and petroleum ether extracts of C. berryi showed good antibacterial activity against Pseudomonas aeruginosa, with a minimum inhibitory concentration (MIC) of 0.26?mg?mL?1, whereas the ethyl acetate and methanol extracts of C. caudata showed moderate antimicrobial activity with an MIC of more than 2.0?mg?mL?1 against P. aeruginosa compared to the petroleum ether and chloroform extracts, which showed an MIC of 1.1?mg?mL?1. The methanolic extracts of C. berryi and C. caudata also showed moderate cytotoxic activity against a human mammary carcinoma cell line (MCF-7), with values IC?? of 82.6 and 88.4?μg?mL?1, respectively.     

Dereplication coupled with in vitro antioxidant assay of two flavonoid glycosides from Diospyros peregrina fruit

Diospyros peregrina is an edible seasonal fruit found in coastal West Bengal, India. The fruits have been reported to possess a significant antioxidant activity. In this study, the aim was to isolate the lead compound responsible for the above-mentioned activity. The aqueous extract of D. peregrina fruit was subjected to dereplication coupled with an in?vitro 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. The n-butanol fraction of the aqueous extract of D. peregrina fruit exhibited significant antioxidant activity (IC(50), 131.10?μg?mL(-1)) as compared with the parent extract (IC(50), 285.15?μg?mL(-1)). The n-butanol fraction was subjected to silica gel column chromatographic separation coupled with a chemo-autographic study of column eluents, employing ethanolic DPPH as a spraying reagent. Two bioactive flavonoid glycosides, namely luteoline-4'-methyl-ether-7-O-glucoside and quercetin-3-O-(glucosyl)-glucoside, were identified to exhibit IC(50) values of 74.04 and 65.78?μg?mL(-1), respectively in the DPPH assay.     

Cytotoxic compounds from the leaves of Gaillardia aristata Pursh. growing in Egypt

Ten compounds, neopulchellin (1), 6α- hydroxyneopulchellin (2), β-sitosterol-3-O-β-D-glucoside (3), apigenin (4), quercitin (5), eupafolin (6), kaempferol-3-methoxy-7-O-α-L-rhamnoside (7), apigenin-7-O-β-D-glucopyranoside (8), α-amyrin (9) and β-sitosterol (10), were isolated from the leaves of Gaillardia aristata by applying bioassay guided fractionation. The cytotoxicity was traced against two human cancer cell lines (breast (MCF7) and colon (HCT116)). The highest cytotoxicity was revealed by compounds 1 and 2 (isolated from chloroform extract); with IC(50) values of 0.43, 0.32?μg?mL(-1) against MCF7 and 0.46, 0.34?μg?mL(-1) against HCT116, respectively. Compounds 9 and 10 (isolated from the n-hexane extract) exhibited lower IC(50) values of 3.05, 2.35?μg?mL(-1) against MCF7 and 3.05, 2.35?μg?mL(-1) against HCT116, respectively, while compounds 4-7 obtained from the ethyl acetate extract revealed the lowest cytotoxicity. Identification of the aforementioned compounds was carried out on the basis of their physico-chemical properties and spectral analysis (UV, EI/MS, 1D and 2D).     

Chemical composition and antioxidant activity of the essential oil and various extracts of Haplophyllum robustum Bge

This study was designed to examine the chemical composition and in vitro antioxidant activity of the essential oil and various extracts of Haplophyllum robustum. GC-MS analysis of the oil resulted in the identification of 30 compounds, representing 99.2% of the oil; 1,8-cineole (38.1%), myrcene (10.7%), α-pinene (8.5%), 4-terpineol (7.0%) and sabinene (6.1%) were the main components. The antioxidant potential of the oil and extracts was evaluated using three separate methods: inhibition of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene-linoleic acid assay and reducing power systems. The essential oil of the plant was able to reduce the stable free radical DPPH with an IC(50) of 72.0?±?1.2?μg?mL(-1) (the IC(50) for ascorbic acid was determined as 5.8?±?0.4?μg?mL(-1)). The essential oil also showed strong reducing power. The level of total phenolics was highest in the essential oil (179.5?±?2.1?μg?mg(-1)).     

Composition of essential oil and antioxidant capacity of Centaurea drabifolia Sm. subsp. detonsa (Bornm.) Wagenitz, endemic to Turkey

In this study, composition of essential oil and antioxidant capacity of Centaurea drabifolia subsp. detonsa were investigated. The antioxidant capacity of the methanolic extract was evaluated by various methods including measuring the total phenolic content, total antioxidant capacity, free radical scavenging activity (DPPH assay), β-carotene/linoleic acid bleaching assay and ferric and cupric ion reducing power assay. The composition of essential oil was identified by using gas chromatography-mass spectrometry. Totally, 41 compounds were described in the essential oil. Germacrene D (44.829%) was determined as the major compound of the essential oil. The total phenolic content, total antioxidant capacity, inhibition rate of oxidation of linoleic acid, IC(50) (in DPPH assay) and EC(50) (in reducing power) value were found to be 40.454?mg?GAE/g, 100.840?mg?AAE/g, 65.639%, 39.584?μg?mL(-1) and 0.603?mg?mL(-1), respectively. The results indicated that the extract of C. drabifolia subsp. detonsa has strong antioxidant properties and this species can be used as a natural antioxidant in food processing and pharmaceutical industries.     

Modiolin and phthalide derivatives from the endophytic fungus Microsphaeropsis arundinis PSU-G18

One new modiolin, microsphaerodiolin (1), and seven new phthalides, microsphaerophthalides A-G (2-8), together with 12 known compounds were isolated from the endophytic fungus Microsphaeropsis arundinis PSU-G18. Their structures were elucidated by spectroscopic methods. The new 3-oxygenated phthalides are rare natural products. The known 1-(2,5-dihydroxyphenyl)-2-buten-1-one exhibited significant antifungal activity against Microsporum gypseum SH-MU-4 with an MIC value of 8 μg/mL, moderate antimalarial activity with an IC₅₀ value of 9.63 μg/mL and strong radical scavenging potency with the IC₅₀ value of 0.018 mg/mL. The new compounds 2 and 6 showed moderately antifungal activity against M. gypseum SH-MU-4 and Cryptococcus neoformans, respectively, with equal MIC values of 64 μg/mL.     

Antioxidant and antiproliferative activity of Laurus nobilis L. (Lauraceae) leaves and seeds essential oils against K562 human chronic myelogenous leukaemia cells

The antioxidant and antiproliferative activities of the essential oils from Laurus nobilis leaves and seeds in relation to their composition were analysed. The most abundant components of the leaf essential oil were 1,8-cineole, 1-p-menthen-8-ethyl acetate, linalool and sabinene, while the seed oil was characterised by β-ocimene, 1,8-cineole, α-pinene and β-pinene as main constituents. Both seed and leaf essential oils exhibited a scavenging effect on the DPPH radical, with IC?? values of 66.1 and 53.5?μg?mL?1, respectively. The leaf essential oil showed the strongest antioxidant activity in the β-carotene/linoleic acid system, with an IC?? value of 35.6?μg?mL?1 after 30?min of incubation. Both leaf and seed oils inhibited proliferation of the K562 tumour cell line with IC?? values of 95 and 75?μg?mL?1, respectively. The L. nobilis leaf oil showed a percentage of erythroide differentiation of 15% at a concentration of 10?μg?mL?1. A value of 12% was found for the seed essential oil at a concentration of 50?μg?mL?1. When the oils were added to a suboptimal concentration of the commercial drug, cytosine arabinoside, a clear synergic effect was observed.     

Antioxidant activities of extracts and metabolites isolated from the fungus Antrodia cinnamomea

Three different solvent partitions (n-hexane, ethyl acetate [EtOAc] and n-BuOH) of the culture broth from Antrodia cinnamomea were assayed with two different radical scavenging methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and superoxide radical scavenging (SOD) assay. The EtOAc layer exhibited the best antioxidant activity. Two major antioxidant metabolites were isolated from the active EtOAc layer. The antioxidant activities of compounds 1-6 were further evaluated by DPPH, SOD and trolox equivalent antioxidant capacity (TEAC) assays. Compounds 3 and 5 showed stronger free radical scavenging than the reference BHA, ED???=?1.36 and 34.24 μM. Compound 5 displayed moderate SOD activity (ED???=?310.0?μM), and its antioxidant capacity of TEAC value was 2.2 mM trolox equivalency.     

A new phenolic glycoside from the Idesia polycarpa Maxim. leaves

Phytochemical investigation on the ethyl acetate extract of Idesia polycarpa Maxim. Leaves led to the isolation of four phenolic glycoside isomers (1–4). Compound 2 appeared to be new reported phenolic glycoside, while compound 1 was the first time isolated from the titled species. Their structures were established by IR, UV, HRESI-MS and 1D and 2D NMR spectroscopies analysis and comparison of spectral data with previously reported data. The compounds 3 and 4 showed stronger activity of scavenging the DPPH free radical than the other two compounds, while the compounds 1 and 2 showed a significant activity of scavenging the ABTS free radical. Compounds 2 and 4 exhibited stronger cytotoxicity against HepG2 cell lines compared to compounds 1 and 3. Moreover, compound 3 presented the highest cytotoxicity against MCF cell lines with IC₅₀ value of 37.17?±?0.26?μg/mL than compounds 1, 2 and 4.     

Glutinoin, a novel antioxidative ellagitannin from Alnus glutinosa cones with glutinoic acid dilactone moiety

The crude aqueous ethanol extract of the cones of Alnus glutinosa (L.) Gaertn. (Betulaceae; black alder, European alder) was obtained and further partitioned between water and various organic phases. The active water and butanol phases were subjected to assay-guided (DPPH) fractionation using repetitive RP HPLC until individual compounds were isolated. Their antioxidative activities, measured as SC?? values, were evaluated. The chemical structures of the isolated compounds were elucidated with the help of mass spectroscopy, (1)H NMR technique, UV spectroscopy, and chemical approaches. One novel ellagitannin, glutinoin (2), along with two known compounds, pedunculagin (1) and praecoxin D (3), were isolated and found to contribute to antioxidative activity of the A. glutinosa cones extract. The activities (SC??) of 1-3 were evaluated as 0.95 (1), 1.00 (2) and 1.01?μg?mL?1 (3). The scavenging effects of glutinoin (2) and praecoxin D (3) were reported for the first time.     

Radical scavenging and antioxidant activity of tannic acid

Tannic acid, a naturally occurring plant polyphenol, is composed of a central glucose molecule derivatized at its hydroxyl groups with one or more galloyl residues. In the present paper, we examines the in vitro radical scavenging and antioxidant capacity of tannic acid by using different in vitro analytical methodologies such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination using by Fe³⁺–Fe²⁺ transformation method, superoxide anion radical scavenging by riboflavin–methionine-illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe²⁺) chelating activities. Also, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant radical scavenger compounds.Tannic acid inhibited 97.7% lipid peroxidation of linoleic acid emulsion at 15 μg/mL concentration. On the other hand, the above mentioned standard antioxidants indicated an inhibition of 92.2%, 99.6%, 84.6% and 95.6% on peroxidation of linoleic acid emulsion at 45 μg/mL concentration, respectively. In addition, tannic acid had an effective DPPH scavenging, ABTS⁺ radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, Fe³⁺ reducing power and metal chelating on ferrous ions activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and trolox as references antioxidant compounds. The present study shows that tannic acid is the effective natural antioxidant component that can be used as food preservative agents or nutraceuticals.     

Antioxidant and antiproliferative activity of Stachys glutinosa L. ethanol extract

Ethanol extracts of Stachys glutinosa L. (Lamiaceae) were investigated for antioxidative properties, as well as antiproliferative action on various cell lines. The antioxidant activities were investigated by ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid) assay, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, β-carotene/linoleic acid assay, scavenging of hydrogen peroxide (horseradish peroxidase test), superoxide anion scavenging, and hypochlorous acid scavenging (taurine test). The antioxidant activity was reported as IC₅₀ and reveals antioxidant effects. Antiproliferative effects were measured in vitro on three cell lines: HepG2 (human hepatocarcinoma), MCF7 (breast human adenocarcinoma) and C2C12 (mouse myoblast) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The ethanol extract induced variations in cell viability on all cell lines tested. At 200 μg/mL, the effects on cell viability were ? 23%, ? 27% and ? 37%, respectively, for C2C12, MCF7 and HepG2.     

Antioxidant and α-Glucosidase Inhibitory Compounds of Centella Asiatica

Centella asiatica, as known as Pegagan was previously reported to have anti-hyperglycemic effects in animal diabetic model rats. However, its α-glucosidase activity in vitro assay not yet reported. Our goal in this study is to isolate and identify active compounds as α-glucosidase inhibitor and antioxidant from aqueous ethanol 70% (v/v) extract of C. asiatica. The extract was partitioned by n-hexane, EtOAc, and n-butanol sequentially. Among the fractions tested, EtOAc fraction was showed the highest antioxidant and α-glucosidase inhibitory activities with an IC₅₀ values of 45.42 and 73.17 μg/mL, respectively. The antioxidant activity was conducted by determination of DPPH radical scavenging activity, whereas α-glucosidase inhibitory activity was determined against yeast α-glucosidase. Furthermore, isolation of the ethyl acetate extract yielded two active compounds, which were identified as kaempferol (1) and quercetin (2). Both of the compounds showed good yeast α-glucosidase inhibitory activity with IC₅₀ values of 16.50 and 21.61 μg/mL, respectively. In addition those compounds also could scavenge DPPH radical activity with IC₅₀ values of 9.64 and 11.97 μg/mL, respectively. Due to its ability in reducing α-glucosidase activity and scavenging free radical activity, the C. asiatica appears to be a potential as a good resource for future development of antioxidant and antidiabetic drug.     

Antioxidant activity of clove oil – A powerful antioxidant source

The number of methods to measure the antioxidants in botanicals, foods, nutraceuticals and other dietary supplements has increased considerably in the last decade. Clove oil is obtained by distillation of the flowers, stems and leaves of the clove tree. In the present paper, clove oil was evaluated by employing various in vitro antioxidant assay such as α,α-diphenyl-β-picryl-hydrazyl free radical (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by Fe³⁺–Fe²⁺ transformation method, superoxide anion radical scavenging by riboflavin/methionine/illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe²⁺) chelating activities. Clove oil inhibited 97.3% lipid peroxidation of linoleic acid emulsion at 15 μg/mL concentration. However, under the same conditions, the standard antioxidant compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox demonstrated inhibition of 95.4, 99.7, 84.6 and 95.6% on peroxidation of linoleic acid emulsion at 45 μg/mL concentration, respectively. In addition, clove oil had an effective DPPH scavenging, ABTS⁺ scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe³⁺) reducing power and ferrous ions (Fe²⁺) chelating activities. Also, these various antioxidant activities were compared to BHA, BHT, α-tocopherol and trolox as reference antioxidant compounds.     

In vitro antioxidant activity of the water and ethanol extracts of Forsythia koreana flowers

The antioxidant activities of the water and ethanol extracts of F. koreana flowers were evaluated using DPPH, superoxide anion (?O(-2)), and nitric oxide (?NO) radical scavenging activity assays. The SC(50) values of the water extract of F. koreana on DPPH, ?O(-2) and ?NO were 48.39, 24.36 and 100.21 μg mL(-1), respectively. The SC(50) values of the ethanol extract of F. koreana on the aforesaid free radicals were 57.50, 49.00 and 146.08 μg mL(-1), respectively. Further, the total phenolic contents of both extracts were determined and expressed as milligram gallic acid equivalent (GAE) per gram of extract. The water extract exhibited a higher phenolic content (113.78 mg GAE?g(-1)), while the ethanol extract showed 94.53?mg GAE?g(-1). Our findings demonstrate that the water and ethanol extracts of F. koreana flowers might be potential natural sources of antioxidative additives for use in the food and other allied industries.     

Two new aromatic polyketides from a deep-sea fungus Penicillium sp. SCSIO 06720

Abstract

Two new compounds, 5-[2-hydroxypropane-1-yl]-2,6-dimethlbenzene-1,3-diol (1) and coniochaetone L (2), together with 19 known compounds (3–21), were isolated from a deep-sea fungus, Penicillium sp. SCSIO 06720. Their structures and absolute configurations were elucidated by detailed NMR, MS spectroscopic analyses, chiral-phase HPLC analysis, and electronic circular dichroism spectra. All the isolated compounds (1–21) were tested for their antibacterial and HIV latency-reversal activities. Among these compounds, compound 16 showed moderate antibacterial activities against Staphylococcus aureus ATCC 29213 and Methicillin-Resistant Staphylococcus Aureus-shh-1 with MIC values of 10.4?±?3.7?μg/mL and 46.9?±?29.7?μg/mL, respectively, which were comparable to that of the positive control ampicillin with MIC values of 0.5?±?0.4?μg/mL and 2.7?±?0.9?μg/mL, respectively.     

红花黄色素抗氧化活性研究

通过考察红花黄色素(SY)及其主要化学成分对羟基自由基介导2-脱氧核糖氧化降解的抑制作用,以及对1,1-二苯基-2-苦肼基自由基(DPPH·)的清除能力,探究SY的体外抗氧化活性及其抗氧化的主要有效成分.通过Fenton反应产生羟基自由基,用紫外分光光度计检测了SY及其主要化学成分对2-脱氧核糖降解的抑制作用和对DPPH·的清除能力,同时对红花黄色素B(SYB)抑制2-脱氧核糖降解的作用机制做了初步研究.结果表明SY抑制Fenton反应对2-脱氧核糖的氧化降解的IC50为256.79 μg/mL,对DPPH·清除的IC50值为27.15μg/mL.羟基红花黄色素A(HSYA)和SYB是SY中抗氧化的两个有效成分,抑制2-脱氧核糖的氧化降解的IC50分别为220.68 μg/mL和207.01μg/mL;对DPPH·清除的IC50值分别为55.81 μg/mL和41.25μg/mL.SYB对2-脱氧核糖氧化降解的抑制作用机理研究表明,SYB除了对Fenton反应产生的羟基自由基具有直接清除作用外,又可通过与Fe2+离子的络合作用而阻断Fenton反应产生羟基自由基.由此可知SY具有明显的体外抗氧化活性,SYB和HSYA为其主要抗氧化活性成分.