Vialinin A, a novel 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenger from an edible mushroom in China

While screening for bioactive compounds from edible mushrooms, a new potent antioxidant, vialinin A (1), together with a known compound, ganbajunin B (2), and a mixture of ganbajunins D (3) and E (4), were isolated from the dry fruiting bodies of Thelephora vialis. The structure of 1, 5',6'-bis(phenylacetoxy)-1,1':4',1'-terphenyl-2',3',4,4'-tetraol, was elucidated by spectroscopic and chemical methods. This compound had strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity with an EC(50) value of 14.0 microM, nearly equal to that of butylated hydroxytoluene (BHT; EC(50) = 10.0 microM). A radical scavenging experiment using 1 and DPPH radicals indicated that 1 donated two hydrogen atoms to two molecules of the DPPH radical under hydrophobic conditions.     

Reassessment of antioxidant activity of arbutin: Multifaceted evaluation using five antioxidant assay systems

Abstract

Arbutin, a practically used skin-lightening agent, has been reported to possess a weak antioxidant activity compared to that of its precursor, hydroquinone. However, its antioxidant activity has not been systematically evaluated. Hence, this study reassessed its activity using five assay systems. Assays were first performed using model radicals, DPPH radical and ABTS^?+. Arbutin showed weak DPPH radical-scavenging activity compared to that of hydroquinone, but showed strong ABTS^?+-scavenging activity. Its activity by ORAC assay was then evaluated using a physiologically relevant peroxyl radical. Arbutin exerted weak but long-lasting radical-scavenging activity and showed totally the same antioxidant activity as that of hydroquinone. Finally, it was shown that, in two cell-based antioxidant assays using erythrocytes and skin fibroblasts, arbutin exerted strong antioxidant activity comparable or even superior to that of hydroquinone. These findings indicate that the antioxidant activity of arbutin may have been under-estimated and suggest that it acts as a potent antioxidant in the skin.     

Antioxidative compounds from Crotalaria sessiliflora

Seven antioxidative compounds were isolated from the EtOAc extract of the aerial part of C. sessiliflora (Japanese name, tanukimame) by activity-guided fractionation with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Among the isolated compounds, hydroxyeucomic acid showed the strongest free radical-scavenging activity, which was almost identical to that of epigallocatechin gallate, against DPPH. Orientin and isoorientin showed strong anti-peroxidative activities toward linoleic acid and protective effects against the bactericidal action of the tert-butyl peroxyl radical. Their activities were nearly equal to that of epigallocatechin gallate.     

Antioxidative polyphenols from berries of Pimenta dioica

The ethyl acetate-soluble part of allspice, berries of Pimenta dicica, showed strong antioxidant activity and radical-scavenging activity against 1,1diphenyl-2-picrylhydrazl (DPPH) radical. From the ethyl acetate-soluble part, two new compounds, 5-galloyloxy-3-4-dihydroxypentanoic acid and 5-(5-carboxmethyl-2-oxocyclopenty)3Z-penteny 6-O-galloy-beta-D-glucoside were isolated together with 11 known polyphenols by repeated column chromatography. Their structures were elucidated on the basis of MS and various NMR spectroscopic data. All isolated compounds were evaluated for antioxidative effects on oxidation of methyl linoleate under aeration and heating, anf on peroxidation of liposome induced by 2-2'-azobis-(2-amidinopropane)dihydrocloride (AAPH) as water-soluble initiator along with their radical-scavenging activity against DPPH. Quercetin and its glycoside showed remarkable activity for scavenging DPPH radical and inhibiting peroxidation of liposome. Two new compounds also exhibited strong DPPH radical-scavenging activity and inhibitory effect on the peroxidation od liposome as myricetin.     

Anti-oxidant constituents from Sedum takesimense

As part of an ongoing search for antioxidants from medicinal plants, 14 phenolic constitutents were isolated from the Korean endemic species Sedum takesimense Nakai. Their structures were determined as 1-(4-hydroxyphenyl)-2-(3,5-dihydroxyphenyl)-2-hydroxyethanone (5), gossypetin-8-O-beta-d-xylopyranoside (10), and 2,6-di-O-galloylarbutin (13) on the basis of spectroscopic analyses (IR, UV, 1D and 2D NMR, HR-MS) and chemical degradation, together with 11 previously known phenolics. Two of those (10 and 13) exhibited strong scavenging activities against DPPH and superoxide radicals as well as significant inhibitory effects on lipid peroxidation (IC(50) 14.0 and 10.8 microM, respectively) and LDL oxidation induced by a metal ion Cu(2+) (IC(50) 5.7 and 3.3 microM, respectively).     

New phenolic constituents from Balanophora polyandra with radical-scavenging activity

The 80% acetone extract of Balanophora polyandra Griff. (Balanophoraceae) was found to exhibit high radical-scavenging activity (SC(50)=14.48 mug/ml) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Further chemical investigation led the isolation of two new hydrolysable tannins, balapolyphorins A (1) and B (2), together with 20 known phenolic compounds (3-22). Their structures were established by detailed spectroscopic analysis, and the radical-scavenging properties of all isolated compounds were determined by DPPH assay.     

1,1-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines

Guided by their DPPH radical-scavenging activity, nine compounds were isolated from soybean miso. Of these, 8-hydroxydaidzein, 8-hydroxygenistein and syringic acid had as high DPPH radical-scavenging activity as that of alpha-tocopherol. The antiproliferative activity of four of the isolated isoflavones toward three cancer cell lines was examined. 8-Hydroxygenistein showed the highest activity (IC50=5.2 microM) toward human promyelocytic leukemia cells (HL-60).     

Antioxidant activity and cytotoxicity of methanol extracts from aerial parts of Korean salad plants

The aim of this investigation was to determine the content of total phenolics, antioxidant activity and cytotoxicity of methanol extracts from the aerial parts of 11 Korean medicinal salad plants. The highest total phenolic content of the methanol extracts was found in Aster scaber (17.1 mg 100 g(-1)), followed by Ixeris dentate (16.4 mg 100 g(-1)), Aster yomena (12.0 mg 100 g(-1)) and Sedum sarmentosum (9.1 mg 100 g(-1)) of FW. Methanol extracts of Ixeris dentate and Aster scaber at 50 microg mL(-1) exhibited the highest DPPH radical scavenging activity by 86.4 and 83.3%, respectively. It was registered a dose-dependent increase of DPPH free radical scavenging activity. Total phenolic content of the studied plant extracts was correlated with the DPPH radical scavenging activity. It was found by means of MTT assay, that cytotoxicity of the methanol extracts was the highest against HCT-116. Methanol extracts from Petasites japonicus (IC(50)<25.0 microg mL(-1)) showed the highest activity against HCT-116, following by Angelica gigas (34.75 microg mL(-1)), Erythronium japonicum (44.06 microg mL(-1)), and Aster scaber (54.87 microg mL(-1)). In conclusion, the studied salad plants have high total phenolics content and high antioxidant activity. These plants dose-dependently increased DPPH free radical scavenging activity. The total phenolics level was highly correlated with the free radical scavenging activity. Most of the studied salad plants have potent cytotoxicity activity. The results of this investigation suggest that the extracts of studied salad plants could be an addition to basic medicine for some diseases.     

Efficiency and mechanism of the antioxidant action of trans-resveratrol and its analogues in the radical liposome oxidation.

trans-Resveratrol (trans-3,5,4'-trihydroxystilbene) is a nonflavonoid polyphenol reported to exert different biological activities, among them inhibition of the lipid peroxidation, scavenging of the free radicals, inhibition of the platelet aggregation, and anticancer activity as the most important. In order to enlighten the radical-scavenging mechanism of trans-resveratrol, stationary gamma-radiolytic experiments in liposomes and pulse radiolytic experiments in aqueous solutions were performed. Applying the stationary gamma-radiolysis together with the subsequent product analysis, reactions of lipid peroxyl radicals, LOO*, with trans-resveratrol and other natural antioxidants were investigated. It was found that trans-resveratrol was a better radical scavenger than vitamins E and C but similar to the flavonoids epicatechin and quercetin. The comparison of the radical-scavenging effects of trans-resveratrol and its analogues trans-4-hydroxystilbene and trans-3,5-dihydroxystilbene revealed that trans-resveratrol and trans-4-hydroxystilbene showed almost the same effect and were more efficient than trans-3,5-dihydroxystilbene. These findings indicate greater radical-scavenging activity of trans-resveratrols para-hydroxyl group than its meta-hydroxyl groups. Using the pulse radiolysis, reactions of trans-resveratrol and its analogues with trichloromethylperoxyl radicals, CCl(3)OO*, were studied. Spectral and kinetic properties of the observed transients showed great similarity between trans-resveratrol and trans-4-hydroxystilbene which seems to confirm that para-hydroxyl group of trans-resveratrol scavenges free radicals more effectively than its meta-hydroxyl groups.     

Taxonomic review of the genus Macrosiphum (Sternorrhyncha: Aphididae) for the Korean Peninsula, with description of a new species

Eight species of the genus Macrosiphum Passerini 1860 (Sternorrhyncha: Aphididae) are recognized from the Korean Peninsula. A new species, Macrosiphum ( Macrosiphum ) paektusani n. sp., is described herein for apterous and alate viviparous females on Rosa marretii Lev. (Rosaceae). The taxonomic position of Macrosiphum ( Macrosiphum ) cornifoliae Shinji 1924, com. rev., is transferred from the genus Sitobion Mordvilko 1914 to its original position. Host plants of the Korean Macrosiphum are reviewed and the identification key to subgenera and species is also presented.     

Bioactivity-guided isolation of the active compounds from Rosa nutkana and quantitative analysis of ascorbic acid by HPLC

Rosa nutkana Presl. (Rosaceae) is distributed abundantly throughout central and southern areas of British Columbia, Canada. Aboriginal people in the Pacific Northwest have traditionally used R. nutkana as a food, medicine, and source of cultural material. The methanolic extract of the fruits of R. nutkana was previously found to have inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA). In our study, bioactivity-guided fractionation of the methanol extract from R. nutkana led to the isolation of the following 10 compounds: (i) tormentic acid, (ii) euscaphic acid, (iii) ursolic acid, (iv) maslinic acid, (v) quercetin, (vi) catechin gallate, (vii) quercetin-3-O-glucoside, (viii) 1,2,3,4,6-penta-O-galloyl-beta-D-glucoside, (ix) L-ascorbic acid (vitamin C), and (x) 1,6-digalloyl-beta-D-glucoside. Structures were elucidated by ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance data, as well as by comparison with those of the literature. The compounds quercetin, catechin gallate, quercetin-3-O-glucoside, 1,2,3,4,6-penta-O-galloyl-beta-D-glucoside, and 1,6-digalloyl-beta-D-glucoside exhibited weak antibacterial activity against MRSA. Our research demonstrates the value of traditional knowledge held by Aboriginal people in the Pacific Northwest with respect to uses of R. nutkana. Some described uses in the ethnobotanical literature correspond to activities observed under laboratory conditions. Further work on British Columbia Rosa spp. may contribute to identifying other potential therapeutic uses.     

Antioxidative properties of vanillic acid esters in multiple antioxidant assays

The antioxidative properties of vanillic acid esters were systematically evaluated by multiple assays to compare with the well-known antioxidants, vanillic acid and Trolox. We first performed assays with the model radicals, DPPH, galvinoxyl and ABTS cation (ABTS(?+)) types. Methyl vanillate, ethyl vanillate and butyl vanillate showed stronger activity than Trolox in the ABTS(?+)-scavenging assay, but showed no activity in the DPPH radical- and galvinoxyl radical-scavenging assays. In contrast, vanillic acid could quench the three radicals. We then evaluated their antioxidative activities by an ORAC assay and an oxidative hemolysis inhibition assay (OxHLIA), using physiologically relevant peroxyl radicals. Vanillic acid esters and vanillic acid exerted much stronger activity than Trolox in the ORAC assay and OxHLIA. The antioxidative activity by OxHLIA was strongly correlated to the lipophilicity of vanillic acid and its esters. These results indicate that the protective effect of vanillic acid esters against free radical-induced biomembrane damage increased with increasing lipophilicity.     

Characterization of novel furan compounds on the basis of their radical scavenging activity and cytoprotective effects against glutamate- and lipopolysaccharide-induced insults

There is increasing evidence indicating that free radicals and oxygenases such as cyclooxygenase (COX) and lipoxygenase (LOX) are related to the onset and development of neurodegenerative diseases. In order to prevent and/or delay these diseases, the use of radical-scavenging antioxidants and inhibitors against oxygenases has received much attention. In the present study, we examined the radical-scavenging activity and cytoprotective effects of some novel furan compounds with potent inhibitory activity against oxygenases such as COX-1, COX-2, and 5-LOX. The radical-scavenging activity was assessed by studying the bleaching of beta-carotene by free radicals generated from an azo initiator. In this assay system, the rate constants for scavenging peroxyl radicals by furan S and furan L was estimated to be 2 x 10(4) and 3 x 10(4) M(-1) s(-1), respectively. We also investigated the cytoprotective effects of these compounds against cell death induced by several toxins. We found that the furan compounds exhibited cytoprotective effects against PC12 cell death induced by linoleic acid hydroperoxide, primary neuronal cell death induced by glutamate, and cell death induced by lipopolysaccharide. These results suggest the beneficial effects of the furan compounds against disorders related to glutamate and lipopolysaccharide.     

Free radical scavenging reactions and antioxidant activity of embelin: biochemical and pulse radiolytic studies

Embelin (from Embelia ribes) is a component of herbal drugs and possess wide range of medicinal properties. These properties may be, in part, due to scavenging of oxidizing free radicals. In this context, free radical scavenging reactions and antioxidant activity of embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone) have been studied. It has been found to scavenge DPPH radical and inhibit hydroxyl radical induced deoxyribose degradation. It has been also found to inhibit lipid peroxidation and restore impaired Mn-superoxide dismutase in rat liver mitochondria. Further, kinetics and mechanism of the reactions of embelin with hydroxyl, one-electron oxidizing, organo-haloperoxyl and thiyl radicals have been studied using nanosecond pulse radiolysis technique. Its redox potential has been also evaluated with cyclic voltammetry. These studies suggest that embelin can act as a competitive antioxidant in physiological conditions.     

新疆巩乃斯沟药用植物资源多样性研究

从数量、生活型、药用部位等方面对巩乃斯沟药用植物多样性进行了研究。巩乃斯沟的药用植物资源具有丰富的多样性,共有野生药用植物54科260多种,分别占伊犁河谷地区药用植物科、种数的54.54%和46.34%。其中珍稀濒危药用种子植物21种,新疆道地药材8种,蒙医药地道药材38种;多年生草本类型占该区药用种子植物总数的70%以上;全草类和根类药用植物最多,分别占该区药用种子植物总数的50.84%和21.40%,大多数种类属于北温带分布区类型;优势科主要有菊科、蔷薇科、毛茛科和豆科,优势属主要有蒿属,毛茛属和委陵菜属。本文提出了保护和开发利用的具体建议。     

Antimicrobial and antioxidant activities of methanol extracts of <Emphasis Type="Italic">Evax pygmaea</Emphasis> (Asteraceae) growing wild in Tunisia

Antimicrobial activity of methanolic extracts obtained from the aerial parts of Evax pygmaea was tested against five bacteria and two strains of phytopathogenic fungi using the agar diffusion and broth microdilution methods. Antioxidant properties were evaluated through the ability of the different fractions to scavenge the stable ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals. The TEAC (Trolox Equivalent Antioxidant Capacity) and IC₅₀ values of the fractions were calculated and compared. The experimental data indicated that all fractions exhibit moderate to appreciable antibacterial activities against all Gram-positive cocci and Gram-negative rods except Pseudomonas aeruginosa, but no antifungal activity was observed. Ethyl acetate and methanol fractions were found to cause significant free radical-scavenging effects in both assays. These results may suggest that E. pygmaea could be used as a natural preservative ingredient in the food and/or pharmaceutical industries.     

New antioxidant polyphenols from the medicinal mushroom Inonotus obliquus

The fruiting body of Inonotus obliquus, a medicinal mushroom called chaga, has been used as a traditional medicine for cancer treatment. Although this mushroom has been known to exhibit potent antioxidant activity, the mechanisms responsible for this activity remain unknown. In our investigation for free radical scavengers from the methanolic extract of this mushroom, inonoblins A (1), B (2), and C (3) were isolated along with the known compounds, phelligridins D (4), E (5), and G (6). Their structures were established by extensive spectroscopic analyses. These compounds exhibited significant scavenging activity against the ABTS radical cation and DPPH radical, and showed moderate activity against the superoxide radical anion.     

The Investigation on Utilization of Wild Medicinal Plants in Dietary Culture of Quanzhou,Southern Fujian

An ethnobotanical survey on the medicinal plant species marketed in Quanzhou, southern Fujian, was conducted in order to document traditional medicinal knowledge and application of medicinal plants in dietary. In addition to literature review, data was obtained using ethnobotanical tools and methods, including personal interviews during field trips, collecting herbarium specimens, and species identification by cross referencing. The results showed that: 1) There are 148 wild medicinal species, belonging to 56 plant families and 117 genera present in Quanzhou, southern Fujian. Among them, 46 species are edible wild herbs, 37 species are medicinal plants, 38 species are used as tea substituting plants or herbal tea,22 species are wild fruits, 4 species are used as spices and 1 species is used to make bean jelly; 2) The plant families which comprise a major part of the pool are Compositae, Lamiaceae, Rosaceae, Leguminosae, Rubiaceae, Liliaceae, Orchidaceae and Moraceae; 3) This study explored the utilization of the medicinal plants in Quanzhou area, and proposed methods to inherit the culture of using wild plants in dietary, as well as methods to conserve the edible medicinal wild plant resources.     

Antioxidant activity of 50% aqueous--ethanol extract from Acantholippia deserticola

The antioxidant properties oí Acantholippia deserticola, a herb used in traditional northern Chilean medicine was studied using free radical-generating systems. The 50% aqueous-ethanol extract oí Acantholippia deserticola protected against non-enzymatic lipid peroxidation in microsomal membranes of rat, induced by an Fe++-ascorbate system and measured spectrophotometrically by the TBARS test, and had strong free radical scavenging capacities on stable ABTS and DPPH radicals. The results shows that the IC50 value of the 50% aqueous-ethanolic extract of A.deserticola is 18 +/- 0.5 microg/mL in DPPH radical-scavenging, 15 +/- 0.8 microg/mL in lipid peroxidation , Total Antioxidant Activity (TAA) is 0.95 mM of Trolox per mg/mL of extract. The total phenolics content of extract is 725 +/- 12 mg of gallic acid equivalent per g of dried extract. The results indicate that the 50% aqueous-ethanol extract of Acantholippia deserticola clearly has antioxidant properties.     

Vasodilation and radical-scavenging activity of imperatorin and selected coumarinic and flavonoid compounds from genus Casimiroa

Hypertension is a very widespread condition which is not strictly considered as an illness but if not countered, progressively causes damage to all tissues and loss in their functionality. For this reason the find of new antihypertensive agents is prominent and medicinal plants and their derivatives are valuable for the purpose. The genus Casimiroa (Rutaceae) includes plants from Central America and Mexico; among these, Casimiroa edulis Llave et Lex. and Casimiroa pubescens Ramirez are the most relevant species, even for their medicinal uses. The decoction of leaves and seeds is traditionally taken as a tea mainly to lower blood pressure. The object of this research was the study of vascular activity of coumarinic and flavonoid compounds isolated from seeds of Casimiroa spp. in comparison with Casimiroa edulis and Casimiroa pubescens extracts. The phenolic compounds isolated from Casimiroa were herniarin (Her), imperatorin (Imp), 8-geranyloxypsoralen (GOP) and 5,6,2′,3′,4′-pentamethoxyflavone (PMF). All these compounds induced vasorelaxation on rat arterial tissues although with different effectiveness. To study the cellular mechanisms of the vasorelaxation exhibited by imperatorin, we used selective inhibitors of different receptors and enzymes, such as atropine, pyrilamine, nifedipine, L-NAME and DETC. In a further step of this research, we evaluated the radical-scavenging activity of Casimiroa extracts and isolated compounds by means of DPPH assay. In general, we observed that the scavenging activities increased in a concentration-dependent manner for all substances. The phenolic compounds highlight a synergism of vasodilation and antioxidant activity which may be very useful in the management of cardiovascular diseases. Among the evaluated compounds, imperatorin shows a significant vasorelaxant activity even higher than acetylcholine and similar to nitrite, and also useful antiradical capabilities. All these properties suggest its possible role against hypertension and vasculopathies, even if in vivo studies are needed to determine the actual applications.