Secondary metabolites of ponderosa lemon (Citrus pyriformis) and their antioxidant, anti-inflammatory, and cytotoxic activities

Column chromatography of the dichloromethane fraction from an aqueous methanolic extract of fruit peel of Citrus pyriformis Hassk. (Rutaceae) resulted in the isolation of seven compounds including one coumarin (citropten), two limonoids (limonin and deacetylnomilin), and four sterols (stigmasterol, ergosterol, sitosteryl-3-beta-D-glucoside, and sitosteryl-6'-O-acyl-3-beta-D-glucoside). From the ethyl acetate fraction naringin, hesperidin, and neohesperidin were isolated. The dichloromethane extract of the defatted seeds contained three additional compounds, nomilin, ichangin, and cholesterol. The isolated compounds were identified by MS (EI, CI, and ESI), 1H, 13C, and 2D-NMR spectral data. The limonoids were determined qualitatively by LC-ESI/MS resulting in the identification of 11 limonoid aglycones. The total methanolic extract of the peel and the petroleum ether, dichloromethane, and ethyl acetate fractions were screened for their antioxidant and anti-inflammatory activities. The ethyl acetate fraction exhibited a significant scavenging activity for DPPH free radicals (IC50 = 132.3 microg/mL). The petroleum ether fraction inhibited 5-lipoxygenase with IC50 = 30.6 microg/mL indicating potential anti-inflammatory properties. Limonin has a potent cytotoxic effect against COS7 cells [IC50 = (35.0 +/- 6.1) microM] compared with acteoside as a positive control [IC50 = (144.5 +/- 10.96) microM].     

Antioxidant and anti-inflammatory activity of extract obtained from Aspergillus candidus MTCC 2202 broth filtrate

Antioxidant potential of Aspergillus candidus MTCC 2202 broth filtrate extract was studied using different antioxidant models, whereas anti-inflammatory potential was studied using carrageenan-induced rat paw oedema model. The ethyl acetate extract at 1000 microg/ml showed maximum scavenging activity of the stable radical 1,1-diphenyl,2-picryl hydrazyl upto 96.65% (IC50=430.36 microg/ml) and scavenging of the radical cation, 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonate) upto 92.25% (IC50=606.29 microg/ml) at the same concentration. The extract had good reducing power, however showed moderate inhibition for conjugated dienes and thiobarbituric acid reactive acid substances (59.56 and 51.45%). The total phenolic content of various extracts of A. candidus broth filtrate was measured and a correlation between radical scavenging activities of extracts with total phenolic content was observed. The ethyl acetate extract (125 mg/kg ip) showed significant anti-inflammatory activity in carrageenan-induced rat paw oedema model. The exhibited antioxidant activity of ethyl acetate extract of A. candidus broth filtrate was comparable with BHA and ascorbic acid, while anti-inflammatory activity was comparable with standard diclofenac sodium.     

The activity of an extract and fraction of Agrimonia eupatoria L. against reactive species

Agrimonia eupatoria L. (agrimony) is a medicinal plant largely used in traditional medicine. Recently, phytochemical studies on an agrimony hydro-alcoholic extract and a polyphenol-enriched fraction obtained from it were carried out. The fraction was found to possess a high concentration of flavan-3-ols, flavonols, flavones and phenolic acids. So, the main purpose of this study was to search out, the extract and fraction antioxidant potential and scavenging activity against the reactive species formed during inflammation and to establish a relationship between such activity and the phenolic composition. Results showed that both the extract and the fraction promptly reacted with DPPH denoting a general radical scavenger activity and a potential antioxidant capacity. They also reacted with superoxide anion, peroxyl and hydroxyl radicals as well as with the oxidant species, hydrogen peroxide, hypochlorous acid and peroxynitrite, strengthening their radical scavenger and antioxidant activities. In most assays, the polyphenol-enriched fraction was more efficient, pointing to a significant contribution of the polyphenols content to those activities. Our data suggest that the significant scavenging capacity of reactive species by polyphenols from Agrimonia eupatoria L., could be a mechanism of its anti-inflammatory activity.     

Oligolignans in the wood of <Emphasis Type="Italic">Picea obovata</Emphasis> Ledeb.

We studied the chemical composition of the phenolic complex and the structure of oligomeric lignans in Siberian spruce (Picea obovata Ledeb.). We used the wood of Siberian spruce collected near the city of Irkutsk. The extractives were isolated from ground wood (particle size: 10–15 mm; humidity: 5.9%) by three-stage acetone extraction. The extract was separated by consecutive treatment with the solvents with increasing polarity: hexane, ethyl acetate and n-butanol. The main amount of phenolic compounds (lignans) was concentrated in the ethyl acetate fraction and it was 0.7% in absolutely dry wood (adw).The ethyl acetate fraction of spruce wood extract was separated by silica gel column; a chloroform-acetone mixture was used as the eluent (the concentration of acetone in the mixture was increased from 0 to 100%). Monomeric lignans (~60–65% of the ethyl acetate fraction of spruce wood extract), oligomeric lignans (~20–25%), and polymer lignans (~12–15%) were isolated.We also obtained ¹³C nuclear magnetic resonance (NMR) spectra for the main monomeric, oligomeric and polymeric lignan compounds of phenolic complexes. It was found that oligomeric and polymeric fractions contain monomeric lignan units with the butyrolactone cycle, primarily, the fragments with hydroxymatairesinol structure. Oligomeric lignans contain the fragments with a pinoresinol and lariciresinol structure. All the monomeric structural units are characterized by the guaiacyl substitution type of the aromatic cycles.A preliminary study has been performed on the antiviral and antioxidant activity of the ethyl acetate fraction of acetone extract of Siberian spruce wood. It was found that the lignan complex is active against Coxsackie B4 virus in cell culture and in the pancreatitis model in white mice, reducing the activity of enteroviruses in the cell culture approximately 100 times. The antioxidant activity rate of polyphenol complex of Siberian spruce wood is comparable to that of a known antioxidant dihydroquercetin.     

Chemical constituents and biological activities of Senecio aegyptius var. discoideus Boiss

A new eremophilane sesquiterpene, 1-beta-hydroxy-8-oxoeremophila-7,9-dien-12-oic acid (1), in addition to two known flavonol glycosides, rutin (2) and quercetin-3-O-glucoside-7-O-rutinoside (3), was isolated from the ethyl acetate fraction obtained from the aqueous alcoholic extract of the aerial parts of Senecio aegyptius var. discoideus Boiss. (family Asteraceae). The chemical structures of the isolated compounds were established by 1D and 2D NMR analysis (1H, 13C, COSY, HMQC, HMBC), MS and UV data, and through comparison with the literature. The ethyl acetate fraction and the isolated rutin showed significant cytotoxic activity against colorectal carcinoma (HCT 116) and to less extent against brain (U 251) and breast carcinoma (MCF 7). The ethyl acetate fraction showed a significant level of activity against Klebsiella pneumoniae, while the total extract showed the best antifungal activity against Candida albicans and Saccharomyces cerevisiae. DPPH radical scavenging activity of the ethyl acetate fraction was significant (96.7%) when compared to ascorbic acid. It also showed anti-inflammatory activity but no diuretic effect.     

菹草提取物总黄酮、总酚酸和抗氧化活性含量研究

研究菹草提取物的有效成分,测定其总黄酮含量及总酚酸含量,并确定它的乙酸乙酯和石油醚部位的抗氧化活性成分。采用紫外可见分光光度法,以芦丁和没食子酸作为控制材料,测定菹草的石油醚部位及乙酸乙酯部位中总黄酮和总酚酸含量;采用清除DPPH自由基能力测定法、测定总还原能力铁氰化钾法和水杨酸捕捉羟基自由基法来对菹草各组分提取物的抗氧化能力进行研究。菹草中有一定量的黄酮类化合物和酚酸类化合物存在,不同溶剂提取的部位所含有的总黄酮和总酚酸含量是有差异的,石油醚部位的总黄酮含量要高于乙酸乙酯部位的总黄酮含量,并且总酚酸的含量亦是如此;石油醚部位和乙酸乙酯部位的提取物具有清除DPPH、羟基自由基和还原Fe^3+的能力,各部位清除DPPH、羟基自由基的能力和还原Fe^3+的能力随着样品浓度的增大而增大,且乙酸乙酯部位的测定结果均低于石油醚部位。     

Caesalpinia palmeri: First Report on the Phenolic Compounds Profile,Antioxidant and Cytotoxicity Effect

This study aimed to determine the phenolic compounds profile, antioxidant potential and cytotoxicity of extracts and fractions of Caesalpinia palmeri. Methanolic extracts were generated from C. palmeri berries, stems and flowers. The latter was subjected to liquid-liquid partition, obtaining hexane, ethyl acetate and residues fractions. Results showed that the flower extract and ethyl acetate fraction had a larger concentration of phenolic compounds (148.9 and 307.9 mg GAE/g, respectively), being ellagic acid (6233.57 and 19550.08 μg/g, respectively), quercetin-3-β-glycoside (3023.85 and 8952.55 μg/g, respectively) and gallic acid (2212.98 and 8422.34 μg/g, respectively) the most abundant compounds. Flower extract and ethyl acetate fraction also presented the highest antioxidant capacity on all tested methods (DPPH, ABTS, ORAC and FRAP) and low cytotoxicity against ARPE-19 cells (IC₅₀ >170 μg/mL). C. palmeri possessed high antioxidant potential, associated with the presence of phenolic compounds and low cytotoxicity, suggesting that they could represent an option to counter oxidative stress.     

Antioxidant components of Laetiporus sulphureus (Bull.: Fr.) Murr. fruit bodies

Antioxidant activity of fruit bodies of Laetiporus sulphureus (Bull.: Fr.) Murr. (Polyporales) obtained by the natural plantation growing method in Pribaikal'e (Irkutsk region) has been studied. It was determined that the ethyl acetate fraction of L. sulphureus, which was chromatographically separated into seven compounds identified as quercetin, kaempferol, (+)-catechin, p-coumaric, gallic, caffeic, and chlorogenic acids was characterized with more expressed antioxidant activity. All compounds were extracted from this basidiomycete species for the first time. The quantitative amount of the substances isolated from L. sulphureus was determined by HPLC. It was found that antioxidant activity of preparations obtained from L. sulphureus is conditioned by phenolic compounds.     

Harpagophytum procumbens Prevents Oxidative Stress and Loss of Cell Viability In Vitro

Harpagophytum procumbens, popularly known as devil’s claw, is a plant commonly used in the treatment of diseases of inflammatory origin. The anti-inflammatory effects of H. procumbens have been studied; however, the mechanism of action is not elucidated. It is known that excess of reactive oxygen and nitrogen species may contribute to increasing tissue damage due to inflammation. In the present study, we examined the effects of H. procumbens infusion, crude extract and fractions on lipid peroxidation (brain homogenates) induced by different pro-oxidants (Fe²⁺ or sodium nitroprusside) and the effects of ethyl acetate fraction (rich in phenolic compounds) on antioxidant defenses (catalase activity and thiol levels) and cell damage (brain cortical slices) induced by different pro-oxidants. All tested extracts of H. procumbens inhibited lipid peroxidation in a concentration-dependent manner. Furthermore, the ethyl acetate fraction had the highest antioxidant effects either by decreasing lipid peroxidation and cellular damage or restoring thiols levels and catalase activity. Taken together, our results showed that H. procumbens acts either by preventing oxidative stress or loss of cell viability. Thus, the previously reported anti-inflammatory effect of H. procumbens could also be attributed to its antioxidant activity.     

Recovery of phenolic antioxidants from wine industry by-products

The recovery process of the phenolic compounds contained in the wine industry by-products and their antioxidant activity were examined in this work. To this purpose, a combined process of liquid and supercritical solvent extraction was employed. At first the effect of various process parameters of the liquid solvent extraction--the type of solvent and the pretreatment of the raw material (composition (skins, seeds, stems) and crushing)--on the antioxidant activity of the extract was examined. It was shown that an extract of a higher antioxidant activity was obtained by using ethyl acetate as solvent and raw material free of stems. These extracts were further treated with supercritical carbon dioxide (SC CO(2)) at various extraction pressures, which resulted in their significant enrichment in phenolic compounds and the improvement of their antioxidant and organoleptic properties, especially at pressures higher than 100 bar. The antioxidant activity of the products was determined by using the Rancimat method, as well as a simple and not time-consuming free radical method. It was proved that both the ethyl acetate extracts and those treated with SC CO(2) had antioxidant activity comparable to that of antioxidants commonly used in industry, that is butylhydroxytoluene (BHT), a synthetic antioxidant, and Rosemary extract, a widely known natural one.     

Antioxidant activity of leaf extracts from Bauhinia monandra

Bauhinia monandra Kurz. is used in Brazil for the treatment of diabetes. Since this activity may be correlated with the presence of antioxidant compounds, leaf extracts of B. monandra were evaluated for their radical scavenging capacity (RSC). An ethanolic extract was taken up in aqueous methanol and partitioned with hexane, chloroform, ethyl acetate to yield three organic extracts together with remaining aqueous extract. The RSC was determined spectrophotometrically using 1,1-diphenylpicrylhydrazyl free radical (DPPH). The chloroform and ethyl acetate extracts were the most appropriate as sources of antioxidant compounds as shown by their inhibition concentration (IC50) and inhibition percentage (IP) values. The antioxidant activity of such extracts was attributed to the presence of three compounds of different polarities (flavonoids and steroids). The chloroform and ethyl acetate extracts exhibited an IC50 of approximately 2 mg/g DPPH and IP values in the range of 60-65%. The results indicate that the extracts of B. monandra have a very potent antioxidant activity, compared with the pure catechins used as positive controls and with other plant extracts.     

Antioxidant properties of methanol extract and its solvent fractions obtained from selected Indian red seaweeds

In vitro antioxidant activities of three selected Indian red seaweeds - viz., Euchema kappaphycus, Gracilaria edulis and Acanthophora spicifera were evaluated. Total phenolic content and reducing power of crude methanol extract were determined. The antioxidant activities of total methanol extract and five different solvent fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were also evaluated. EA fraction of A. spicifera exhibited higher total antioxidant activity (32.01 mg ascorbic acid equivalent/g extract) among all the fractions. Higher phenolic content (16.26 mg gallic acid equivalent/g extract) was noticed in PE fraction of G. edulis. Reducing power of crude methanol extract increased with increasing concentration of the extract. Reducing power and hydroxyl radical scavenging activity of E. kappaphycus were higher compared to standard antioxidant (alpha-tocopherol). The total phenol content of all the seaweeds was significantly different (P<0.05). In vitro antioxidant activities of methanol extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.     

基于ORAC评价多酚类化合物抗氧化活性

采用氧自由基清除能力(ORAC)方法考察20种多酚类化合物的抗氧化活性。结果表明,该方法具有较优的线性关系(R2=0.997）;检测限(LOD）和定量限(LOQ）为0.5～3.1 μmol·L-1,精密度＜18%,准确度91%～105%。比较20种多酚类化合物抗氧化活性,对羟基苯甲酸类化合物中,鞣花酸和没食子酸具有较强的抗氧化活性;对羟基肉桂酸类以咖啡酸及其衍生物抗氧化活性最高;在类黄酮组分中,黄烷-3-醇表现出优良的抗氧化特性,黄酮醇次之。ORAC可作为评价多酚类化合物抗氧化的简便、高效的标准化检测方法。     

Evaluation of free radical scavenging activity of Butea monosperma Lam

In the present study, ethyl acetate, butanol and aqueous fractions derived from total methanol extract of Butea monosperma flowers were evaluated for radical scavenging activities using different in vitro models like reducing power assay, scavenging of 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and inhibition of erythrocyte hemolysis using 2, 2' azo-bis (amidinopropane) dihydrochloride (AAPH). Methanol extract along with its ethyl acetate and butanol fractions showed potent free radical scavenging activity, whereas aqueous fraction was found to be devoid of any radical scavenging properties. The observed activity could be due to the higher phenolic content in the extracts (16.1, 25.29, and 17.74% w/w in methanol extract, ethyl acetate and butanol fractions respectively). HPTLC fingerprint profile of the ethyl acetate and butanol fractions were developed which would serve as reference standard for quality control of the extracts.     

裸花紫珠提取物及其主要成分抗氧化活性研究

裸花紫珠是海南一种道地药材,具有消炎止血的功效。裸花紫珠富含黄酮类和苯乙醇苷类化学成分,它们已经被证实是天然抗氧化剂的主要来源之一。为了考察裸花紫珠药材的抗氧化活性,该研究采用DPPH.自由基清除法测定裸花紫珠醇提物、4个不同极性部位(石油醚、乙酸乙酯、正丁醇、水)及其7个主要成分的抗氧化作用。结果表明：裸花紫珠醇提物、醇提物的水部位、正丁醇部位、乙酸乙酯部位和化合物木犀草素、木犀草苷、毛蕊花糖苷具有较强的抗氧化活性,而5-羟基-3,7,3′,4′-四甲氧基黄酮的抗氧化活性则较弱。该研究结果为裸花紫珠的保健功能开发提供了依据。     

益智的抗氧化作用

本文探讨了益智(Alpinia oxyphylla Miquel)超临界CO2提取物及其渣的水提物、正丙醇提取物和乙酸乙酯提取物的抗氧化作用,测定了总酚含量、黄酮含量、抗氧化力、还原能力、DPPH清除率.结果表明,益智超临界CO2提取物和正丙醇提取物的总酚含量最高,均为5.53%,乙酸乙酯提取物的总酚含量为4.04%,水提物总酚含量最低,为O.89%.抗氧化力与酚含量相关(R2=0.703).四种提取物中黄酮含量顺序为:乙酸乙酯提取物(6.29%)＞丙醇提取物(5.81%)＞水提取物(4.85%)＞超临界CO2提取物(4.70%).在还原能力、清除DPPH自由基和羟自由基方面,乙酸乙酯提取物表现出了很强的抗氧化能力,呈现剂量依赖关系.     

Biological Insights and NMR Metabolic Profiling of Different Extracts of Spermacoce verticillata (L.) G. Mey.

Spermacoce verticillata (L.) G. Mey. is commonly used in the folk medicine by various cultures to manage common diseases. Herein, the chemical and biological profiles of S. verticillata were studied in order to provide a comprehensive characterization of bioactive compounds and also to highlight the therapeutic properties. The in vitro antioxidant activity using free-radical scavenging, phosphomolybdenum, ferrous-ion chelating and reducing power assays, and the inhibitory activity against key enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase of S. verticillata extracts (dichloromethane, ethyl acetate, methanol and water) were investigated. The highest total phenolic and flavonoid content were observed in the methanolic and aqueous extracts. Exhaustive 2DNMR investigation has revealed the presence of rutin, ursolic and oleanoic acids. The methanolic extract, followed by aqueous extract have showed remarkable free radical quenching and reducing ability, while the dichloromethane extract was the best source of metal chelators. The tested extracts showed notable inhibitory activity against cholinesterases (AChE: 1.63–4.99 mg GALAE/g extract and BChE: 12.40–15.48 mg GALAE/g extract) and tyrosinase (60.85–159.64 mg KAE/g extract). No inhibitory activity was displayed by ethyl acetate and aqueous extracts against BChE and tyrosinase, respectively. All the tested extracts showed modest α-amylase inhibitory activity, while only the ethyl acetate and aqueous extracts were potent against α-glycosidase. This study further validates the use of S. verticillata in the traditional medicine, while advocating for further investigation for phytomedicine development.     

Antimicrobial activity and phytochemical screening of Ocimum americanum L extracts against pathogenic microorganisms

The aim of the present study is to assess the antimicrobial activities of various leaf extracts of Ocimum americanum were tested against pathogenic microorganisms. Preparation of different extracts viz., aqueous, acetone, ethyl acetate and methanol through soxhlet extraction method. Various extracts were investigated against MTCC strains of Bacillus cereus, Clostridium penfrigens, Klebsilla pnemoniae, Salmonella paratyphi, Candida albicans and Aspergillus niger by agar well diffusion and disc diffusion methods. Minimum inhibitory concentration (MIC), Minimum Bactericidal/Fungicindal Concentration (MBC/MFC) were determined through micro dilution method. Elucidation of phytochemicals and functional groups were observed by HPLC and FT-IR respectively. Ethyl acetate leaf extract of O.americanum showed significant antimicrobial activity against the all tested pathogens in agar well diffusion method in which B.cereus (17 mm) was observed high zone of inhibition. Whereas lowest inhibition was observed in aqueous extract against C.pentrigens (7 mm). The ranges of MIC values from 0.78 μg/ml to 50 μg/ml and MBC/MFC 1.56 μg/ml to 50 μg/ml were observed. Phytochemicals such as alkaloids, steroids, saponins, flavonoids, tannins, terepenes, phenolic compounds cardiac glycosides were detected. Saponinns, flavonoids, tannins, phenolic compounds were observed in only ethyl acetate leaf extracts. Functional group of the leaf extracts was exhibited by FTIR and HPLC analysis of the ethyl acetate leaf extract was elutated at six peaks. Based on the results we concluded that ethyl acetate leaf extract of O.americanum has proved to be potentially effective than the other extracts. Therefore, ethyl acetate leaf extract of O.americanum could act as antimicrobial agent and further studies are recommended for isolation of compounds and toxicological studies.