Chemical investigations of male and female leaf extracts from Schinus molle L.

The pepper-tree Schinus molle is an evergreen ornamental plant with various and diversified list of medical uses. In this article we analysed the chemical composition of male and female leaves of this plant during the off-flowering and flowering seasons. The leaf extracts were obtained by using a sequential extraction with solvents of different polarities and the chemical composition was investigated by GC-MS. The results showed a total of twenty-three components, in which elemol is the most abundant constituent followed by bicyclogermacrene, γ-eudesmol, α-eudesmol, β-eudesmol and isocalamendiol. The petroleum ether and diethyl ether extracts from male and female flowering and off-flowering leaves consisted of sesquiterpene hydrocarbons as a major constituent followed by monoterpene hydrocarbons, while the acetone extracts showed a different composition. The obtained results show differences in the chemical composition between male and female and flowering and not flowering.     

竹叶提取物的抗氧化活性研究

一般认为黄酮是竹叶提取物中抗氧化作用的有效成分,黄酮含量越高,抗氧化能力越强[1-3]。本实验对不同溶媒竹叶提取物的抗氧化能力做了比较研究,发现抗氧化作用与黄酮含量并不完全成正比关系;并通过进一步的定性实验,证明黄酮并不是竹叶提取物中的唯一的抗氧化有效成分,还有其它     

Antimicrobial activity-guided identification of compounds from the deciduous leaves of Malus doumeri by HPLC-ESI-QTOF-MS/MS

This paper intends to identify the antimicrobial activity compounds from the deciduous leaves of Malus doumeri (Dong Li Tea) by HPLC-ESI-QTOF-MS/MS. The ethanol extracts of Malus doumeri were partitioned into petroleum ether, dichloromethane, ethyl acetate, n-butanol and water fraction, respectively. The antimicrobial screening experiments showed that ethyl acetate fraction has a certain antibacterial activity by inhibition zone method in vitro. And then we used the HPLC-ESI-QTOF-MS/MS method to verify the identities of bioactive compounds. Finally, 41 compounds were determined and 11 of which were firstly reported in this plant. Notably, compounds (32, 34, 38) are new dihydrochalcones, and three chlorogenic acid analogues (10, 13, 17) may be potential antimicrobial active ingredient. Which is of great significance to the isolation of novel compounds and the discovery of new natural preservative candidates from the deciduous leaves of Malus doumeri.     

Biphenyl esters and biflavonoids from the fruits of <Emphasis Type="Italic">Schinus terebenthefolus</Emphasis>

Two new biphenyl esters and three biflavonoids were isolated from the aqueous methanol extract of the fruits of Schinus terebenthefolus. The spectral data of tetrahydrorobustaflavone have been recorded and assigned for the first time. Characterization of the structures was achieved by various spectroscopic methods.Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 369–371, September–October, 2004.     

Essential oil composition and acaricidal activity of Schinus terebinthifolius from Atlantic Forest of Pernambuco, Brazil against Tetranychus urticae

The compositions of the essential oils from unripe (UFr) and ripe (RFr) fruits of Schinus terebinthifolius were analyzed by GC and GC/MS. The major compound identified in both oils was limonene (UFr = 44.1 +/- 1.3%; RFr = 31.8 +/- 1.2%), followed by alpha-phellandrene (15.7 +/- 0.4%) in the UFr oil and thujene (21.7 +/- 0.9%) in the RFr oil. Repellent and toxicity activities of the two oils were also evaluated, and the results compared with eugenol. The UFr oil was more active in the fumigation tests (LC50 = 1.46 microL/L of air), whereas the RFr oil was more active in the sealed dishes (SD) than open dishes (OD) contact assay (LC50 = 3.04 microL/cm2) and not significantly different from eugenol. Both oils exhibited significant repellent activity comparable with that of eugenol. The results suggest that the repellent activity of these oils in association with its toxicity could be a great advantage for the integrated management of T. urticae.     

Enhancement of the antibiotic activity of aminoglycosides by extracts from Anadenanthera colubrine (Vell.) Brenan var. cebil against multi-drug resistant bacteria

The aim of this work was to evaluate the antimicrobial activity of ethanol (EEAC) and hexane (HFAC) extracts from the stem bark of Anadenanthera colubrina (Vell.) Brenan var. cebil alone or in combination with aminoglycosides against multi-drug resistant (MDR) bacteria. Minimal inhibitory concentrations (MICs) of the extracts were determined by using microdilution assay. For the evaluation of extracts as modulators of antibiotic resistance, MICs of neomycin and amikacin were determined in presence or absence of each compound at sub-inhibitory concentrations. Both EEAC and HFAC did not show antimicrobial activity against MDR strains tested. However, the addition of EEAC and HFAC enhanced the activity of neomycin and amikacin against Staphylococcus aureus SA10 strain. When the natural products were replaced by chlorpromazine, the same effect was observed. Anadenanthera colubrine var. cebil may be a source of phytochemicals able to potentiate the aminoglycoside activity against MDR S. aureus by the inhibition of efflux pump.     

Allelopathic activity and chemical constituents of extracts from roots of Euphorbia heterophylla L

Euphorbia heterophylla L. is regarded as a major weed worldwide. Its high aggressiveness in agricultural environment prompted us to investigate the allelopatic activity and chemical constitution of extracts from roots of this plant. Hexane extract showed low phytotoxic activity. Methanol extract at 2.0 mg mL^?1 inhibited 100% of germination, root and shoot growth of the indicator plants Sorghum bicolor and Lactuca sativa. β-sitosterol, stigmasterol, and esters of lupeol, germanicol, taraxasterol, pseudotaraxasterol, α-amyrin and β-amyrin were isolated from the hexane extract and their structures elucidated on the basis of MS and ¹H, ¹³C and DEPT-135 NMR data. GC-MS analysis of the derivatized methanol extract allowed for identifying a series of allelopathic organic acids potentially involved in allelopathic interactions of E. heterophylla. This is the first study on the allelopathic activity of extracts and identification of metabolites from roots of E. heterophylla.     

Acylphloroglucinol derivatives from the twigs and leaves of Callistemon salignus

Three new acylphloroglucinol derivatives, callisalignones A–C (1–3), six new meroterpenoids, callisalignenes A–F (4–9), along with 18 known analogues (10–27) were isolated from the twigs and leaves of Callistemon salignus. Their structures and absolute configurations were established by comprehensive spectroscopic evidences (NMR, MS, amd electronic circular dichroism calculations). The absolute configurations of callistenones B (13) and H (14) were determined by comparison of their ECD spectra with that of callisalignone B (2). Callisalignones B and C are new adducts of β-triketone and acylphloroglucinol, whereas callisalignenes A–D are new meroterpenoids of acylphloroglucinol and α-phellandrene with different coupling models via hetero-Diels-Alder reaction, respectively. Myrtucommulone D (15) showed significant antibacterial activity against Staphylococcus aureus and three drug resistant S. aureus strains with MIC values of 1.953 and 0.975 μg/mL, respectively. Isomyrtucommulone B (17) displayed remarkable antibacterial activity against Escherichia coli with an MIC value of 0.122 μg/mL. Cytotoxic assay revealed that isomyrtucommulone B (17) was the most active against HCT116 with an IC₅₀ value of 2.09 ± 0.10 μM.     

Extraction technology,component analysis,and in vitro antioxidant and antibacterial activities of total flavonoids and fatty acids from Tribulus terrestris L. fruits

The current study focused on the extraction technology, components analysis, in vitro antioxidant and antibacterial activities of total flavonoids and fatty acids from Tribulus terrestris L. fruits. The extraction process of total flavonoids and fatty acids was optimized by the response surface method, and the compositions were identified from the two extracts by HPLC–DAD–ESI–MS^? and GC–MS, respectively. In addition, the antioxidant and antibacterial activities were evaluated by assay of ABTS, DPPH radical scavenging activity, ferric reducing antioxidant power and minimal inhibitory concentration. The yields of total flavonoids and fatty acids were 0.46 and 9.76% under the optimized conditions. Moreover, nine and eight compositions were identified from the two extracts based on the related references, respectively. In addition, total flavonoids and fatty acids extracts both exhibited certain antioxidant and antibacterial activities. The present findings suggest that total flavonoids extracted from T. terrestris L. fruits comprised a more interesting candidate than fatty acids for the research and development of natural and healthy antioxidants and antibacterial agents for the pharmaceutical and food industries.     

黄树莓叶片中黄酮类物质的提取及抗氧化性

黄酮类物质具有降血糖、降血脂、抗心律失常、抗氧化高效性与低毒性、抗衰老等生理活性1 2 。从药食两种植物中筛选出高效低毒且经济的抗氧化性强的物质 ,必将是近一步开发天然高效食品抗氧化剂的重要途径[3 5] 。黄树莓是我国北方地区小浆果树种之一 ,其中以黑龙江分布较多。黄树莓的浆果甜而芳香 ,营养丰富 ,是鲜美的生食果品 ,也可加工制成果酱、果酒、果汁和蜜饯等。它又是密源植物和药用植物 ,有止渴、痰、发汗、活血的效用。本实验以测定黄树莓叶片总黄酮含量并考察了提取物粗黄酮对猪油的抗氧化性。1　实验部分1 1　主要试剂及仪…     

GC-EIMS analysis,antifungal and anti-aflatoxigenic activity of Capsicum chinense and Piper nigrum fruits and their bioactive compounds capsaicin and piperine upon Aspergillus parasiticus

Abstract

GC-EIMS analysis, antifungal- and anti-aflatoxigenic activities of the ethanolic extract of Capsicum chinense and Piper nigrum fruits and their main bioactive compounds were evaluated upon Aspergillus parasiticus. The GC-EIMS analysis showed capsaicin (50.49%) and piperine (95.94%) as the major constituents in C. chinense and P. nigrum, respectively. MIC₅₀ values revealed that capsaicin (39?μg/mL) and piperine (67?μg/mL) were lower than those from fruit extracts of C. chinense (381?μg/mL) and P. nigrum (68?μg/mL). Extracts and bioactive compounds showed anti-aflatoxigenic activity. Maximum aflatoxin inhibition occurred at 150?µg/mL of extracts and compounds. The present study showed satisfactory results concerning the effects of ethanolic extract of C. chinense and P. nigrum fruits upon A. parasiticus, showing the capabilities of inhibiting fungal growth development and altering aflatoxins production.     

Isolation and antiproliferative activity of chemical constituents from Asystasia buettneri Lindau

N-hexane and methanol extracts of Asystasia buettneri Lindau aerial parts exhibited antiproliferative activity on leukaemia blood carcinoma, K-562. Hexadecane (1), 1,3-propan-2-ol (9Z,12′Z,15″Z)-bis(doeicos-9,12,15-trienoate) (2), hydrocarbon, 2,3,3,10,23-pentamethyl tetraeicos-10,13,16-trien-1-ol (3), hexadecanoic acid (4) and taraxerol (5) were isolated from n-hexane extract; stigmasterol (6) and (Z)-9-octadecenoic acid (7) were isolated from ethyl acetate extract; while unsaturated hydrocarbons, octadecene (8), 8-methyl tetradec-6-ene (9) and 19-methyl eicos-1-ene (10), fatty acids, (Z)-5-hexadecenoic acid (11), 11,22-dimethyl ethyltrieicos-11-enoate (12) and taraxasterol (13) were isolated from methanol extract of the plant. Compounds 4, 5, 7, 11, 12 and 13 exhibited antiproliferative activity against K-562, while compounds 5, 6, 7 and 9 revealed antiproliferative activity by inhibiting hepatic liver (WRL68) cell lines.     

几种天然植物提取物对酪氨酸酶活性的抑制作用

选择合适的溶剂体系,用维生素C(Vc)作为阳性对照物,采用分光光度法测定了不同浓度的茶多酚、丹皮酚及金银花叶子总黄酮提取物(乙酸乙酯相)对酪氨酸酶活性的抑制作用.结果表明:采用1%丙三醇和1%吐温-80(体积比1∶1)混合液作溶剂可显著增加丹皮酚和金银花叶子总黄酮提取物在水中的溶解度;茶多酚、丹皮酚、金银花叶子总黄酮提取物对酪氨酸酶的活性都有一定的抑制作用,其抑制作用从强到弱依次为Vc、Vc∶丹皮酚=1∶2(质量比)、Vc∶丹皮酚=1∶1(质量比)、茶多酚、茶多酚∶丹皮酚=2∶1(质量比)、丹皮酚、金银花叶子总黄酮提取物.     

Threonine Facilitates Cd Excretion by Increasing the Abundance of Gut Escherichia coli in Cd-Exposed Mice

Cadmium (Cd) can easily enter the body through the food chain and threaten health since Cd pollution is prevalent in the environment. Gut microbiota is necessary for the reduction of metal ions. To reduce Cd-induced harmful impacts and Cd accumulation in the body, we investigated the effect of amino acids on gut microbiota and Cd excretion in (fecal Cd) Cd-exposed mice. The screening of 20 amino acids showed that threonine (Thr) effectively increased fecal Cd, and reduced Cd-induced intestinal structural damage. The abundance of Escherichia-Shigella genus and KF843036_g significantly increased after the oral administration of Thr. As the type species of the Escherichia-Shigella genus, Escherichia coli exhibited high similarity to KF843036_g species and significantly decreased Cd-induced gut damage. Cd contents in the liver, kidney, and gut of Cd-exposed mice were also significantly (p < 0.05) decreased after E. coli treatment, while the contents in the feces were increased. The results demonstrated the potential roles that gut E. coli might play in Thr-mediated Cd excretion in Cd-exposed mice. The findings may provide important data for better understanding the molecular biological mechanism of Thr in reducing Cd accumulation in the body.     

Antioxidant activity of crude extracts and essential oils from flower buds and leaves of Cistus creticus and Cistus salviifolius

Volatile oils from flowers and leaves of C. creticus L. and C. salviifolius L. were extracted by two extraction methods; namely, hydrodistillation and solid-phase micro-extraction (SPME). The chemical composition of essential oils was analyzed by GC and GC–MS. The volatile extracted from leaves and flowers of C. criticus using SPME was dominated by monoterpenes and sesquiterpenes hydrocarbon with α-pinene, camphene and α-cubebene as major components. In hydrodistillation, the oil extracted from leaves was dominated by oxygenated diterpenes and diterpenes hydrocarbon with manoyl oxide and sclarene as major components, whereas, the oil extracted from flowers was dominated by oxygenated diterpenes and diterpenes hydrocarbon with manoyl oxide and abietatriene as major components. The volatile from flowers and leaves of C. salviifolius obtained by SPME were dominated by monoterpenes and sesquiterpenes with δ-3-carene, α-pinene, β-pinene, and E-caryophyllene as major constituents. On the other hand, the oils from flowers and leaves of C. salviifolius obtained by hydrodistillation were dominated by oxygenated diterpenes, diterpenes hydrocarbon and esters with dehydro abietol, abietol, manoyl oxide and methyl octadecenoate as major components. In the leaves, the major components of the oil were manoyl oxide, E-ethyl cinnamate, and Z-ethyl cinnamate. These oils showed weak antioxidant activity when compared to the positive controls α-tocopherol, ascorbic acid, and EDTA, while the crude extracts aq. MeOH, butanol, and water showed good antioxidant activity. Discriminating between the studied plants based on the extraction method was also possible upon applying Principle component analysis (PCA) to the obtained GC–MS data.     

GSH Protects the Escherichia coli Cells from High Concentrations of Thymoquinone

The aim of the present study was to evaluate the potential protective effect of glutathione (GSH) on Escherichia coli cells grown in a high concentration of thymoquinone (TQ). This quinone, as the main active compound of Nigella sativa seed oil, exhibits a wide range of biological activities. At low concentrations, it acts as an antioxidant, and at high concentrations, an antimicrobial agent. Therefore, any interactions between thymoquinone and glutathione are crucial for cellular defense against oxidative stress. In this study, we found that GSH can conjugate with thymoquinone and its derivatives in vitro, and only fivefold excess of GSH was sufficient to completely deplete TQ and its derivatives. We also carried out studies on cultures of GSH-deficient Escherichia coli strains grown on a minimal medium in the presence of different concentrations of TQ. The strains harboring mutations in gene ΔgshA and ΔgshB were about two- and fourfold more sensitive (256 and 128 µg/mL, respectively) than the wild type. It was also revealed that TQ concentration has an influence on reactive oxygen species (ROS) production in E. coli strains—at the same thymoquinone concentration, the level of ROS was higher in GSH-deficient E. coli strains than in wild type.     

Chemical profiling and anticoagulant activity of Ginkgo Biloba leaves under the influence of harvesting time

Gingko biloba, family Gink, is used as a source of food and in traditional medicine for treatment of cough and promoting blood circulation, etc. The aim of the present work is to determine the chemical variation of G. biloba leaves collected from different harvesting time and in vitro anti-platelet aggregation effects, respectively. Methanol extract of G. biloba leaves was subjected to ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry analysis and triple quadrupole mass spectrometry. The anti-platelet aggregation effects induced by platelet-activating factor (PAF) and adenosine diphosphate (ADP) was measured by Born’s method. UHPLC-QTOF-MS analysis confirmed the presence of flavonoids, phenolic acid and terpene lactones in different sample. Partial least square discriminant analysis based on chemical profiling conducted to differentiate the samples according to their harvest time. All samples found highly effective against PAF-induced platelet aggregation with IC₅₀ of 98.87?μg/mL (summer sample) and 51.55?μg/mL (autumn sample). However, on ADP-induced platelet aggregation, IC50 of these samples were greater than 200?μg/mL. Both total contents of flavonoids and terpene lactones in autumn sample were greater than that in summer sample. Qualitative and quantitative analysis showed that the distribution of chemicals was variation in different harvesting time.     

Enhanced Inhibition of Drug-Resistant Escherichia coli by Tetracycline Hydrochloride-Loaded Multipore Mesoporous Silica Nanoparticles

Drug-resistant bacterial infections exhibit a major threat to public health. Thus, exploring a novel antibacterial with efficient inhibition is urgently needed. Herein, this paper describes three types of MSNs (MSNs-FC2-R1, MSNs-FC2-R0.75, MSNs-FC2-R0.5) with controllable pore size (4–6 nm) and particle size (30–90 nm) that were successfully prepared. The MSNs were loaded with tetracycline hydrochloride (TCH) for effective inhibition of Escherichia coli (ATCC25922) and TCH-resistant Escherichia coli (MQ776). Results showed that the loading capacity of TCH in three types of MSNs was as high as over 500 mg/g, and the cumulative release was less than 33% in 60 h. The inhibitory rate of MSNs-FC2-R0.5 loaded with TCH against E. coli and drug-resistant E. coli reached 99.9% and 92.9% at the concentration of MIC, respectively, compared with the other two types of MSNs or free TCH. Modified MSNs in our study showed a great application for long-term bacterial growth inhibition.     

Statistical mixture design investigation of fractionated and total extracts from Erythrina speciosa Andrews leaves

The simplex centroid mixture design for the ethanol, dichloromethane, hexane and acetone solvents has been applied to the extraction of crude mass and the fiber, organic, neutral and basic fractions as well as the fractionation residues of Erythrina speciosa Andrews leaves. Binary and ternary synergic solvent interactions are seen to provide dominant contributions to the extraction of both crude mass and all the fractions. Quadratic and special cubic mixture models precisely predict the extracted quantities of each fraction and the residue as a function of the proportions of the four solvents. Different solvent mixtures are found to be the most efficient extractors for the different fractions: binary dichloromethane‐hexane mixtures for the fiber fraction, ternary ethanol‐dichloromethane‐acetone mixtures for the neutral fraction, binary ethanol‐dichloromethane mixtures for the organic fraction, crude extract and residue values and ternary ethanol‐dichloromethane‐hexane mixtures for the basic fraction. Principal component analysis shows that the ethanol‐dichloromethane mixtures are important for extracting large quantities of the basic and organic fractions as well as of the residue and crude masses.