Antimicrobial and antioxidant activities of the flower essential oil of Halimodendron halodendron

The essential oil obtained by hydro-distillation from the flowers of Halimondendron halodendron (Leguminosae) was analyzed for its chemical composition by gas chromatography-mass spectrometry (GC-MS). Undecane (16.4%), dodecane (15.3%), tridecane (12.5%), decane (8.2%), 6,10,14-trimethyl-pentadecan-2-one (6.3%), methyl palmitate (6.0%), methyl linolenate (4.1%) and ethylcyclohexane (4.1%) were the major compounds of the thirty-five identified components of the oil. The essential oil was shown to have a broad spectrum of antimicrobial activity with MIC values ranging from 100 to 250 microg/mL, and IC50 values from 40.4 to 193.8 microg/mL. The oil also showed strong antioxidant activity, with an especially high metal chelating capacity of ferrous ions with an IC50 value of 7.4 microg/mL on ferrozine-Fe2+ complex formation.     

Ultrasound-assisted extraction of phenolic antioxidants from Acacia confusa flowers and buds

Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been used in traditional medicines. In this study, the application of ultrasound-assisted extraction was used to extract the phenolic compounds from A. confusa flowers and buds for the first time. Among the extraction methods, it can significantly enhance the contents of phenolic compounds and antioxidant activities in A. confusa flower and bud extracts using ultrasound-assisted extraction (10 min×12 times). Considering both the solvent consumption and the time needed for extraction, ultrasound-assisted extraction was found to be the most practical approach for the rapid and efficient extraction of bioactive phenolic constituents. In addition, gallic acid, myricitrin-3-rhamnoside, quercitrin-3-rhamnoside, europetin-3-rhamnoside, kaempferol-3-rhamnoside, rhamnetin-3-glucoside, and rhamnetin-3-rhamnoside were also quantified in different extracts by RP-HPLC. It is clear that ultrasound-assisted extraction is an efficient method for extracting phenolic compounds from A. confusa flowers and buds.     

Essential oil composition of endemic Tanacetum zahlbruckneri (Nab.) and Tanacetum tabrisianum (Boiss.) Sosn. and Takht. from Turkey

In this study, water-distilled essential oils from the flowers of Tanacetum zahlbruckneri and flowers and stems of Tanacetum tabrisianum from Turkey were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The flower oil of T. zahlbruckneri was characterised by the sesquiterpenes germacrene D (29.7%) and spathulenol (12%). Flower (A) and stem (B) oil of T. tabrisianum was characterised by 1,8-cineole: 17.6% (A), 22.5% (B), hexadecanoic acid: 10.3% (A), 8% (B), decanoic acid: 5.8% (A) and trans-linalooloxide acetate: 5.3% (A), 4% (B). Unlike a previous report on the essential oil composition of T. tabrisianum, in this study a 1,8-cineole and hexadecanoic acid-rich oil with a low percentage of caryophyllene oxide and spathulenol was obtained. The composition of the essential oil of endemic T. zahlbruckneri was investigated for the first time.     

Anthemis cotula L. from Jordan: Essential oil composition,LC-ESI-MS/MS profiling of phenolic acids - flavonoids and in vitro antioxidant activity

Essential oils of the leaves and flowers of Anthemis cotula L. (family Asteraceae) grown in Jordan were extracted by hydro-distillation and then analyzed by GC–MS. Sesquiterpenes hydrocarbons (SH) were the dominant components in the oils extracted from leaves and flowers of A. cotula. γ-Muurolene and aromadendrene, were the major compounds that were obtained from the flowers oil, while γ-muurolene and trans-cadinene ether were detected as major ingredients in the leaves extract. LC-MS analysis was carried out to identify the significant compounds from each extract. Additionally, butanol (B), aqueous methanol (M) and water (W) extracts prepared from the flowers and the leaves of A. cotula were analysed by LC-MS/MS. Apigenin and chlorogenic acid were the main constituents detected in the flowers’ alcoholic extracts and leaves’ aqueous extract. Moreover, the essential oils and all prepared extracts were assayed for their total antioxidant activity using the DPPH, ABTS, and ferrous ion chelating effect (FIC) assay methods. All investigated oils and extracts showed interesting activity as compared to the positive controls employed (α-tocopherol and ascorbic acid).     

Determination of chlorpyrifos 20% EC (Dursban 20 EC) in scented rose and its products

The method for determination of chlorpyrifos is validated and dissipation behaviour of residue in scented rose and percent transfer in different products is described. GC-electron-capture detection with a HP-1, 30 m x 0.53 mm, 3.0 microm capillary column and nitrogen at 1 ml/min was used in the study. Plant matrices studied were: leaves, flowers, soil, rose water, absolute and concrete. Detector response linearity and sensitivity, limit of detection and determination, percent recovery were determined based on area response (mm2) of the standard. Analytical field and laboratory samples (rose water by hydro-distillation of the flowers, concrete and absolute by hexane extraction and condensation) were analysed for evaluation of the method. Samples were extracted with acetone, partitioned with water, saturated sodium chloride solution and dichloromethane. The organic layer was rotary-evaporated to 2 ml for cleanup with silica-carbon column. The column was eluted with dichloromethane-toluene-acetone (10:2:2, v/v/v) and the derived solution was rotary-evaporated to 5 ml for end analysis. Matrix enhancement effect was observed for leaf and soil samples for which corrective approach was followed to compensate for overestimation of the residue. Limit of detection for chlorpyrifos standard was 0.05 mg/l with good linearity of detector response (R2 = 0.99). Percent recovery ranged from 78 to 117% in different plant matrices (fortification level 1, 4 and 8 mg/l). Dissipation behaviour showed that chlorpyrifos was below detection limit by the 12th day of application on the scented rose with half life of 3.40 days on leaves and 3.10 days on flowers at 0.1% dosage. Percent transfer studies showed that 5.71, 46.91 and 38.80% of the residue from flowers was transferred to rose water, concrete and absolute, respectively.     

High-performance liquid chromatographic determination of oligomeric procyanidins from dimers up to the hexamer in hawthorn

An HPLC method using UV diode array detection was developed for analysing procyanidins qualitatively and quantitatively up to the hexameric level in hawthorn samples. The analysed compounds included procyanidin dimers B-2, B-4 and B-5, procyanidin trimers C-1, epicatechin-(4beta-->8)-epicatechin-(4beta-->6)-epicatechin and epicatechin-(4beta-->6)-epicatechin-(4beta-->8)-epicatechin, a tetramer D-1 and a pentamer E-1 both consisting of (-)-epicatechin units linked through C-4beta/C-8 bonds. The concentrations of two unknown tetramers and a hexamer F were also quantified. The oligomeric procyanidins (OPs) were specifically determined due to the development of a method for isolating them from hawthorn during sample preparation. The pattern of oligomeric procyanidins in the leaves, flowers and fruits was similar, but the concentrations varied depending on the part of the plant. The concentration in leaves was 1.6%, in flowers 1.2% and in fruits 0.2% of the dry mass. The method was validated with respect to repeatability, recovery, linearity, and sensitivity. The repeatability for the quantitative analytical method of all the OPs in leaves was 7.7%, in flowers 8.8%, and in fruits 12.3%. The recovery of the main OPs ranged from 91 to 97%. The correlation coefficients of calibration curves were between 0.997 and 1.000. The limits of quantitation for different procyanidin standards were 0.05-0.12 mg/ml, when 10 microl of each standard solution was injected into the HPLC.     

Distribution and chemical polymorphism of the essential oils of Achillea cartilaginea growing wild in Lithuania

The essential oils from 14 Achillea cartilaginea samples (leaves and flowers) collected from natural habitats in Lithuania were analysed by GC-MS. In total, 97 compounds were identified, 69 of which have not been reported previously in this species. In general, the essential oils of A. cartilaginea were rich in oxygenated monoterpenes. Remarkable chemical polymorphism was observed within the population of A. cartilaginea in Lithuania. It was observed that 1,8-cineole, camphor, cis-chrysanthenol, β-thujone, sabinol, chrysanthenone, terpinen-4-ol, bornyl acetate and β-sesquiphellandrene were the major constituents in the oils of the analysed plants. Hierarchical cluster analysis, which was based on the 19 major components exceeding 5% in the total oil, indicates the presence of several main chemical groups in the analysed plant populations.     

Separation and determination of anthraquinones in Cassia obtusifolia (Leguminosae) by micellar electrokinetic capillary electrophoresis

An MEKC method was developed for the determination of the five pharmaceutically important anthraquinones: chrysophanol (1), physcion (2), emodin (3), aloe-emodinin (4), and rhein (5) in Cassia obtusifolia (Leguminosae). A buffer solution (pH 9.00) composed of 20 mM sodium borate, 20 mM sodium deoxycholate (DOC), and 15% ACN was found to be the most suitable electrolyte for this separation. Regression equations revealed linear relationships (correlation coefficients: 0.9993, 0.9992, 0.9996, 0.9989, and 0.9991) between the peak area of each compound (1, 2, 3, 4, and 5) and its concentration. The RSDs of migration times and peak areas were <1.23 and 2.72% within 1 day, respectively. The effects of pH value, surfactant (DOC) concentration, and organic modifier on the migration were also studied. By this way, the contents of five anthraquinones in the extracts of the seed of C. obtusifolia (Leguminosae) from different sources were successfully determined within 14 min.     

Chemical composition, antioxidant and antimicrobial activity of the extracts of the flowers of the Chinese plant Chimonanthus praecox

This study investigated the antimicrobial and antioxidant activity of the extracts of the flowers, essential oil (EO) and semi-volatile fractions (SVF) of Chimonanthus praecox. The chemical composition of the EO was analysed by gas chromatography-mass spectroscopy (GC-MS) which revealed that the EO contained elemene, muurolene, caryophyllene, cadinol and spathulenol. The effective antibacterial activity of the EO suggested that its different responses on the microorganisms studied depended on the synergistic effects of the compounds contained in the EO. The effective antioxidant activity of the EO showed that the EO had a more marked antioxidant effect on scavenging O2(-)· and OH· than DPPH·, and SVF had a higher potential for scavenging DPPH· than the EO. Our data suggested that the flowers of Chimonanthus praecox had pharmaceutical benefits, and are also a potential source of natural antioxidants and biocides.     

Separation of flavonol-2-O-glycosides from Calendula officinalis and Sambucus nigra by high-performance liquid and micellar electrokinetic capillary chromatography.

Calendula officinalis and Sambucus nigra flowers were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC) and micellar electrokinetic capillary chromatography (MECC). RP-HPLC was performed on C8 Aquapore RP 300 columns with eluents containing 2-propanol and tetrahydrofuran. MECC was carried out on a 72-cm fused-silica capillary using sodium dodecyl sulphate and sodium borate (pH 8.3) as the running buffer. The results obtained by these techniques are compared.     

Two novel tetracycles,cassibiphenols A and B from the flowers of Cassia siamea

Chemical investigation of the flowers of Cassia siamea (Leguminosae), resulted in the isolation of two novel tetracycles connecting 5-(2-hydroxypropyl)benzene-1,3-diol, cassibiphenols A (1) and B (2). The structures were elucidated by analysis of the 1D, 2D NMR, and HRMS spectra. Synthesis of a tetracyclic core of 1 and 2 led to determine the absolute configuration of 1 and C-12 of 2.     

Characterization ofMatricaria recutita L. Flower extracts by HPLC-MS and HPLC-DAD analysis

Summary Matricaria recutita L. is a spontaneous herbaceous perennial plant and its drug is largely used, as an infusion, for its anti-inflammatory properties, especially for respiratory and gastroenteric tracts. Granular soluble extracts of this drug are also used in children’s diets. The purpose of this work was to investigate the polyphenolic content of different parts of chamomile flowers. Methanolic extracts were compared and directly analysed by HPLC-DAD and HPLC-MS. The comparison between UV-Vis and MS spectra, carried out in positive and negative ionisation mode, allows identification of all the main polyphenolic compounds present in different parts of the flowers. The findings reported herein both confirm the presence of several flavonoids, described previously, and evidence large amounts of caffeic and ferulic acid derivatives. No other evidence of the presence of these compounds in chamomile flowers has been previously reported. Quantitative comparison of the flavonoid and phenolic acid derivatives present in receptacles, ligulate, tubular and total flowers was also performed.     

Chemical composition and antibacterial activity of essential oils from leaves, stems and flowers of Salvia reuterana Boiss. grown in Iran

The essential oils obtained by hydrodistillation of the leaves, stems and flowers of Salvia reuterana (Lamiaceae) were analysed by GC and GC/MS. Germacrene D and beta-caryophyllene were the major constituents in all the three oils: (28.5, 27.7 and 32.5%) and (15.5, 11.4 and 16.6%), respectively. Bicyclogermacrene (10.2 and 13.2%) was also prodominated in the stem and flower oils. The composition of the oils was mostly quantitativel rather than qualitatively different. All the oils consisted mainly of sesquiterpenes and a small percentage of non-terpenoid compounds. In all the three oils, monoterpenes were in a concentration less than 0.5%. Antibacterial activity was determined by the measurement of growth inhibitory zones.     

Red Horse Chestnut and Horse Chestnut Flowers and Leaves: A Potential and Powerful Source of Polyphenols with High Antioxidant Capacity

Aesculus flowers and leaves are an excellent source of bioactive compounds, including flavanols, phenolic acids, and anthocyanins, and the leaves also contain antioxidant carotenoids and chlorophylls. The aim of this study was to analyse and compare the amounts of bioactive compounds present in Aesculus hippocastanum and Aesculus × carnea flowers and leaves over two years. These two species from six independent locations (parks and green areas) located in Warsaw were assessed in this study. The dry matter by the scale method and polyphenol, carotenoid, and chlorophyll content by the HPLC method of the flowers and leaves was evaluated. Red horse chestnut flowers contained significantly more total carotenoids (40.6 µg/g FW) and chlorophylls (36.9 µg/g FW) than horse chestnut flowers, and red horse chestnut flowers contained higher levels of anthocyanins (5.41 µg/g FW) than other species. We observed that horse chestnut flowers were characterized by a higher total polyphenols concentration (9.45 µg/g FW) compared to red horse chestnut flowers. In addition, the analysis of leaves showed that all quality parameters were higher in red horse chestnut species. Five individual anthocyanins were identified in both species’ flowers, but a higher concentration was found in red horse chestnut flowers, and pelargonidin-3-O-glucoside was the predominant form among a pool of total anthocyanins. In both experimental years, leaves (109.25 mMol/100 g FW and 112.0 mMol/100 g FW) were characterized by a higher antioxidant activity than flowers (27.0 mMol/100 g FW and 27.5 mMol/100 g FW).     

Phenolic glycosides from the stem bark of Albizzia julibrissin

From the stem bark of Albizzia julibrissin DURAZZ (Leguminosae), two new phenolic glycosides (albibrissinosides A and B) were isolated. Their structures were determined by spectroscopic analysis. The albibrissinoside B was found to be a radical scavenger on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.     

Seasonal variation in total phenolic and flavonoid contents and DPPH scavenging activity of Bellis perennis L. flowers

Variations in total phenolic and flavonoid contents as well as antioxidant activity of Bellis perennis (common daisy) flowers were investigated. The flowers were collected monthly (from March to October, i.e., during the usual flowering season of the plant) at three localities in three different years. Total flavonoids were determined spectrophotometrically by two methods: by formation of a complex with aluminium chloride after acidic hydrolysis of flower extracts (method 1) and by reaction with boric and oxalic acids in extracts without their modification (method 2). Total phenolics were determined spectrophotometrically using the Folin-Ciocalteu reagent. The antioxidant activity was determined spectrophotometrically by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The contents of flavonoids varied from 0.31 to 0.44 mg quercetin equivalent/100 mg dry weight (method 1) and from 1.37 to 2.20 mg pigenin-7-glucoside equivalent/100 mg dry weight (method 2). Total phenolics ranged from 2.81 to 3.57 mg gallic acid equivalent/100 mg dry weight. The antioxidant activity expressed as IC(50) values varied from 66.03 to 89.27 μg/mL; it is about 50, 30, 20, and 10 times lower as compared with quercetin, ascorbic acid, Trolox?, and butylhydroxytoluene, respectively, and about five times higher in comparison with apigenin-7-glucoside. There is a significant correlation between antioxidant activity and total phenolics. No correlation between total flavonoid contents and antioxidant activity was observed. Contents of phenolics and flavonoids as well as antioxidant activity of daisy flowers vary to a relatively small extent during the year and are not dependant on the time of collection. Thus, the flowers possess comparable quality as to these characteristics over the whole flowering season of Bellis perennis. Effects of environmental factors on the amounts of secondary metabolites in plants are also discussed.     

Effects of irradiation on epidermis ultrastructure of fresh day-lily flowers

Effects of gamma irradiation on epidermis ultrastructure of fresh day-lily (Hemerocallis fulva L.) flowers were studied by scanning electron microscopy. Damaged cells of petal epidermis were found in the day-lily flowers irradiated with 1.0 or more kGy. The cells damaged by irradiation broke and lost cytoplasm, and therefore, showed a serious shrinkage. The compartment of the cells disappeared in injury. With 1.0 or more kGy irradiation, the damaged cells were also observed on the epidermis of the sepal and receptacle cells. The injury was found in a small spot or area on the epidermis of the sepal as well as the petal. The injury spot of the sepal epidermis was shown to resemble ashes and no cell wall of the epidermis was found. On the other hand, the epidermis of the receptacle was torn away with 1.0 or more kGy irradiation. The damaged spots of the receptacle epidermis also appeared after irradiation. Irradiation was not recommended for treating the fresh day-lily flowers as vegetables since the dosage (2.0 or more kGy) needed for inhibiting the flower blooming as shown in our previous works, caused injury on the epidermis of the flowers.     

Salvia broussonetii Benth.: aroma profile and micromorphological analysis

The volatile profiles (VOC) and the essential oil (EO) composition from the aerial parts of Salvia broussonetii were analysed. Sesquiterpene hydrocarbons dominate the VOCs from leaves (95.7%) and flowers (67.6%), followed by monoterpene hydrocarbons (2.6 and 29.7%, respectively). The main common compounds are germacrene D, β-bourbonene, α-pinene, α-copaene and α-gurjunene, even if with divergent relative abundances. In the leaf EOs the sesquiterpenes prevail, even if not overwhelmingly (about 50.0%), followed by monoterpenes (23.0–35.0%) and by minor fractions of diterpene hydrocarbons and non-terpene derivates. The most abundant common compounds across the two sampling periods are α-pinene, β-pinene, isobornyl acetate, α-gurjenene, germacrene D and bifloratriene. A morphological characterisation of the trichomes responsible for the productivity in terpenes was also performed. Four different morphotypes were observed on the above ground organs of S. brussonetii: peltates and capitates of type II and III resulted the only producers of volatile substances.     

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.     

Color versus bioactivity in the flowers of Bougainvillea spectabilis (Nyctaginaceae)

The methanolic extracts of Bougainvillea spectabilis (Nyctaginaceae) flowers (five different colors) were screened biologically by performing four bioassays: antibacterial, antifungal, brine shrimp lethality and phytotoxicity. It was observed that the methanolic extract of white flowers was the most biologically active among all tested extracts. The extracts of white, orange and shocking pink flowers inhibit, while the extracts of red and violet flowers promote, the growth of Lemna plants. The extract of white flowers also exhibits toxicity against shrimp larvae with a LD50 value of 33.5627 microg/mL. However, none of the tested samples gave positive responses against any tested fungi.