Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros

Base de dados
País como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Chem Biodivers ; 21(7): e202400194, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38717321

RESUMO

Bee-collected pollen is one of the most important bee products. In order to predict its chemical composition and nutritional value botanical origin of pollen plays a crucial role. This review intended to collect all available data published about botanical origin of pollen collected all around the world. Due to enourmous amount of data and variables nonlinear principal component analysis (NLPCA), by applying Categorical Principal Component Analysis (CATPCA), was conducted in order to try to determine any specifity and/or differences among samples. Also, importance of some plant families/genera/species for bees was monitored. Based on CATPCA results families can serve in order to distinct samples from North/South America. Also, some samples from Europe (Turkey and Serbia) were characterized with presence of some specific families. Genera were excellent tool to distinguish samples from different parts of Brazil as well as Australia, Asia and Africa. Due to high and specific biodiversity pollen samples obtained from Sonoran desert (USA) completely were separated during analysis. This review presents the first attempt to summarize and classify a large number of data about botanical sources of bee-collected pollen.


Assuntos
Pólen , Pólen/química , Abelhas , Animais , Análise de Componente Principal
2.
Biol Trace Elem Res ; 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702515

RESUMO

The aim of this study was to characterise the elemental and radiological composition of strawberry tree (Arbutus unedo L.) leaves and tea preparations and compare it with commercial Uvin H herbal mixture, widely used in treatment of urinary tract infections. The concentration of 17 elements and the activity concentration of selected radionuclides were measured in strawberry tree leaves/Uvin H herbal mixture, as well as in herbal tea prepared by infusion or decoction of leaves for 5 or 10 min. In both leaves and tea preparations, Ca, K, Mg, and Na were the most abundant elements, while the lowest levels were measured for As, Co, Mo, and Se. Only 137Cs and 40K were detected in analysed leaves/herbal mixture, while the activity of radionuclides in tea preparations was below the detection limit. The maximum possible health benefits can be obtained by a 10-min decoction of leaves, which resulted in the highest total phenolic content and antioxidant activity and levels of K, Ca, Mg, Na, Fe, Mn, and Se in comparison to the other preparation methods evaluated in this study. The calculated intake of potentially toxic elements and radionuclides does not represent a health risk to consumers.

3.
Plants (Basel) ; 11(1)2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-35009028

RESUMO

The strawberry tree (Arbutus unedo L., Ericaceae family) is an evergreen Mediterranean shrub whose leaves and fruits are used in traditional medicine due to their antioxidant, antimicrobial, antidiabetic, diuretic, and antiproliferative properties. The health benefits are mainly attributed to the presence of phenolic compounds. The aim of this study was to compare the phenolic profiles, total phenolic content (TPC), and radical scavenging activity (RSA) of A. unedo leaves and fruits collected at two locations in Croatia. Phenolic profiles were identified using an ultra-high-performance liquid chromatograph (UHPLC) coupled with a hybrid mass spectrometer (LTQ Orbitrap MS). TPC was determined by Folin-Ciocalteu's assay, while RSA was investigated using DPPH reagent. A total of 64 phenolics (60 and 42 compounds in leaves and fruits, respectively) were identified. Hyperoside and flavan-3-ols were predominant compounds in leaves, while gallocatechin and catechin were the major compounds found in fruits. To the authors' knowledge, 16 and 5 phenolics in leaves and fruits, respectively, were reported for the first time. Principal component analysis (PCA) showed that UHPLC-LTQ Orbitrap MS could be used to identify which phenolics were able to discriminate samples regarding plant tissue and geographical origin. TPC in leaves and fruits were in the ranges of 67.07-104.74 and 16.78-25.86 mg gallic acid equivalents (GAE)/g dried weight (dw), respectively. RSA for leaves and fruits were in the ranges of 408.92-430.98 and 74.30-104.04 µmol Trolox equivalents (TE)/g dw, respectively. The number of identified phenolics was lower in fruits compared to leaves. Such a large number of bioactive phenolics identified and the strong antioxidant activity pointed to A. unedo as a promising health-promoting plant and natural food preservative.

4.
Food Chem ; 354: 129507, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33756329

RESUMO

The effects of organic versus integral and conventional crop management on content and distribution of major and trace elements in different varieties of potato were investigated in a three year field trial. A set of 48 potato tubers of four varieties with different harvesting times, cultivated in three types of agricultural systems: conventional (C), integral (I), and organic (O) were characterized based on the composition of the elements of their bulk and peel. A total of 16 elements were quantified. In order to determine the source of variation among the types of production, parts of potato and varieties, multivariate analysis of variance (MANOVA) was conducted. The results indicate that Ca, Mg, and K may be considered as important indicators of the type of production, genotypes of potato, and harvesting time. Additionally, the analyses show that ten microelements are able to distinguish between production types and genotypes of potato.


Assuntos
Tubérculos/química , Solanum tuberosum/química , Oligoelementos/análise , Agricultura , Análise de Variância , Genótipo , Micro-Ondas , Tubérculos/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/crescimento & desenvolvimento , Espectrofotometria Atômica
5.
J AOAC Int ; 103(2): 365-372, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31511123

RESUMO

Phytochemical analysis, the chemical investigation of plants, is a rapidly developing chemical discipline with various goals such as the determination of the substance classes and the isolation and qualitative and/or quantitative analyses of bioactive compounds or their structural analysis. The analysis of plants begins with optimizing extraction procedures because they play a key role in extraction outcomes, i.e., the isolation of bioactive compounds from natural products and the selection of the subsequent tests used in the analyses. The extraction is a critical step because it is necessary to extract the desired components of the complex natural matrix without destroying them. A wide range of techniques for the extraction of bioactive compounds from natural matrixes are currently available. This review aims to describe and compare the most commonly used methods, traditional/conventional and innovative/green. It will focus on the principles behind each method and on their strengths and limitations in order to help evaluate their suitability and economic feasibility, highlighting the advantages of new innovative techniques over conventional extraction procedures. Finally, the recent application of deep eutectic solvents as a new, eco-friendly method for the extraction of bioactive compounds from natural matrixes is also discussed.


Assuntos
Produtos Biológicos , Extratos Vegetais , Compostos Fitoquímicos , Solventes
6.
Curr Pharm Biotechnol ; 18(4): 343-350, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28294060

RESUMO

BACKGROUND: Three clones of Cabernet Franc (Nos. 02, 010 and 012) were selected in the last phase of clonal selection in Serbia. Wines made from each clone were assessed for quality parameters and taste during five consecutive vintages (2008-2012) and compared to the standard. The wine quality was determined based on the following parameters: alcohol, total extract, anthocyanins, tannins, pH, titratable acidity, volatile acidity, aldehydes, esters and reducing sugars, relative density, ash, colour, tonality, and tasting score. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. METHODS: Chemical analyses of grapes and wines along with sensory and radical scavenging activity evaluations were done according to the standard procedures. RESULTS: The wines of the clone No. 010 showed some superior properties compared to the other two clones and the standard; in five-year period the average concentration of anthocyanins (179±3.8 mg/L) and polyphenolics (1.85±0.02 g/L) was significantly higher than in wines of clones and the standard, (168-173 mg/L and 1.63-1.74 g/L for anthocyanins and phenolics, respectively). Furthermore, the same clone had a higher alcohol content (13.97±0.03%) in each year of the study, which indicated that it ripened faster than other clones (13.06-13.08 %) and compared to the standard (13.04±0.07%). This finding suggested that the clone No. 010 could possibly have a significant economic impact and further increase popularity of Cabernet Franc in a cooler climate viticultural region. It was also found to have the highest contents of aldehydes (488±1.54 mg/L) and esters (322±0.71 mg/L) compared to aldehydes (452-467 mg/L) and esters (290-310 mg/L) measured in other wines. Finally, the highest amount of phenolic compounds (1220±40 mg/kg) and resveratrol (70±3.3 mg/kg) were found in the grapes of the clone No. 010. The present study revealed a strong correlation of total phenolic contents and anthocyanins with radical scavenging activities (0.936 and 0.929, P<0.001, respectively) indicating that this activity of wines was derived mainly from their phenolic compounds. CONCLUSION: The wine of the clone No. 010 contained the highest concentration of aldehydes, esters, anthocyanins, polyphenolics and resveratrol and consequently achieved the best tasting score. This clone may offer a new Cabernet Franc wine with geographical indication.


Assuntos
Sequestradores de Radicais Livres/farmacologia , Vitis/química , Vinho/análise , Antocianinas/análise , Cor , Sequestradores de Radicais Livres/isolamento & purificação , Fenóis/análise , Análise de Componente Principal , Resveratrol , Sérvia , Estilbenos/análise , Taninos/análise , Paladar , Vitis/classificação , Vitis/crescimento & desenvolvimento , Vinho/normas
7.
Food Chem ; 217: 705-715, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-27664689

RESUMO

Spice peppers (Capsicum annuum L.) var. Lemeska and Lakosnicka paprika were investigated to evaluate their polyphenolic and carbohydrate profiles and antioxidant activity. A total of forty-nine polyphenolics were identified using ultrahigh-performance liquid chromatography (UHPLC) coupled to LTQ OrbiTrap mass analyzer. Twenty-five of them were quantified using available standards, while the other compounds were confirmed by exact mass search of their deprotonated molecule [M-H](-) and its MS(4) fragmentation. Thirteen carbohydrates were quantified using high-performance anion exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). Radical scavenging activity (RSA) ranged from 17.32 to 48.34mmol TE (Trolox equivalent)/kg DW (dry weight) and total phenolics content (TPC) was ranged between 7.03 and 14.92g GAE (gallic acid equivalents)/kg DW. To our best knowledge, five polyphenolic compounds were for the first time tentatively identified in paprika: 5-O-p-coumaroylquinic acid, luteolin 7-O-(2″-O-pentosyl-4″-O-hexosyl)hexoside, quercetin 3-O-(2″-O-hexosyl)rhamnoside, isorhamnetin 3-O-[6″-O-(5-hydroxyferuloyl)hexoside]-7-O-rhamnoside, and luteolin 7-O-[2″-O-(5'″-O-sinapoyl)pentosyl-6″-O-malonyl]hexoside.


Assuntos
Capsicum/química , Carboidratos/análise , Polifenóis/análise , Especiarias/análise , Capsicum/classificação , Cromatografia Líquida de Alta Pressão/métodos , Geografia , Luteolina/análise , Extratos Vegetais/análise , Quercetina/análogos & derivados , Sérvia
8.
J Chromatogr A ; 1458: 136-44, 2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27378251

RESUMO

Soil-water partition coefficient normalized to the organic carbon content (KOC) is one of the crucial properties influencing the fate of organic compounds in the environment. Chromatographic methods are well established alternative for direct sorption techniques used for KOC determination. The present work proposes reversed-phase thin-layer chromatography (RP-TLC) as a simpler, yet equally accurate method as officially recommended HPLC technique. Several TLC systems were studied including octadecyl-(RP18) and cyano-(CN) modified silica layers in combination with methanol-water and acetonitrile-water mixtures as mobile phases. In total 50 compounds of different molecular shape, size, and various ability to establish specific interactions were selected (phenols, beznodiazepines, triazine herbicides, and polyaromatic hydrocarbons). Calibration set of 29 compounds with known logKOC values determined by sorption experiments was used to build simple univariate calibrations, Principal Component Regression (PCR) and Partial Least Squares (PLS) models between logKOC and TLC retention parameters. Models exhibit good statistical performance, indicating that CN-layers contribute better to logKOC modeling than RP18-silica. The most promising TLC methods, officially recommended HPLC method, and four in silico estimation approaches have been compared by non-parametric Sum of Ranking Differences approach (SRD). The best estimations of logKOC values were achieved by simple univariate calibration of TLC retention data involving CN-silica layers and moderate content of methanol (40-50%v/v). They were ranked far well compared to the officially recommended HPLC method which was ranked in the middle. The worst estimates have been obtained from in silico computations based on octanol-water partition coefficient. Linear Solvation Energy Relationship study revealed that increased polarity of CN-layers over RP18 in combination with methanol-water mixtures is the key to better modeling of logKOC through significant diminishing of dipolar and proton accepting influence of the mobile phase as well as enhancing molar refractivity in excess of the chromatographic systems.


Assuntos
Carbono/análise , Cromatografia de Fase Reversa/métodos , Cromatografia em Camada Fina/métodos , Compostos Orgânicos/análise , Solo/química , Água/química , Acetonitrilas/química , Calibragem , Carbono/química , Cromatografia Líquida de Alta Pressão , Modelos Lineares , Metanol/química , Octanóis/química , Compostos Orgânicos/química
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa