The extraction of phenolic compounds from 4 different sea algae samples, three brown algae (Cystoseira abies-marina, C. abies-marina grinded under cryogenic conditions with liquid nitrogen, Undaria pinnatifida and Sargassum muticum) and one red algae (Chondrus crispus) via solid phase extraction using micro-elution solid-phase extraction (μ-SPE) plate method was studied. Prior to μ-SPE, 50mg of algae with 80% methanol mixture was extracted in hyphenated series by various extraction techniques, such as pressurized liquid extraction and Ika Ultra-Turrax(®) Tube Drive, in combination with ultrasound assisted extraction. The μ-SPE plate technique reduced the time of sample pre-treatment thanks to higher sensitivity and pre-concentration effect. Selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic, and syringic acids), hydroxybenzaldehydes (4-hydroxybenzaldehyde, and 3,4-dihydroxybenzaldehyde), and cinnamic acid derivatives (p-coumaric, caffeic, ferulic, sinapic, and chlorogenic acids) were determined using rapid resolution liquid chromatography coupled to mass spectrometry detection with negative ion electrospray ionization (RRLC-ESI-MS) using multiple reactions monitoring. LOQs of measured samples varied in the range 0.23-1.68ng/mL and LODs in the range 0.07-0.52ng/mL. The applied method allowed a simultaneous determination of phenolics (i.e. free, esters soluble in methanol, glycosides, and esters insoluble in methanol) in less than 5min (including alkaline or acidic hydrolysis of raw extracts) from sea algae extracts.
New hyphenated technique for the extraction and determination of isoflavones in sea and freshwater algae and cyanobacteria was developed. The method consists of sonication sample pretreatment, extraction by supercritical CO(2) modified by 3% (v/v) of MeOH/H(2)O mixture (9:1, v/v) at 35 MPa and 40°C for 60 min, fast chromatography analysis by the means of Agilent 1200 Series Rapid Resolution and MS/MS determination. Agilent 1200 Series RRLC was used with Zorbax SB-CN chromatographic column (100 mm × 2.1mm, particle size 3.5 μm), 3μl injection volume, mobile phase consisting of 0.2% (v/v) acetic acid in water (solvent A) and acetonitrile (solvent B) and used with linear gradient (30% B at 0 min, from 0 min to 3 min up to 50% B, from 3 to 6 min up to 80% B and from 6 to 10 min down to 30% B). The flow-rate was 0.4 mL/min, column oven temperature 35°C. MS detector Agilent Technologies 6460 Triple quadrupole LC/MS with Agilent Jet Stream was used in a negative ESI mode under following conditions: gas temperature 350°C, gas flow 13 L/min, nebulizer gas pressure 50 psi, sheath gas temperature 400°C, sheath gas flow 12L/min, capillary voltage was 4 kV. Samples were analysed in the multiple reaction monitoring (MRM) mode. Eight isoflavone compounds were found for the first time in seven real samples of sea algae and in three control samples of freshwater algae and cyanobacteria. Usual optimisation study of extraction parameters was performed. Pressure and temperature optima for algae matrix are different from those obtained sooner for other matrices for most of the analytes, but the results of modifier optimisation study are in good accordance with those obtained sooner for spiked samples and red clover matrix. It seems that matrix has very small or no effect on the modifier selection. Two different approaches of sonication pretreatment were tested: sonication bath and the thorn instrument. In longer extraction time experiments, thorn sonication was more efficient and recovery of following supercritical fluid extraction was higher.
- MeSH
- chromatografie kapalinová metody MeSH
- isoflavony analýza izolace a purifikace MeSH
- Phaeophyceae chemie MeSH
- Rhodophyta chemie MeSH
- superkritická fluidní chromatografie přístrojové vybavení metody MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- ultrazvuk MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Isoflavony jsou přírodní látky s řadou fyziologických účinků na živé organismy a představují významný doplněk ve výživě člověka. V předkládaném přehledu jsou popsány moderní instrumentální přístupy ke studiu isoflavonů v rostlinných materiálech a potravinářských produktech, jakož i vhodné techniky chemické analýzy isoflavonů v lidských tělních tekutinách. Článek je zaměřen na chromatografickou analýzu isoflavonů. Jsou rovněž diskutovány efektivní techniky izolace, jako je extrakce pevnou fázi, extrakce kapalinou v nadkritickém stavu nebo Soxhletova extrakce. Jsou zde zmíněny i aplikace některých dalších analytických technik, jako je imunochemická analýza, spektrometrické (především hmotnostní spektrometrie) a elektrochemické metody. Část textu je věnována studiu interakcí isoflavonů s celou řadou biologicky aktivních látek, jako je DNA a proteiny. Cílem práce není podat ucelený přehled dané problematiky, spíše poukázat na moderní přístupy ve studiu isoflavonů.
Isoflavones belong to the natural substances exhibiting a number of physiological effects in living organisms. The substances are synthesized in plant tissues as protective agents against biotic stress (i.e. bacterial infection). Isoflavones are also an important dietary constituent in human nutrition. The review discusses modern trends in the studies of isoflavones in plant materials and foodstuffs and procedures for chemical analyses of isoflavones in human body fluids and plant tissues. Highly effective extraction and purification techniques, i.e. solid–phase extraction (SFE), accelerated–solvent extraction (ASE), and Soxhlet extraction, are presented. Latest procedures in chromatographic separation of isoflavones that apply different types of stationary phases are described. Immunochemical analysis, electrochemical sensing of isoflavones, spectrometric and other analytical techniques and their applications are also mentioned. Special attention is focused on a highly selective and sensitive technique of mass spectrometry and its application for identification of isoflavones and their glucosides in plants. Studies of interactions of isoflavones with cell receptors and a number of biologically active substances such as DNA and proteins are described. The reason for the presentation of the review was not to give a full overview of the presented topics but mainly to show modern and the most recent methods in the studies of isoflavones.
Isoflavones are natural substances which elicit a number of physiological effects in living organisms. The substances are synthesized in plant tissues as protective agents against biotic stress (i. e. bacterial infection). Isoflavones are also an important dietary constituent in human nutrition. Modern trends in studies of isoflavones in plant materials and foodstuffs and procedures for chemical analyses of isoflavones in human body fluids and plant tissues are discussed in this review. Highly effective extraction and purification techniques, i. e. solid-phase extraction, accelerated-solvent extraction, and Soxhlet extraction, are presented. Latest procedures in chromatographic separation of isoflavones that apply different types of sorbents are described. Immunochemical analysis, electrochemical sensing of isoflavones, and spectrometric and other analytical techniques and their applications are also mentioned. Special attention is paid to the highly selective and sensitive technique of mass spectrometry and its application for identification of isoflavones and their glucosides in plants. Studies of interactions of isoflavones with cell receptors and a number of biologically active substances such as DNA and proteins are described. The review does not intend to give a complete overview of the topics considered but rather to present modern and most recent methods used in studies of isoflavones.
A method for the simultaneous determination of 4(5)-methylimidazole (4MeI) and 2-acetyl-4(5)-(1,2,3,4-tetrahydroxybutyl)-imidazole (THI) was developed using SPE and HPLC/MS. Solid-phase extraction using SCX Disc cartridges was used for isolation of the analytes from liquid samples. The lower LOQwas 0.1 ng/mL for 4MeI and 0.2 ng/ mL for THI. The linearity of the calibration curves was satisfactory as indicated by correlation coefficients >0.999. The CV for the intra- and inter-day precision was <5% (n = 6); the accuracy was in the range 98-103%. The recovery was > or = 97 and > or = 98% for THI and 4MeI, respectively. The method was used to determine THI and 4MeI in beverages, coffee, caramel colours and other samples.
The fruits of Schisandra chinensis (Turcz.) Baill. (Schisandraceae/Magnoliaceae) are a traditional Oriental medicine possessing adaptogenic and hepatoprotective activities. The lignan content in seeds and fruits of the species cultured in various European locations has been investigated. The lignans were extracted from 17 samples of the seeds with supercritical CO2 and the major components--schizandrin (1), gomisin A (2), de-oxyschizandrin (3), gomisin N (4), and wuweizisu C (5)--were quantified by HPLC. Compounds 1-5 were present in the seeds in the range 0.75-1.86, 0.13-0.90, 0.07-1.09, 0.24-1.49, and 0.01 -0.34 %, respectively. It was found that the plants cultivated in Europe accumulated comparable amounts of lignans as those of the natural distribution range.
- MeSH
- lignany MeSH
- Schisandra MeSH
- semena rostlinná MeSH
- Publikační typ
- dopisy MeSH
