共查询到20条相似文献,搜索用时 15 毫秒
1.
Niu HY Cai YQ Shi YL Wei FS Liu JM Jiang GB 《Analytical and bioanalytical chemistry》2008,392(5):927-935
A new kind of solid-phase extraction disk based on a sheet of single-walled carbon nanotubes (SWCNTs) is developed in this
study. The properties of such disks are tested, and different disks showed satisfactory reproducibility. One liter of aqueous
solution can pass through the disk within 10–100 min while still allowing good recoveries. Two disks (DD-disk) can be stacked
to enrich phthalate esters, bisphenol A (BPA), 4-n-nonylphenol (4-NP), 4-tert-octylphenol (4-OP) and chlorophenols from various volumes of solution. The results show that SWCNT
disks have high extraction ability for all analytes. The SWCNT disk can extract polar chlorophenols more efficiently than
a C18 disk from water solution. Unlike the activated carbon disk, analytes adsorbed by the new disks can be eluted completely with
8–15 mL of methanol or acetonitrile. Finally, the DD-disk system is used to pretreat 1000-mL real-world water samples spiked
with BPA, 4-OP and 4-NP. Detection limits of 7, 25, and 38 ng L−1 for BPA, 4-OP, and 4-NP, respectively, were achieved under optimized conditions. The advantages of this new disk include
its strong adsorption ability, its high flow rate and its easy preparation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
A simple solid-phase extraction (SPE) procedure with an octadecyl bonded phase silica (C18) was developed for clean-up of the fungicide thiram from aqueous solutions containing high concentrations of humic substances, for future studies of thiram adsorption onto solid humic substances or soils. Suspensions of humic acids and soil, in aqueous 0.01 M CaCl2 solution, were prepared and used as samples. These extracts were spiked with thiram and immediately applied to a C18-SPE cartridge. Thiram was eluted with chloroform and its concentration measured by spectrophotometry at 283 nm. Non-spiked aqueous extracts (blanks) and a control sample of thiram in 0.01 M CaCl2 aqueous solution were also prepared and submitted to the same SPE procedure. The results show that humic substances are extensively retained by the C18 cartridge but are not eluted with CHCl3. Recoveries of 100-104% were obtained for thiram in the presence of humic substances. The SPE procedure described in this work is an efficient clean-up step to remove the interference of humic substances absorbance and to be coupled to any spectrophotometric or HPLC-UV method, usually used for thiram analysis in food extracts. 相似文献
3.
Determination of triazine herbicides in fruits and vegetables using dispersive solid-phase extraction coupled with LC-MS 总被引:1,自引:0,他引:1
A simple, rapid, and sensitive liquid chromatography-mass spectrometry (LC-MS) method was successfully developed for the determination of three chloro-s-triazine herbicides, viz. atrazine, simazine, and propazine, two thiomethyl-s-triazine ones, viz. ametryn and prometryn, and prometon in fruits and vegetables. The instrumental parameters affecting LC separation and MS detection were investigated and the best conditions were selected. Samples were extracted and purified by dispersive solid-phase extraction (dispersive-SPE) with a primary-secondary amine sorbent. Three typical representative samples (luffa, broad bean, and grape) were selected to investigate the effect of different matrices on pesticide recoveries and assay precision after spiking at 0.05 mg/kg. Matrix composition did not interfere significantly with the determination of these pesticides. The recoveries were, with a few exceptions, in the range of 80-110% with relative standard deviations less than 10% (n = 5). In addition, this method was also applied to 21 different kinds of agriculture products collected from the local market, and two of the six triazines could be detected and quantified. 相似文献
4.
Inoue K Ikemura A Tsuruta Y Tsutsumiuchi K Hino T Oka H 《Biomedical chromatography : BMC》2012,26(2):137-141
We developed a high-throughput method based on on-line solid-phase extraction liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) to determine N-terminal thymosin-β fragment peptide (N-acetyl-seryl-aspartyl-lysyl-proline, Ac-SDKP) in human plasma samples. Quantification of Ac-SDKP was performed using direct injection for on-line SPE based on C(18), reversed-phase LC separation and stable isotope dilution electrospray ionization-MS/MS in multiple reaction-monitoring (MRM) mode. The Ac-SDKP-(13)C(6), (15)N(2) (m/z 496 → 137) was synthesized for the internal standard. The MRM ion for Ac-SDKP was m/z 488 → 129 (quantitative ion)/226. The limit of detection and lower limit of quantitation were 0.05 and 0.1 ng/mL in standard solution, respectively. Recovery values were 98.3-100.4% with inter-day (relative standard deviation, RSD, 0.4-14.1%) and intra-day (RSD, 0.8-19.7%) assays. This method was applied to the measurement of Ac-SDKP levels in plasma from hemodialyzed subjects. Concentrations were 0.59 ± 0.23 ng/mL (pre-hemodialyzed subjects, n = 9) and 0.44 ± 0.19 ng/mL (post-hemodialyzed subjects, n = 9). All plasma Ac-SDKP levels were decreased by dialysis. Thus, plasma Ac-SDKP was decreased through dialysis in chronic kidney disease. The findings in this study will be useful for the treatment of anemia in chronic kidney disease with dialysis. 相似文献
5.
Lung-Cheng Lin Hsin-Yi Wu Vincent Shin-Mu Tseng Lien-Chin Chen Yu-Chen Chang Pao-Chi Liao 《Journal of the American Society for Mass Spectrometry》2010,21(2):232-241
The tracing of metabolite signals in LC-MS data using stable isotope-labeled compounds has been described in the literature.
However, the filtering efficiency and confidence when mining metabolite signals in complex LC-MS datasets can be improved.
Here, we propose an additional statistical procedure to increase the compound-derived signal mining efficiency. This method
also provides a highly confident approach to screen out metabolite signals because the correlation of varying concentration
ratios of native/stable isotope-labeled compounds and their instrumental response ratio is used. An in-house computational
program [signal mining algorithm with isotope tracing (SMAIT)] was developed to perform the statistical procedure. To illustrate
the SMAIT concept and its effectiveness for mining metabolite signals in LC-MS data, the plasticizer, di-(2-ethylhexyl) phthalate
(DEHP), was used as an example. The statistical procedure effectively filtered 15 probable metabolite signals from 3617 peaks
in the LC-MS data. These probable metabolite signals were considered structurally related to DEHP. Results obtained here suggest
that the statistical procedure could be used to confidently facilitate the detection of probable metabolites from a compound-derived
precursor presented in a complex LC-MS dataset. 相似文献
6.
Use of micellar liquid chromatography to analyze darunavir,ritonavir, emtricitabine,and tenofovir in plasma
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Juan Peris‐Vicente Mónica Villarreal‐Traver Inmaculada Casas‐Breva Samuel Carda‐Broch Josep Esteve‐Romero 《Journal of separation science》2014,37(20):2825-2832
Danuravir, ritonavir, emtricitabine, and tenofovir are together prescribed against AIDS as a highly active antiretroviral therapy regimen. Micellar liquid chromatography has been applied to determine these four antiretroviral drugs in plasma. The sample preparation is shortened to the dilution of the sample in a micellar solution, filtration, and injection. Clean‐up steps are avoided, due to the solubilization of plasma matrix in micellar media. The drugs were analyzed in <20 min using a mobile phase of 0.06 M sodium dodecyl sulfate/2.5% 1‐pentanol (pH 7) running under isocratic mode through a C18 column at 1 mL/min at room temperature. Absorbance wavelength detection was set at 214 nm. The method was successfully validated following the ICH Harmonized Tripartite Guideline in terms of selectivity, limit of detection (0.080–0.110 μg/mL), limit of quantification (0.240–0.270 μg/mL), linearity between 0.25 and 25 μg/mL (r2 > 0.995), accuracy (89.3–103.2%), precision (<8.2%) and robustness (<7.5%). Real plasma sample from patients taking this therapy were analyzed. This is the first paper showing the simultaneous detection of this four drugs. Therefore, the methodology was proven useful for the routine analysis of these samples in a hospital laboratory for clinical purposes. 相似文献
7.
The design of a mixed indicator-buffer system which yields a linear change of absorbance versus pH over a wide pH range is described. Its use for enzymatic analysis in continuous and stopped flow f.i.a. systems is demonstrated for the determination of urea via degradation by urease. A microcomputer (PET) was connected to the f.i.a. systems, and the programs used for retrieving peak-height values and computing buffering capacities are described. 相似文献
8.
Patrícia S. Peixoto Ildikó V. Tóth Luisa Barreiros Ana Machado Adriano A. Bordalo José L. F. C. Lima 《International journal of environmental analytical chemistry》2019,99(3):258-269
Fluoroquinolones are in the order of the day concerning environmental contamination through anthropogenic activities, resulting in increased risk for antibiotic resistance dissemination. In this context, accessible, low-cost analytical methods are required for implementation of comprehensive surveillance and screening schemes. In this work, we propose a down-scaled disk-based solid-phase extraction system from which the eluate can be first screened by miniaturized fluorimetric reading, followed by individual determination of target fluoroquinolones (ciprofloxacin, norfloxacin, and enrofloxacin) by liquid chromatography combined to tandem mass spectrometry. The fluorimetric measurement is based on the intrinsic fluorescence of fluoroquinolones. Disk-based retention was performed after sample acidification (pH 4.0) by mixed-mode cation exchange using polystyrene divinylbenzene sulphonated sorbent. Sample loading was precisely controlled in a dedicated flow system operating at 4.0 mL min?1. Different eluent compositions were tested, with elution performed by 1.00 mL of methanol-ammonium hydroxide (98:2, v/v), with subsequent reading of eluate in both detectors. Quantification was attained for 2–25 µg L?1 range, with LOD values at 1 µg L?1. The proposed approach was successfully applied to estuarine waters from the Douro River, with comparable results to a conventional SPE-LC-MS/MS procedure. 相似文献
9.
Since methylation at the N-7 and O6 positions of guanine and the N-3 position of adenine in DNA are the predominant reaction sites, N
7-methylguanine (N
7-MeG), O
6-methylguanine (O
6-MeG), and N
3-methyladenine (N
3-MeA) have been suggested as good biomarkers for assessing exposure to methylating agents. Here, we report the development
of a sensitive and selective assay based on liquid chromatography–tandem mass spectrometry (LC-MS/MS) to simultaneously measure
N
7-MeG, O
6-MeG, and N
3-MeA in DNA hydrolysates. With the use of isotope internal standards (15N5-N
7-MeG, d
3-O
6-MeG, and d
3-N
3-MeA) and online solid-phase extraction, DNA hydrolysates can be directly analyzed within 12 min without prior sample purification.
The limits of detection were 0.02, 0.002, and 0.01 ng/mL on-column (6.1, 0.6, and 3.4 fmol) for N
7-MeG, O
6-MeG, and N
3-MeA, respectively. Inter- and intraday imprecision (CV) were 3.6–9.6% and 2.7–13.6%, respectively. Mean recoveries were 96–109%.
This method was then applied to quantitate the amounts of methylated purines in calf thymus DNA treated with methyl methanesulfonate
(MMS). The levels of N
7-MeG, O
6-MeG, and N
3-MeA in calf thymus DNA increase with MMS concentration and incubation time. The ratio of relative yields of N
7-MeG, O
6-MeG, and N
3-MeA in MMS-treated DNA was found to be 1.00:0.0032:0.119, respectively. This LC-MS/MS assay provides the sensitivity and
high throughput required to evaluate the extent of methylated lesions in DNA induced by methylating agents. 相似文献
10.
Alendronate is an important representative of bisphosphonates, strongly polar compounds that lack chromophores. With rare
exceptions, derivatization of the analytes is necessary for bioanalysis. In this study, a rapid liquid chromatography–tandem
mass spectrometry method employing pre-column derivatization was developed and validated for the determination of alendronate
concentrations in human plasma. The procedure was based on derivatization with trimethylsilyldiazomethane during solid-phase
extraction on a weak anion-exchange solid-phase cartridge, which integrated sample purification and derivatization into one
step. The alendronate derivative was eluted with methanol. Chromatographic separation was performed on a Capcell PAK-C18 column.
The total run time was 6.5 min. The calibration curve was linear in the range 1.00–1,000 ng/mL using d6-alendronate as the
internal standard. The lower limit of quantification was 1.00 ng/mL. The intra- and inter-assay precision (in RSD) calculated
from quality control samples was less than 15%, and the accuracy was between 98.1% and 100.2%. The validated method was successfully
applied to characterize the pharmacokinetic profiles of alendronate following the intravenous infusion of 5 or 10 mg alendronate
sodium to healthy volunteers. 相似文献
11.
A rapid, specific and sensitive LC-MS/MS assay using solid-phase extraction (SPE) for the determination of pravastatin, in human plasma is described. The plasma filtrate obtained after SPE, using a polymer base, a hydrophilic-lipophilic balance (HLB) cartridge, was submitted directly to short-column liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay, with negligible matrix effect on the analysis. For validation of the method, the recovery of the free analytes was compared with that from an optimized extraction method, and the analyte stability was examined under conditions mimicking the sample storage, handling, and analysis procedures. The extraction procedure yielded extremely clean extracts with a recovery of 107.44 and 98.93% for pravastatin and IS, respectively. The intra-assay and inter-assay precisions for the samples at the LLOQ were 3.30 and 7.31% respectively. The calibration curves were linear for the dynamic range 0.5-200 ng/mL with correlation coefficient r > or = 0.9988. The intra- and inter-assay accuracy ranged from 95.87 to 112.40%. The method is simple and reliable with a total run time of 3 min. This novel validated method was applied to the pharmacokinetic (PK) study in human volunteers receiving a single oral dose of 40 mg immediate release (IR) formulation. 相似文献
12.
Jing Yang Lianfang Chen Qingying Wang Xiaolin Mei Xiupei Yang Feng Huo 《Electrophoresis》2023,44(7-8):634-645
For a long time, the detection of nitroimidazole antibiotics (NIABs) has been a research focus in environmental analytical chemistry. In this work, a novel technique for the analysis of nitroimidazoles was established based on capillary electrophoresis (CE). UiO-66, synthesized using a solvothermal method, was utilized as an adsorbent in the dispersive solid-phase extraction (DSPE) of five different NIABs. The separation and detection of NIABs in environmental water samples were accomplished using the CE diode array detection method. The optimal extraction conditions were obtained after systematically studying the effects of adsorption time, the amount of extractant, and elution solvent on extraction efficiency. According to the results of the study, the limit of detections of the five NIABs were between 16 and 97 ng/mL, the relative standard deviations were between 0.32% and 0.55%, and the spike recoveries were between 87.43% and 104.8%. This study presents a novel technique for measuring NIABs in complex water samples. 相似文献
13.
Beretta G Caneva E Regazzoni L Bakhtyari NG Maffei Facino R 《Analytica chimica acta》2008,620(1-2):176-182
The aim of this work was to establish an analytical method for identifying the botanical origin of honey, as an alternative to conventional melissopalynological, organoleptic and instrumental methods (gas-chromatography coupled to mass spectrometry (GC–MS), high-performance liquid chromatography HPLC). The procedure is based on the 1H nuclear magnetic resonance (NMR) profile coupled, when necessary, with electrospray ionisation-mass spectrometry (ESI-MS) and two-dimensional NMR analyses of solid-phase extraction (SPE)-purified honey samples, followed by chemometric analyses. Extracts of 44 commercial Italian honeys from 20 different botanical sources were analyzed.Honeydew, chestnut and linden honeys showed constant, specific, well-resolved resonances, suitable for use as markers of origin. Honeydew honey contained the typical resonances of an aliphatic component, very likely deriving from the plant phloem sap or excreted into it by sap-sucking aphids. Chestnut honey contained the typical signals of kynurenic acid and some structurally related metabolite.In linden honey the 1H NMR profile gave strong signals attributable to the mono-terpene derivative cyclohexa-1,3-diene-1-carboxylic acid (CDCA) and to its 1-O-β-gentiobiosyl ester (CDCA-GBE). These markers were not detectable in the other honeys, except for the less common nectar honey from rosa mosqueta. We compared and analyzed the data by multivariate techniques. Principal component analysis found different clusters of honeys based on the presence of these specific markers.The results, although obviously only preliminary, suggest that the 1H NMR profile (with HPLC–MS analysis when necessary) can be used as a reference framework for identifying the botanical origin of honey. 相似文献
14.
Shah HJ Kundlik ML Pandya A Prajapati S Subbaiah G Patel CN Patel DM Suhagia BN Suhagiya BN 《Biomedical chromatography : BMC》2009,23(2):141-151
A selective, rapid and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described for assay of donepezil in human plasma using escitalopram as an internal standard. Chromatographic separation was achieved on a Betabasic-C(8), 5 microm, 100 x 4.6 mm column using methanol:water:formic acid (90:9.97:0.03, v/v/v) as mobile phase. Detection of donepezil and internal standard was achieved by ESI MS/MS in positive ion mode using 380.20/91.10 and 325.13/262.00 transitions, respectively. The linearity over the concentration range of 0.15-50 ng/mL for donepezil was obtained and the lower limit of quantification was 0.15 ng/mL. For each level of quality control samples, inter-day and intra-day precisions (RSD) were < or =8.92 and 10.35% and accuracy (%RE) were < or =7.33% and 9.33%, respectively. The recovery was more than 88.50% for both donepezil and internal standard by solid-phase extraction, eliminating evaporation and reconstitution steps. 相似文献
15.
Saracino MA Gandolfi O Dall'olio R Albers L Kenndler E Raggi MA 《Journal of chromatography. A》2006,1122(1-2):21-27
A sensitive and selective method was developed for the determination of the antipsychotic drug Olanzapine levels in rat brain tissue, based on HPLC with electrochemical detection. The analyses were carried out on a C8 reversed phase column (150 mm x 4.6 mm, 5 microm), using a mobile phase composed of methanol and a phosphate buffer (44.0 mM, pH 3.5), containing triethylamine (21:79, v/v), flowing at 1.2 mL min(-1). A high sensitivity coulometric detection analytical cell containing two flow-through low volume working electrodes was used: electrode 1 was set at +0.350 V and electrode 2 at -0.200 V. Olanzapine, administered to rats in different doses or in different times, was extracted from tissue homogenate of either the whole brain or specific areas (cortex, hyppocampus, nucleus striatum) with a rapid solid phase extraction procedure (SPE) on Oasis HLB cartridges. The method provided a high extraction yield of Olanzapine and internal standard (2-methylolanzapine) from brain tissue homogenate with absolute recovery values higher than 90.0%. The detector response was linear over a concentration range of 0.2-100.0 ng mL(-1) of Olanzapine. The limit of quantification (LOQ) was 0.2 ng mL(-1). Precision results, expressed by the intra-day and the inter-day relative standard deviation values, were satisfactory, better than 4.6%. Accuracy was satisfactory as well. This method proved to be suitable for the analysis of Olanzapine in rat brain tissues and for the study of distribution and pharmacokinetics of Olanzapine in rat brain after a single treatment with the antipsychotic drug. 相似文献
16.
Bugamelli F Mandrioli R Cavallini A Baccini C Conti M Raggi MA 《Journal of separation science》2006,29(15):2322-2329
A precise and feasible HPLC method has been developed for the analysis of amphetamine (AMPH), methamphetamine (MAMPH) and methylenedioxymethamphetamine (MDMA, ecstasy) in human urine. A chromatographic run on a C8 Genesis (150 mm x 4.6 mm, 5 microm) column maintained at 30 degrees C lasts about 17 min, using a mobile phase composed of ACN (12%) and a pH 2.5 phosphate buffer (88%) containing 0.3% triethylamine. Mirtazapine was used as the internal standard. Good linearity was found in the 100-2000 ng/mL concentration range for AMPH and MAMPH and in the 12-2000 ng/mL concentration range for MDMA. The pretreatment of urine samples was carried out by means of a careful SPE procedure on C2 cartridges. The extraction yields were very satisfactory for all analytes, with average values greater than 97%. The leading conditions allowed the determination of AMPH, MAMPH and MDMA with satisfactory precision and accuracy. The method has been successfully applied to the determination of the analytes in urine of AMPH users. 相似文献
17.
Luisa Gallo-Martinez Adela Sevillano-Cabeza Pilar Campí ns-Falc Francisco Bosch-Reig 《Analytica chimica acta》1998,370(2-3):115-123
The present report shows how to derivatize cephalexin with 1,2-naphthoquinone-4-sulphonate (NQS) into solid-phase extraction cartridges (C18) using UV–visible detection. Optimum conditions for this new procedure are: hydrogen carbonate/carbonate buffer pH=10.5, 5 min reaction time at 25°C and NQS concentration of 7.1×10−3 mol l−1. The accuracy and the precision of the method were tested. The procedure was used to measure cephalexin in pharmaceutical and urine samples. The results obtained were contrasted with those reported by UV-spectrophotometric and HPLC methods for pharmaceutical samples and with HPLC method for urine samples. The H-point standard additions method was used to measure cephalexin in pharmaceutical samples, and the generalized H-point standard additions method was used to measure cephalexin in urine samples. 相似文献
18.
Gabriel Dasilva Manuel Pazos José M. Gallardo Isaac Rodríguez Rafael Cela Isabel Medina 《Analytical and bioanalytical chemistry》2014,406(12):2827-2839
The present work describes the development of a robust and sensitive targeted analysis platform for the simultaneous quantification in blood plasma of lipid oxygenated mediators and fatty acids using solid-phase extraction (SPE) and high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The concurrent analysis of these lipid mediators is challenging because of their instability, differences in solubility, and the frequent occurrence of isobaric forms with similar fragmentation patterns. Results demonstrated that the reduction of SPE temperature to 4 °C is a critical parameter for preserving the hydroperoxy derivatives. Polymeric HLB cartridges increased 40–50 % ARA, EPA, and DHA sensitivity compared to C18 sorbent and also provided higher global performance for most hydroxides and other oxidation products. The proposed method for the two tested mass analyzers yields high sensitivity, good linearity, and reproducibility, with detection limits ranging 0.002–7 ng/mL and global recoveries as high as 85–112 %. However, the additional advantage of the linear ion trap (LIT) mass analyzer working in full scan product ion mode, compared to the triple quadrupole (QqQ) operating in multiple reaction monitoring (MRM), should be noted: the full scan product ion mode provides the full fragmentation spectra of compounds that allowed the discrimination of coeluting isomers and false positive identifications without additional chromatography development. The proposed lipidomic procedure demonstrates a confident, simple, and sensitive method to profile in plasma a wide range of lipid eicosanoid and docosanoid mediators, including innovatively the analysis of hydroperoxy congeners and nonoxidized PUFA precursors. Figure
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19.
van Kan HJ Spieksma M Groeneveld GJ Toraño JS van den Berg LH Guchelaar HJ 《Biomedical chromatography : BMC》2004,18(9):723-726
A specific, accurate and precise high-performance liquid chromatographic assay was developed for the determination of riluzole, a drug used to treat patients with amyotrophic lateral sclerosis. Samples were treated by extraction with dichloromethane followed by reversed-phase chromatography with ultraviolet detection at 260 nm. Preset validation criteria were met from 20 to 2000 ng/mL with a linear response curve. Extraction recovery of riluzole was 65-76%. The accuracy of the method was 102-103%. Intra- and inter-day coefficients of variation were in the ranges 2.8-4.9% and 1.8-9.7%. A detection limit of 5 ng/mL was found. Determination of concentrations in serum and plasma resulted in similar results below 500 ng/mL. At higher values a matrix effect cannot be excluded. This presented method can be used to monitor plasma or serum levels in ALS patients treated with riluzole. 相似文献
20.
A high throughput screening assay for the identification of ligands to pharmacologically significant receptors was developed based on magnetic particles containing immobilized receptors followed by liquid chromatography-mass spectrometry (LC-MS). This assay is suitable for the screening of complex mixtures such as botanical extracts. For proof-of-principle, estrogen receptor-alpha (ER-alpha) and ER-beta were immobilized on magnetic particles functionalized with aldehyde or carboxylic acid groups. Alternatively, biotinylated ER was immobilized onto streptavidin-derivatized magnetic particles. The ER that was immobilized using the streptavidin-biotin chemistry showed higher activity than that immobilized on aldehyde or carboxylic acid functionalized magnetic particles. Immobilized ER was incubated with extracts of Trifolium pratense L. (red clover) or Humulus lupulus L. (hops). As a control for non-specific binding, each botanical extract was incubated with magnetic particles containing no ER. After magnetic separation of the particles containing bound ligands from the unbound components in the extract, the particles were washed, ligands were released using methanol, and then the ligands were identified using LC-MS. The estrogens genistein and daidzein were identified in the red clover extract, and the estrogen 8-prenylnaringenin was identified in the hop extract. These screening results are consistent with those obtained using previous screening approaches. 相似文献