红花罂粟植物的各个部分中蒂巴因含量的测定

采用甲醇浸泡、超声波一次提取处理样品,气相色谱内标法定量测定不同种类及不同培育方法的红花罂粟植物的全果、根、叶、苞片、果盖、果壳、茎中蒂巴因的含量。方法采用多点校正,其线性相关系数为０．９９６,变异系数为２．９％～５．４％,最低绝对检出量可达２ｎｇ。蒂巴因的色谱峰为双峰,经质谱确证为异构体,这两种异构体的比例不固定,取其峰面积之和定量。应用该方法对前后３年共１６８个样品进行了测定,提取样品中蒂巴因的图谱与蒂巴因标准品的图谱完全一致,样品中的其它杂质均不干扰蒂巴因的测定。     

One-pot synthesis of magnetic sulfonated covalent organic polymer for extraction of protoberberine alkaloids in herbs and human plasma

A novel magnetic sulfonated covalent organic polymer was prepared for magnetic solid-phase extraction of protoberberine alkaloids. The magnetic sulfonated covalent organic polymer was rapidly synthesized under mild conditions. The physicochemical properties of the prepared materials were characterized by Fourier-transform infrared spectrometry, transmission electron microscopy, and X-ray photoelectron spectroscopy. Several extraction parameters were systematically investigated, including desorption time, pH of sample solution, acetonitrile content, acetic acid content in the eluent, extraction time, and sample volume. By coupling magnetic solid-phase extraction and high-performance liquid chromatography, an efficient and sensitive method for the extraction and determination of protoberberine alkaloids in complex samples was developed. The proposed method showed great linearity (r > 0.9989), low limits of detection (0.2–0.3 ng/ml), and high precision (relative standard deviations ≤ 5.74%). The proposed method was further applied to the analysis of protoberberine alkaloids in Cortex phellodendri and human plasma samples. The recoveries were 91.50%–110.31% with relative standard deviations less than 6.63% in Cortex phellodendri and 96.12%–111.20% with relative standard deviations lower than 5.56% in plasma samples.     

微波辅助提取-高效液相色谱法测定苦参中5种苦参生物碱的含量

取粒径在0.18～0.25mm的药材粉末于提取罐中,用水作提取剂,在110℃、压力为15MPa、功率为780W的条件下进行微波提取(PMAE)5min,经离心后取上清液为提取液。提取液经无水乙醇处理提纯后得到待测物的甲醇溶液,从中分取部分溶液按选定条件用液相色谱-质谱(LC-MS)联用做定性分析,用高效液相色谱(HPLC)做定量分析。LC-MS结果表明:提取液中含有氧化苦参碱、氧化槐果碱、槐定碱、苦参碱和槐果碱,与其它3种提取方法比较,PMAE的提取率高且提取时间短。HPLC定量时,采用C18色谱柱,以不同比例的甲醇、乙腈和0.1%氨水溶液(pH 10.3)的混合溶液作流动相进行梯度淋洗,可分离上述5种生物碱,以峰面积和浓度间的线性关系进行定量。5种生物碱的回收率在93.9%～101.0%之间,测定值的相对标准偏差(n=5)在0.53%～2.6%之间。     

Solid-liquid extraction and cation-exchange solid-phase extraction using a mixed-mode polymeric sorbent of Datura and related alkaloids

Tropane alkaloids solid-liquid extraction methods were developed and comprised ambient pressure ones: extraction with hot solvent, extraction at room temperature, on ultrasonic bath as well as pressurised liquid extraction (PLE) techniques. The highest yields of l-hyoscyamine in methanol PLE method (3 x 5 min, 110 degrees C) and scopolamine extracted with 1% tartaric acid in methanol (15 min, 90 degrees C) were determined. A mixed-mode reversed-phase cation-exchange solid-phase extraction (SPE) procedure was optimised for simultaneous recoveries of L-hyoscyamine, scopolamine, scopolamine-N-oxide from plant extracts as well as quaternary alkaloid representative: scopolamine-N-methyl bromide. First three alkaloids were efficiently eluted (recoveries 80-100%) from an Oasis MCX cartridge with methanol-10% ammonia (3:1, v/v) solution, whereas for the quaternary salt tetrahydrofuran-methanol-25% ammonia (6:1:3, v/v) was used with recoveries 52-6%. HPTLC-densitometric assay on silica gel plates was elaborated at 205 nm without derivatization and included: single development (over a distance 9.5 cm) with acetone-methanol-water-25% ammonia (85:5:5:8, v/v) mobile phase for L-hyoscyamine and scopolamine separation, whereas for scopolamine-N-oxide and scopolamine-N-methyl bromide a second development (to a distance 5.5 cm) with acetonitrile-methanol-85% formic acid (120:5:5, v/v) was applied. Newly elaborated RP-HPLC-diode array detection method was performed on Waters XTerra RP-18 column with gradient of acetonitrile in 15 mM ammonia solution and alkaloids were baseline separated within 20 min. Both chromatographic methods were validated and their quantitative results were compared. Good correlation between HPLC and HPTLC quantitative results was measured (correlation coefficients of mean values were 0.92086 and 0.99995 for L-hyoscyamine and scopolamine, respectively). In the RP-HPLC method, which was from 1.5- up to 7-fold more sensitive than HPTLC, limits of detection (LOD) and limits of quantitation (LOQ, in bracket) were (in ng/microl) as follows: 0.25 (0.82) for L-hyoscyamine, 0.29 (0.97) for scopolamine, 0.13 (0.45) for scopolamine-N-oxide and 0.58 (1.91) for scopolamine-N-methyl bromide. By the use of the optimised chromatographic methods, 14 various samples from the leaves and fruits of Datura sp. were screened for L-hyoscyamine and scopolamine contents and the most promising samples were established.     

Liquid chromatographic analysis of cinchona alkaloids in beverages

A method for the determination of Cinchona extract (whose main components are the alkaloids cinchonine, cinchonidine, quinidine, and quinine) in beverages by liquid chromatography was developed. A beverage with an alcohol content of more than 10% was loaded onto an OASIS HLB solid-phase extraction cartridge, after it was adjusted to pH 10 with 28% ammonium hydroxide. Other beverages were centrifuged at 4000 rpm for 5 min, and the supernatant was loaded onto the cartridge. The cartridge was washed with water followed by 15% methanol, and the Cinchona alkaloids were eluted with methanol. The Cinchona alkaloids in the eluate were chromatographed on an L-column ODS (4.6 mm id x 150 mm) with methanol and 20 mmol/L potassium dihydrogen phosphate (3 + 7) as the mobile phase. Cinchona alkaloids were monitored with an ultraviolet (UV) detector at 230 nm, and with a fluorescence detector at 405 nm for cinchonine and cinchonidine and 450 nm for quinidine and quinine (excitation at 235 nm). The calibration curves for Cinchona alkaloids with the UV detector showed good linearity in the range of 2-400 microg/mL. The detection limit of each Cinchona alkaloid, taken to be the concentration at which the absorption spectrum could be identified, was 2 microg/mL. The recovery of Cinchona alkaloids added at a level of 100 microg/g to various kinds of beverages was 87.6-96.5%, and the coefficients of variation were less than 3.3%. A number of beverage samples, some labeled to contain bitter substances, were analyzed by the proposed method. Quinine was detected in 2 samples of carbonated beverage.     

Determination of quinolizidine alkaloids in traditional Chinese herbal drugs by nonaqueous capillary electrophoresis.

A rapid method for the determination of quinolizidine alkaloids by nonaqueous capillary electrophoresis was developed. A total of 10 alkaloids (matrine, sophocarpine, oxymatrine, oxysophocarpine, sophoridine, cytisine, sophoramine, aloperine, lehmannine and dauricine) could be easily separated within 18 min. A running buffer composed of 50 mM ammonium acetate, 10% tetrahydrofuran and 0.5% acetic acid in methanol was found to be the most suitable for this separation. Five of these alkaloids were selected for further studies. The linear calibration ranges were 2.51-50.1 microg/ml for sophoridine and sophocarpine, 2.71-54.2 microg/ml for matrine, 3.30-65.9 microg/ml for oxymatrine, and 3.10-62.0 microg/ml for oxysophocarpine. The recovery of the five alkaloids was 98.0-101.3% with relative standard deviations from 1.03 to 2.68% (n=5). The limits of detection for all 10 alkaloids were over the range 0.93-2.31 microg/ml. The method was successfully applied to the phytochemical analysis of alkaloid extracts from three commonly used traditional Chinese herbal drugs: Sophora flavescens Ait. (Kushen), S. alopecuroides L. (Kudouzi or Kugancao) and S. tonkinensis Gapnep (Shandougen).     

同位素内标-多反应监测同步在线质谱全扫描确证火锅料中罂粟壳成分

建立了高效液相色谱-三重四极杆线性离子阱质谱测定火锅料中吗啡、可待因、蒂巴因、罂粟碱、那可丁等5种生物碱残留的确证方法。样品采用稀盐酸加热提取,正己烷除脂,阳离子混合机理固相萃取柱净化,5%氨化乙酸乙酯-甲醇洗脱,PAK ST色谱柱分离,5 mmol/L乙酸铵甲醇溶液-10 mmol/L乙酸铵水溶液(pH 3.6)作为流动相洗脱,电喷雾正离子模式下多反应监测同步增强子离子在线全扫描(EPI)。在该实验条件下,5种生物碱的LOD在0.05~0.5 μg/kg之间,增强型子离子全扫描水平限和LOQ在0.2~2 μg/kg之间,方法回收率为64.2%~110.6%, RSD为4.2%~12.5%。阳性样品的定性确证需采用其子离子全扫描质谱图与标准图库中子离子质谱图检索匹配。经测定多种火锅料,表明本方法操作简单、测定结果准确,可用于火锅料中5种生物碱残留的阳性结果确证分析。     

High-performance liquid chromatographic determination of phenolic compounds in rice

A method has been developed for the determination of 6'-O-feruloylsucrose, 6'-O-sinapoylsucrose, ferulic acid, sinapinic acid, p-coumaric acid, chlorogenic (3-caffeoylquinic) acid, caffeic acid, protocatechuic acid, hydroxybenzoic acid, vanillic acid, and syringic acid in rice. The rice samples were extracted with 70% ethanol, filtered, and defatted. The defatted aqueous solution was subjected to solid-phase extraction using a C18 silica gel cartridge; no analyte was lost in this procedure. The 70% acidic methanol elution was analyzed directly by HPLC and HPLC-ESI-MS. Phenolic compounds were separated with a C18 reversed-phase column by gradient elution using 0.025% trifluoroacetic acid in purified water (A)--acetonitrile (B) (0 min, 5% B; 5 min, 9% B; 15 min, 9% B; 22 min, 11% B; and 38 min, 18% B) as the mobile phase at a flow rate of 0.8 ml/min. Detection limits ranged from 0.10 to 0.35 ng per injection (5 microl). Relative standard deviations of 0.22-3.95% and recoveries of 99-108% were obtained for simultaneous determination of these phenolic compounds. This method was applied to analysis of phenolic compounds in brown rice and germinated brown rice soaked in 32 degrees C water for varying durations.     

Screening for pyrrolizidine alkaloids in plant materials by electron ionization RP-HPLC-MS with thermabeam interface

Plant samples from leaves of Cerinthe minor, Cynoglossum clandestinum, Echium tuberculatum (as well roots), Eritrichium rupestre, Lithospermum purpureo-coerulem, Nonnea lutea, Nonnea setosa, Onosma stellulatum and Cynoglossum amabile were screened for toxic pyrrolizidine alkaloids (PAs) with a newly elaborated procedure comprising gradient HPLC with diode array (DAD) and thermabeam electron impact mass spectrometry (EI-MS). Dried plant material was extracted with boiling 1% tartaric acid in methanol for 2 h on an electric basket and crude extracts purified with cation-exchange solid phase extraction (CE-SPE). Purified extracts containing alkaloids were separated on Zorbax SB RP18 stationary phase in gradient of 0.1% formic acid in methanol. The flow rate was 0.25 mL/min and was suitable both for DAD and EI MS detections. Applied gradient procedure permitted quite sufficient separation of PAs in various plant extracts. On the basis of EI MS spectra, toxic PAs with unsaturated 1,2-double bond in the necine moiety were found in all plant materials and in nine of them (excluding only Cynoglossum amabile) for the fi rst time. They included the following types of structures: 9- and 7-viridifloryl-retronecine monoesters, 9-angeloyl-7-viridifloryl-retronecine, 9-angeloyl-retronecine diester, 9-viridifloryl-retronecine saturated ester, 7-angeloyl-9-viridifloryl-retronecine, 7-angeloyl-9-echimidinyl-retronecine, trachelanthamine and others. Selected ion monitoring (SIM) chromatograms at m/z 119, 120 and 136 together with analysis of UV spectra from DAD detector can be applied in rapid screening for toxic PAs in new plant extracts but to obtain detailed structural information (molecular weight and stereochemistry) more expensive hyphenation is required. Consumption of all analysed plants should be avoided as carcinogenic and hepatotoxic properties of the alkaloids detected are expected.     

Molecularly imprinted solid-phase extraction for the screening of antihyperglycemic biguanides

A new molecularly imprinted polymer (MIP) was specifically synthesized as a smart material for the recognition of metformin hydrochloride in solid-phase extraction. Particles of this MIP were packed into a stainless-steel tubing (50 mm x 0.8 mm i.d.) equipped with an exit frit. This micro-column was employed in the development of a molecularly imprinted solid-phase extraction (MISPE) method for metformin determination. The MISPE instrumentation consisted of a micrometer pump, an injector valve equipped with a 20-microl sample loop, a UV detector, and an integrator. With CH3CN as the mobile phase flowing at 0.5 ml/min, 95 +/- 2% binding could be achieved for 1200 ng of metformin from one injection of a phosphate-buffered sample solution (pH 2.5). Methanol + 3% trifluoroacetic acid was good for quantitative pulsed elution (PE) of the bound metformin. The MISPE-PE method, with UV detection at 240 nm, afforded a detection limit of 16 ng (or 0.8 microg/ml) for metformin. However, the micro-column interacted indiscriminately with phenformin with a 49 +/- 2% binding. A systematic investigation of binding selectivity was conducted with respect to sample composition (including the solvent, matrix, pH, buffer and surfactant effects). An intermediate step of differential pulsed elution used acetonitrile with 5% picric acid to remove phenformin and other structural analogues. A final pulsed elution of metformin for direct UV detection was achieved using 3% trifluoroacetic acid in methanol.     

A rapid cleanup method for the isolation and concentration of pyrrolizidine alkaloids in comfrey root

Preparations from comfrey (Symphytum officinale and S. x uplandicum) root and leaf contain varying levels of the hepatotoxic pyrrolizidine alkaloids (PAs). Reference compounds for comfrey are not commercially available, and there is currently no rapid extraction or analytical method capable of determining low levels in raw materials or as adulterants in commercially available extracts. A solid-phase extraction (SPE) method was developed using an Ergosil cleanup column that specifically binds the PAs. With this method, powdered comfrey root was extracted by sonication and shaking with basic chloroform. The extract was applied to the cleanup column under vacuum, washed with 2 mL acetone-chloroform (8 + 2, v/v) followed by 2 mL petroleum ether to remove excess chloroform. The column was dried under vacuum, and the PAs were eluted with 2 successive 1 mL aliquots methanol. Percent recoveries of the PAs following Ergosil SPE had an overall average of 96.8%, with RSD of 3.8% over a range of 1.0 to 25.0 g extracted in 100 mL. Average precision of the method (n = 3 over 4 extraction concentrations) gave an overall RSD of 6.0% for the 5 alkaloids, with a range of 0.8% (5 g in 100 mL) to 11.2% (25 g in 100 mL). Recovery optimization testing showed that 1.0 g comfrey root extracted in 100 mL yielded the greatest recovery (% dry weight) of the PAs, with an extraction efficiency and accuracy of 94.2%, and RSD of 1.7% (n = 9). The unique properties of the Ergosil cleanup column provide rapid sample cleanup, volume reduction, and concentration of PAs from comfrey extracts, and allow the eluant to be analyzed directly by traditional chromatographic methods.     

Detection and validated quantification of toxic alkaloids in human blood plasma--comparison of LC-APCI-MS with LC-ESI-MS/MS

Poisonings with toxic plants may occur after abuse, intentional or accidental ingestion of plants. For diagnosis of such poisonings, multianalyte procedures were developed for detection and validated quantification of the toxic alkaloids aconitine, atropine, colchicine, coniine, cytisine, nicotine and its metabolite cotinine, physostigmine, and scopolamine in plasma using LC-APCI-MS and LC-ESI-MS/MS. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a C8 base select separation column and gradient elution (acetonitrile/ammonium formate, pH 3.5). Calibration curves were used for quantification with cotinine-d(3), benzoylecgonine-d(3), and trimipramine-d(3) as internal standards. The method was validated according to international guidelines. Both assays were selective for the tested compounds. No instability was observed after repeated freezing and thawing or in processed samples. The assays were linear for coniine, cytisine, nicotine and its metabolite cotinine, from 50 to 1000 ng/ml using LC-APCI-MS and 1 to 1000 ng/ml using LC-ESI-MS/MS, respectively, and for aconitine, atropine, colchicine, physostigmine, and scopolamine from 5 to 100 ng/ml for LC-APCI-MS and 0.1 to 100 ng/ml for LC-ESI-MS/MS, respectively. Accuracy ranged from -38.6 to 14.0%, repeatability from 2.5 to 13.5%, and intermediate precision from 4.8 to 13.5% using LC-APCI-MS and from -38.3 to 8.3% for accuracy, from 3.5 to 13.8%, for repeatability, and from 4.3 to 14.7% for intermediate precision using LC-ESI-MS/MS. The lower limit of quantification was fixed at the lowest calibrator in the linearity experiments. With the exception of the greater sensitivity and higher identification power, LC-ESI-MS/MS had no major advantages over LC-APCI-MS. Both presented assays were applicable for sensitive detection of all studied analytes and for accurate and precise quantification, with the exception of the rather volatile nicotine. The applicability of the assays was demonstrated by analysis of plasma samples from suspected poisoning cases.     

Analysis of buprenorphine and its N-dealkylated metabolite in plasma and urine by selected-ion monitoring

A selected-ion monitoring method was developed for determination of buprenorphine and its N-dealkylated metabolite (norbuprenorphine) in human plasma and urine. N-Propylnorbuprenorphine was added as internal standard to 2-3 ml of sample and the alkaloids were extracted with toluene-2 butanol at pH 9.4. After back-extraction in dilute sulphuric acid, the compounds were heated at 110 degrees C. This procedure led to quantitative loss of methanol followed by ring formation between the 6-methoxy group and the branched side-chain of all compounds. The derivatives were extracted into dichloromethane-2-butanol and treated with pentafluoropropionic anhydride. The resulting derivatives were suitable for selected-ion monitoring analysis. The coefficient of variation was found to be 4.5% at 5 ng/ml and 8.9% at 50 ng/ml in urine. The corresponding values for plasma were 6.2% and 5.3%, respectively. The lower limit of detection in plasma was 150 pg/ml, permitting analysis of plasma levels of buprenorphine for 24 h and urine levels of buprenorphine and norbuprenorphine for more than seven days after a therapeutic dose of buprenorphine. This method is the first with sufficient specificity and sensitivity for characterization of the clinical pharmacokinetics of buprenorphine.     

Matrix Solid-Phase Dispersion for the HPLC–DAD Determination of Psychoactive Phenylpropylamino Alkaloids from Khat (Catha edulis Forsk) Chewing Leaves

A fast and simple procedure based on matrix solid-phase dispersion was developed for the extraction of psychoactive phenylpropylamino alkaloids; cathinone, cathine and norephedrine, from khat (Catha edulis Forsk) chewing leaves, a stimulant and drug of abuse plant. Determination of the alkaloids was carried out by high performance liquid chromatography with diode array detection. Several extraction parameters, such as type of dispersant, type and volume of elution solvent and the ratio of sample to sorbent material were evaluated and optimized. Mean recoveries ranging from 89 to 92 % with relative SD of less than 6 % were obtained. A marked diversity in the phenylpropylamino alkaloid content and composition was found in seventeen different cultivars of Ethiopian khat. ANOVA results showed the existence of significant differences between the alkaloids profiles among samples of different varieties from different geographical locations in Ethiopia. The proposed method is simpler, faster and comparably more efficient than the frequently reported maceration followed by liquid–liquid extraction but as good and efficient as ultrasonic assisted extraction followed by solid-phase extraction.     

高效液相色谱法测定化妆品中的泛酸及D-泛醇

建立了对不同基质化妆品(膏霜、乳液、水剂化妆品、油剂化妆品、蜡基化妆品、指甲油等)中泛酸(维生素B5)及D-泛醇(维生素原B5)的富集方法及同时测定的高效液相色谱(HPLC)法。利用水和与水不互溶的有机溶剂组成的双液相体系,首先将泛酸及D-泛醇与化妆品中油溶性成分及表面活性剂等基质成分初步分离,然后用亚铁氰化钾-乙酸锌共沉淀剂去除提取液中的水溶性成分,继而在酸性条件下将泛酸和D-泛醇富集于C18固相萃取填料上,脱除其他水溶性干扰物后,用40%甲醇水溶液洗脱,用HPLC分离,紫外检测器检测,外标法定量。该方法在泛酸和D-泛醇的含量为0.1～10 μg/g范围内有很好的线性,线性相关系数分别为0.9989和0.9996。不同化妆品基质中目标成分的方法回收率均在90%以上。对泛酸及D-泛醇的检出限均为30 μg/g,定量限均为100 μg/g。实验表明该方法可用于化妆品中泛酸及D-泛醇的同时测定,结果准确可靠。     

Gas chromatographic-electron-impact mass fragmentometric determination of lysergic acid diethylamide in urine

A sensitive method for the detection and quantitation of lysergic acid diethylamide (LSD) in urine was developed. After initial solvent extraction, the compound was further purified by liquid-liquid extraction or by solid-phase extraction. The trimethylsilyl derivative of LSD was detected by gas chromatography-mass spectrometry (GC-MS) operated in the electron-impact mode with selected-ion monitoring. The presence of LSD was confirmed by comparing retention times and relative abundances of ions of unknowns with that of a standard. The recovery of this procedure was greater than 89%. The intra-run and inter-run coefficients of variation were less than 5% and less than 7%, respectively. This procedure allows detection of LSD concentrations as low as 29 pg/ml. Quantitation of LSD was linear over the concentration range 50-2000 pg/ml.     

Analysis of polychlorinated biphenyls in aqueous samples by microwave-assisted headspace solid-phase microextraction

The hyphenated technique namely microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) was developed and studied for the simultaneous extraction/enrichment of polychlorinated biphenyls (PCBs) in aqueous samples prior to the quantification by gas chromatography (GC). The PCBs in aqueous media are extracted onto a solid-phase micro fibre via the headspace with the aid of microwave irradiation. The optimum conditions for obtaining extraction efficiency, such as the extraction time, addition of salts, addition of methanol, ratio of sample to headspace volume, and the desorption parameters were investigated. Experimental results indicated that the proposed MA-HS-SPME method attained the best extraction efficiency under the optimized conditions, i.e., irradiation of extraction solution (20 ml aqueous sample in 40 ml headspace vial with no additions of salt and methanol) under 30 W microwave power for 15 cycles (1 min power on and 3 min power off of each cycle). Desorption at 270 degrees C for 3 min provided the best detection results. The detection limit obtained were between 0.27 and 1.34 ng/l. The correlation coefficient for the linear dynamic range from 1 to 80 ng/l exceeded 0.99 for 18 PCBs.     

Development and Comprehensive SPE-UHPLC-MS/MS Analysis Optimization,Comparison, and Evaluation of 2,4-Epibrassinolide in Different Plant Tissues

A determination method for trace 24-epibrassinolide (EBL) in plant tissues was developed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). The plant tissue samples were extracted using a methanol–formic acid solution, and the corresponding supernatant was purified with ODS C18 solid-phase extraction column. The extracts were separated using a Zorbax Eclipse Plus C18 (2.1 mm × 50 mm, 1.8 μm) column with methanol and 0.1% formic acid as the mobile phase. The ion source for the mass spectrometry was an electrospray ionization source with positive ion mode detection. The linear range of the target compound was 0.7~104 μg/kg, the limit of detection (LOD) was 0.11~0.37 μg/kg, the limit of quantification (LOQ) was 0.36~1.22 μg/kg, the recovery rate was 84.0~116.3%, and the relative standard deviation (RSD%) was 0.8~10.5. The samples of maize plumule, brassica rapeseed flower, and marigold leaf were detected using the external standard method. The optimization of the extraction method and detection method of EBL improved the detection sensitivity, laid a foundation for the artificial synthesis of EBL, improved the extraction rate of EBL, and provided a theoretical basis for the study of EBL in many plants.     

Thin-layer chromatography-densitometry and liquid chromatography analysis of alkaloids in leaves of Papaver somniferum under stress conditions

The effect of stress conditions on the concentrations of secondary metabolites were examined during various developmental stages of Papaver somniferum plants. P. somniferum plants were grown in laboratory conditions (Budakalász). The experiment consisted of 22 treatments. Significantly different alkaloid contents can be observed under different stress conditions. In general, the alkaloid contents of plants are very low; therefore, a highly sensitive and reliable method has to be developed for analysis. The amount of alkaloids was measured by 2 separation and detection techniques. Accuracy of the thin-layer chromatography method for quantitative analysis is limited. Without purification of samples the background is too noisy. Column liquid chromatography is a sensitive and relatively inexpensive method that allows precise quantitative determination of the alkaloid content.     

Identification and metabolite profiling of alkaloids in aerial parts of Papaver rhoeas by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry

Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty‐five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine‐type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.