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31.
Eight extraction agents (water, methanol–water mixtures in various ratios, methanol, a 20 mmol l?1 ammonium phosphate buffer, and a methanol–phosphate buffer) were tested for the extraction of arsenic compounds from fruits, stems + leaves, and roots of pepper plants grown on soil containing 17.2 mg kg?1 of total arsenic. The arsenic compounds in the extracts were determined using high‐performance liquid chromatography–hydride generation inductively coupled plasma mass spectrometry. Whereas pure water was the most effective extraction agent for fruits (87 ± 3.3% extraction yield) and roots (96 ± 0.6% extraction yield), the 20 mM ammonium phosphate buffer at pH 6 extracted about 50% of the arsenic from stems + leaves. Decreasing extractability of the arsenic compounds was observed with increasing methanol concentrations for all parts of the pepper plant. In pepper fruits, arsenic(III), arsenic(V), and dimethylarsinic acid (DMA) were present (25%, 37%, and 39% respectively of the extractable arsenic). Arsenic(V) was the major compound in stems + leaves and roots (63% and 53% respectively), followed by arsenic(III) representing 33% and 42% respectively, and small amounts (not exceeding 5%) of DMA and methylarsonic acid were also detected. Hence, for a quantitative extraction of arsenic compounds from different plant tissues the extractant has to be optimized individually. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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33.
Detection of pyridaben residue levels in hot pepper fruit and leaves by liquid chromatography–tandem mass spectrometry: effect of household processes
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Sung‐Woo Kim A. M. Abd El‐Aty Md. Musfiqur Rahman Jeong‐Heui Choi Ok‐Ja. Choi Gyu‐Seek Rhee Moon‐Ik Chang Heejung Kim Morad D. N. Abid Sung Chul Shin Jae‐Han Shim 《Biomedical chromatography : BMC》2015,29(7):990-997
Following quick, easy, cheap, effective, rugged and safe (QuEChERS) and LC/MS/MS analysis, pyridaben residual levels were determined in unprocessed and processed hot pepper fruit and leaves. The linearities were satisfactory with determination coefficients (R2) in excess of 0.995 in processed and unprocessed pepper fruit and leaves. Recoveries at various concentrations were 79.9–105.1% with relative standard deviations ≤15%. The limits of quantitation of 0.003–0.012 mg/kg were very low compared with the maximum residue limits (2–5 mg/kg) set by the Ministry of Food and Drug Safety, Republic of Korea. The effects of various household processes, including washing, blanching, frying and drying under different conditions (water volume, blanching time and temperature) on residual concentrations were evaluated. Both washing and blanching (in combination with high water volume and time factor) significantly reduced residue levels in hot pepper fruit and leaves compared with other processes. In sum, the developed method was satisfactory and could be used to accurately detect residues in unprocessed and processed pepper fruit and leaves. It is recommended that pepper fruit/leaves be blanched after washing before being consumed to protect consumers from the negative health effects of detected pesticide residues. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Samantha Reale Alessandra Biancolillo Chiara Gasparrini Luciano Di Martino Valter Di Cecco Aurelio Manzi Marco Di Santo Angelo Antonio DArchivio 《Molecules (Basel, Switzerland)》2021,26(20)
Dried and ground red pepper is a spice used as seasoning in various traditional dishes all over the world; nevertheless, the pedoclimatic conditions of the diverse cultivation areas provide different chemical characteristics, and, consequently, diverse organoleptic properties to this product. In the present study, the volatile profiles of 96 samples of two different ground bell peppers harvested in diverse Italian geographical areas, Altino (Abruzzo) and Senise (Lucania), and a commercial sweet paprika, have been studied by means of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The investigation of their volatile profile has led to the identification of 59 analytes. Eventually, a discriminant classifier, Partial Least Squares Discriminant Analysis (PLS-DA), was exploited to discriminate samples according to their geographical origin. The model provided very accurate results in external validation; in fact, it correctly classified all the 30 test samples, achieving 100% correct classification (on the validation set). Furthermore, in order to understand which volatiles contribute the most at differentiating the bell peppers from the different origins, a variable selection approach, Variable Importance in Projection (VIP), was used. This strategy led to the selection of sixteen diverse compounds which characterize the different bell pepper spices. 相似文献
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外源Ca2+、La3+和EGTA处理对辣椒叶片热激反应的影响 总被引:4,自引:0,他引:4
以湘研十号辣椒为材料 ,研究了外源 Ca2 、L a3 和 EGTA处理对热胁迫下叶片生理代谢的影响 .结果表明 :Ca2 处理能降低热胁迫下细胞质膜的透性 ,而 L a3 和 EGTA处理略增加了细胞质膜透性 ;Ca2 处理能够降低 As A和 GSH在热胁迫下的氧化 ,而 L a3 和 EGTA处理却没有这种作用 ;Ca2 处理的叶绿素 a和叶绿素 b在热胁迫下降解较慢 ,L a3 和 EGTA处理的则降解较快 .本文认为 ,Ca2 处理能够提高辣椒叶片的抗热性 ,而 L a3 和 EGTA处理却在一定程度上降低了其抗热性 . 相似文献
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Rattanaporn Wansri Aye Chan Khine Lin Jutharat Pengon Sumalee Kamchonwongpaisan Nitipol Srimongkolpithak Roonglawan Rattanajak Patcharin Wilasluck Peerapon Deetanya Kittikhun Wangkanont Kowit Hengphasatporn Yasuteru Shigeta Jatupol Liangsakul Aphinya Suroengrit Siwaporn Boonyasuppayakorn Taksina Chuanasa Wanchai De-eknamkul Supot Hannongbua Thanyada Rungrotmongkol Supakarn Chamni 《Molecules (Basel, Switzerland)》2022,27(9)
Piper nigrum, or black pepper, produces piperine, an alkaloid that has diverse pharmacological activities. In this study, N-aryl amide piperine analogs were prepared by semi-synthesis involving the saponification of piperine (1) to yield piperic acid (2) followed by esterification to obtain compounds 3, 4, and 5. The compounds were examined for their antitrypanosomal, antimalarial, and anti-SARS-CoV-2 main protease activities. The new 2,5-dimethoxy-substituted phenyl piperamide 5 exhibited the most robust biological activities with no cytotoxicity against mammalian cell lines, Vero and Vero E6, as compared to the other compounds in this series. Its half-maximal inhibitory concentration (IC50) for antitrypanosomal activity against Trypanosoma brucei rhodesiense was 15.46 ± 3.09 μM, and its antimalarial activity against the 3D7 strain of Plasmodium falciparum was 24.55 ± 1.91 μM, which were fourfold and fivefold more potent, respectively, than the activities of piperine. Interestingly, compound 5 inhibited the activity of 3C-like main protease (3CLPro) toward anti-SARS-CoV-2 activity at the IC50 of 106.9 ± 1.2 μM, which was threefold more potent than the activity of rutin. Docking and molecular dynamic simulation indicated that the potential binding of 5 in the 3CLpro active site had the improved binding interaction and stability. Therefore, new aryl amide analogs of piperine 5 should be investigated further as a promising anti-infective agent against human African trypanosomiasis, malaria, and COVID-19. 相似文献
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《Analytical letters》2012,45(16):2583-2596
Molecularly imprinted polymers grafted on to the surface of carboxyl-modified multiwalled carbon nanotubes were developed using methacrylic acid as a functional monomer and trihydroxymethylpropyl trimethylacrylate as a crosslinker for application to rhodamine B determination. The synthesis, characteristics, and evaluation of the molecularly imprinted polymer are described. The apparent morphology of the polymers was characterized by scanning electron microscopy. To evaluate the binding ability of the molecularly imprinted polymers, equilibrium binding experiments were conducted and revealed the maximal binding capacity to be 561.54 µg g?1. The introduction of nanomaterials into the polymer composite made important contributions to the affinity enhancement and recognition properties of the molecularly imprinted polymers. Moreover, the polymers were preliminarily applied as an adsorbent for separation and extraction of Rhodamine B from dried chili powder samples, based on solid phase extraction technology. The calibration curve was linear in the range of 0–7 µg mL?1. For all tested samples, recoveries were reliable and in the range of 101.75–109.73%. The relative standard deviation ranged from 6.43–14.32%, which demonstrated that the polymer has potential for preconcentration of Rhodamine B from chili powder samples. 相似文献
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Simultaneous determination and method validation of difenoconazole,propiconazole and pyraclostrobin in pepper and soil by LC–MS/MS in field trial samples from three provinces,China
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《Biomedical chromatography : BMC》2018,32(2)
A liquid chromatography–electrospray ionization tandem mass spectrometry method was developed for simple and accurate detection of the fungicides difenoconazole, propiconazole and pyraclostrobin in peppers and soil. Three fungicides residues were extracted from samples by acetonitrile and cleaned up by dispersive solid‐phase extraction before instrumental analysis. The accuracy and precision of the method were evaluated by conducting an intra‐ and inter‐day recovery experiment. The limits of quantification and detection of difenoconazole, propiconazole and pyraclostrobin in pepper and soil were 0.005 and 0.0015 mg/kg, respectively. The recoveries were investigated by spiking pepper and soil at three levels, and were found to be in the ranges 79.62–103.15% for difenoconazole, 85.94–103.35% for propiconazole and 80.14–97.69% for pyraclostrobin, with relative standard deviations <6.5%. Field experiments were conducted in three locations in China. The half‐lives of difenoconazole, propiconazole and pyraclostrobin were 5.3–11.5 days in peppers and 6.1–32.5 days in soil. At harvest, pepper samples were found to contain difenoconazole, propiconazole and pyraclostrobin well below the maximum residue limits of European Union at the interval of 21 days after last application following the recommended dosage. 相似文献
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Phunsuk Anantaworasakul Songyot Anuchapreeda Songwut Yotsawimonwat Ornchuma Naksuriya Suree Lekawanvijit Napatra Tovanabutra Pimporn Anantaworasakul Wajee Wattanasri Narinthorn Buranapreecha Chadarat Ampasavate 《Molecules (Basel, Switzerland)》2020,25(23)
Capsaicin is an active compound in chili peppers (Capsicum chinense) that has been approved for chronic pain treatment. The topical application of high-strength capsaicin has been proven to reduce pain; however, skin irritation is a major drawback. The aim of this study was to investigate an appropriate and scalable technique for preparing nanostructured lipid carriers (NLCs) containing 0.25% capsaicin from capsicum oleoresin (NLC_C) and to evaluate the irritation of human skin by chili-extract-loaded NLCs incorporated in a gel formulation (Gel NLC_C). High-shear homogenization with high intensity (10,000 rpm) was selected to create uniform nanoparticles with a size range from 106 to 156 nm. Both the NLC_C and Gel NLC_C formulations expressed greater physical and chemical stabilities than the free chili formulation. Release and porcine biopsy studies revealed the sustained drug release and significant permeation of the NLCs through the outer skin layer, distributing in the dermis better than the free compounds. Finally, the alleviation of irritation and the decrease in uncomfortable feelings following the application of the Gel NLC_C formulation were compared to the effects from a chili gel and a commercial product in thirty healthy volunteers. The chili-extract-loaded NLCs were shown to be applicable for the transdermal delivery of capsaicin whilst minimizing skin irritation, the major noncompliance cause of patients. 相似文献
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高效液相色谱-串联质谱法测定辣椒及辣椒制品中金刚烷胺残留 总被引:3,自引:0,他引:3
建立了高效液相色谱-串联质谱(HPLC-MS/MS)测定辣椒及辣椒制品中金刚烷胺残留的分析方法。样品采用1%三氯乙酸溶液-甲醇(1∶1)提取,经Oasis-MCX固相萃取小柱净化后用Atlantis T3 C18柱进行分离,以0.1%甲酸水-乙腈(85∶15)作为流动相进行等度洗脱,电喷雾正离子(ESI+)扫描方式下多反应监测(MRM)模式对样品进行检测。实验结果表明,金刚烷胺在1.0~50μg/kg范围内线性关系良好,鲜辣椒样品的定量下限为1.0μg/kg,干辣椒及干辣椒制品为5.0μg/kg。鲜辣椒在1.0,2.0,5.0μg/kg加标水平下的回收率为72.2%~98.2%,相对标准偏差(n=6)为1.2%~4.6%;干辣椒及干辣椒制品在5.0,10.0,25.0μg/kg加标水平的回收率为64.2%~81.6%,相对标准偏差(n=6)为1.3%~6.3%。该方法操作简单、灵敏度高、重现性好,可用于辣椒及辣椒制品中金刚烷胺残留量的检测。 相似文献