Decaffeination and Neuraminidase Inhibitory Activity of Arabica Green Coffee (Coffea arabica) Beans: Chlorogenic Acid as a Potential Bioactive Compound

Coffee has been studied for its health benefits, including prevention of several chronic diseases, such as type 2 diabetes mellitus, cancer, Parkinson’s, and liver diseases. Chlorogenic acid (CGA), an important component in coffee beans, was shown to possess antiviral activity against viruses. However, the presence of caffeine in coffee beans may also cause insomnia and stomach irritation, and increase heart rate and respiration rate. These unwanted effects may be reduced by decaffeination of green bean Arabica coffee (GBAC) by treatment with dichloromethane, followed by solid-phase extraction using methanol. In this study, the caffeine and chlorogenic acid (CGA) level in the coffee bean from three different areas in West Java, before and after decaffeination, was determined and validated using HPLC. The results showed that the levels of caffeine were reduced significantly, with an order as follows: Tasikmalaya (2.28% to 0.097% (97 ppm), Pangalengan (1.57% to 0.049% (495 ppm), and Garut (1.45% to 0.00002% (0.2 ppm). The CGA levels in the GBAC were also reduced as follows: Tasikmalaya (0.54% to 0.001% (118 ppm), Pangalengan (0.97% to 0.0047% (388 ppm)), and Garut (0.81% to 0.029% (282 ppm). The decaffeinated samples were then subjected to the H5N1 neuraminidase (NA) binding assay to determine its bioactivity as an anti-influenza agent. The results show that samples from Tasikmalaya, Pangalengan, and Garut possess NA inhibitory activity with IC₅₀ of 69.70, 75.23, and 55.74 μg/mL, respectively. The low level of caffeine with a higher level of CGA correlates with their higher levels of NA inhibitory, as shown in the Garut samples. Therefore, the level of caffeine and CGA influenced the level of NA inhibitory activity. This is supported by the validation of CGA-NA binding interaction via molecular docking and pharmacophore modeling; hence, CGA could potentially serve as a bioactive compound for neuraminidase activity in GBAC.     

Quantification of Total Phenols and Antioxidants in Coffee Samples of Different Origins and Evaluation of the Effect of Degree of Roasting on Their Levels

Phenolic and antioxidant compounds have received considerable attention due to their beneficial effects on human health. The aim of this study is to determine the content of total phenols and antioxidants in fifty-two coffee samples of different origins, purchased from the Jordanian local market, and investigate the effect of the degree of roasting on the levels of these compounds. The coffee samples were extracted using the hot water extraction method, while Folin–Ciocalteu (FC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay methods were used to analyze these compounds. The results showed that the highest content of total phenol (16.55 mg/g equivalent to GAE) was found in the medium roasted coffee, and the highest content of antioxidants (1.07 mg/g equivalent to TEAC) content was found in the green coffee. Only light and medium roasted coffee showed a significant correlation (p < 0.05, R² > 0.95) between the average of total phenolic and antioxidant content. A negative correlation between the antioxidant content and the degree of roasting (p < 0.05, R² > 0.95) were shown, while it did not correlate with phenolic contents. Previously, a positive correlation between antioxidant and chlorogenic acids content was observed, with no correlation between the origin of coffee samples nor heavy metal content, which was previously determined for the same coffee samples. These findings suggest that the antioxidant content for coffee extracts is largely determined by its chlorogenic acid content, rather than the coffee origin or total phenolic and heavy metals content.     

Determination of Chlorogenic Acid in a Herbal Medicinal Product with Preconcentration by Ionic Liquid-Modified Magnetic Nanoparticles and High-Performance Liquid Chromatography

Magnetic nanoparticles (MNPs) have been widely used in herbal analysis, and potential ionic liquid-based MNPs are expected in similar applications. In this study, the new functional Fe₃O₄ nanoparticles combined with a previously unreported ionic liquid were synthesized by three methods and used to enrich chlorogenic acid from aqueous solution and crude herbal extracts for the first time. The combination of pyrrole cation and proline anion immobilized on Fe₃O₄ nanoparticles had higher immobilized concentrations and ideal morphology, which can be easily adsorbed and recovered by an external magnetic field from the nanosuspension. When the mobile phase composed of acetonitrile and 0.5% phosphate aqueous solution (3:22, v:v) was used on a C₁₈ chromatographic column (4.6?×?250?mm, 5?µm) at 25°C, the concentration of chlorogenic acid in herbal product was determined to be 7.01?mg/g. The validation indicated the method had good linearity, recovery, repeatability, and precision. These results show that the ionic liquid has been chemically bonded to the magnetic nanoparticles through the developed procedures and may be effectively used for the high-performance liquid chromatographic determination of chlorogenic acid in herbal products.     

Quantification of Major Bioactive Constituents,Antioxidant Activity,and Enzyme Inhibitory Effects of Whole Coffee Cherries (Coffea arabica) and Their Extracts

Coffee cherry is a rich source of chlorogenic acids (CGAs) and caffeine. In this study we examined the potential antioxidant activity and enzyme inhibitory effects of whole coffee cherries (WCC) and their two extracts on α-amylase, α-glucosidase and acetylcholinesterase (AChE) activities, which are targets for the control of diabetes and Alzheimer’s diseases. Whole coffee cherry extract 40% (WCCE1) is rich in chlorogenic acid compounds, consisting of a minimum of 40% major isomers, namely 3-caffeoylquinic acids, 4-caffeoylquinic acids, 5-caffeoylquinic acids, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, 4-feruloylquinc acid, and 5-feruloylquinc acid. Whole coffee cherry extract 70% (WCCE2) is rich in caffeine, with a minimum of 70%. WCCE1 inhibited the activities of digestive enzymes α-amylase and α-glucosidase, and WCCE2 inhibited acetylcholinesterase activities with their IC₅₀ values of 1.74, 2.42, and 0.09 mg/mL, respectively. Multiple antioxidant assays—including DPPH, ABTS, FRAP, ORAC, HORAC, NORAC, and SORAC—demonstrated that WCCE1 has strong antioxidant activity.     

RP-HPLC法测定烟草中绿原酸含量的研究

采用超声波提取、反相高效液相色谱测定烟叶中绿原酸,用内标法进行定量,并对超声波提取烟叶中绿原酸的提取条件进行了优化,结果表明:用60%的乙醇溶液,在50 ℃、pH 4条件下,超声提取 45 min效果最佳.该法具有良好的线性(相关系数为0.999 9),检测限为 1.4×10-2 mg/10 mL (S/N=3) 加标回收率为 101.5%,方法RSD为1.58%.方法快速、简单、准确.     

场放大进样-扫集胶束电动色谱法测定金银花中的咖啡酸与绿原酸

以场放大进样-扫集胶束电动色谱法( FASI - sweeping-MEKC)测定了金银花中的咖啡酸、绿原酸.考察了SDS浓度、进样电压、进水时间与进样时间比值、进样时间以及缓冲液组成对分离效果的影响.最佳分离条件为:采用未涂层熔融石英毛细管(50 cm × 50 μm,有效柱长33 cm),缓冲体系为100 mmol...     

The Effect of Brewing Process Parameters on Antioxidant Activity and Caffeine Content in Infusions of Roasted and Unroasted Arabica Coffee Beans Originated from Different Countries

Coffee is one of the most often consumed beverages almost all over the world. The multiplicity of beans, as well as the methods and parameters used to brew, encourages the optimization of the brewing process. The study aimed to analyze the effect of roasting beans, the brewing technique, and its parameters (time and water temperature) on antioxidant activity (determined using several in vitro methods), total polyphenols, flavonoids, and caffeine content. The infusions of unroasted and roasted Arabica beans from Brazil, Colombia, India, Peru, and Rwanda were analyzed. In general, infusions prepared from roasted beans had higher antioxidant activity and the content of above-mentioned compounds. The hot brew method was used to obtain infusions with a higher antioxidant activity, while the cold brew with higher caffeine content. The phenolic compound content in infusions prepared using both techniques depended on the roasting process. Moreover, the bean’s origin, roasting process, and brewing technique had a significant effect on the tested properties, in contrary to brewing time and water temperature (below and above 90 °C), which had less impact. The results confirm the importance of coffee brewing optimization.     

反相高效液相色谱法同时分离测定杜仲雄花及其产品中的 京尼平苷酸和绿原酸

建立了利用反相高效液相色谱法（RP-HPLC）同时测定杜仲雄花及其产品中京尼平苷酸和绿原酸的方法。所用的色谱柱为Shim-pack VP-ODS(150 mm×4.6 mm,5 μm),流动相组成为甲醇-水-乙酸(体积比为24∶75∶1),检测波长为240 nm。在该色谱条件下,京尼平苷酸的含量在0.025~0.400 g/L、绿原酸的含量在0.075~1.200 g/L范围内线性关系良好,相关系数分别为0.9997和0.9999;加标回收率分别为100.2%和100.5%。该法适用于杜仲雄花及其产品中这2种成分的含量分析。     

超声波萃取-高效液相色谱测定咖啡粉和速溶咖啡中的葫芦巴碱

建立了高效液相色谱测定咖啡粉和速溶咖啡中葫芦巴碱含量的方法。采用Waters BondPak NH2色谱柱(250 mm×4.6 mm, 5 μm),以甲醇-水(82:18, v/v)为流动相,流速0.8 mL/min,检测波长260 nm。葫芦巴碱线性范围为1～40 mg/L (相关系数为0.9998)。分别进行日内、日间和人员比对测定葫芦巴碱的重复性试验及加标回收率试验。经测定,样品的加标回收率大于90%,相对标准偏差小于3%。比较了超声波萃取和热浸提萃取方法测定葫芦巴碱含量的差异,两个方法的测定结果符合线性关系,相关系数为0.9964。该法简便、快速、灵敏度高,适用于咖啡豆中葫芦巴碱分析以及咖啡豆原料与制品的质量控制。     

食品中甲硝唑残留的碳纳米管固相萃取-高效液相色谱法测定

建立了以多壁碳纳米管为固相萃取吸附剂分离富集牛奶、鸡蛋以及蜂蜜中的甲硝唑残留,并用高效液相色谱法测定的分析方法。考察了碳纳米管对甲硝唑的吸附效果,洗脱剂的种类及其用量、碳纳米管的长度及大小和上样速率对萃取率的影响,优化了固相萃取条件。在优化实验条件下,方法的线性范围为0.01~10 mg/L,检出限为0.25μg/kg;对3种实际样品分别进行1、10、50μg/kg 3种水平下的加标回收实验,样品回收率为68%~112%,RSD为3.3%~17.1%,定量下限为0.8μg/kg。方法灵敏度高、简便快速且成本低,符合食品中低浓度兽药残留的分析方法要求。     

生物样品中短链脂肪酸的提取与测定

综述了生物样品(主要为粪便、尿液、血液和培养液)中短链脂肪酸的提取与测定方法,讨论了各种样品提取方法的优缺点,并比较了气相色谱、高效液相色谱和毛细管电泳分离检测的优点和局限性。引用文献63篇。     

分散固相萃取-高效液相色谱法测定水产品中7种麻醉剂

随着麻醉剂广泛用于渔业生产过程和水产品运输等领域,建立水产品中麻醉剂残留的检测方法具有重要意义.由于水产品基质复杂且麻醉剂残留水平低,因此需要合适的前处理方法以提高检测灵敏度.该研究基于分散固相萃取-高效液相色谱,建立了一种同时检测水产品中普鲁卡因、丁氧卡因、三卡因、丁香酚、甲基丁香酚、异丁香酚、甲基异丁香酚7种麻醉剂...     

Determination of Hydroxy-2-ethylenediaminetriacetic Acid (HEEDTA) and Fe-HEEDTA in Nutrient Solutions by Ion-Pair Reversed-Phase High-Performance Liquid Chromatography

A reversed-phase ion-pair liquid chromatography method for the accurate detection and determination of hydroxy-2-ethylenediaminetriacetic acid (HEEDTA) and Fe-HEEDTA has been developed. Three mobile phases containing 0.05 M tetrabutylammonium hydroxide, 0.05 M tetrabutylammonium bromide, or 0.05 M tetrabutylammonium bromide + phosphate buffer were employed in this method. Iron was added to each mobile phase after addition of the selected ion pair reagent to determine the amount of HEEDTA in both the free and/or the metal chelated forms at concentrations as low as 50 μM. The method depends on the formation of the iron chelate with HEEDTA in the mobile phase at pH 7. Calculation of the amounts of chelated HEEDTA with iron in the mobile phase was verified using the Geochem-PC computer program, which showed that 99.95% of HEEDTA was chelated to iron at pH 7.     

高效液相色谱-串联质谱法分离鉴定绿原酸及其相关杂质

建立了高效液相色谱-串联质谱法（HPLC-MS/MS)分离和鉴定绿原酸及其相关杂质的方法。采用C18色谱柱(5 μm,4.6 mm×150 mm),乙腈-水（含0.1%甲酸）(体积比为8∶92)为流动相,经HPLC-MS/MS和HPLC-二极管阵列检测器在线检测,对工业绿原酸中的奎尼酸、咖啡酸、绿原酸同分异构体等8个相关杂质的结构进行了鉴定。     

固相萃取/高效液相色谱法测定茶油中的多种天然酚类物质

建立了同时分离、检测茶油中23种酚类物质的高效液相色谱方法.比较了液液萃取、固相萃取两种方法的提取效果,并优化了流动相、检测波长、进样量等参数.23种酚类物质在优化条件下均可有效分离,并在0.059～9.115μg/g范围内具有良好的线性关系,相关系数为0.9776～1.0000,检出限为0.041～0.379μg/g...     

Application of d-SPE before SPE and HPLC-FLD to Analyze Bisphenols in Human Breast Milk Samples

In this study, we propose a simple, cost-effective, and sensitive high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous determination of seven bisphenols (bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB), BADGE (bisphenol A diglycidyl ether), BADGE∙2H₂O, BADGE∙H₂O, BADGE∙2HCl) in human breast milk samples. The dispersive solid phase extraction (d-SPE) coupled with solid phase extraction (SPE) procedure performed well for the majority of the analytes with recoveries in the range 57–88% and relative standard deviations (RSD%) of less than 9.4%. During the d-SPE stage, no significant matrix effect was observed thanks to the application of different pairs of salts such as zirconium-dioxide-based sorbents (Z-Sep or Z-Sep +) and primary secondary amine (PSA) or QuEChERS Enhanced Matrix Removal-Lipid (EMR-Lipid) and PSA. The method limits of quantification (mLOQs) for all investigated analytes were set at satisfactory low values in the range 171.89–235.11 ng mL⁻¹. Analyte concentrations were determined as the average value from human breast milk matrix samples. The results show that the d-SPE/SPE procedure, especially with the application of EMR-Lipid and PSA, could be used for further bisphenol analyses in human breast milk samples.     

高效液相色谱法测定大鼠血浆中的原儿茶酸

建立了大鼠血浆中原儿茶酸含量测定的高效液相色谱方法。采用的色谱柱为DiamondsilTM C18 柱(150 mm×4.6 mm,5 μm);流动相为乙腈-水(体积比为9∶91,用H3PO4 调pH至2.5);流速1.2 mL/min;检测波长260 nm;内标为对羟基苯甲酸。原儿茶酸的线性范围为0.050~3.20 mg/L,线性相关系数为0.9978，最低定量限为0.050 mg/L,日内和日间测定的精密度（以相对标准偏差表示）均低于7.0%,准确度（以相对误差表示）为-1.4%～2.6%；在0.050,0.40,3.20 mg/L低、中、高3个添加浓度水平下，血浆样品的提取回收率分别为83.4%,87.3%,91.1%。该方法简便,灵敏,准确,适用于大鼠体内原儿茶酸的药物动力学研究。     

绿原酸亲水性磁性分子印迹树脂的合成及其固相萃取性能评价

以绿原酸（CGA）为模板分子、间苯二酚和三聚氰胺为双功能单体、甲醛为交联剂在磁性介孔二氧化硅（Fe₃O₄@mSiO₂）的介孔中一步聚合形成亲水性磁性分子印迹树脂（MMIRs）。除去mSiO₂载体后，MMIRs具有多孔结构且印迹位点位于材料表面。透射电镜、傅里叶变换红外光谱、振动样品磁强计、热重分析和水接触角实验表明：分子印迹聚合物层成功地包覆在Fe₃O₄表面，MMIRs具有良好的亲水性和磁固相萃取性能。MMIRs对CGA具有较强的吸附容量（50.87 mg/g）、较快的吸附速率（吸附平衡时间70 min）和较好的特异性吸附性能。将MMIRs用于杜仲黑茶中CGA的选择性分离，采用高效液相色谱分析检测，检出限为0.7 mg/L，回收率为93.1%~109.4%，相对标准偏差（RSD）小于9.6%。结果表明MMIRs可简单、快速、高选择性地分离富集复杂水体系样品中的CGA。     

反相高效液相色谱法分离测定烟草中的多酚类化合物

对植物中9种多酚类化合物的色谱分离条件进行了优化,分别探讨了流动相组成、流动相中醋酸浓度、醋酸溶液与甲醇的比例对保留时间的影响,确定了梯度分离条件,并对9种天然多酚类化合物进行了定量分析。该方法的检测限为13.26~59.29 mg/kg (S/N=3)。在3.0～100.0 mg/L 范围内呈良好的线性关系,相关系数r2为 0.9979~0.9999。9种待测化合物的加标回收率为96.8%~108%,相对标准偏差(RSD)小于3.8% (n=3)。用80%甲醇超声提取烟草样品,并通过优化的色谱条件对其进行分析,测定了实际烟草样品中芸香苷和绿原酸的含量。结果表明,该方法具有一定的实用价值。     

Determination of Explosives in Water Using Disposable Pipette Extraction and High Performance Liquid Chromatography

The use of disposable pipette extraction was examined for the simple and rapid determination of seven high explosives (cyclotrimethyl-enetrinitramine, cyclotetramethyl-enetetranitramine, 2,4,6-trinitrophenyl-methylnitramine, 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, nitroglycerin, and pentaerythritol tetranitrate) in water. The current study involved the determination of slightly polar and nonpolar explosives in water with a reversed phase sorbent followed by high performance liquid chromatography. The method was based on a styrene divinylbenzene sorbent loosely placed inside a 5-mL pipette tip. Water samples were drawn into the tip and mixed with the sorbent. Air bubbles were also drawn through the tip following sample solution to enhance mixing. Because disposable pipette extraction uses small amounts of sorbent, minimal solvent is required to elute analytes and solvent evaporation is not necessary. The method provided rapid sample preparation, and required less than five minutes to extract 1.0 mL of water sample in the current study. Matrix-matched calibration was performed, and the limits of detection (LOD) were determined to be below 0.1 µg mL^?1 for all targeted explosives in water with an enrichment factor of two. Coefficients of determination (r²) were greater than 0.9990 for all studied explosives, and the recoveries ranged from 69.76% to 87.51%, 83.77% to 91.25%, and 83.62% to 98.99% for samples spiked at 0.25 µg mL^?1, 1.0 µg mL^?1, and 5.0 µg mL^?1, respectively. The relative standard deviations of recoveries at all spiked levels were below 8.97%. These results indicate that the disposable pipette extraction method provided good accuracy and precision for the determination of explosives in water.