HPLC Column Research Articles

A new dihydrostilbene from aerial part of Cannabis sativa

The present study investigated the chemical constituents in the aerial part of Cannabis sativa. The chemical constituents were isolated and purified by silica gel column chromatography and HPLC and identified according to their spectral data and physicochemical properties. Thirteen compounds were isolated from the acetic ether extract of C. sativa and identified as 3',5',4″,2-tetrahydroxy-4'-methoxy-3-methyl-3″-butenyl p-disubstituted benzene ethane(1), 16R-hydroxyoctadeca-9Z,12Z,14E-trienoic acid methyl ester(2),(1'R,2'R)-2'-(2-hydroxypropan-2-yl)-5'-methyl-4-pentyl-1',2',3',4'-tetrahydro-(1,1'-biphenyl)-2,6-diol(3), β-sitosteryl-3-O-β-D-glucopyranosyl-6'-O-palmitate(4), 9S,12S,13S-trihydroxy-10-octadecenoate methyl ester(5), benzyloxy-1-O-β-D-glucopyranoside(6), phenylethyl-O-β-D-glucopyranoside(7), 3Z-enol glucoside(8), α-cannabispiranol-4'-O-β-D-glucopyranose(9), 9S,12S,13S-trihydroxyoctadeca-10E,15Z-dienoic acid(10), uracil(11), o-hydroxybenzoic acid(12), and 2'-O-methyladenosine(13). Compound 1 is a new compound, compound 3 is a new natural product, and compounds 2, 4-8, 10, and 13 were isolated from Cannabis plant for the first time.

LC-MS/MS Analytical Method for Determination of Montelukast in Human Plasma and its Application to a Bioequivalence Study

Background: This study aimed to develop a sensitive, rapid method based on HPLC-MS/MS for the quantification of Montelukast in human plasma utilizing Montelukast-D6 as an internal standard. Montelukast is a leukotriene inhibitor and is used to prevent asthma attacks in adults and children. Method: Separation was achieved using Thermo Hypersil GOLD™ Cyano HPLC columns (50 × 4.6 mm; 5 μm) with a mobile phase consisting of 0.5 mM ammonium chloride: ACN (20:80%; v/v). Results: The method was found to be linear over a concentration range of 10.0 - 600.0 ng/mL with a correlation coefficient (r2) ≥ 0. 0.9989. The stabilities of Montelukast and internal standard were assessed in several conditions with recovery results > 85%. The precision results were less than 4.0%, while the accuracy results were within 93.0 107.0%. The method proved to be selective with no matrix effect. Conclusion: This method was found to be highly reproducible and was utilized successfully for the analysis of plasma samples following the oral administration of Montelukast (10 mg) in 28 healthy male human volunteers.

Separation of chiral compounds using high performance liquid chromatography stationary phase based on covalent organic framework material TpPa-NH2-Glu

Covalent organic frameworks （COFs） are an emerging class of porous crystalline materials composed of multidentate organic units connected by covalent bonds. COFs have been demonstrated to exhibit great potential and research value in many fields， including gas storage and separation， photoelectric devices， fluorescence sensors， catalysis， drug delivery， dye and pollutant adsorption， and electronic devices， and so on. The COFs obtained by post-synthesis modification tend to exhibit high crystallinities and porosities， thereby rendering them suitable materials for use in the fields of chiral resolution， asymmetric catalysis， and chromatography. In this work， TpPa-NO2 was synthesized from 1，3，5-tricarbaldehyde phloroglucinol and 2-nitro-1，4-phenylenediamine， which was then reduced to TpPa-NH2. Subsequently， this material was modified with D-glucose via a post-synthesis modification strategy to obtain the TpPa-NH2-Glu. TpPa-NH2-Glu were characterized by nuclear magnetic resonance （NMR） spectroscopy， Fourier transform-infrared （FT-IR） spectroscopy， X-ray powder diffraction （XRD） analysis， etc. In the XRD pattern， the peaks observed at 4.7°， 8.1°， 11.1°， and 27° were attributed to the TpPa-NH2-Glu， and these peaks are consistent with previous reports， thereby confirming the successful synthesis of this derivative. In addition， circular dichroism experiments indicated that the TpPa-NH2-Glu exhibited a Cotton effect， further confirming the chiral COF was prepared. Subsequently， this material was immobilized on the surface of spherical silica gel particles via the net-wrapping method to prepare a stationary phase for high performance liquid chromatographic column. Using n-hexane-isopropanol （9∶1， v/v） or methanol-water （9∶1， v/v） as mobile phases at a flow rate of 0.5 mL/min， 16 racemates and two benzene-based positional isomers （o，m，p-nitroaniline and o，m，p-Iodoaniline） were successfully resolved by this chiral column. In addition， under methanol-water （9∶1， v/v） mobile phase conditions， five racemates were separated， among which propranolol hydrochloride， warfarin， and metoprolol reached baseline separation. Furthermore， under n-hexane-isopropanol （9∶1， v/v） mobile phase conditions， 11 racemates were resolved， among which ethyl 2-bromopropionate and 3-butyn-2-ol reached baseline separation. Meanwhile， the effect of temperature on the TpPa-NH2-Glu liquid chromatography column and the repeatability of the TpPa-NH2-Glu liquid chromatography column were also explored. The HPLC column prepared by TpPa-NH2-Glu had good repeatability， and its relative standard deviation （RSD） was 1.55% and 1.46%， respectively. It is demonstrated that the TpPa-NH2-Glu material has good resolution ability for chiral compounds.

An improved and sensitive method for nitrotyrosine estimation by reverse phase-high performance liquid chromatography

Reactive nitrogen species such as peroxynitrite anion (ONOO-), nitrogen oxide radical (NO.) may lead to nitrotyrosine formation by oxidative nitration of tyrosine. Nitrotyrosine is considered as an important marker to estimate the severity of biological oxidative damage. Therefore, in the present study, we evaluated a reverse phase-high performance liquid chromatography (RP-HPLC) method to improve the sensitivity and specificity of the nitrotyrosine estimation. The mobile phase used in the present study was methanol (pH 4.7) and 0.1% phosphoric acid (60:40%). The standard serial dilutions were injected onto the HPLC column (C-18) at a flow rate of 1 ml/min mobile phase with a time window of 6 min. The results were monitored on the Diode Array detector at wavelength 210 nm. The evaluation and quantification of output signals were made on the Chromelion software version 6.80 which controls the whole liquid chromatography system. The same standard serial dilutions were monitored spectrophotometrically at 210nm. We found the standard curves were linear over the concentration range of 0.3 to 20 ng/ml for both RP-HPLC with UV detector (r2 = 0.997) and spectrophotometric (r2 = 0.999) methods. In spectrophotometric method, only four standard points were detected out of seven and represented on a straight line, this shows the spectrophotometric method was unable to measure less than 2.5 ng/ml concentration. On the other hand, in RP-HPLC method, all the seven standards were lying on a straight line and HPLC machine can detect up to 1ng/ml or 1pg/µl. The present study established the highly specific, sensitive, accurate and cost-effective RP-HPLC with UV detector method for nitrotyrosine estimation.

Development and validation of apalutamide-related substances method in solid dosage forms using HPLC.

A related-substances method was developed for the anticancer drug formulation apalutamide 60 mg tablets and validated using a liquid chromatography gradient elution method. All of the impurities and degradants were separated using the Luna Omega 5μm Polar C18 , (250 × 4.6) mm HPLC column with a 1.0 ml min-1 flow rate. The detection was done at 225 nm by injecting the 10μl of injection volume, controlling the sample temperature at 10°C and maintaining the column compartment temperature at 30°C. The total run time was 85 min. A 0.01m disodium phosphate dihydrate pH4.20 ± 0.05 buffer mixed with acetonitrile in the ratio of 73:27 (v/v) was used as mobile phase A. Mobile phase B consisted of water and acetonitrile in the ratio 30:70 (v/v). The proposed method was validated as per the current regulatory guidelines. The method precisions (RSD) at 100% specification level were 1.41, 1.74, 1.84, and 1.66% for the four impurities. The accuracy results were obtained between 96.0 and 106.3% for the limit of quantitation to the 150% level. The standard and sample solutions stability were established for 44 h at 10°C. The correlation coefficient (r) value was >0.999 for all four impurities, indicating good linearity between the concentration and peak response: 0.9999, 0.9999, 0.9999 and 1.0000. These results show the method's linearity. The three filter compatibility was proved and it was concluded that 0.45 μm Nylon, PTFE and PVDF filters are suitable. The robustness of the method was established by varying the conditions. The method specificity was proved and the forced degradation data reveal the method's stability-indicating nature.

Development, Validation, and Application of a Simple and Rugged HPLC Method for Boswellic Acids for a Comparative Study of Their Abundance in Different Species of Boswellia Gum Resins

The resin of Boswellia plant species has been used since ancient times for its several bio-active curative effects. In modern times, extracts of this resin are still widely commercialized on the food supplements and nutraceuticals market. Nowadays the legislation on botanical extracts and the increasing demand for their safety and traceability are setting new standards for their chemical characterization. In this work we present an easy, feasible and rugged HPLC-UV-based approach for the quantitation of boswellic acids in food-supplement-grade resin extracts of Boswellia plant species. This method can be used for quality control purposes as well as for studying their differences in regional origin, years of harvesting and species-related differences. The method employs a C18 (3 × 150 mm, 3 µm) analytical HPLC column, and the separation is carried out through a gradient of acetonitrile/water with 0.1% formic acid. The method was validated following the ICH guidelines and used to quantitate different samples of commercial resin of Boswellia carteri and serrata together with other samples from unknown species. The six known boswellic acids were identified and quantified in all the analyzed samples. The results were used to build a multivariate model to graphically appreciate their difference through their clustering. The model was then augmented by adding further quantitation data for boswellic acids belonging to different species of Boswellia obtained by another scientific publications to increase the number of studied samples.

Stereoselective analysis of chiral succinate dehydrogenase inhibitors (SDHIs) in foods of plant origin and animal origin by supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS)

The stereoisomers of chiral SDHIs were prepared using Autoprep HPLC and chiral columns. The method of combining theoretical calculation with experimental determination was used to confirm the absolute configuration of stereoisomer. SFC-MS/MS and four kinds of chiral columns were used to separate the eight chiral SDHIs, and they could be separated simultaneously using OD-3 column in 6.5 min. The integrated QuEChERS strategy was used to analyse the chiral SDHIs in foods of plant and animal origin, and the average recoveries ranged from 71 % to 119 % with RSD ≤ 18 %, and the LOQ was 1 ng/g. There were 99.2 % and 63.6 % matrix effects were in the range of 0.8–1.2 in foods of plant and animal origin, respectively, showing weak matrix effects. The study provided methods for monitoring chiral SDHIs stereoisomers residues, which were crucial for stereoselective evaluations and improving risk assessments.

Chemical Constituents from Mycelia of Lepista sordida (Agaricomycetes) and Their ABTS Radical Scavenging Activity.

Lepista sordida is an edible mushroom possessing high nutritional value and high medicinal value. The artificial cultivation technology of L. sordida made a breakthrough and has been popularized in Yunnan, Guizhou, Sichuan province with good economic benefits. The secondary metabolites were investigated from ethyl EtOAc (acetate extract) of solid cultures of L. sordida. Silica gel column chromatography, semi-preparation HPLC, recrystallization, and medium pressure column chromatography were applied to obtain 15 compounds. Nine compounds were first isolated from genus Lepista and 11 compounds were first isolated from species L. sordida. Moreover, compounds 13 and 14 exhibited strong scavenging activity of ABTS.

Simultaneous Determination of Vitamin E and γ-Oryzanol in Rice Bran Oil via HPSEC-PDA without Sample Pretreatment.

Vitamin E (tocopherols and tocotrienols) and γ-oryzanol are two minor constituents of rice bran oil (RBO) and are known to be potential bioactive compounds. The content of γ-oryzanol, a unique antioxidant found only in RBO, is a key factor in determining the retail price of the oil. Limitations of conventional HPLC columns for vitamin E and γ-oryzanol analysis are the alteration of these components and the time-consuming need for pretreatment of samples by saponification. High-performance size exclusion chromatography (HPSEC) equipped with a universal evaporative light scattering detector (ELSD) is a versatile tool for screening optimum mobile phase conditions because components of the sample can be separated and detected in the same run. In this work, the RBO components (triacylglycerol, tocopherols, tocotrienols, and γ-oryzanol) assessed on a single 100-Å Phenogel column using ethyl acetate/isooctane/acetic acid (30:70:0.1, v/v/v) as the mobile phase provided baseline separations (R s >1.5) with a total run time of 20 min. The HPSEC condition was then transferred to determine the content of tocopherols, tocotrienols, and γ-oryzanol in RBO products using a selective PDA detector. The limit of detection (LOD) and limit of quantification (LOQ) of α-tocopherol, α-tocotrienol, and γ-oryzanol were 0.34 and 1.03 μg/mL, 0.26 and 0.79 μg/mL and 2.04 and 6.17 μg/mL, respectively. This method was precise and accurate, with a percentage of relative standard deviation (%RSD) of the retention time of less than 0.21%. The intra-day and inter-day variations were 0.15-5.05% and 0.98-4.29% for vitamin E and γ-oryzanol, respectively. The recoveries of tocopherols, tocotrienols, and γ-oryzanol ranged between 90.75% and 107.98%. Thus, the developed HPSEC-ELSD-PDA method is a powerful analytical tool for determining the vitamin E and γ-oryzanol present in oil samples without requiring any sample pretreatment.

Preparation and application of 3D solid structure high performance liquid chromatography fillers in the detection of phthalates

Materials of 3D structure for HPLC columns have been prepared. Silica spheres with high purity were first funetionalized with Substance A and a range of other substances, and finally followed by quaternization with iodomethane to form the final product. A standard solution of four certain phthalates was used to verify the chromatographic performance of the resulting packing materia1. Quantification analysis was performed by the external standard method. Linear relationships were found between the peak areas and the mass concentrations of the four certain phthalates in definite ranges, with detection limits (3S/N) of 5 mg·kg-1 and the low limits of determination (10S/N) of 10 mg·kg-1. Recovery rates obtained by standard addition method were in the range of 100.8~106.8% and RSDs (n=6) were less than 4%, which meeting the requirement of routine experiment.

Evaluation of separation performance for eggshell-based reversed-phase HPLC columns by controlling particle size and application in quantitative therapeutic drug monitoring.

Eggshell-based reversed-phase packing materials were applied to an analytical column for high-performance liquid chromatography. Commercially available eggshell powder was classified by a cyclone system to obtain three types of particles with different diameters (arithmetic mean ± standard deviation: 4.3 ± 3.8, 5.6 ± 3.3, and 9.5 ± 5.5 μm). Sedimentation separation removed tiny particles from each sample, resulting in particles with arithmetic means of 6.6 ± 5.5, 7.3 ± 4.5, and 10.2 ± 5.0 μm, respectively. The unclassified particles and three particle types treated with sedimentation separation were subsequently packed into analytical columns (150 mm × 4.6 mm I.D.), and their separation efficiencies were evaluated by comparing their height equivalent to a theoretical plate (HETP). The column without sedimentation separation exhibited the highest HETP, whereas the columns with sedimentation separation showed better separation efficiency and lower back pressure. The column with the best separation efficiency was applied for the separation of 10 alkylbenzenes and 5 steroids, and all peaks were observed with complete separation (peak resolution: RS > 1.5). Finally, the column was used for quantitative analysis of voriconazole, an azole antifungal agent, and imatinib, a first-generation molecularly targeted drug for cancer treatment, in spiked whole blood. Excellent accuracy (99.1-102.8%) and precision (0.6-1.9%) were observed for the spiked drugs and long-term stability (>3000 column volumes of mobile phase flow) indicated good applicability of the developed eggshell-based column as an analytical column for routine analyses of therapeutic drugs in blood.

Rapid Analysis of Four Alkaloids in Uncaria rhynchophylla by Core-Shell Column HPLC and Quantitative Analysis of Multi-Components by Single Marker (QAMS)

As a traditional herbal medicine, the major alkaloids in Uncaria rhynchophylla have been proven to have blood pressure-lowering and sedative effects. It is essential to develop an effective method for the determination of the major alkaloids in U. rhynchophylla. In this research, a rapid quantitative analysis involving multi-components analysis by a single marker strategy coupled with core-shell column HPLC was adopted to analyse four alkaloids (corynoxeine, isocorynoxeine, isorhynchophylline, rhynchophylline) in U. rhynchophylla. Isorhynchophylline was selected as the internal reference substance, the content of which was determined by the traditional external standard method. Relative correction factors (RCF) between isorhynchophylline and the other three alkaloids were calculated respectively. The results showed that the QAMS method had good robustness under different HPLC instruments. Nineteen batches of U. rhynchophylla were tested. No significant difference was observed between the results by QAMS and EMS (Correlation coefficient > 0.99, p > 0.05). The QAMS method could be employed as a rapid, effective technique for the quality control of U. rhynchophylla.

Identification and Quantification of 29 Active Substances by HPLC–ESI-MS/MS in Lyophilized Swine Manure Samples

Veterinary drugs are frequently employed to treat and prevent diseases in food-producing animals to improve animal health and to avoid the introduction of microorganisms into the food chain. The analysis of the presence of pharmaceutical residues in animal manure could help to evaluate the legal and illegal practices during food production without harming the animals and to correctly manage manure when it is going to be applied as a fertilizer. This article describes a method for the simultaneous analysis of 29 active substances, mostly antibiotics and antiparasitic agents. Substances were extracted from lyophilized manure with a methanol:McIlvaine solution and analyzed with HPLC-ESI-MS/MS and a C18 HPLC column. The method was validated following European guidelines, the achieved trueness was between 63 and 128% (depending on the analytes), and the linearity was between 100 and 1500 µg/kg. The applicability of the method was demonstrated in 40 manure samples collected from pig farms where tetracycline was quantified in 7.5% of the samples. These results show the viability of this non-invasive method for the control of the legal and illegal administration of pharmaceuticals in food-producing animals.

Development of Targeted Protein-Displaying Technology with a Novel Carbon Material

This study reports a new carbon material and its specific display of targeted protein. The properties of the carbon materials fabricated with carbon black MOGUL® were analyzed. The carbon materials were spherical structures with 55.421 µm as a median value. The specific surface area, pore volume, average pore diameter, and total of the acidic functional group were 130 m2·g-1, 0.55 cm3·g-1, 17.2 nm, and 0.29 mEq·g-1, respectively. The adsorption-desorption isoform of the carbon materials showed type IV of the hysteresis loop as defined by IUPAC, indicating non-uniform mesoporous structures (2-50 nm). The distribution of the log differential pore volume also indicated non-uniform porous structures because (i) the difference between the average pore size and the most frequent pore size was significant and (ii) the σ value was larger than the average value regarding the pore sizes. However, 10-90% of the integrated values of the log differential pore volume were 57.4% of the total integrated values, and the distribution was similar to the Gauss distribution model. Although the value of the total of the acidic functional group was 2.5-5.4 times lower than the values of the HPLC columns, the carbon materials require good scaffold quality rather than good HPLC quality. Therefore, the amounts could be enough for the scaffold of biotin hydrazide. To demonstrate the property of displaying the targeted proteins, carbon materials displaying biotin hydrazide by covalent bonding were prepared and avidin-labeled horse radish peroxidase (HRP) was bound to the biotin region. The carbon materials were porous structures, so the unspecific adsorption of HRP was estimated. Then, the maintenance ratios of HRP activities were analyzed in the repeated-use-with-wash processes after each evaluation, resulting in the activities of HRP on the carbon materials being treated with biotin hydrazide being significantly maintained compared to that of the ones without biotin hydrazide. The study revealed the properties of the carbon materials and indicated the display of HRP, suggesting that the carbon materials could be a new material for displaying targeted proteins.

Development of an HPLC Method for the Determination of Levothyroxine Applied to Four Different Preparations

HPLC is an important research tool that can identify, extract and measure the substance, its numerous components and drug-related additives that may occur during either the manufacture or storage of the medication. Understanding the chemistry of the drug ingredient is required for this, which makes it easier to create analytical methods. To find the most effective way to conduct the procedure, many chromatographic parameters were investigated and tested. It is essential to identify a suitable mobile phase, column, column temperature, wavelength, and gradient to achieve the desired suitability and durability of the medicine in addition to its degradants and contaminants. This study aims to develop simply and rapidly the HPLC method for the determination of levothyroxine and its different brands. Levothyroxine is the drug of choice for hypothyroidism. In this study, a high liquid chromatography method was developed for the quantification of different brands of levothyroxine. The chromatographic study was analyzed at an ambient temperature of 28°C with isocratic elution. The mobile phase of the chromatograph was water and methanol Me OH (45:55) (1:1V/V) or 0.01 M phosphate buffer, the solution with adjusted pH=3. The flow rate of the pump was set at 1.5ml/min, the volume of the solution was 20 ml injected into the HPLC column, and the wavelength at 225 nm. The accuracy (99.9% recovery), precision (99.9 to 100% recovery), linearity (³ 0.99), and retention time (16.8 min) were observed for all brands of levothyroxine. In this study, we have evaluated the HPLC method for the quantification of levothyroxine and its different brands. Levothyroxine is considered as a controversial drug throughout the globe. In the recent past, we have found no study that proved clinical and biological interchangeability between levothyroxine brands. Our study is its self-unique in its case. There is no such publication proving that generic drugs are equivalent.

Montmorillonite-based polymethacrylate composite monoliths as stationary phase materials for food and pharmaceutical analysis in capillary liquid and gas chromatography

This work relates to the preparation of novel and promising stationary phases containing inorganic-organic composites for capillary liquid and gas chromatography. A naturally occurring montmorillonite was introduced to polymethacrylate monoliths, then used under different conditions of GC and HPLC at the same time. The performance of the columns was evaluated for the separation of alkane and alkylbenzene series in GC and capillary HPLC, respectively. While the bare monoliths failed to separate the model analytes, montmorillonite-based polymethacrylate allowed a full separation of the mixtures with Rs≥1.42. The columns were applied for the determination of myrcene and limonene isomers in the peel extracts of some fruits using GC, and for the analysis of active ingredients including aspirin, vitamin-C, caffeine, and ibuprofen extracted from common drugs using capillary HPLC. In GC, fast separation was achieved in 1.0 min with Rs of 6.53. The columns exhibited the best efficiency for myrcene with 20,900 plates/m. Using the capillary HPLC columns, the active ingredients were resolved in 10 min with Rs≥5.72. The efficiency values located between 12,800–21,700 plates/m in all cases. The developed methods were found to be linear in the range of 0.10–10.0 and 0.20–180 μg/mL for GC and HPLC, respectively. In comparison with commercial columns, the results in GC methods reveal that, despite their much shorter length, the prepared columns proved a faster separation with higher efficiency and comparable detection limits and chromatographic resolution. The prepared HPLC capillaries exposed lower run times and detection limits with comparable efficiency and resolution, and consume fewer samples and mobile phase solvents. The results demonstrate that the montmorillonite-based polymethacrylate composites are applicable as stationary phases for routine analysis and quality control of important fields such as food and pharmaceutical samples.

Naturally Occurring Montmorillonite-Based Polymer Monolith Composites as Stationary Phases for Capillary Liquid and Gas Chromatography

This work is associated with the preparation of capillary chromatographic columns containing inorganic-organic composites comprised of naturally occurring montmorillonite (MMT) clay mineral and polymethacrylate monolithic material. The prepared composites combine the best qualities of both constituents, offering desirable properties for use under the disparate conditions of both GC and HPLC at the same time. The stationary phases were investigated by scanning electron microscopy (SEM), the specific surface area, and thermogravimetric analysis (TGA) and examined in terms of various conditions utilized for GC and HPLC methods. The prepared columns demonstrated an excellent permeability and stability against common chromatographic conditions, such as the eluent type, flow rate, pressure, and temperature. The results confirmed that the addition of small amounts of MMT into the monolith induced significant improvement in the specific surface area, which contributed to the formation of more active sites and enhanced the retention of analytes. The registered column backpressures did not exceed 980 kPa and 16,500 kPa for the prepared GC and HPLC columns, respectively. The prepared columns were subjected to the separation of various interesting compounds possessing different chemistries and polarities, including alkanes, alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs), alcohols, ketones, phenols, some common organic solvents, and isomeric mixtures. Under the optimal conditions, the efficiency of the columns fell between 4900–38,500 plates m−1 for GC and 3400–58,800 plates m−1 for capillary HPLC applications. In all cases, the measured chromatographic resolution was more than 1.38, with excellent an peak symmetry and low tailing factors. In comparison with the most commonly used commercial columns, the polysiloxane open tubular column for GC and silica-based C18 packed column for HPLC, the prepared GC columns demonstrated a faster separation with a higher efficiency, comparable resolution and tailing factors, and lower consumption of carrier gas. Regarding the capillary columns prepared for HPLC, the chromatographic experiments exposed a much lower run time with a comparable efficiency and resolution and drastically lower consumption of mobile phase solvents and samples. The results demonstrate that the MMT-based polymethacrylate monolith composites are applicable as novel and promising separation media for analyzing various mixtures of interest in different fields, such as petrochemical and environmental samples.

Qualitative and Quantitative Analysis of Nicotine, Nicotine Derivatives, and Nicotine-Related Alkaloid Optical Isomers: A Review

Summary During the last 35 years technologies and hardware for the separation of enantiomers have advanced tremendously. Today, complete resolution of the enantiomers of nicotine and related compounds can effectively be attained within a few seconds and most often less than 10 minutes. In some unique cases, enantiomeric separation for nicotine-related compounds having a wide variety of functional groups has been demonstrated. Particularly, the successful wedding of short HPLC and SFC columns containing very small particle size materials bonded to chiral stationary phase materials coupled with information-rich detectors like electrospray ionization mass spectrometry/mass spectrometry has facilitated this remarkable transition. Taken collectively the HPLC and SFC technologies will allow for very rapid (seconds), reliable, and reproducible (% RSD routinely < 5%) for nicotine and related alkaloid enantiomers.

Terpenoids from fruits of Amomum villosum and their hypoglycemic activity

Eight terpenoids were isolated from the fruits of Amomum villosum by silica gel, Sephadex LH-20, Rp-C_(18), MCI GEL CHP20 P column chromatography, preparative TLC, and HPLC. Their structures were identified by HR-ESI-MS, ~1H and ~(13)C-NMR, IR, UV, [α]_D, and ECD spectroscopic data as kravanhin A 3-O-β-D-glucopyranoside(1), kravanhin B(2), 6-eudesmene-1β,4β-diol(3), oplodiol(4), vicodiol(5),(1R,2S,4R,7S)-vicodiol 9-O-β-D-glucopyranoside(6),(1R,2S,4S,5R)-angelicoidenol 2-O-β-D-glucopyranoside(7), and(1S,2S,4R,6S)-bornane-2,6-diol 2-O-β-D-glucopyranoside(8). Compound 1 was a new compound, and compounds 2-5 were isolated from A. villosum for the first time. Their hypoglycemic activity was tested based on STC-1 cell model and two enzymatic models(GPa and PTP1 B). The results showed that compounds 1, 7, and 8 could stimulate GLP-1 with the secretion rates of 692.8%, 398.6%, and 483.3% at 25.0 μmol·L~(-1), and compound 6 showed inhibitory activity against GPa with an IC_(50) value of 78.6 μmol·L~(-1).

Development of Highly Sensitive Method for Sugar Determination in Herbal Medicine; Application of Monosaccharides and Oligosaccharides in Japanese Angelica Root and Rehmannia Root.

We have developed a simple and accurate method for quantifying sugars in herbal medicines, which have hitherto been difficult to quantify. Using ultra performance liquid chromatography-quadrupole-time-of-flight (UPLC-Q-TOF)-MS and two types of columns with different chemical properties, we determined the optimum conditions for separating nine sugars (fructose, galactose, glucose, mannitol, sucrose, melibiose, raffinose, manninotriose, and stachyose) commonly found in herbal medicines. Separation was completed within 10 min when an apHera NH2 HPLC column was used, although galactose and glucose could not be separated. On the other hand, the nine sugars were completely separated within 16 min when a hydrophilic interaction chromatography (HILIC)pak VG-50 2D column was used. The calibration curves obtained using those two columns gave good linearity for the sugar standards, and the coefficient of determination was 0.995 or higher. Both columns showed excellent performance with short analysis time and high sensitivity. Using our developed method, we were able to quantify sugars in galactose-free herbal medicines within 10 min and in herbal medicines containing galactose within 16 min. We revealed that our method could be used for the analysis of sugars in Angelica acutiloba and Rehmannia glutinosa roots.