High-performance Liquid Chromatography Coupled With A Diode Array Detector Research Articles

Derivative spectrophotometry-assisted determination of tryptophan metabolites emerges host and intestinal flora dysregulations during sepsis

Sepsis is a life-threatening condition characterized by organ dysfunction resulting from a dysregulated host response to infection. Dysregulated tryptophan (TRP) metabolites serve as significant indicators for endogenous immune turnovers and abnormal metabolism in the intestinal microbiota during sepsis. Therefore, a high coverage determination of TRP and its metabolites in sepsis is beneficial for the diagnosis and prognosis of sepsis, as well as for understanding the underlying mechanism of sepsis development. However, similar structures in TRP metabolites make it challenging for separation and metabolite identification. Here, high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) was developed to determine TRP metabolites in rat serum. The first-order derivative spectrophotometry of targeted metabolites in the serum was investigated and proved to be promising for chromatographic peak annotation across different columns and systems. The established method separating the targeted metabolites was optimized and validated to be sensitive and accurate. Application of the method revealed dysregulated TRP metabolites, associated with immune disorders and NAD + metabolism in both the host and gut flora in septic rats. Our findings indicate that the derivative spectrophotometry-assisted method enhances metabolite identifications for the chromatographic systems based on DAD detectors and holds promise for precision medicine in sepsis.

Enhancing the Nutritional Profile of Crataegus monogyna Fruits by Optimizing the Extraction Conditions

Crataegus monogyna (CM) fruits are highly regarded for their rich nutritional content, boasting elevated levels of various beneficial secondary metabolites like total polyphenols, including anthocyanins, and ample amounts of ascorbic acid and antioxidant activity. Despite the acknowledged benefits of CM fruits, researchers have directed more attention toward its leaves and flowers. Consequently, the current research attempts to optimize extraction techniques for CM fruit using a multifaceted approach involving varied durations, temperatures, and concentrations of ethanol solvent to isolate the diverse range of bioactive components present effectively. High-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) is employed for the identification and quantification of polyphenolic compounds. According to the results, by following the optimum extraction parameters (50% ethanolic solvent, 50 °C extraction temperature, and 60 min extraction time), the total polyphenol content can be increased up to 410%, reaching 55.59 mg gallic acid equivalents/g. Using 50% ethanolic solvent, 80 °C extraction temperature, and extraction time of 90 min, the total anthocyanin content can be enhanced by more than 560%, reaching a quantity of 51.83 μg cyanidin equivalents/g. Moreover, the antioxidant activity of CM fruit extracts can reach 415.95 μmol ascorbic acid equivalents (AAE)/g dw (by FRAP method), using 50% ethanolic solvent, 50 °C extraction temperature, and 60 min extraction time, and 270.26 μmol AAE/g dw (by DPPH method) and 1053.28 mg/100 g dw ascorbic acid content, using 50% ethanolic solvent, 80 °C extraction temperature, and 90 min extraction time. This comprehensive study seeks to augment the already substantial content of bioactive compounds found in CM, resulting in an extract with promising applications across the pharmaceutical, food, and cosmetics industries.

Phytochemical Screening of Ultrasonic Extracts of Salix Species and Molecular Docking Study of Salix-Derived Bioactive Compounds Targeting Pro-Inflammatory Cytokines.

Willow bark (Salix spp., Salicaceae) is a traditional analgesic and antirheumatic herbal medicine. The aim of this study was to evaluate and compare the phytochemical and antioxidant profiles of leaf and bark extracts of six species of the genus Salix obtained by ultrasound-assisted extraction (UAE) and to examine the inhibitory potential of target bioactive compounds against two inflammatory mediators, tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), through in silico molecular docking. The total phenolic and flavonoid content of the extracts was estimated using spectrophotometric methods and the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and hydroxyl radical (•OH) scavenging assays. Chemical profiling of extracts was carried out using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Principal component analysis (PCA) was performed to differentiate the sample extracts based on their phytochemical profiles and amounts of target bioactive compounds. Chemical composition varied among the analyzed willow species and also among the plant organs of the same species. The major bioactive compounds of the extracts were salicin, chlorogenic acid, rutin and epicatechin. The extracts exhibited significant DPPH● and ●OH scavenging activities. Results of molecular docking revealed that chlorogenic acid had the highest binding affinity toward TNF-α and IL-6. UAE extracts represent valuable sources of antioxidant and anti-inflammatory compounds.

A novel integrated platform enabling simultaneous microextraction and chemical analysis on-chip

The nature and size of biological, pharmaceutical or environmental analytes complicates their extraction and detection outside of laboratories and near the site of interest by the current chromatographic methods because they require the combination of bulky extraction and detection methods. In order to solve this inefficient centralized control, a ground-breaking and miniaturized proof of concept platform is developed in this work. The platform integrates for the very first time an electro-membrane extraction process and an accurate analyte quantification method in the same device, by using electrochemical impedance spectroscopy (EIS) as analytical technique. The microfluidic flow cell, including the microfluidic components, is fabricated in polymeric materials by rapid prototyping techniques. It comprises a four-electrode platinum thin-film chip that enables the control of the microextraction and the full characterization of the process, i.e., extraction efficiency determination, at the same time. The microfluidic system has been simulated by using computational tools, enabling an accurate prediction of the effect of the different experimental conditions in the microextraction efficiency. The platform has been validated in the microextraction of the nonsteroidal anti-inflammatory drug ketoprofen in a range from 0.5 ppm to 6 ppm. The predicted microextraction efficiency values obtained by EIS were compared with those calculated from the high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), showing an excellent agreement. This validates the high potential of this integrated and miniaturized platform for the simultaneous extraction by electro-membrane and also the analysis within the platform, solving one of the of most important limitations of current systems.

The effects of regions and the wine aging periods on the condensed tannin profiles and the astringency perceptions of Cabernet Sauvignon wines.

This study sought to determine the effects of wine-producing regions and aging periods on the astringency and chemistry of condensed tannins of Cabernet Sauvignon dry red wines. A wine quality study was performed with 5 vintages of 32 Cabernet Sauvignon wines produced in four Chinese wine-producing regions, Hebei (H), Xinjiang (X), Inner Mongolia (NM), and Ningxia (NX). Condensed tannin profiles were assessed by high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). The (-)-epicatechin as the terminal subunit (tEC) is the major differential component between regions. Correlation analysis revealed that condensed tannin concentration and composition significantly affected the sensory evaluation of astringency. Condensed tannin concentrations were significantly and negatively correlated with wine aging periods. However, no significant correlation was found between aging periods and condensed tannin subunits (as mole%) composition. The current findings enhance the understanding of condensed tannins' chemical and astringency characteristics in Cabernet Sauvignon wines.

A nanostructured o-hydroxyazobenzene porous organic polymer as an effective sorbent for the extraction and preconcentration of selected hormones and insecticides in river water

A nanostructured o-hydroxyazobenzene porous organic polymer (Hazo-POP) was synthesized by the diazo coupling reaction and characterised using various analytical techniques. The nanostructured Hazo-POP material was applied for the extraction and enrichment of neonicotinoid insecticides and steroid hormones in river water samples. The surface characterization techniques confirmed that the synthesized Hazo-POP had a specific surface area of 251 m2 g−1 and it was mesoporous. The influential factors affecting the UA-D-µ-SPE of the neonicotinoid insecticides and steroid hormones were studied using the design of experiments. The quantification of the target analytes in samples was performed using high performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used for the confirmation and validation of the results obtained using HPLC-DAD. At optimal experimental conditions, the UA-D-µ-SPE/HPLC-DAD method displayed low limits of detection (LODs) ranging from 0.4 to 1.3 ng/L for steroid hormones and 0.7–1.2 ng/L for neonicotinoid insecticides. Whereas the limits of quantification (LOQs) were 1.3–4.3 ng/L and 2.3–4.0 ng/L for steroid hormones and neonicotinoid insecticides. For UA-D-µ-SPE/UHPLC-MS/MS procedure, LOQs for steroid hormones ranged from 0.03 to 0.50 ng/L and 0.05–0.50 ng/L for neonicotinoid insecticides. The LOQs were 0.10–0.53 ng/L and 0.13–1.70 ng/L for the steroid hormones and insecticides. The accuracy of the method was assessed using a spike recovery test and recoveries of 93.7%–99.5% (n = 4) with precision (relative standard deviation), below 5% for spiked samples at different levels. The applicability of the UA-D-µ-SPE method was evaluated for the analysis of neonicotinoid insecticides and steroid hormones in real water samples before HPLC-DAD and UHPLC-MS/MS determination. The analytical results obtained using HPLC-DAD water samples were < LOQ-56.3 ng/L and < LOQ-56.3 ng/L for steroid hormones and neonicotinoid insecticides. In comparison with the HPLC-DAD results, the concentration of steroid hormones and neonicotinoid insecticides ranged from 0.19 to 55.9 ng/L and 0.38–55.2 ng/L when using UHPLC-MS/MS.

In Vitro and In Vivo Studies of Anti-Lung Cancer Activity of Artemesia judaica L. Crude Extract Combined with LC-MS/MS Metabolic Profiling, Docking Simulation and HPLC-DAD Quantification.

Artemisia judaica L. (Family: Asteraceae) exhibited antioxidant, anti-inflammatory, and antiapoptotic effects. The in vitro cytotoxic activity of A. judaica ethanolic extract was screened against a panel of cancer cell lines. The results revealed its cytotoxic activity against a lung cancer (A549) cell line with a promising IC50 of 14.2 μg/mL compared to doxorubicin as a standard. This was confirmed through the downregulation of antiapoptotic genes, the upregulation of proapoptotic genes, and the cell cycle arrest at the G2/M phase. Further in vivo study showed that a solid tumor mass was significantly reduced, with a tumor inhibition ratio of 54% relative to doxorubicin therapy in a Xenograft model. From a chemical point of view, various classes of natural products have been identified by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). The docking study of the detected metabolites approved their cytotoxic activity through their virtual binding affinity towards the cyclin-dependent kinase 2 (CDK-2) and epidermal growth factor receptor (EGFR) active sites. Finally, A. judaica is a fruitful source of polyphenols that are well-known for their antioxidant and cytotoxic activities. As such, the previously reported polyphenols with anti-lung cancer activity were quantified by high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Rutin, quercetin, kaempferol, and apigenin were detected at concentrations of 6 mg/gm, 0.4 mg/gm, 0.36 mg/gm, and 3.9 mg/gm of plant dry extract, respectively. It is worth noting that kaempferol and rutin are reported for the first time. Herein, A. judaica L. may serve as an adjuvant therapy or a promising source of leading structures in drug discovery for lung cancer treatment.

GC-MS and HPLC-DAD analysis of fatty acid profile and functional phytochemicals in fifty cold-pressed plant oils in Thailand

Cold-pressed oil is one of the healthiest plant extracts, but its use is limited only in some kinds of plants. Therefore, we aimed to investigate some potential cold-pressed oils with attractive fatty acid profiles and high amounts of functional phytochemicals. Fifty cold-pressed plant oils were prepared from various plant materials in Thailand, in which some of them were from uncommon or unattended plant materials. The oils included were nut oils (n = 9), pseudo-cereal oils (n = 9), legume oils (n = 3), amaranth oils (n = 3), marrow seed oils (n = 8), cruciferous seed oils (n = 7), and leafy green seed oils (n = 11). Gas-chromatography mass-spectrometry (GC-MS) and high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) were employed to analyze fatty acid profile and five functional phytochemicals (e.g., phytosterols, cholecalciferol, and squalene). Saturated fatty acids were detected around 7.87–36.04%, monounsaturated fatty acids 10.17–80.25%, and polyunsaturated fatty acids nondetectable (ND)–78.25%, phytosterols 663–15123 μg g−1, squalene 265–5979 μg g−1, and cholecalciferol ND–1287.75 μg g−1. The study showed chemical characteristic of the analyzed oils: some contained good fatty acid composition and some were rich in functional phytochemical content. Among the obtained oils, marrow seed oils are a good source of phytosterol, cholecalciferol, and linoleic acid. Pseudo-cereal oils are rich in squalene and linolenic acid. Legume oils are rich in phytosterols and oleic acid. Besides, principal component analysis (PCA) was applied to identify the significance of oils that share compositional similarity (e.g., the samples from pseudo-cereal oil were found on the lower side of the PCA space, which separated them from marrow and leafy green seed oils distributed on the upper part of the plot). In summary, the qualitative and quantitative data would provide a good foundation for further application or selection of those plant oils for health purposes.

Extraction optimization of accelerated solvent extraction for eight active compounds from Yaobitong capsule using response surface methodology: Comparison with ultrasonic and reflux extraction

This work described the development of a novel method for simultaneous extraction of eight active compounds (including catechin, albiflorin, paeoniflorin, ferulic acid, ginsenoside Rg1, tetrahydropalmatine, ginsenoside Rb1 and osthole) from Yaobitong capsule by accelerated solvent extraction (ASE). Response surface methodology (RSM) with desirability functions was employed to optimize the extraction conditions yielding the optimal conditions of ASE (extraction time 8 min, extraction temperature 80 °C, extraction solvent 70% methanol and flushing volume 100%). A high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) method was developed and validated for simultaneous quantification of the eight compounds in Yaobitong capsule. The values of correlation coefficient (R) were satisfactory between 0.9992 and 0.9999 over the linear concentration range of 0.5–1000 μg mL−1. It was found that the limits of detection (LODs) and the limits of quantification (LOQs) for the eight active compounds were 0.10–2.90 μg•mL−1 and 0.30–9.40 μg•mL−1, respectively. The recoveries of the eight main active compounds in Yaobitong capsule were in the range of 93.31%–106.22%. And the contents of the analytes extracted by ASE under the optimal conditions were compared to traditional solvent extraction methods, such as ultrasonic and reflux extraction. The results indicated that the ASE method proved to be more suitable for the extract of active compounds in Yaobitong capsule, which could obtain higher extraction efficiency. At last, the proposed method was applied to analyze ten batches of actual samples, which provided high extraction efficiency and had wide potential application in the analysis of traditional Chinese medicines.

Analysis of Polyphenolic Composition of a Herbal Medicinal Product-Peppermint Tincture.

The pharmacological activity of peppermint leaf (Menthae piperitae folium) for medical use is mainly attributed to the presence of essential oil, which, according to the European Pharmacopoeia (Ph. Eur.), should constitute not less than 12 mL/kg of raw material. The content of polyphenols in peppermint-based preparations, except peppermint leaf dry extract, has not yet been considered as an essential parameter in the pharmacopeial assessment of peppermint quality. This study concerns the evaluation of the presence of representatives of polyphenolic compounds in 23 commercial peppermint tinctures (ethanolic extracts) purchased in pharmacies in Poland. The non-volatile polyphenolic fraction was investigated, and the presence of flavonoids and phenolic acids was quantified. High performance liquid chromatography coupled with a diode-array detector (HPLC-DAD) and an electrospray ionization mass spectrometer (U(H)PLC-ESI-MS) were used in the experiment. The study showed that eriocitrin, luteolin-7-O-rutinoside, and rosmarinic acid were the main polyphenolic components of the peppermint tinctures, as previously reported for peppermint leaf. Despite this, the research shows the extremely diverse content of the mentioned compounds in analyzed commercial medicinal products. In light of these results, it seems that the pharmacopeial assessment for the peppermint leaf (Ph. Eur.) and peppermint tincture (Polish Pharmacopoeia (FP)) requires correction and supplementation.

A Beta/ZSM-22 Zeolites-Based-Mixed Matrix Solid-Phase Dispersion Method for the Simultaneous Extraction and Determination of Eight Compounds with Different Polarities in Viticis Fructus by High-Performance Liquid Chromatography.

Viticis Fructus (VF) was named Manjingzi as a commonly used traditional Chinese medicine (TCM) targeting various pains and inflammation for more than 2000 years. To guarantee the quality of Viticis Fructus, a simple, quick and eco-friendly Beta/ZSM-22 zeolites-based-mixed matrix solid-phase dispersion method (B/Z-MMSPD) was established for simultaneous extraction and determination of eight compounds (two phenolic acids, two iridoid glycosides, vanillin and three flavonoids) with different polarities from Viticis Fructus by high performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Beta and ZSM-22 were mixed as the sorbent. Water, tetrahydrofuran and methanol were blended with certain ratio as the eluent. Several parameters including types of sorbents, mass ratio of Beta to ZSM-22, mass ratio of matrix to sorbent, grinding time, types, concentration and volume of eluent were optimized. The recoveries of eight analytes were within the range of 95.0%–105% (RSDs ≤ 4.13%). The limits of detection and limits of quantitation ranged from 0.5 to 5.5 μg/g and from 1.5 to 16 μg/g, respectively. Compared to the traditional extract methods, it was a simple, rapid, efficient and green method. The results demonstrated that a simple, rapid, efficient and green B/Z-MMSPD was developed for the simultaneous extraction and determination of eight target analytes with different polarities for quality control of Viticis Fructus.

Total flavonoid contents in bamboo diets and reproductive hormones in captive pandas: exploring the potential effects on the female giant panda (Ailuropoda melanoleuca).

Phytoestrogens have been shown to affect the reproductive hormone levels in both humans and animals. As the main category of phytoestrogens, total flavonoids have a particularly important impact on female animals. To investigate the potential relationship between the total flavonoids in bamboo and the reproductive hormones in female giant pandas, urinary samples and dietary bamboo samples were collected from three main breeding locations (Beijing, Shaanxi and Sichuan). The chemical constituents of the total flavonoids in the bamboo were analysed and quantified using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Estradiol (E2), progestin (P), testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were measured via radioimmunoassay (RIA). The results revealed that the total flavonoids in the bamboo from Sichuan were significantly higher than those in the bamboo from Beijing and Shaanxi, and the concentration in bamboo from Shaanxi was higher than that from Beijing (P < 0.05). The urinary E2, P, T, FSH and LH levels in pandas from Beijing were significantly lower than those in pandas from Sichuan and Shaanxi (P < 0.05). The concentrations of six reproductive hormones were positively associated with the total flavonoid contents in bamboo. In addition, the birth rate of pandas in Sichuan was significantly higher than the birth rate of pandas in Beijing and Shaanxi (P < 0.05). Thus, the flavonoids of bamboo may be related to reproduction and giant pandas might retain a sensitive adaptation to phytoestrogens from bamboo. The total flavonoids of bamboo may play a distinct role in the reproductive success of giant pandas.

Development of a simple HPLC-DAD multi-analyte procedure and its application in cases evaluated by the Poison Control Center of São Paulo, Brazil.

This work describes a simple approach to overcome challenges in emergency toxicological analysis, using liquid-liquid extraction and high-performance liquid chromatography coupled with a diode-array detector (HPLC-DAD). A rapid procedure has been developed, for the extraction and detection of 19 analytes from the following drug classes: analgesics, benzodiazepines, antidepressants, anticonvulsants and drugs of abuse. These substances are relevant in the context of emergency toxicology in Brazil. The method has been validated according to international guidelines by establishing parameters such as lower limit of quantification, sensitivity, linearity, accuracy and precision. The intra and inter-day precision values, at the lowest concentration levels, have always been less than 20% considering its relative standard deviation. As for accuracy values, these have also been satisfactory (above 81.3%). This method was successfully applied in 201 blood samples from patients with suspected poisoning of the Poison Control Center of São Paulo (PCC-SP), Brazil. Finally, the developed method has shown to be relevant for emergency toxicology due to its high sensitivity and it could be also very useful in both fields of clinical and forensic toxicology.

Biological activity of Hyptis Jacq. (Lamiaceae) is determined by the environment

The evolution of plant special metabolites is currently viewed within a phylogenetic perspective: the biosynthetic machinery needed to produce plant defense must be well-conserved and this origin should be monophyletic. But some questions thus arise: does a species occurring in different biogeographic domains present different levels of special metabolites? And if so, will it also represent a difference in its biological activity? For this study, seven Hyptis (Lamiaceae) species was collected and extracted by maceration in 70% ethanol, analyzed by highperformance liquid chromatography coupled with a diode array detector (HPLC-DAD) and performing antioxidants assays: DPPH (2,2-Diphenyl-1- picrylhydrazyl) and ABTS (2,20-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity, Iron (III) reduction to iron (II) and oxygen radical absorbance capacity (ORAC). Phenolic classes observed for Hyptis spp. were: phenolic acids, flavonoids, chlorogenic acid derivatives, and cinnamic acid derivatives. Results point out to a tendency of Hyptis populations growing at Cerrado domain present lower levels of phenolic compounds when compared to populations growing at Atlantic Forest. Furthermore, the abiotic microenvironment seems to exert a stronger influence regarding the phenolic composition and consequently the antioxidant activity of a plant extract than the phytogeographic domain.

Determination of Carotenoids in Human Serum and Breast Milk Using High Performance Liquid Chromatography Coupled with a Diode Array Detector (HPLC-DAD)

High performance liquid chromatography (HPLC) coupled with a diode array detector (HPLC-DAD) for the identification and quantification of carotenoids, namely all-trans lutein, zeaxanthin, β-cryptoxanthin, α-carotene, and β-carotene, in biological samples such as human serum and breast milk, has been developed and validated. Good chromatography separation was achieved using a binary mobile phase system on a YMC C30 column (150 × 2.1 mm, 3 µm) at 30 °C. Owing to the smaller column particle size and diameter of the column, the separation was achieved in 18 min, which is significantly reduced from the typical 30–40 min of other methods. The diode array detector (DAD) acquisition was set at a wavelength of 445 nm; 3D spectra ranging from wavelengths of 240–600 nm were also recorded. Peaks were identified by matching their retention time and spectra with those of standards. Quantification was achieved by internal standard calibration using echinenone as the internal standard. Good linearity was obtained for each compound (R2 &gt; 0.9999). The method quantification limits (MQLs) for serum and breast milk were 10 ng/mL and 5 ng/mL, in matrix, respectively. A spike recovery study and standard reference material (SRM) from the National Institute of Standards and Technology (NIST) 968e analysis has proven that the method has a high degree of accuracy, precision, and robustness. The stability study showed that the carotenoid standard and sample extracts could be stored in a chilled autosampler at 8 °C up to 48 h without being comprised, which provides guidance on re-test time frames. The freeze/thaw process was found to be detrimental to carotenoids, and should always be avoided. Most importantly, UV standardization of the stock standard is to be performed prior to each assay, and simply taking the values on Certificate of Analysis (CoA) for calculation of the standard concentration is not recommended.

The cosmetic dye quinoline yellow causes DNA damage in vitro

Quinoline yellow (QY) is a chinophthalon derivative used in cosmetic compositions for application to the skin, lips, and/or body surface. However, regulatory data about the genotoxicity and/or mutagenicity of this compound are still controversial. Therefore, this work evaluated the genotoxicity of QY using the comet assay and the cytokinesis-block micronucleus cytome assay (CBMN-Cyt) in the metabolically competent cell line HepG2, which closely mimics phase I metabolism. This research also identified the products formed after electrochemical oxidation of the QY dye, which simulates hepatic biotransformation. The primary products generated after the oxidation process were analyzed by High Performance Liquid Chromatography coupled with a Diode Array Detector (HPLC/DAD), which detected the production of 4,4′-diaminodiphenylmethane, 2-methoxy-5-methylaniline and 4,4′-oxydianiline. The results demonstrated that low (from 0.5 to 20μgmL−1) QY concentrations were genotoxic in HepG2 cells on both assays and those harmful compounds were detected after the oxidation process. Our findings suggest that this colorant could cause harmful effects to humans if it is metabolized or absorbed through the skin.

Phytochemical analysis of Rosa hybrida cv. ‘Jardin de Granville’ by HPTLC, HPLC-DAD and HPLC-ESI-HRMS: Polyphenolic fingerprints of six plant organs

The Rosa hybrida cultivar ‘Jardin de Granville’, a delicate clear pink flower, is here investigated through a progressive analytical strategy using complementary phytochemical screening methods in order to characterize the polyphenol content of several parts of the plant. The microwave hydro-ethanolic extract analysis of six different parts of the plant, carried out by High Performance Thin Layer Chromatography (HPTLC) and High Performance Liquid Chromatography coupled with a Diode Array Detector (HPLC-DAD) enabled initial identification of the polar molecular families present in each organ, namely tannins and flavonoids (quercetin and kaempferol derivatives). The HPLC fingerprints displayed different profiles for each organ, attesting to the original composition and potential valuation of the different plant parts. More detailed analyses of the extracts were then carried out by High Performance Liquid Chromatography coupled with electrospray ionization (ESI) mass spectrometry with a Q-TOF analyzer (ESI-HR-Q-TOF). Around 60 compounds were identified, mainly gallo-tannins, ellagi-tannins, catechin derivatives and glycoside derivatives of quercetin and kaempferol. Some compounds such as hyperoside or ellagic acid appeared to be ubiquitous and were found in abundance in each plant part. Woods were the richest organ in catechin and proanthocyanidin derivatives while kaempferol derivatives were more numerous and abundant in bud and flower parts.

A simple approach to quantitative analysis using three-dimensional spectra based on selected Zernike moments

A very simple approach to quantitative analysis is proposed based on the technology of digital image processing using three-dimensional (3D) spectra obtained by high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). As the region-based shape features of a grayscale image, Zernike moments with inherently invariance property were employed to establish the linear quantitative models. This approach was applied to the quantitative analysis of three compounds in mixed samples using 3D HPLC-DAD spectra, and three linear models were obtained, respectively. The correlation coefficients (R(2)) for training and test sets were more than 0.999, and the statistical parameters and strict validation supported the reliability of established models. The analytical results suggest that the Zernike moment selected by stepwise regression can be used in the quantitative analysis of target compounds. Our study provides a new idea for quantitative analysis using 3D spectra, which can be extended to the analysis of other 3D spectra obtained by different methods or instruments.

Development of a Liquid Chromatographic Method for the Simultaneous Determination of Six Benzodiazepines in Human Plasma After Solid-Phase Extraction

A simple and fast procedure is presented for the simultaneous determination of alprazolam, bromazepam, diazepam, lorazepam, lormetazepam, and tetrazepam in human plasma. The drugs were isolated by solid-phase extraction, and the subsequent analysis was carried out by high-performance liquid chromatography coupled with a diode-array detector (HPLC-DAD). This allowed recoveries of around 90% to be obtained with good sensitivity, selectivity, and resolution of the eluting peaks. The detector response at 230 nm was linear within the benzodiazepine concentration range of 20–4000 ng/mL in human plasma, with values of less than 6.7% and 5.4% for precision and accuracy, respectively.

Phenolic Content, Composition, Antioxidant Activity, and Their Changes during Domestic Cooking of Potatoes

Potatoes in the diet contribute significantly to antioxidant daily intake worldwide. The influence of different domestic cooking conditions, boiling, microwaving, and baking, on total phenolics (TP), antioxidant capacity, phenolic composition, and tryptophan content was studied using eight commercial potato varieties. The antioxidant capacity was detected by the methods of oxygen radical absorbance capacity assay (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH(*)) assay. The phenolic composition and tryptophan content were determined using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), whereas phenolics and tryptophan were identified by means of HPLC-mass spectrometry, HPLC-DAD, and authentic standards. Antioxidant capacity was influenced by potato variety and cooking conditions; however, cooked potatoes retained 68-97% ORAC value depending on cooking procedure and variety. Chlorogenic acid and its isomers dominated the phenolic composition of each variety involved in this study. ORAC and TP were highly and positively correlated (r = 0.9119). Norkotah ranked highest in chlorogenic acid content and antioxidant value. Principal component analysis showed different cooking processes did not influence the trend of the antioxidant profile of the eight potato varieties, but specific compounds exert influence on the antioxidant capacity. The results imply that the potato varieties rich in antioxidant components could be good antioxidant sources as activities are not greatly affected by different cooking conditions.