Development of a high-performance liquid chromatography using rhodamine B hydrazide as the derivatization reagent for determination of ß propiolactone residues in inactivated COVID-19 vaccines.

ß-propiolactone (BPL) is an alkylating agent used for inactivation of biological samples such as vaccines. Due to its known carcinogenic properties, complete hydrolysis of BPL is essential, and the detection of trace amounts is crucial. In this study a novel High-Performance Liquid Chromatography-Ultraviolet (HPLC-UV) method was developed. Rhodamine B hydrazide (RBH) was synthesized and utilized as a derivatizing reagent to react with BPL. The reaction was optimized in a weak acidic solution, resulting in a high yield. The separation of the RBH-derivatized BPL was achieved on a C8 column and detected by a UV detector at a wavelength of 560 nm. The method's validation demonstrated a high linearity (r2 > 0.99) over a concentration range of 0.5-50 µg/mL, with detection and quantification limits of 0.17 µg/mL and 0.5 µg/mL, respectively. The average recovery of samples was 85.20 % with a relative standard deviation (RSD) of 1.75 %. This method was successfully applied for BPL residue analysis in inactivated COVID-19 vaccines. This novel derivatization method offers a promising solution for monitoring BPL residues in the vaccine production process for quality control purposes and compliance with regulatory standards.

Chemical detection and analysis of Astragalus-Cassia twig drug pair using UHPLC-Q-TOF-MS and HPLC-UV methods.

The classic Astragalus-Cassia twig drug pair has a long history of proven efficacy. However, a fewer studies on material basis of the Astragalus and Cassia twig decoction (ACD) was researched at present. The method of UPLC-Q-TOF-MS for classifying and identifying the main chemical components of ACD was established and the differences in composition between single decoction and co-decoction were compared by using HPLC-UV. The therapeutic role of ACD on type 2 diabetes (T2D) rats was investigated. Thirty-five compounds were resolved from the ACD. Fifteen compounds were deduced from the decoction of Astragalus, whereas nine compounds were identified from Cassia twig. Pairing of herbs make a significant effect on the chemical composition of herbal decoction. ACD can play a more obvious role in alleviating the symptoms of T2D rats, compared to the application of single herb.

Free serum concentrations of antibiotics determined by ultrafiltration: extensive evaluation of experimental variables.

Aim: To assess the impact of experimental conditions on free serum concentrations as determined by ultrafiltration and HPLC-DAD analysis in a wide range of antibiotics. Materials & methods: Relative centrifugation force (RCF), temperature, pH and buffer were varied and the results compared with the standard protocol (phosphate buffer pH 7.4, 37°C, 1000 × g). Results: Generally, at 10,000 × g the unbound fraction (fu) decreased with increasing molecular weight, and was lower at 22°C. In unbuffered serum, the fu of flucloxacillin or valproic acid was increased, that of basic or amphoteric drugs considerably decreased. Comparable results were obtained using phosphate or HEPES buffer except for drugs which form metal chelate complexes. Conclusion: Maintaining a physiological pH is more important than strictly maintaining body temperature.

[Box: see text].

Phytochemical Analysis and Evaluation of Antioxidant and Antimicrobial Properties of Essential Oils and Seed Extracts of Anethum graveolens from Southern Morocco: In Vitro and In Silico Approach for a Natural Alternative to Synthetic Preservatives.

Anethum graveolens is an aromatic plant traditionally used as an antispasmodic and carminative. The objective of this study is to analyze the chemical composition of the essential oils and extracts obtained from seeds gathered in Errachidia, southern Morocco. Additionally, the antioxidant and antimicrobial properties of these oils and extracts will be evaluated. GC-MS analysis of the EO isolated by hydrodistillation revealed that its main compounds were E-anethole (38.13%), estragole (29.32%), fenchone (17.21%), and α-pinene (7.37%). The phenolic components were extracted using the methods of decoction and Soxhlet. The assay of the phenolic compounds showed that A. graveolens seeds contained considerable amounts of polyphenols, flavonoids, and condensed tannins, with variable levels depending on the extract analyzed. HPLC/UV-ESI-MS analyses performed on the decoction revealed a structural diversity of the molecules present in this extract, the most important of which were umbelliferone (12.35%), 3-hydroxyflavone (11.23%), rosmanol (8.95%), biotin (8.36%), emmotin H (4.91%), and coumarin (4.21%). The antioxidant activity, as determined by three techniques (DPPH•, FRAP, and CAT), demonstrated that the essential oils (EOs) and extracts had a potent capacity to counteract detrimental free radicals, control the generation of reactive oxygen species, and mitigate oxidative damages. The antimicrobial activity of the Eos and extracts was carried out in a liquid medium against five strains (E. cloacae, K. pneumoniae, E. coli, S. aureus, and S. epidermidis) and four candidiasis (C. albicans, C. dubliniensis, C. tropicalis, and C. parapsilosis) and Aspergillus niger. The results showed the effectiveness of the EOs compared to the aqueous, ethanolic, and decoction extracts against most of the microorganisms tested. In addition, the ethanolic extract showed antifungal activity that was distinguished from that of the other extracts. The antimicrobial efficacy of the essential oils under study can primarily be attributed to the synergistic interactions among its three principal constituents (E-anethole, estragole, and fenchone). Furthermore, molecular docking and molecular dynamics simulation results reveal significant interactions and stability between the selected bioactive compounds and different target proteins involved in antimicrobial and antioxidant activities. Compounds like 3-hydroxyflavone, emmotin H, trans-caftaric acid, methyl rosmarinate, 1-caffeoyl-beta-D-glucose, and kaempferol exhibited better binding energies with the explored proteins, indicating their potential as antimicrobial and antioxidant agents. Finally, our findings emphasize the significance of A. graveolens seeds as a promising reservoir of advantageous health compounds that can serve as organic substitutes for the presently employed synthetic preservatives.

Validation of a bioanalytical HPLC-UV method to quantify Α-Bisabolol in rat plasma applied to pharmacokinetic pilot study with the drug nanoemulsion.

α-Bisabolol (α-BIS) is a sesquiterpene alcohol present in chamomile essential oil [Chamomilla recutita (L.) Rauschert]. Despite its numerous pharmacological effects, its pharmacokinetics remain understudied. An analytical method capable of quantifying α-BIS in plasma is crucial to enable pharmacokinetic analysis. Presently, only one study has quantified it using mass spectrometry. Administering α-BIS requires a nanoemulsion for intravenous injection. This study aimed to develop and validate a bioanalytical method using high-performance liquid chromatography with an ultraviolet detector to quantify α-BIS in rat plasma. The method employed acetonitrile and ultrapure water (80:20, v/v) as the mobile phase, with a flow rate of 1 ml/min and concentrations ranging from 465 to 29.625 µg/ml. All US Food and Drug Administration-designated assays were successful, indicating the method's precision, accuracy, sensitivity and linearity in determining α-BIS in rat plasma. The developed nanoemulsion, assessed through dynamic light scattering analysis, the ensemble collection of particles and polydispersity index evaluation, proved safe and effective for intravenous administration. The pharmacokinetic parameters such as volume of distribution, clearance and half-life indicated that α-BIS tends to persist in the body. This study provides a foundation for further research to explore α-BIS's potential pharmaceutical applications in the future.

Evaluation of parenteral diluent contamination by caprolactam.

DISCLAIMER: In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. PURPOSE: A leachable cyclic amide (caprolactam) can be found in normal saline (NS) and 5% dextrose in water (D5W) plastic bags widely used in clinical practice if they contain polyamide in a multilayer sheeting. This contamination and the parameters that could influence its content have never been studied in a public work such as a scientific publication. METHODS: Two independent laboratories validated a caprolactam dosing method and studied contamination levels in several containers. RESULTS: Caprolactam content in multilayer polypropylene/polyamide/polypropylene plastic bags ranged from a mean (SD) of 5.43 (0.21) mg/L (D5W 1,000 mL) to 22.83 (1.26) mg/L (NS 50 mL). NS and D5W can be intravenously administered with a total daily dose of 3 L, corresponding to a minimal daily dose of 16.3 mg of caprolactam. CONCLUSION: The high levels of contamination we have reported and the possibility of administering caprolactam to high-risk patients (eg, neonates, the elderly) should make it imperative for pharmaceutical companies to communicate publicly on the safety of caprolactam.

An HPLC-UV Method to Assess Human Plasma 25(OH)D3.

The aim of this study was to validate an HPLC-UV method to assess vitamin D status by determining the linearity and precision of the 25-hydroxyvitamin D3 (25(OH)D3) calibration curve, the limits of detection, quantitation and robustness of the method, and its accuracy. A second stock solution of 25(OH)D3 was prepared (500 ng/mL), and working dilutions (5, 10, 20, 30, 40, and 50 ng/mL) were prepared for a calibration curve. The HPLC equipment had a UV-Vis diode-array detector and utilized an AcclaimTM 120 C18 column (5 µm, 4.6 × 250 mm) with a flow rate of 1.2 mL/min, a column temperature of 30 °C, and the standards and samples were maintained at 4 °C, with an injection volume of 100 µL. Detection of 25(OH)D3 was determined at 265 nm, with a retention time of 4.0 min. The validation was conducted according to the FDA Validation of Analytical Procedures: Guidance for Industry. Vitamin D was extracted from plasma samples using acetonitrile (ACN)-0.1% formic acid (2:1 v/v), and the percentage of recovery was calculated. The proposed method conditions gave excellent linearity (R2 = 0.9989) and the linearity coefficient was R2 > 0.99 for 25(OH)D3. The detection and quantification limits were 1.1703 ng/mL and 3.5462 ng/mL, respectively. Decreasing or increasing the reading temperature by 1 °C decreased the response units (AU) of vitamin D, 25(OH)D3. When the current flow rate decreased by 0.2 mL/min (1.0 mL/min), the retention time increased to 4.913 min, whereas an increase of 0.2 mL/min of the proposed flow rate (1.4 mL/min) decreased the retention time to 3.500 min. The percentage of recovery varied from 92.2% to 97.1%. The proposed method to quantify a vitamin D metabolite (25(OH)D3) in human plasma samples was reliable and validated.

Pesticide residues in traditional and industrial honey marketed in Morocco and potential health risk.

This study evaluated the presence of the three pesticides methomyl (MET), carbendazim (CBZ) and chlorpyrifos-ethyl (CPE), as well as the degradation product of CPE (3,5,6-trichloro-2-pyridinol; TCP), in 44 honey samples from all 12 regions of Morocco. With a validated HPLC-UV method occurrence frequencies of 63.6% for MET, 54.5% for CBZ, 95.1% for CPE and 34.1% for TCP were obtained, even at concentrations higher than the maximum residue limits for MET, CPE and TCP. Based on the predominant pesticide, principal component analysis separated sampling regions into three groups. Risk assessment indicated that ingestion of these pesticides, alone or in combination, in honey did not pose a risk to consumers (HQ and HI < 1).

Tetrodotoxin Derivatization with a Newly Designed Boron Reagent Leads to Conventional Reversed-Phase Liquid Chromatography.

Tetrodotoxin (TTX) is a representative natural toxin causing pufferfish food poisoning, which is especially prominent in East and Southeast Asia, including Japan. TTX has been analyzed through post-column derivatization high-performance liquid chromatography (HPLC), ion-pair LC-MS(/MS), and hydrophilic interaction liquid chromatography (HILIC)-MS(/MS) as alternatives to the mouse bioassay method. However, post-column derivatization requires a system for online derivatization reactions, and with the ion-pair LC-MS approach, it is difficult to remove residual ion-pair reagents remaining in the equipment. Moreover, HILIC-MS provides poor separation compared to reversed-phase (RP) HPLC and requires a long time to reach equilibration. Therefore, we decided to develop a TTX analytical method using pre-column derivatization and RP HPLC for the rapid assessment of outbreak samples, including food remnants. In this study, we focused on the vic-diol moiety of TTX and designed a new derivatization reagent coded as NBD-H-DAB. This NBD-H-DAB was synthesized from 4-hydrazino-7-nitro-2,1,3-benzoxadiazole (NBD-H) and 3-fluoro-2-formylphenylboronic acid (FFPBA) with a simple reaction system and rapidly converted to its boronate form, coded NBD-H-PBA, in an aqueous reaction solution. The NBD-H-PBA demonstrated appropriate hydrophobicity to be retained on the RP analytical column and successfully detected with a UV spectrometer. It was easily reacted with the vic-diol moiety of TTX (C6 and C11) to synthesized a boronic ester. The derivatized TTX could be detected using the RP HPLC-UV, and the limit of detection in the fish flesh samples was 0.06 mg/kg. This novel pre-column derivatization of TTX with NBD-H-PBA proves capable for the analysis of TTX.

Quantitative Analysis of Vitamin D2 and Ergosterol in Yeast-Based Supplements Using High-Performance Liquid Chromatography with Ultraviolet Detection.

Owing to ergosterol content, after UV irradiation yeast become a well-known source of ergocalciferol (vitamin D2). Additionally, pharmaceutical yeast-based supplements may represent a suitable option for treating hypovitaminosis, especially in patients adhering to a vegan diet. Using the high-performance liquid chromatography-ultraviolet (HPLC-UV) methodology our study sought to analyse three commercially available yeast-based vitamin D2 supplements while comparing the effect of UV-C irradiation (254 nm) on yeast biomass derived from the brewing process and pure ergosterol. The two compounds were precisely separated under the described conditions in an efficient and quick manner with a retention time (Rt) of 4.152 ± 0.018 minutes for vitamin D2 and 5.097 ± 0.013 minutes for ergosterol. However, when approaching the quantitative analysis, based on our findings, it appears that the pharmaceutical supplements deviate from the declared amount of substance indicated on the label. 15 minutes of UV-C irradiation generates vitamin D2 in yeast biomass with a conversion rate of 1.78%. Also, high content of ergosterol, beside vitamin D2 formation after irradiation, may trigger the appearance of secondary products such as tachysterol.

Ceftobiprole quantification in human serum by HPLC-UV to implement routine TDM in clinical practice.

BACKGROUND AND AIMS: Ceftobiprole is a recent 5th generation parenteral cephalosporin with antibacterial activity against a large range Gram+ and Gram- bacteria. Therapeutic drug monitoring (TDM) is an essential tool for maintaining plasma concentrations of antibiotics above the MIC by the end of the dosing interval, thus preventing the resistant strain diffusion. TDM is already recommended for other cephalosporins, and it is a reasonable tool contributing to the safety and efficacy of these drugs. During the treatment of patients in real-life, a number of pharmacokinetic (PK) changes not normally seen in healthy volunteers can occur which can impair the pharmacokinetic/pharmacodynamic target attainment. We aimed to develop simple and rapid HPLC-UV method for determination of ceftobiprole in human serum to implement TDM in clinical practice and support PKs and pharmacokinetic/pharmacodynamic (PK/PD) studies. MATERIALS AND METHODS: Samples preparation of calibration standards, QC, and anonymous patients serum samples was performed by protein precipitation by adding 0.01 ml of sulphosalicylic acid at 30 % to 0.1 ml of each sample. Then samples were vortexed and the centrifuged at 12,000 rpm for 10 min at 4 °C. Fifty microlitres of clear supernatant were diluted 1:1 with mobile phase and transferred into HPLC autosampler held at 8 °C. Chromatographic separation was carried out in a gradient mode at 35 °C on an ultra-Biphenyl column using a Thermo Scientific chromatographic system with a Diode array. Data management was performed with Chromeleon 7.4 software. RESULTS: The HPLC-UV method proved to be linear over wide concentration ranges (0.5-50.0 mg/L) and was accurate and reproducible in the absence of matrix effects, allowing for robust, specific, and rapid quantification of ceftobiprole from a low amount of serum (0.1 mL). The mean steady state Ctrough and Cend values measured in the anonymous patients' samples were 6.26 ± 3.81 mg/L and 22.56 ± 15.69 mg/L, respectively. CONCLUSIONS: We report a broadened simple and fast HPLC with UV detection method for quantification of ceftobiprole in human serum to implement ceftobiprole TDM as clinical routine, and support future (PK/PD) studies in special patients' population.

Development and Validation of a Simple and Reliable HPLC-UV Method for Determining Gemcitabine Levels: Application in Pharmacokinetic Analysis.

Background and Objectives: Gemcitabine has been used to treat various solid cancers, including, since 1997, metastatic pancreatic cancer. Here, we developed an HPLC-UV method to determine serum gemcitabine levels and use it in pharmacokinetic studies. Materials and Methods: The analysis was performed after a single protein precipitation step on a reversed-phase column, isocratically eluted with sodium phosphate buffer and methanol. For the pharmacokinetic study, NOD/SCID mice received a single dose of gemcitabine at 100 mg/kg by either subcutaneous (SC) or intraperitoneal (IP) administration. Blood samples were collected at 5, 15, and 30 min and 1, 2, 4, and 6 h after the administration of gemcitabine for further analysis. Results: The duration of the analysis was ~12.5 min. The calibration curve was linear (r2 = 0.999) over the range of 1-400 µM. The mean recovery of GEM was 96.53% and the limit of detection was 0.166 µΜ. T1/2, Tmax, Cmax, AUC0-t, and clearance were 64.49 min, 5.00 min, 264.88 µmol/L, 9351.95 µmol/L*min, and 0.0103(mg)/(µmol/L)/min, respectively, for the SC administration. The corresponding values for the IP administration were 59.34 min, 5.00 min, 300.73 µmol/L, 8981.35 µmol/L*min and 0.0108(mg)/(µmol/L)/min (not statistically different from the SC administration). Conclusions: A simple, valid, sensitive, and inexpensive method for the measurement of gemcitabine in serum has been developed. This method may be useful for monitoring gemcitabine levels in cancer patients as part of therapeutic drug monitoring.

Development, optimization and validation of an analytical method for the determination of voriconazole in plasma by high-performance liquid chromatography-ultraviolet detection: Application for comprehensive study.

OBJECTIVES: Voriconazole is a widely used antifungal agent in clinical settings. However, its use has been associated with neurological side effects in some patients. For this reason, it is crucial to monitor its plasma levels to ensure that they are within the therapeutic range. Thus, in this study, we aimed to develop a simple, fast, and efficient method for the determination of voriconazole in plasma using reversed-phase HPLC-UV. We also aimed to validate the method for its application to routine analysis of immunocompromised patients. MATERIAL AND METHODS: Plasma samples from immunocompromised patients were subjected to deproteinization with acetonitrile followed by centrifugation. Chromatographic separation was carried out on a C18 column with UV detection at 254nm in isocratic mode. The concentrations were calculated by comparing peak areas to those of the internal standard, ketoconazole. The method was validated using the accuracy profile, which uses a calibration curve established for the therapeutic range of 1 to 5.5µg/mL. RESULTS: The developed method was proved to be rapid by giving a short analysis time for voriconazole at around 5.5min. Additionally, no interference with the biological matrix was detected. The obtained recoveries were higher than 90%. The accuracy profile showed that the method was accurate and precise for the determination of voriconazole in plasma. CONCLUSION: The developed method was proved to be simple, efficient, that requires minimal sample preparation. Thus, it can be routinely applied for the therapeutic monitoring of voriconazole.

Development and validation of HPLC-ultraviolet method for quantitative determination of pritelivir in human placental perfusion medium.

A simple and reliable HPLC-ultraviolet (HPLC-UV) method was developed and validated for the quantification of pritelivir in the samples of medium from the experiments utilizing the ex vivo technique of dual perfusion of the human placental lobule. Phenacetin was used as an internal standard (IS) in our HPLC-UV method. Chromatographic separation of pritelivir and phenacetin was achieved on a Waters Symmetry C18 HPLC column (100 × 2.1 mm, 3.5 µm) at ambient temperature (22-25°C). The mobile phase was composed of 50% methanol in deionized water (v/v), the flow rate for isocratic elution was established at 0.25 mL/min, and the detection wavelength for pritelivir and IS was set at 254 nm. Pritelivir and IS were extracted with the protein precipitation method using methanol as a solvent. The calibration curve for pritelivir exhibited linearity (r2 > 0.99) within the concentration range from 0.155 to 6.62 µg/mL. Within- and between-day accuracy ranged from 97% to 110% with relative standard deviation (RSD) values not exceeding 10%. The extraction recovery of pritelivir and IS ranged from 89% to 91% with RSD not exceeding 7%. Pritelivir was stable under the storage and sample handling conditions. This validated HPLC-UV method was utilized to quantify pritelivir in the placental perfusion medium samples, and the resulting concentrations were authenticated with incurred sample reanalysis to confirm the reliability of the method.

HPLC-Based Metabolomic Analysis and Characterization of Amaranthus cruentus Leaf and Inflorescence Extracts for Their Antidiabetic and Antihypertensive Potential.

The aim of this study was to investigate the potential of Amaranthus cruentus flavonoids (quercetin, kaempferol, catechin, hesperetin, naringenin, hesperidin, and naringin), cinnamic acid derivatives (p-coumaric acid, ferulic acid, and caffeic acid), and benzoic acids (vanillic acid and 4-hydroxybenzoic acid) as antioxidants, antidiabetic, and antihypertensive agents. An analytical method for simultaneous quantification of flavonoids, cinnamic acid derivatives, and benzoic acids for metabolomic analysis of leaves and inflorescences from A. cruentus was developed with HPLC-UV-DAD. Evaluation of linearity, limit of detection, limit of quantitation, precision, and recovery was used to validate the analytical method developed. Maximum total flavonoids contents (5.2 mg/g of lyophilized material) and cinnamic acid derivatives contents (0.6 mg/g of lyophilized material) were found in leaves. Using UV-Vis spectrophotometry, the maximum total betacyanin contents (74.4 mg/g of lyophilized material) and betaxanthin contents (31 mg/g of lyophilized material) were found in inflorescences. The leaf extract showed the highest activity in removing DPPH radicals. In vitro antidiabetic activity of extracts was performed with pancreatic α-glucosidase and intestinal α-amylase, and compared to acarbose. Both extracts exhibited a reduction in enzyme activity from 57 to 74%. Furthermore, the in vivo tests on normoglycemic murine models showed improved glucose homeostasis after sucrose load, which was significantly different from the control. In vitro antihypertensive activity of extracts was performed with angiotensin-converting enzyme and contrasted to captopril; both extracts exhibited a reduction of enzyme activity from 53 to 58%. The leaf extract induced a 45% relaxation in an ex vivo aorta model. In the molecular docking analysis, isoamaranthin and isogomphrenin-I showed predictive binding affinity for α-glucosidases (human maltase-glucoamylase and human sucrase-isomaltase), while catechin displayed binding affinity for human angiotensin-converting enzyme. The data from this study highlights the potential of A. cruentus as a functional food.

Exploring a Lux® i-Amylose-3 column in normal phase and polar-organic mode for chiral separation of cathinone derivatives and pyrovalerones using high-performance liquid chromatography.

Each year, new psychoactive substances appear on the global drug market leading to constant changes. Most of these compounds with stimulating effect possess a chiral center, thus leading to two enantiomers with presumably different pharmacological properties. Among them, synthetic cathinones, often misleadingly traded as "bath salts," play an important role. There is little knowledge about the distinct effect of the enantiomers. The aim of this study was to test a commercially available Lux® i-Amylose-3 column by HPLC-UV for enantiorecognition of cathinone derivatives. Overall, 80 compounds were tested in normal phase mode, where 75 substances were separated under initial conditions. After method optimization, at least partial separation was achieved for the remaining compounds. The same set of substances was measured in polar-organic mode, where 63 analytes were resolved into their enantiomers under initial conditions with very short retention times. Both modes showed complementary results for the individual compounds. Furthermore, the tested methods proved to be suitable for differentiation of positional isomers, which can be useful for drug checking programs. All measurements were carried out under isocratic conditions, and intraday and interday repeatability tests were performed.

Flavonoids with lipase inhibitory activity from lemon squeezing waste: isolation, multispectroscopic and in silico studies.

BACKGROUND: Obesity is recognized as a lifestyle-related disease and the main risk factor for a series of pathological conditions, including cardiovascular diseases, hypertension and type 2 diabetes. Citrus limon is an important medicinal plant, and its fruits are rich in flavonoids investigated for their potential in managing obesity. In the present work, a green extraction applied to lemon squeezing waste (LSW) was optimized to recover pancreatic lipase (PL) inhibitors. RESULTS: The microwave-assisted procedure yielded an extract with higher lipase inhibitory activity than those obtained by maceration and ultrasound. The main compounds present in the extract were identified by high-performance liquid chromatographic-mass spectrometric analysis, and hesperidin, eriocitrin and 4'-methyllucenin II were isolated. The three compounds were evaluated for in vitro PL inhibitory activity, and 4'-methyllucenin II resulted in the most promising inhibitor (IC50 = 12.1 µmol L-1; Ki = 62.2 µmol L-1). Multispectroscopic approaches suggested the three flavonoids act as competitive inhibitors and the binding studies indicated a greater interaction between PL and 4'-methyllucenin II. Docking analysis indicated the significant interactions of the three flavonoids with the PL catalytic site. CONCLUSION: The present work highlights flavonoid glycosides as promising PL inhibitors and proposes LSW as a safe ingredient for the preparation of food supplements for managing obesity. © 2024 Society of Chemical Industry.

Effects of Growing Areas, Pruning Wound Protection Products, and Phenological Stage on the Stilbene Composition of Grapevine (Vitis vinifera L.) Canes.

Applying plant protection products (PPP) on grapevine pruning wounds is a viticultural practice used to mitigate the spread of grapevine tuck disease, which is posing serious economic losses in the vine-wine industry. However, the impact of PPP on woody tissues remains unclear. Our study, conducted in two European vineyards, investigated the effects of Cuprocol, Tessior, Esquive, and Bentogran on stilbenes, in canes of Cabernet sauvignon and Syrah, at three phenological stages. Main stilbenes, quantified by HPLC-UV-DAD (1260 Agilent Infinity System) and identified by HPLC-ESI/MS (Thermo Scientific LCQ FLEET system), included E-resveratrol, E-ε-viniferin, E-piceatannol, and E-polydatin. Canes exhibited varying proportions of individual stilbenes, reflecting differences based on climatic conditions and phenological phases, rather than on the application of specific PPP. Vines grown in cool-climate conditions exhibited higher levels of E-resveratrol, whereas vines from the Mediterranean climate area exhibited higher levels of E-ε-viniferin. We also observed divergences in the accumulation trend of wood stilbenes throughout the season in canes collected in the two different growing areas.

High-Performance Liquid Chromatographic Quantification of the Plant Hormone Abscisic Acid at ppb Levels in Plant Samples after a Single Immunoaffinity Column Cleanup.

High-performance liquid chromatography with ultraviolet detection (HPLC-UV) is a common analysis technique due to its high versatility and simple operation. In the present study, HPLC-UV detection was integrated with immunoaffinity cleanup (IAC) of the sample extracts. The matrix effect was greatly reduced, and the limit of detection was as low as 1 ng/g of free abscisic acid (ABA) in fresh plant tissues. A monoclonal antibody 3F1 (mAb 3F1) was developed to specifically recognize free ABA but not ABA analogues. The mAb 3F1-immobilized immunoaffinity column exhibited a capacity of 850 ng/mL and an elution efficiency of 88.8-105% for standards. The extraction recoveries of the column for ABA ranged from 80.4 to 108.9%. ABA content was detected in various plant samples with IAC-HPLC-UV. The results were verified with ultraperformance liquid chromatography-electrospray tandem mass spectrometry. IAC-HPLC-UV can be a sensitive and cost-efficient method for plant hormone analysis.

Assessing ß-Sitosterol Levels in Dietary Supplements for Benign Prostatic Hyperplasia: Implications for Therapeutic Efficacy.

Introduction Benign prostatic hyperplasia (BPH) is a prevalent condition among aging men that affects their life quality due to urinary symptoms. Current pharmacologic treatments, often lead to sexual dysfunction, so dietary supplements (DS) containing plant-based compounds such as ß-sitosterol (SIT) are preferred. DS are highly accessible and widely used, but poorly regulated, so often patients are victims of fraud. The use of DS to treat BPH symptoms is questionable, and this may be due not to the efficacity of the active compound but to the quality of commonly available DS. Aim This study aimed to assess the concentration of SIT in DS available on the market and evaluate whether the concentration of the active compound at the recommended dosage is sufficient to elicit beneficial effects in BPH. Method An HPLC-UV method based on direct saponification and acid hydrolysis was developed for the quantification of free and conjugated SIT in DS. The concentration of SIT in various DS was determined and compared with the one declared on the label. Results The chromatographic analysis confirmed the presence of SIT in all the DS but also showed a considerable variability of SIT content among DS, with only one product meeting the necessary concentration to bring potential benefits in BPH. Conclusion The study highlights inconsistencies in SIT content among DS and the importance of DS containing a standardized extract of SIT. Quality control measures are imperative to ensure that consumers receive effective and safe SIT-based DS to manage BPH symptoms. Further research is needed to establish standardized dosages and to evaluate their long-term efficacy and safety.