The aim of the presented study was to qualitatively and quantitatively determine the chemical composition of oak bark extracts in order to gain insights into the effectiveness as alternative medication for various diseases. The primary emphasis was on developing a near-infrared spectroscopy (NIRS) method for precise quantification of two key polyphenolic compounds, specifically gallic acid and catechin, in form of a fast and non-destructive quality control. A comprehensive dataset consisting of 48 samples from various production batches was analyzed throughout this research. Qualitative analysis was conducted using High Performance Liquid Chromatography coupled with a mass detector (LC-MS) to separate and identify individual components of the oak bark extract. Individual components were identified, confirmed and quantified using existing literature combined with appropriate standard references. Whereas the predominant nature of identified substances was of polyphenolic nature. Furthermore, a semi-quantitative assessment was additionally performed for eight identified constituents to identify their chemical stability or possible occurring transformations during storage, utilizing quantification via internal standard met in order to identify fluctuations and chemical variability within oakbark, five key components were precisely quantified using LC-MS and corresponding standard substances. For this purpose, HPLC measurements coupled to an Ultraviolet/Visible (UV/Vis) detector were utilized as reference method. NIRS measurements were performed on a FT-NIR benchtop device in transmission mode. Partial least squares regression (PLSR) was then applied for model building, after identifying the optimal spectral pretreatment. Model evaluation was performed using leave-one-out-cross validation followed by evaluation of an independent test set. The model proved promising results for the quantification of gallic acid on the benchtop device with a standard error of cross validation (SECV) of 13.41 mg/L and a standard error of prediction (SEP) of 19.33 mg/L, while the absolute concentrations of the different batches analyzed ranged from 126.49 to 332.54 mg/L. For the quantification of catechin the SECV was reported at 23.61 mg/L, the SEP at 32.35 mg/L with sample concentrations falling between 13.50 and 383.72 mg/L. In this study, we introduce various analytical methodologies for both qualitative and quantitative assessment of a complex phytochemical sample, specifically oak bark extract, aimed at identifying and confirming the presence of active compounds within the extract.

The aim of this work was to develop and validate a rapid dispersive-solid-phase extraction method for the quantification of pyrrolizidine alkaloids (PA) from plant extracts. The method was focused on the significant removal of the intricate matrix to ensure good sensitivity for the subsequent instrumental analysis of PA. This was achieved by employing nano-zirconium silicate (NZS) as a dispersive-SPE sorbent. The specific affinity of NZS for PAs allowed for the effective removal of a substantial portion of the complex matrix, thereby significantly improving the sensitivity of the method, compared to the common methods, were no specific enrichment of the PAs on the SPE sorbent is achieved. Ultra-high-performance liquid chromatography coupled to high resolution time-of-flight mass spectrometry (UHPLC/TOF MS) was used for the qualitative and quantitative analysis of PA. The procedure demonstrated high recoveries for the standard compounds spiked into a blank verbena extract at different concentrations. Recovery rates of 72-95 % for PA, and 30-70 % for their respective N-oxides (PANO) could be obtained. The method was compared to the most commonly used C18 SPE sorbent, and demonstrated a significant lower limit of quantification (LOQ) of 0.64-4.5 ng mL^-1 as compared to 4.98-25.7 ng mL^-1. The method was validated in accordance with ICH guidelines. PA standards had a linear response between 5 and 150 ng mL ^-1 and demonstrated a co-efficient of variance below ± 3 % with a % relative error below ± 15. The presented analytical approach was also tested for the determination of PA from contaminated Verbenae herba extract with success. The presented scheme improves the clean-up efficacy of the already used stationary phases for PA analysis and provides a great alternative analytical tool for the isolation of PAs from plant extracts.

This study provides a phytochemical characterization of Sambucus nigra L. (elderflower) and correlates its chemical profile with anti-inflammatory bioactivity, establishing an optimized extraction methodology. A comparative analysis of ultrasound-assisted extraction (UAE), accelerated solvent extraction (ASE), and shaking maceration was conducted using solvents of varying polarity (ethanol, ethanol–water mixture (1:1, v/v), and water). High-resolution fingerprinting via HPLC-ESI-QTOF-MS/MS confirmed a rich polyphenolic profile, dominated by flavonoids such as rutin, naringenin, and phenolic acids, notably chlorogenic acid. Quantitative analysis revealed that UAE with ethanol–water mixture (1:1, v/v) for 20 min yielded the highest recovery of rutin (4.87%) and chlorogenic acid (8.22%). The anti-inflammatory potential was evaluated in TNFα-stimulated HaCaT NF-κB Luc reporter keratinocytes. Anhydrous ethanolic extracts demonstrated superior efficacy, significantly inhibiting NF-κB pathway activation at non-cytotoxic concentrations. Chemometric analysis, specifically PLS-DA, identified naringenin as a principal contributor to this observed anti-inflammatory effect. These findings underscore the critical role of solvent selection in modulating the phytochemical composition and resultant bioefficacy of elderflower extracts. The potent, naringenin-driven inhibition of NF-κB in keratinocytes highlights the significant therapeutic potential of optimized S. nigra extracts for applications in dermatological and cosmetic formulations aimed at managing inflammatory skin disorders.

Pyrrolizidine alkaloids (PAs) are a chemically diverse group of plant-derived toxins whose quantification in botanical materials remains analytically challenging. This study integrates previously established nano zirconium silicate (NZS) enrichment with one-pot lithium aluminium hydride reduction/hydrolysis and LC–HRMS determination of the resulting necine-base response. The workflow targets retronecine- and heliotridine-type PAs and their N-oxides, with results expressed as retronecine equivalents. In Radix Primulae, three independent samples were spiked at each of 200, 250 and 300 µg/kg retronecine equivalents and processed through the complete analytical workflow. Mean recoveries were 83.0%, 94.2% and 92.5%, with between-preparation RSDs of 3.12%, 1.55% and 1.96%, respectively. Matrix-matched regression was evaluated using six calibration levels (10, 100, 200, 300, 400, 500; Day-1 R² = 0.99936). Calculated Day-1 LOD and LOQ estimates were 14.94 and 45.27 µg/L. Remeasurement of the same extracts after 24 h, using a separate daily calibration, gave paired concentration changes of −0.67% to +1.23%. Application to a naturally contaminated comfrey sample demonstrated the workflow’s applicability beyond spiked samples, with agreement between the conversion-based result and the summed intact-PA reference approach.