Fluorescence technology offers a highly sensitive, rapid, and efficient approach for drug screening at the cellular level, enabling the direct quantification of drug‐target binding interactions through precise measurement of fluorescence intensity changes. In our previous research, a small‐molecule fluorescent probe targeting epidermal growth factor receptor (EGFR) was successfully developed, featuring strong targeting specificity, low background signal, and an “off–on” response feature. Based on the EGFR‐overexpressing A431 cell line, this study established a cell‐based screening system for EGFR inhibitors and successfully identified flavokawain A (FKA), a novel potential EGFR inhibitor. FKA notably reduces the expression levels of p ‐EGFR and its downstream molecule p ‐Erk in the EGFR signaling pathway. It demonstrates a potent inhibitory effect on the proliferation of A431 cells, effectively suppressing clone formation and cellular migration, and exhibits a strong apoptosis‐inducing effect against A431 cells. This fluorescence‐based high‐throughput screening method has demonstrated its effectiveness in identifying novel EGFR inhibitors from a wide range of natural materials. It holds significant application potential and plays a crucial role in expediting the discovery of EGFR inhibitors from medicinal sources.
We present a portable, low-cost, modular spectrophotometric platform designed for wavelength-selective optical measurements using interchangeable visible LEDs, an AS7343 multichannel spectral sensor, and Arduino-based data acquisition. The system was developed to provide a compact alternative for optical absorbance and fluorescence measurements while maintaining performance comparable to conventional laboratory instrumentation. The device was evaluated using aqueous solutions of copper (II) sulfate (CuSO4) and potassium permanganate (KMnO4), and results were benchmarked against a standard UV–Vis spectrophotometer. The system demonstrated concentration-dependent absorbance responses consistent with the Beer–Lambert law, with strong calibration linearity (R2 = 0.99 for CuSO4 and R2 = 0.97 for KMnO4). In addition, the platform was adapted for fluorescence measurements of Rhodamine B via a simple reconfiguration to a 90° excitation–emission geometry. The fluorescence response showed linear behavior over the 0–4-μM range, yielding an R2 value of 0.97. The results indicate that the proposed system provides reliable optical measurements for both absorbance and fluorescence modalities, offering a flexible and cost-effective alternative for analytical spectrophotometry applications in resource-limited laboratory settings.
Piperine, a major active component isolated from the traditional Mongolian medicine Piper longum L. , exhibits antihyperlipidemic activity but also demonstrates inherent toxicity. In this study, ethylene glycol monopiperate (EGM), a piperine derivative, was synthesized via concentrated H 2 SO 4 ‐catalyzed esterification. Its structure was systematically characterized by FTIR, MS, 13 C NMR, and 1 H NMR, with a yield of 60% and a purity of 99.2%. Subsequently, the in vitro cytotoxicity of EGM on HepG2 cells was evaluated, and the results indicated that over 90% cell viability was observed at concentrations up to 150 μg/mL. It was also investigated in male Wistar rats, and a sensitive, rapid, and accurate solid‐phase extraction (SPE)–UPLC method was developed and validated for the quantification of EGM in rat plasma. The novel method showed good linearity over the concentration range of 1–16 µg/mL, a limit of detection (LOD) of 1 μg/mL, and high accuracy and precision (relative error [RE%] < 15%, relative standard deviation [RSD%] < 10%). In terms of antihyperlipidemic efficacy, EGM demonstrated excellent performance in reducing total cholesterol (TC), glucose (GLU), and low‐density lipoprotein cholesterol (LDL‐C), as well as elevating high‐density lipoprotein cholesterol (HDL‐C); these effects were notably better than the conventional control drug simvastatin. Pharmacokinetic analysis revealed that the plasma concentration‐time profile of EGM followed a first‐order open one‐compartment model. Calculations using WINNONLIN software (ver. 5.2) showed a half‐life ( t 1/2 ) of 1.46 ± 0.67 h and an area under the curve (AUC 0 –∞) of 7,15,530 ± 522.4 ng h/mL. EGM was stable in plasma over 24 h at room temperature and one month at −20°C, after three freeze–thaw cycles. These results verified that EGM may serve as a promising candidate for an antihyperlipidemic prodrug.
Indigo naturalis (IN, Qing‐Dai) is a well‐established traditional Chinese medicine (TCM) with extensive biological activities, particularly in the clinical management of ulcerative colitis (UC) and psoriasis. However, the comprehensive in vivo metabolic behavior of IN extract remains inadequately characterized. This research employed ultra‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry (UPLC–Q‐TOF MS) methodology to comprehensively examine the metabolic characteristics of IN in rat models. Biological samples, including plasma, bile, urine, and feces, were obtained from rats following single oral administration of IN extract. Sample preparation techniques involved protein precipitation, solid‐phase extraction, and ultrasonic extraction for processing plasma, bile, urine, and feces specimens, respectively. Through precise mass measurement and fragment ion analysis, we identified 24 prototype compounds and 37 metabolites and clarified the transformation relationships between prototypes and their metabolites. The biotransformation pathways of IN components in rats primarily involved N‐ or O‐glucuronidation, N‐ or O‐sulfation, hydroxylation, dehydroxylation, demethylation, demethoxylation, decarbonylation, and reduction reactions. Our findings demonstrate that N‐glucuronidation and N‐sulfation represent the predominant metabolic reactions. This investigation marks the first systematic report on metabolite identification and metabolic pathway speculation of major constituents following oral administration of IN extract, providing a scientific foundation for understanding its in vivo processes.
Boron trichloride (BCl3) is highly reactive and degrades rapidly when exposed to moisture, complicating analyses, and posing safety risks under standard laboratory conditions. To address these challenges, quantitative 11B nuclear magnetic resonance (qNMR) spectroscopy has been introduced as an analytical method to accurately quantitate boron trichloride in solution. This technique involves the reaction of boron trichloride with methanol to produce trimethyl borate, which is then quantified using an external standard. The preparation process allows for the reaction and sample preparation to occur in a single step within the same vial, ensuring a safe, fast, and reliable analysis. The 11B qNMR method was validated, demonstrating linearity (0.02 M to 0.50 M with r = 0.9999), accuracy (recovery of 100.05%), precision (inter- and intraday), stability, and robustness. This paper highlights the effectiveness of the 11B qNMR method for the accurate, reliable, fast, and safe quantification of boron trichloride in organic solvents such as dichloromethane.
