[Applications of ion chromatography for the analysis of Chinese herbal medicine components].

Ion chromatography (IC) is a novel high performance liquid chromatographic technique that is suitable for the separation and analysis of ionic substances in different matrix samples. Since 1975, it has been widely used in many fields, such as the environment, energy, food, and medicine. IC compensates for the separation limitations of traditional gas chromatography and high performance liquid chromatography and can realize the qualitative analysis and quantitative detection of strongly polar components. This chromatographic technique features not only simple operations but also rapid analysis. The sensors used in IC are characterized by high sensitivity and selectivity, and the technique can simultaneously separate and determine multiple components. Several advances in IC instrumentation and chromatographic theories have been developed in recent years. IC can analyze various types of samples, including ions, sugars, amino acids, and organic acids (bases). Chinese herbal medicines are typically characterized by highly complex chemical compositions and may contain carbohydrates, proteins, alkaloids, and other active components. They also contain toxic residues such as sulfur dioxide, which may be produced during the processing of medicinal materials. Therefore, the analysis and elucidation of the precise chemical constituents of Chinese herbal medicines present key problems that must be resolved in modern Chinese herbal medicine research. In this context, IC has become an important method for analyzing and identifying the complex components of Chinese herbal medicines because this method is suitable for detecting a single active ingredients among complex components. This paper introduces the different types and principles of IC as well as research progress in this technique. As the applications of IC-based methods in pharmaceutical science, cell biology, and microbiology increase, further development is necessary to expand the applications of this technique. The development of innovative techniques has enabled IC technologies to achieve higher analytical sensitivity, better selectivity, and wider application. The components of Chinese herbal medicines can be divided into endogenous and exogenous components according to their source: endogenous components include glycosides, amino acids, and organic acids, while exogenous components include toxic residues such as sulfur dioxide. Next, the applications of IC to the complex components of Chinese herbal medicines in recent decades are summarized. The most commonly used IC technologies and methods include ion exchange chromatography and conductivity detection. The advantages of IC for the analysis of alkaloids have been demonstrated. This method exhibits better characteristics than traditional analytical methods. However, the applications of IC for the speciation analysis of inorganic anions are limited. Moreover, few reports on the direct application of the technique for the determination of the main active substances in Chinese herbal medicines, including flavonoids, phenylpropanoids, and steroids, have been reported. Finally, this paper reviews new IC technologies and their application progress in Chinese herbal medicine, focusing on their prospects for the effective separation and analysis of complex components. In particular, we discuss the available sample (on-line) pretreatment technologies and explore possible technologies for the selective and efficient enrichment and separation of different components. Next, we assess innovative research on solid-phase materials that can improve the separation effect and analytical sensitivity of IC. We also describe the features of multidimensional chromatography, which combines the advantages of various chromatographic techniques. This review provides a theoretical reference for the further development of IC technology for the analysis of the complex chemical components of Chinese herbal medicines.

A breakthrough in phytochemical profiling: ultra-sensitive surface-enhanced Raman spectroscopy platform for detecting bioactive components in medicinal and edible plants.

A perennial challenge in harnessing the rich biological activity of medicinal and edible plants is the accurate identification and sensitive detection of their active compounds. In this study, an innovative, ultra-sensitive detection platform for plant chemical profiling is created using surface-enhanced Raman spectroscopy (SERS) technology. The platform uses silver nanoparticles as the enhancing substrate, excess sodium borohydride prevents substrate oxidation, and methanol enables the tested molecules to be better adsorbed onto the silver nanoparticles. Subsequently, nanoparticle aggregation to form stable "hot spots" is induced by Ca2+, and the Raman signal of the target molecule is strongly enhanced. At the same time, deuterated methanol was used as the internal standard for quantitative determination. The method has excellent reproducibility, RSD ≤ 1.79%, and the enhancement factor of this method for the detection of active ingredients in the medicinal plant Coptis chinensis was 1.24 × 109, with detection limits as low as 3 fM. The platform successfully compared the alkaloid distribution in different parts of Coptis chinensis: root > leaf > stem, and the difference in content between different batches of Coptis chinensis decoction was successfully evaluated. The analytical technology adopted by the platform can speed up the determination of Coptis chinensis and reduce the cost of analysis, not only making better use of these valuable resources but also promoting development and innovation in the food and pharmaceutical industries. This study provides a new method for the development, evaluation, and comprehensive utilization of both medicinal and edible plants. It is expected that this method will be extended to the modern rapid detection of other medicinal and edible plants and will provide technical support for the vigorous development of the medicinal and edible plants industry.

Discrimination and prediction of Qingzhuan tea storage year using quantitative chemical profile combined with multivariate analysis: Advantages of MRMHR based targeted quantification metabolomics.

The duration of storage significantly influences the quality and market value of Qingzhuan tea (QZT). Herein, a high-resolution multiple reaction monitoring (MRMHR) quantitative method for markers of QZT storage year was developed. Quantitative data alongside multivariate analysis were employed to discriminate and predict the storage year of QZT. Furthermore, the content of the main biochemical ingredients, catechins and alkaloids, and free amino acids (FAA) were assessed for this purpose. The results show that targeted marker-based models exhibited superior discrimination and prediction performance among four datasets. The R2Xcum, R2Ycum and Q2cum of orthogonal projection to latent structure-discriminant analysis discrimination model were close to 1. The correlation coefficient (R2) and the root mean square error of prediction of the QZT storage year prediction model were 0.9906 and 0.63, respectively. This study provides valuable insights into tea storage quality and highlights the potential application of targeted markers in food quality evaluation.

Characterization of alkaloids and phenolics in Nitraria roborowskii Kom. fruit by UHPLC-triple-TOF-MS/MS and its sucrase and maltase inhibitory effects.

Nitraria roborowskii Kom (NRK), with high economic and ecological value, is mainly distributed in the Qaidam Basin, China. However, research on its chemical components and bioactivities is still rare. In this study, its chemical constituents (52) including 10 ß-carboline alkaloids, nine cyclic peptides, three indole alkaloids, five pyrrole alkaloids, eight phenolic acids and 17 flavonoids were identified tentatively using UPLC-triple-TOF-MS/MS. Notablely, one new ß-carboline alkaloid and five new cyclic peptides were confirmed using MS/MS fragmentation pathways. In addition, experiments in vitro indicated that NRK-C had strong maltase and sucrase inhibitory activities (IC50 of 0.202 and 0.103 mg/mL, respectively). Polysaccharide tolerance experiments confirmed NRK-C (400 mg/kg) was associated with decreased postprandial blood glucose (PBG) in diabetic mice. These results suggested that NRK fruit might be used as a functional ingredient in food products.

Current perspectives on fenugreek bioactive compounds and their potential impact on human health: A review of recent insights into functional foods and other high value applications.

Despite long-standing uses in several food and medicine traditions, the full potential of the leguminous crop fenugreek (Trigonella foenum-graecum L.) remains to be realized in the modern diet. Not only its seeds, which are highly prized for their culinary and medicinal properties, but also its leaves and stems abound in phytochemicals with high nutritional and health promoting attributes. Fenugreek dual food-medicine applications and reported metabolic activities include hypoglycemic, antihyperlipidemic, antioxidative, anti-inflammatory, antiatherogenic, antihypertensive, anticarcinogenic, immunomodulatory, and antinociceptive effects, with potential organ-protective effects at the cardiovascular, digestive, hepatic, endocrine, and central nervous system levels. Effectiveness in alleviating certain inflammatory skin conditions and dysfunctions of the reproductive system was also suggested. As a food ingredient, fenugreek can enhance the sensory, nutritional, and nutraceutical qualities of a wide variety of foods. Its high nutritive density can assist with the design of dietary items that meet the demand for novelty, variety, and healthier foods. Its seeds provide essential protective nutrients and other bioactive compounds, notably galactomannans, flavonoids, coumarins, saponins, alkaloids, and essential oils, whose health benefits, alone or in conjunction with other bioactives, are only beginning to be tapped into in the food industries. This review summarizes the current state of evidence on fenugreek potential for functional food development, focusing on the nutrients and non-nutrient bioactive components of interest from a dietary perspective, and their applications for enhancing the functional and nutraceutical value of foods and beverages. New developments, safety, clinical evidence, presumed mechanisms of action, and future perspectives are discussed. HIGHLIGHTS: Fenugreek seeds and leaves have long-standing uses in the food-medicine continuum. Fenugreek phytochemicals exert broad-spectrum biological and pharmacological activities. They show high preventive and nutraceutical potential against common chronic diseases. Current evidence supports multiple mechanisms of action mediated by distinct bioactives. Opportunities for fenugreek-based functional foods and nutraceuticals are expanding.

Tissue-specific variations of piperine in ten populations of Piper longum L.: bioactivities and toxicological profile.

P. longum L., one of the most significant species of the genus Piperaceae, is most frequently employed in Indian-Ayurvedic and other traditional medicinal-systems for treating a variety of illnesses. The alkaloid piperine, is the key phytoconstituent of the plant, primarily responsible for its' pharmacological-impacts. The aim of the study is to analyse the intra-specific variation in piperine content among different chemotypes (PL1 to PL 30) and identify high piperine yielding chemotype (elite-chemotype) collected from 10 different geographical regions of West Bengal by validated HPTLC chromatography method. The study also focused on the pharmacological-screening to better understand the antioxidant activity of the methanol extracts of P. longum by DPPH and ABTS radical-scavenging activity and genotoxic activity by Allium cepa root tip assay. It was found that the P. longum fruit chemotypes contain high amount piperine (highest 16.362 mg/g in chemotype PL9) than the stem and leaf chemotypes. Both DPPH and ABTS antioxidant assays revealed that P. longum showed moderate radical-scavenging activity and the highest activity was found in PL9 (fruit) chemotype with IC50 values of 124.2 ± 0.97 and 104 ± 0.78 µg/ml respectively. The A. cepa root tip assay showed no such significant genotoxic-effect and change in mitotic-index. The quick, reproducible, and validated HPTLC approach offers a useful tool for determining quantitative variations of piperine among P. longum chemotypes from different geographical-regions and also according to the different tissues and choose elite genotypes with high piperine production for continued propagation and commercialization for the pharmaceutical sector. Additionally, the plant's in-vitro antioxidant property and lack of genotoxicity directly supports its' widespread and long history of use as a medicinal and culinary plant.

Death of Socrates: a likely case of poison hemlock (Conium maculatum) poisoning.

INTRODUCTION: The death of Socrates in 399 BCE is described in Plato's dialogue, the Phaedo, written an unknown time afterwards from accounts by others. THE EVIDENCE: Socrates' death has almost always been attributed to his drinking an extract of poison hemlock, Conium maculatum, despite apparent discrepancies between the clinical features described in classical translations of the Phaedo and general clinical experience of poisoning with the toxic alkaloids it contains. EVALUATION: Recent acute philological analysis of the original Greek text has resolved many of the discrepancies by showing that the terms used in the classical translations were misinterpretations of the clinical signs described. It is also likely that the unpleasant clinical effects, such as vomiting, abdominal pain, diarrhoea and muscle fasciculation commonly described in modern reports of poison hemlock poisoning, were not mentioned to present the death of Socrates in a way consistent with his philosophical ideals and those of his pupil Plato. CONCLUSIONS: Seen in this way, the death of Socrates can be accepted as a limited case report of Conium maculatum poisoning. Even after reaching that conclusion, intriguing scientific questions remain about the toxicity of the coniine alkaloids and the mechanisms of their effects.

New indolequinazoline alkaloids from the fruits of Tetradium ruticarpum.

In this research, five new indolequinazoline alkaloids (1-5), along with six known indolequinazoline alkaloids (6-11) were obtained from the fruits of Tetradium ruticarpum. Their structures were elucidated through comprehensive spectroscopic data of 1D and 2D NMR, HRESIMS and ECD spectra. Additionally, all isolates were assayed for their SIRT1 inhibitory activities in vitro and compounds 2, 7, 10 and 11 exhibited activities with IC50 values ranged from 43.16 to 118.35 µM.

Genome-wide identification of the alkaloid synthesis gene family CYP450, gives new insights into alkaloid resource utilization in medicinal Dendrobium.

The medicinal Dendrobium species of Orchidaceae possess significant pharmaceutical value, and modern pharmacological research has shown that Dendrobium contains many important active ingredients. Alkaloids, the crucial components of medicinal Dendrobium, demonstrate beneficial healing properties in cardiovascular, cataract, gastrointestinal, and respiratory diseases. Members of the cytochrome P450 monooxygenase (CYP) gene family play essential roles in alkaloid synthesis, participating in alkaloid terpene skeleton construction and subsequent modifications. Although studies of the CYP family have been conducted in some species, genome-wide characterization and systematic analysis of the CYP family in medicinal Dendrobium remain underexplored. In this study, we identified CYP gene family members in the genomes of four medicinal Dendrobium species recorded in the Pharmacopoeia: D. nobile, D. chrysotoxum, D. catenatum, and D. huoshanense. Further, we analyzed the motif composition, gene replication events, and selection pressure of this family. Syntenic analysis revealed that members of the clan 710 were present on chromosome 18 in three medicinal Dendrobium species, except for D. nobile, indicating a loss of clan 710 occurring in D. nobile. We also conducted an initial screening of the CYP genes involved in alkaloid synthesis through transcriptome sequencing. Quantitative real-time reverse transcription PCR showed that the expression of DnoNew43 and DnoNew50, homologs of secologanin synthase involved in the alkaloid synthesis pathway, was significantly higher in the stems than in the leaves. This result coincided with the distribution of dendrobine content in Dendrobium stems and leaves, indicating that these two genes might be involved in the dendrobine synthesis pathway. Our results give insights into the CYP gene family evolution analysis in four medicinal Dendrobium species for the first time and identify two related genes that may be involved in alkaloid synthesis, providing a valuable resource for further investigations into alkaloid synthesis pathway in Dendrobium and other medicinal plants.

New cassane-type alkaloids and diterpenoids from the pericarps of Caesalpinia bonduc.

The phytochemical investigation of the pericarps of Caesalpinia bonduc led to the isolation and identification of five new cassane-type alkaloids: caesalminines C - G (1-5) and six new diterpenoids: caesalbonducin K - P (6-11), along with seven known compounds (12-18). Compounds 1-5 were identified as a group of rare alkaloids possessing a tetracyclic cassane-type diterpenoid skeleton with a lactam D-ring instead of a typical furan or lactone moiety. The structures of 1-11 were elucidated on the basis of 1D and 2D NMR including HSQC, HMBC, COSY and NOESY, and other spectroscopic analyses. The cytotoxic activities of the isolated compounds were evaluated in the A431, A549 and U87MG cancer cell lines.

Transcriptome analysis reveals cadmium exposure enhanced the isoquinoline alkaloid biosynthesis and disease resistance in Coptis chinensis.

Coptis chinensis Franch is a perennial herb from the Ranunculaceae family with a long history of medicinal use. As the medicinal part, the rhizome of coptis often accumulates excessive cadmium (Cd) even at low concentrations in the soil, which not only compromises its medicinal safety but also raises concerns about adverse effects on human health. Therefore, effective strategies are needed to mitigate this accumulation and ensure its safe use in traditional medicine. This study utilized transcriptome profiling and physiological analysis to explore molecular mechanisms associated with ecological significance and the active accumulation of Cd in C. chinensis. The response to Cd in C. chinensis was assessed through RNA sequencing, Cd determination and isoquinoline alkaloid measurement using its roots, stems, and leaves. The transcriptome revealed, a total of 2667, 2998, or 2815 up-regulated deferentially expressed genes in roots, stems or leaves in response to Cd exposure. Furthermore, we identified phenylpropanoid and isoquinoline alkaloid biosynthesis as the key pathways response to Cd exposure, which suggests that C. chinensis may improve its tolerance to Cd through regulating the phenylpropanoid biosynthesis pathway. Under Cd exposure, plant-pathogen interaction in leaves was identified as the key pathway, which indicates that upregulation of genes involved in plant-pathogen interaction could enhance disease resistance in C. chinensis. WGCNA analysis identified WRKY8 (Cluster-55763.31419) and WRKY47 (Cluster-55763.221590) as potential regulators of secondary metabolic synthesis and plant-pathogen interaction pathway in C. chinensis triggered by Cd. The measurement of berberine, coptisine, palmatine, and epiberberine also demonstrated that Cd simulated the four isoquinoline alkaloids in roots. Therefore, our study not only presented a transcriptome expression profiles that revealed significant upregulation of genes involved in metal transport and detoxification pathways but also suggested a possible mechanism to cope with Cd accumulation. This knowledge provides a new insight into gene manipulation for controlling Cd accumulation, enhancing resistance and promoting synthesis of secondary metabolites with potential medicinal properties in other medicinal plant species.

High-performance liquid chromatography analysis of alkaloids in various parts of lotus extracts with ion mobility spectrometry and mass spectrometry dual detection.

Using high-performance liquid chromatography coupled with electrospray ionization-ion mobility spectrometry and mass spectrometry, we proposed a dual-detection method for the identification and profiling of alkaloids in various lotus parts including leaf, plumule, stem, seed epicarp, and receptacle. The eluent from high-performance liquid chromatography was split and conducted to electrospray ionization-ion mobility spectrometry and time-of-flight mass spectrometry separately to facilitate the compound identification. In total, 23 kinds of alkaloids were identified based on m/z, drift time, and retention time, including alkaloid isomers such as lirinidine, N-nornuciferine, and O-nornuciferine with identical m/z that are difficult to differentiate using mass spectrometry alone. Using this method, we investigated the changing dynamics of alkaloid accumulation in lotus leaves and lotus stems at different harvesting periods. The total alkaloid content showed an increasing trend with the growth and development of leave and stem. Overall, the developed dual detection method has the advantages of high peak capacity and high sensitivity compared with the conventional detection method and facilitates the identification of detected compounds.

Assessment of multi-biomedical efficiency of Andrographis paniculata shoot extracts through in-vitro analysis and major compound identification.

The present investigation looked into the various biomedical potentials of Andrographis paniculata shoot extracts. The results showed that the methanol extract (Met-E) of A. paniculata contains more phytochemicals than the acetone and petroleum ether extracts, including alkaloids, saponins, tannins, phenolics, flavonoids, glycosides, terpenoids, phytosterol, steroids, and protein. Accordingly, the Met-E alone showed considerable bactericidal activity (through agar well diffusion method) against the bacterial pathogens namely Shigella dysenteriae, Bacillus cereus, Salmonella typhi, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphlococcus aureus, E. coli, and B. subtilis. This bactericidal activity was found as dose dependent manner, since at 1000 µg ml concentration, the Met-E showed better antibacterial activity. Similarly, at increased concentration (1000 µg ml) it showed notable antidiabetic (α-amylase inhibition: 74.31% and α-glucosidase inhibition: 72.34%), antioxidant (DPPH: 78.24%), and anti-inflammatory (albumin denaturation inhibition: 79.84% and lipoxigenase inhibition: 69.4%) activities. The phytochemical profiling of Met-E was characterized by UV-visible spectrophotometer (UV-vis), Gas Chromatography-Mass Spectrometry (GC/MS), Fourier transform infrared (FTIR), and High Performance Liquid Chromatography (HPLC) analyses. The results showed the Met-E contain bioactive compounds such as gallic acid, epicatechin, catechin, naringin, vitexin-2-rhamnoside, taxifolin, kaempferol, hesperidin, myricetin, rutin, quercetin, phloretin, and ursolic acid compounds. While most of these substances have been recognised for their pharmacological application perspective, the biological properties of particular substances must be studied in the future using in-vivo strategies.

Comparison of direct analysis in real-time mass spectrometry, atmospheric solids analysis probe-mass spectrometry, and ion mobility spectrometry for ensuring food safety by rapid screening of poppy seeds.

The opium poppy (Papaver somniferum) is a global commercial crop that has been historically valued for both medicinal and culinary purposes. Naturally occurring opium alkaloids including morphine, codeine, thebaine, noscapine, and papaverine are found primarily in the latex produced by the plant. If the plant is allowed to fully mature, poppy seeds that do not contain the opium alkaloids will form within the pods and may be used in the food industry. It is possible for the seeds to become contaminated with alkaloids by the latex during harvesting, posing a potential health risk for consumers. In the USA, there have been more than 600 reported adverse events including 19 fatalities that may be linked to the consumption of a contaminated poppy-containing product such as home-brewed poppy seed tea. Unwashed poppy seeds and pods may be purchased over the Internet and shipped worldwide. The Forensic Chemistry Center, US Food and Drug Administration (FDA) has evaluated several mass spectrometers (MS) capable of rapid screening to be used for high-throughput analysis of samples such as poppy seeds. These include a direct analysis in real-time (DART) ambient ionization source coupled to a single-quadrupole MS, an atmospheric solids analysis probe (ASAP) ionization source coupled to the same MS, and ion mobility spectrometers (IMS). These instruments have been used to analyze 17 poppy seed samples for the presence of alkaloids, and the results were compared to data obtained using liquid chromatography with mass spectral detection (LC-MS/MS). Results from the 17 poppy seed samples indicate that the DART-MS, ASAP-MS, and IMS devices detect many of the same alkaloids confirmed during the LC-MS/MS analyses, although both the false-positive and false-negative rates are higher, possibly due to the non-homogeneity of the samples and the lack of chromatographic separation.

Assessment of tropane alkaloid levels in Brazilian buckwheat flour products: A novel LC-UHPLC-MS/MS approach using solid-liquid extraction at low temperature.

In recent years, the monitoring of tropane alkaloids, specifically hyoscyamine and scopolamine, in food has become a pressing concern. This is due to increasing reports of food contamination with these compounds worldwide, raising awareness about the potential risks associated with their consumption. A novel method is proposed here for the determination of the sum of (+)-hyoscyamine, (-)-hyoscyamine, and (-)-scopolamine in buckwheat-based matrices, using solid-liquid extraction at low temperature and quantification by bidimensional chromatography coupled to tandem mass spectrometry. The validated method presented a linear response in the concentration range of 2.5-15 µg kg-1 (r > 0.99). The precision and accuracy were in the ranges from 0.8 to 11.0 % and from 96 to 103 %, respectively. The limit of quantification (LOQ) was 2.5 µg kg-1. No contamination was found at levels above the LOQ in any of the 18 samples analyzed (buckwheat flour, grains, and gluten-free mix).

Bioactive polysaccharides in different plant parts of Aconitum carmichaelii.

BACKGROUND: Aconitum carmichaelii is an industrially cultivated medicinal plant in China and its lateral and mother roots are used in traditional Chinese medicine due to the presence of alkaloids. However, the rootlets and aerial parts are discarded after collection of the roots, and the non-toxic polysaccharides in this plant have attracted less attention than the alkaloids and poisonous features. In this study, five neutral and 14 acidic polysaccharide fractions were isolated systematically from different plant parts of A. carmichaelii, and their structural features and bioactivity were studied and compared. RESULTS: The neutral fraction isolated from the rootlets differed from those isolated from the lateral and mother roots. It consisted of less starch and more possible mannans, galactans, and/or xyloglucans, being similar to those of the aerial parts. Pectic polysaccharides containing homogalacturonan and branched type-I rhamnogalacturonan (RG-I) were present in all plant parts of A. carmichaelii. However, more arabinogalactan (AG)-II side chains in the RG-I backbone were present in the aerial parts of the plants, while more amounts of arabinans were found in the roots. Various immunomodulatory effects were observed, determined by complement fixation activity and anti-inflammatory effects on the intestinal epithelial cells of all polysaccharide fractions. CONCLUSION: This study highlighted the diversity of polysaccharides present in A. carmichaelii, especially in the unutilized plant parts, and showed their potential medicinal value. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Simultaneous estimation of total phenolic and alkaloid contents in the tea samples by utilizing the catechin and caffeine oxidation signals through the square-wave voltammetry technique.

This work outlines the simultaneous estimation of the total phenolic and alkaloid contents in the tea samples by using catechin (C) and caffeine (CAF) oxidation signals at a non-modified boron-doped diamond (BDD) electrode. Two irreversible oxidation peaks, about + 1.03 (for C) and + 1.45 V (for CAF) vs Ag/AgCl in acetate buffer solution at pH 4.7, were seen in the cyclic voltammetric profile of the binary mixtures of C and CAF. In optimal conditions and utilizing the square-wave mode, the BDD electrode allows for simultaneous quantification of C and CAF within the concentration ranges of 5.0-100.0 µg mL-1 (1.72 × 10-5 - 3.45 × 10-3 mol/L) and 1.0-50.0 µg mL-1 (5.15 × 10-6 - 2.57 × 10-4 mol/L) respectively. The corresponding detection limits are 1.22 µg mL-1 (4.21 × 10-6 mol/L) for C and 0.11 µg mL-1 (5.66 × 10-7 mol/L) for CAF. Other phenolic compounds (like tannic acid, gallic acid, epicatechin, and epigallocatechin gallate) and other alkaloids (theophylline and theobromine) present in tea samples were examined for selectivity assessment. Ultimately, the applicability of the proposed approach was demonstrated by estimating the total phenolic and alkaloid contents in the black and green tea samples, expressed as C and CAF equivalents. The results obtained were contrasted against those acquired using UV-Vis spectrometry.

Innovative spectrofluorometric method for determination of harmaline and harmine in different matrices.

Harmaline and harmine are naturally occurring closely related ß-carboline alkaloids found in Peganum and Banisteriopsis plants. They have historical significance in traditional practices due to their potential psychoactive and therapeutic properties. Herein, a highly sensitive spectrofluorometric method was developed for the quantifying of harmaline and harmine in diverse matrices, including pure forms, seed samples, and spiked plasma. The procedures lie in addressing the challenge of overlapping fluorescence spectra exhibited by harmaline and harmine through the incorporation of hydroxypropyl-ß-cyclodextrin, altering their chemical properties and fluorescence characteristics. Synchronous fluorescence measurements coupled with first derivative mathematical technique make it possible to distinguish between the harmaline and harmine at 419 and 456 nm, respectively. The method effectiveness is demonstrated through spectral analysis, optimization of the measurement conditions, adopting validation parameters and application to the pure form, seed samples and spiked human plasma. This methodology facilitates accurate determination of these alkaloids over the concentration range of 10─200 ng/mL. Thus, the developed approach provides a robust mean for the precise determination of harmaline and harmine, contributing to analytical chemistry's ongoing efforts to address complex challenges in quantification across diverse matrices.

Doped nanomaterial facilitates 3D printing target plate for rapid detection of alkaloids in laser desorption/ionization mass spectrometry.

This work aims to rapidly detect toxic alkaloids in traditional Chinese medicines (TCM) using laser desorption ionization mass spectrometry (LDI-MS). We systematically investigated twelve nanomaterials (NMs) as matrices and found that MoS2 and defect-rich-WO3 (D-WO3) were the best NMs for alkaloid detection. MoS2 and D-WO3 can be used directly as matrices dipped onto conventional ground steel target plates. Additionally, they can be conveniently fabricated as three-dimensional (3D) NM plates, where the MoS2 or D-WO3 NM is doped into resin and formed using a 3D printing process. We obtained good quantification of alkaloids using a chemothermal compound as an internal standard and detected related alkaloids in TCM extracts, Fuzi (Aconiti Lateralis Radix Praeparata), Caowu (Aconiti Kusnezoffii Radix), Chuanwu (Aconiti Radix), and Houpo (Magnoliae Officinalis Cortex). The work enabled the advantageous "dip and measure" method, demonstrating a simple and fast LDI-MS approach that achieves clean backgrounds for alkaloid detection. The 3D NM plates also facilitated mass spectrometry imaging of alkaloids in TCMs. This method has potential practical applications in medicine and food safety. Doped nanomaterial facilitates 3D printing target plate for rapid detection of alkaloids in laser desorption/ionization mass spectrometry.

Sophora tonkinensis: response and adaptation of physiological characteristics, functional traits, and secondary metabolites to drought stress.

The medicinal plant Sophora tonkinensis is a characteristic Chinese shrub of karst areas. The arid climate in karst areas produces high-quality S. tonkinensis; however, the mechanisms of drought tolerance are not clear, which restricts sustainable plantings of S. tonkinensis. This study involved a 20-day drought stress experiment with potted S. tonkinensis and threee soil water regimes: control (CK), mild drought (MDT), and severe drought (SDT). Plant morphology, biomass, physiological indicators, alkaloid content, and other changes under drought stress were monitored. The content of soluble sugars and proteins, and activity of antioxidant enzymes in leaves and roots were higher under drought than CK, indicating that S. tonkinensis is tolerant to osmotic stress in early drought stages. Content of matrine and oxymatrine increased gradually with increasing drought duration in the short term. The epidermis of S. tonkinensis leaves have characteristics of desert plants, including upper epidermal waxy layer, lower epidermal villi, and relatively sunken stomata, suggesting that S. tonkinensis has strong drought tolerance. In conclusion, drought stress changed the cell structure of S. tonkinensis, induced antioxidant enzyme activity and increased its resistance to drought.