Simultaneous determination of 16 alkaloids in blood by ultrahigh-performance liquid chromatography-tandem mass spectrometry coupled with supported liquid extraction

Qualitative and Quantitative Analysis of Phytochemicals in Sayeok-Tang via UPLC-Q-Orbitrap-MS and UPLC-TQ-MS/MS

Sayeok-tang (SYT) is a traditional herbal formula comprising three medicinal herbs: Glycyrrhiza uralensis, Zingiber officinale, and Aconitum carmichaeli. Several studies have employed liquid chromatography-mass spectrometry (LC-MS) to qualitatively analyze the components and metabolites of SYT in vitro and in vivo; however, studies on quantitative analysis of SYT, which is important for quality control, are absent or limited to only a few components. In this study, ultrahigh-performance liquid chromatography coupled with quadrupole (UPLC-Q)-Orbitrap-MS was used to screen the phytochemicals of SYT, revealing a total of 42 compounds. Among them, 24 compounds were simultaneously quantified within 20 min via UPLC-TQ-MS/MS in the multiple reaction monitoring mode. The developed analytical method was validated for its linearity (r2 ≥ 0.9992), precision (0.36-2.96%), accuracy (-6.52-4.64%), and recovery (94.39-119.07%) for all analytes, exhibiting acceptable results. The validated method was applied in the analysis of SYT extracts, and the 24 compounds were quantified in the range of 0.004-6.882 mg/g (CV ≤ 3.746%). Among them, liquiritin apioside (6.870-6.933 mg/g), glycyrrhizic acid (5.418-5.540 mg/g), and liquiritin (1.303-1.331 mg/g) from G. uralensis were identified as the relatively abundant compounds. The presented validated analytical method is highly promising for the comprehensive quality control of SYT, offering fast, highly sensitive, and reliable analysis.

Comparative pharmacokinetic study of Anisodamine Hydrobromide tablets and injection in septic acute lung injury rats

Aim: We aimed to establish a sensitive LC-MS/MS method to analyze the pharmacokinetics of Ani HBr tablets and injection.Methods: Around 10 mmNH4Ac containing 0.1% formic acid and acetonitrile were used as the mobile phase. Acute lung injury in septic and normal rats, respectively, were administered Ani HBr tablets at doses of 12.5, 25 and 50 mg/kg and injection at doses of 4, 8 and 16 mg/kg, followed by extraction of the drugs from plasma using ethyl acetate for subsequent analysis.Results & conclusion: The method met the requirements for biological analysis. Ani HBr tablets absorbed slowly in rats with disease, tail vein administration was a more promising approach for treating septic acute lung injury.

Easily Operable Quantification Method of 21 Plant-Derived Alkaloids in Human Serum by Automatic Sample Preparation and Liquid Chromatography-Tandem Mass Spectrometry

In this study, we developed an easily operable quantification method for 21 plant-derived alkaloids in human serum by automatic sample preparation and liquid chromatography-tandem mass spectrometry. We designed to perform parallel sample preparation by a developed apparatus, which increased sample throughput. We conducted an automatic sample preparation through de-proteinization with 0.1% formic acid in methanol and achieved recovery rates of 89-107% (2.0-14% RSD) for all targeted analytes, demonstrating its high repeatability. The method validation results were satisfactory as follows: the linearity (r 2) of each calibration curve ranged from 0.978 to 1.000; the inter- and intra-day accuracies were 89.0-125% and 82.1-110%, respectively; the inter- and intra-day precisions were below 13% and 10%, respectively. Additionally, the lower limits of detection and quantification were 0.0044-0.047 and 0.013-0.14 ng/mL, respectively. Finally, the developed method was applied to pseudo-protoveratrine A poisoning serum and pseudo-colchicine poisoning serum, which were prepared by diluting acute-poisoning mice serum with human serum. Our method successfully quantitated protoveratrine A (0.15-0.25 ng/mL) and colchicine (4.8-6.0 ng/mL). Thus, our method is essential for prompt clinical treatment and critical care on patient in acute intoxication cases caused by plant-derived alkaloids.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10337-022-04212-5.

Kapok fiber-supported liquid extraction for convenient oil samples preparations: A feasibility and proof-of-concept study

In this study, a novel kapok fiber-supported liquid extraction (KF-SLE) method was developed for conveniently extracting analytes from oil samples. Natural kapok fiber without any pretreatment was directly used as an oil support medium. The extraction device was conveniently constructed by directly packing some kapok fibers into a syringe tube. Due to the fibrous property of the kapok fiber, no filter plate was needed. The cost of a KF-SLE device was as low as 0.5 CNY. The KF-SLE process was conveniently conducted using a simple three-step protocol: (1) the oil sample without any pretreatment including dilution was added directedly; (2) then, the oil-immiscible extractant was added; (3) after waiting a certain time for static extraction, the extractant was eluted out by pressing the kapok fibers with the syringe plunger. The extractant could be directly transferred for subsequent instrumental detection. For the feasibility and proof-of-concept study, the method was applied to quantify four synthetic flavor chemicals in edible oils. Satisfied quantification results were obtained with the correlation coefficient (R²) being greater than 0.996, the relative recoveries ranging from 92.90% to 107.53% and intra- and inter-day RSDs being less than 7.56%. All in all, for the first time, the SLE technique was expanded to process oil samples and the method has the characteristics of low cost, environmental friendliness, high sample processing throughput and ease of automation, offering a promising approach for edible oil sample preparations.

Scopolamine analysis in beverages: Bicolorimetric device vs portable nano liquid chromatography

Scopolamine (SCP) is often involved in sexual assaults and robberies, particularly in recreational environments. Therefore, analytical tools are required for the analysis of this compound amenable for the field. In this work, a sensor for SCP is described based on the entrapment of KMnO₄ into polydimethylsiloxane (PDMS). The possibility of using KMnO₄ in combination with the reagent 1,2-naphtoquinone-4-sulfonate (NQS) giving a double sensor acting as a bicolorimetric device is also demonstrated. In contact with the sample, the PDMS composite delivers MnO₄^-, which reacts rapidly with SCP under basic conditions causing a change of the color of the solution that can be related to the concentration of drug using both, absorbances and color coordinates, while the NQS part of the sensor remains unchanged. After an exposure time to the sensors of 10 min, satisfactory linearity was obtained for concentrations of SCP up to 865 μg/mL, being the limit of detection (LOD) 108 μg/mL. A method using a portable nano liquid chromatograph with detection at 255 nm has been also developed; in this case the LOD was 100 μg/mL and the working linear interval was 250-2000 μg/mL. The precision, expressed as relative standard deviation (RDS), was ≤8% for both methods. Different beverages (cola, cola-whisky, tonic water-vodka, red wine and green tea) were assayed. The potential of the two proposed approaches for on-site tests is discussed.

A high-throughput screening assay for dipeptidyl peptidase-IV inhibitors using human plasma

Dipeptidyl peptidase-IV (DPP-IV) plays a critical role in glucose metabolism and has become an important target for type 2 diabetes mellitus. We previously reported a two-photon fluorescent probe glycyl-prolyl-N-butyl-4-amino-1,8-naphthalimide (GP-BAN) for DPP-IV detection with high specificity and sensitivity. In this study, a high-throughput screening (HTS) method for DPP-IV inhibitors using human plasma as the enzyme source was established and optimized. Further investigations demonstrate that the IC50 value of sitagliptin (listed as the DPP-IV inhibitor) determined with human recombinant DPP-IV (36.22 nM) is very similar to that in human plasma (39.18 nM), and sitagliptin acts as a competitive inhibitor against human plasma DPP-IV-mediated GP-BAN hydrolysis. These results indicate that expensive human recombinant DPP-IV can be replaced by human plasma in this GP-BAN-based assay. On this basis, GP-AMC (commercial probe) was used as a comparison to verify this method, and the catalytic efficacy (Vmax/Km) for GP-AMC (0.09 min-1) hydrolysis in human plasma is lower than that for GP-BAN (0.21 min-1). Further analysis of inhibition kinetics (sitagliptin) and molecular docking (GP-BAN and GP-AMC) showed that GP-BAN has better specificity and affinity for enzymes than GP-AMC. Finally, the optimized method was used for the HTS of DPP-IV inhibitors in 69 natural alkaloids.

Fabrication of edge-curled petals-like covalent organic frameworks and their properties for extracting indole alkaloids from complex biological samples

In this study, a functionalized covalent-organic framework (COF) was first synthesized using porphyrin as the fabrication unit and showed an edge-curled, petal-like and well-ordered structure. The synthesized COF was then introduced to prepare porous organic polymer monolithic materials (POPMs). Two composite POPM/COF monolithic materials with rod shapes, referred to as sorbent A and sorbent B, were prepared in stainless steel tubes using different monomers. Sorbents A and B exhibited relatively uniform porous structures and enhanced specific surface areas of 153.14 m²/g and 80.01 m²/g, respectively. The prepared composite monoliths were used as in-tube solid-phase extraction (SPE) sorbents combined with HPLC for the on-line extraction and quantitative analytical systems. Indole alkaloids (from Catharanthus roseus G. Don and Uncaria rhynchophylla (Miq.) Miq. Ex Havil.) contained in mouse plasma were extracted and quantitatively analyzed using the online system. The two composite multifunctional monoliths showed excellent clean-up ability for complex biological matrices, as well as superior selectivity for target indole alkaloids. Method validation showed that the RSD values of the repeatability (n=6) were ≤ 3.46%, and the accuracy expressed by the spiked recoveries was in the ranges of 99.38%–100.91% and 96.39%–103.50% for vinca alkaloids and Uncaria alkaloids, respectively. Furthermore, sorbents A and B exhibited strong reusability, with RSD values ≤ 5.32%, which were based on the peak area of the corresponding alkaloids with more than 100 injections. These results indicate that the composite POPM/COF rod-shaped monoliths are promising media as SPE sorbents for extracting trace compounds in complex biological samples.

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Edge-curled petals-like COF was synthesized using porphyrin as the fabrication unit.

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In-tube monolithic POMP/COF composite SPE sorbents with rod-shape were fabricated.

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The in-tube sorbents were used to extract hence indole alkaloids from complex samples.

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The two homemade sorbents show strong reusability of more than 100 times.

A facile one step solvothermal controllable synthesis of FeS2 quantum dots with multiple color emission for the visual detection of aconitine

Iron disulfide (FeS₂) quantum dots have potential applications in various fields such as photocatalysis, lithium-ion batteries and bioimaging. At present, there is no report on the fluorescent characteristics of FeS₂ quantum dots (FeS₂ QDs). In this work, a synthesis of multiple-color emission FeS₂ QDs by changing the temperature, time and raw ratio has been reported. The blue, green, yellow and red emission FeS₂ QDs can be obtained, respectively. They were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM). On this basis, a novel molecular imprinting ratiometric fluorescence sensor (MIR sensor) had been constructed, in which the blue-emission FeS₂ QDs (b-FeS₂ QDs) was used as a fluorescent responsive signal material and the yellow-emission FeS₂ QDs (y-FeS₂ QDs) was served as a reference signal material. And this MIR sensor was applied for highly selective and sensitive detection of ACO in traditional Chinese medicine (TCM). Under the optimum conditions, the MIR sensor exhibited an excellent linear relationship between the fluorescence intensity ratio (I₄₄₃/I₅₉₀) and the concentration of ACO in the range of 0.05-5.0 μM with a detection limit of 24 nM. Furthermore, the established method was successfully utilized to the detection of ACO in TCM Fuzi Lizhong Pills with satisfactory results. It provided a reference for the application of the FeS₂ QDs with multiple color emission and the detection of the hazardous alkaloids.

A highly sensitive quantification method for 12 plant toxins in human serum using liquid chromatography tandem mass spectrometry with a quick solid-phase extraction technique

We developed a highly sensitive quantification method using liquid chromatography tandem mass spectrometry (LC/MS/MS) for 12 plant toxins in human serum. In this paper, we selected lycorine, galanthamine, protoveratrine A, protoveratrine B, veratramine, veratridine, jervine, cyclopamine, cevadine, α-solanine, α-chaconine, and solanidine as targeted analytes. The ADME column was utilized for LC separation and a Monolithic SPE column (MonoSpin® C18) for analyte extraction. The total time for SPE clean-up and LC/MS/MS analysis was completed within 30 min. The method validation results were as follows: the linearity (r²) of each calibration curve was over 0.99; the inter- and intra-day accuracies were 92.7 %-116 % and 91.6 %-106 %, respectively; and the inter- and intra-day precisions were below 14 % and 11 %, respectively. Also, the lower limits of detection and quantification were 0.0071-0.15 and 0.022-0.46 ng/mL, respectively, indicating the method's high sensitivity. Finally, to confirm its feasibility, our method was applied to two model samples: (1) commercially available human serum and (2) pseudo poisoning serum via dilution of mouse serum with human serum. We were able to quantify α-chaconine at 0.84 ± 0.02 ng/mL in the serum (Case 1) and protoveratrine A at 0.15 ± 0.032 ng/mL in the pseudo poisoning serum (Case 2), demonstrating our method's practicality. This is the first time that the 12 plant toxins in human serum were simultaneously quantitated. Our method can investigate accidental poisonings involving toxic plants, enabling prompt decisions on patient treatment.

A novel hybrid micro extraction for the sensitive determination of 17β-estradiol in water samples

A novel and green hybrid of pipette tip micro solid-phase extraction (PT-μSPE) and supported liquid extraction (SLE) was tailored and established for efficient and sensitive determination of 17β-estradiol (E2) in water samples. The hybrid design used chitin as a solid phase in PT-μSPE and applies the SLE principle on it for micro extraction. The analytical setup was termed as chitin-supported pipette tip-micro liquid extraction (CPT-μLE). E2 is a highly active environmental endocrine disruptor, widely spread in the water environment, and thus it is relevant to develop a novel and noble method for its monitoring at trace concentrations in water. The detection and quantification of E2 were performed via HPLC-UV. Under the optimal conditions, E2 showed excellent linearity in the lower scale range of 0.02-20 ng mL-1, and the correlation coefficient (R2) value was 0.9958. The limit of quantitation (LOQ) and limit of detection (LOD) were 0.01 ng mL-1 and 0.008 ng mL-1, respectively, with inter-day and intra-day precision in the range of 3.2-5.1% and 3.6-4.8%, respectively. The method was successfully applied for the sensitive determination of E2 in real water samples. Overall, the method is simple, rapid, technically innovative, cost-effective, highly sensitive, environment friendly, and highly efficient. Furthermore, this method should allow easy expansion to pharmaceutical and biological samples. Finally, this novel hybrid analytical approach proposes a new direction in sample pre-treatment advancements and should act as a reference for other noble analytical advancements in the trace analysis of various emerging contaminants in environmental and biological matrices.