Limitation standard of toxic aconitines in Aconitum proprietary Chinese medicines using on-line extraction electrospray ionization mass spectrometry

Rapid toxicity characterization of Aconitum herbal medicines using perfusion nano-electrospray ionization mass spectrometry

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Sensitive quantitation of ultra-trace toxic aconitines in complex matrices by perfusion nano-electrospray ionization mass spectrometry combined with gas-liquid microextraction

The accurate analysis of ultra-trace (e.g. <10-4 ng/mL) substances in complex matrices is a burdensome but vital problem in pharmaceutical analysis, with important implications for precise quality control of drugs, discovery of innovative medicines and elucidation of pharmacological mechanisms. Herein, an innovative constant-flow perfusion nano-electrospray ionization (PnESI) technique was developed firstly features significant quantitative advantages in high-sensitivity ambient MS analysis of complex matrix sample. More importantly, double-labeled addition enrichment quantitation strategies of gas-liquid microextraction (GLME) were proposed for the first time, allowing highly selective extraction and enrichment of specific target analytes in a green and ultra-efficient (>1000-fold) manner. Using complex processed Aconitum herbs as example, PnESI-MS directly enabled the qualitative and absolute quantitative analysis of the processed Aconitum extracts and characterized the target toxic diester alkaloids with high sensitivity, high stability, wide linearity range, and strong resistance to matrix interference. Further, GLME device was applied to obtain the highly specific enrichment of the target diester alkaloids more than 1000-fold, and accurate absolute quantitation of trace aconitine, mesaconitine, and hypaconitine in the extracts of Heishunpian, Zhichuanwu and Zhicaowu was accomplished (e.g., 0.098 pg/mL and 0.143 pg/mL), with the quantitation results well below the LODs of aconitines from any analytical instruments available. This study built a systematic strategy for accurate quantitation of ultra-trace substances in complex matrix sample and expected to provide a technological revolution in many fields of pharmaceutical research.

Development of sequential online extraction electrospray ionization mass spectrometry for accurate authentication of highly-similar Atractylodis Macrocephalae

The accurate and rapid authentication techniques and strategies for highly-similar foods are still lacking. Herein, a novel sequential online extraction electrospray ionization mass spectrometry (S-oEESI-MS) was developed to achieve spatio-temporally resolved ionization and comprehensive characterization of complex foods with multi-components (high, medium, and low polarity substances). Meanwhile, a characteristic marker screening method and an integrated research strategy based on MS fingerprinting, characteristic marker and chemometrics modeling were established, which are especially suitable for the accurate and rapid authentication of highly-similar foods that are difficult to be authenticated by traditional techniques (e.g., LC-MS). Thirty-two batches of highly-similar Atractylodis macrocephalae rhizome from four different origins were used as model samples. As a result, S-oEESI-MS enabled a more comprehensive MS characterization of substance profiles in complex plant samples in 1.0 min. Further, 22 characteristic markers of Atractylodis macrocephalae were ingeniously screened out and combined with multivariate statistical analysis model, the accurate authentication of highly-similar Atractylodis macrocephalae was realized. This study presents a comprehensive strategy for accurate authentication and origin analysis of highly-similar foods, which has potentially significant applications for ensuring food quality and safety.

Combination of Internal Extractive Electrospray Ionization Mass Spectrometry and Statistical Analysis for High-Throughput Molecular Differentiation of Rehmannia glutinosa Samples

Rehmannia glutinosa (Gaert.) Libosch. ex Fisch. et Mey. is a perennial herb of the Scrophulariaceae family, which has long enjoyed a good reputation in China, and has a wide range of pharmacological effects and clinical applications. The place of origin is an important factor affecting the chemical composition of R. glutinosa, resulting in different pharmacological effects. Herein, internal extractive electrospray ionization mass spectrometry (iEESI-MS) combined with statistical techniques was established for high-throughput molecular differentiation of different R. glutinosa samples. Dried and processed R. glutinosa samples from four different places of origin were analyzed by iEESI-MS with high throughput (>200 peaks) and rapidness (<2 min/sample) without sample pretreatment. Clear separation models created by OPLS-DA were then established for distinguishing the places of origin of dried and processed R. glutinosa by using the obtained MS data. In addition, the molecular differences between the pharmacological effects of dried and processed R. glutinosa were also investigated by OPLS-DA, and 31 different components were screened out. This work provides a promising method for evaluating the quality of traditional Chinese medicines and studying the biochemical mechanism of processing.

Comprehensive quality evaluation of Aconiti Lateralis Radix Praeparata based on pseudotargeted metabolomics and simultaneous determination of fifteen components, and development of new processed products of black slices with less toxicity

Aconiti Lateralis Radix Praeparata is one of the most famous traditional Chinese medicines possessing a variety of pharmacological activities on top of the toxicities. Due to the heterogeneity and non-standardization of the processing procedures, the subtypes and contents of the differential compounds between different processed products still remained indistinct, causing great risk in their proper use. In order to achieve the comparison and quality evaluation of different processed products of Aconiti Lateralis Radix Praeparata and develop new processed products with less toxicity, a quantification and pseudotargeted metabolomics method was developed based on the dynamic MRM mode of triple quadrupole (QqQ) mass spectrometry, and multivariate statistical analysis methods were applied to compare different processed products. Method validation results indicated good specificity, linearity, repeatability, precision, stability and recovery of the established quantification method and good linearity, precision and stability of the pseudotargeted metabolomics method. Differential compounds of different processed products were screened out and further confirmed by the quantification results. At last, the processing procedures were optimized to obtain new processed products of "Heishunpian" (black slices) with less toxicity, in which the contents of the toxic diester-type diterpenoid alkaloids were reduced from 106.98 μg/g to 0.85-12.96 μg/g. This study provided a valuable reference for the establishment of comprehensive quality evaluation methods of herbal medicines and a scientific basis for the optimization of processing procedures of Aconiti Lateralis Radix Praeparata.

Rapid authentication of different herbal medicines by heating online extraction electrospray ionization mass spectrometry

The rapid and accurate authentication of traditional Chinese medicines (TCMs) has always been a key scientific and technical problem in the field of pharmaceutical analysis. Herein, a novel heating online extraction electrospray ionization mass spectrometry (H-oEESI-MS) was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps. The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10-15 s, with minimal sample (<0.5 mg) and solvent consumption (<20 μL for one sample). Furthermore, a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed, including metabolic profile characterization, characteristic marker screening and identification, and multivariate statistical analysis model validation. In an analysis of 52 batches of seven types of Aconitum medicinal materials, 20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines, respectively, and the possible structures of all the characteristic markers were comprehensively identified based on Compound Discoverer databases. Finally, multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified (R²X > 0.87, R²Y > 0.91, and Q² > 0.72), which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS. In summary, this rapid authentication strategy realized the ultra-high-throughput, low-cost, and standardized detection of various complex TCMs for the first time, thereby demonstrating wide applicability and value for the development of quality standards for TCMs.

Rapid quality evaluation of Chinese herbal medicines using a miniature mass spectrometer: Lygodium japonicum (Thunb.) Sw. as an example

The quality of Chinese herbal medicine (CHM) raw materials is essential, and mass spectrometry (MS)-based technologies have been playing key roles in the quality control of CHMs. However, the use of miniature mass spectrometry (mini-MS) for quality control of CHMs has rarely been reported. In this work, we developed a rapid analytical method for the quality evaluation of CHMs based on paper spray ionization (PSI)-mini-MS/MS. The quality evaluation of Lygodium japonicum (Thunb.) Sw. was used as an example. Following a "multi-component" quality evaluation strategy, nine active constituents of L. japonicum were selected to be used as analytes for quality control. We confirmed that the precursor-product ion information in the MS/MS spectra of each analyte in the herbal extracts was consistent with the standards. Also, we developed a mini-MS-based quantitative method for each analyte using its quantification ion. The quantitative methodology was rigorously validated using quality control samples. Finally, the quality evaluation of L. japonicum was carried out using the established MS/MS method combined with statistical analysis. A wide range of common quality issues with L. japonicum can be effectively determined, including whether it is adulterated with sand and distinguishing among different parts and species. This study demonstrates that mini-MS for quality evaluation of CHMs is feasible. Mini-MS for quality evaluation of herbal medicines will potentially have a good prospect due to its many advantages such as low cost, low power consumption, and portability in the future.

Compatibility of Fuzi and Ginseng Significantly Increase the Exposure of Aconitines

The herb-pair ginseng-Fuzi (the root of Aconitum carmichaelii) is the material basis of Shenfu prescriptions and is popular in traditional Chinese medicine for the treatment of heart failure, and even shock with severe-stage of COVID-19. A narrow therapeutic window of Fuzi may cause significant regional loss of property and life in clinics. Therefore, systemic elucidation of active components is crucial to improve the safety dose window of Shenfu oral prescriptions. A high performance liquid chromatography-mass spectrometry method was developed for quantification of 10 aconitines in SD rat plasma within 9 min. The limit of detection and the limit of quantification were below 0.032 ng/ml and 0.095 ng/ml, respectively. Furthermore, a systemic comparison with their pharmacokinetic characteristics after oral administration of a safe dosage of 2 g/kg of Fuzi and ginseng-Fuzi decoction for 24 h was conducted. Eight representative diester, monoester, and non-ester aconitines and two new active components (i.e., songorine and indaconitine) were all adopted to elucidating the differences of the pharmacokinetic parameters in vivo. The compatibility of Fuzi and ginseng could significantly increase the in vivo exposure of active components. The terminal elimination half-life and the area under the concentration-time curve of mesaconitine, benzoylaconitine, benzoylmesaconitine, benzoylhypaconitine, and songorine were all increased significantly. The hypaconitine, benzoylmesaconitine, and songorine were regarded as the main active components in vivo, which gave an effective clue for the development of new Shenfu oral prescriptions.

Discovery of the directionally detoxification effect and chemical mechanism of Ginseng-Fuzi co-decoction based on real-time online filtration electrospray ionization mass spectrometry

BACKGROUND

The synergic action of compound prescriptions is an important feature and core advantage of traditional medicine. Ginseng-Fuzi decoction is a classic compatible phytomedicine in China, of which Ginseng can effectively reduce the toxicity of Fuzi in clinical, but the detoxification chemical mechanism is still unclear.

PURPOSE

Develop a novel method for real-time tracking and monitoring of complex substances in the decoction system of traditional Chinese medicine to uncover the detoxification effect Ginseng on Fuzi and explore the possible chemical reaction mechanism of Ginseng-Fuzi co-decoction.

METHODS

A novel real-time monitoring system, online filtration electrospray ionization mass spectrometry, was developed for extremely complex substances analysis in the decoction of traditional medicine compounds to uncover the directionally detoxification effect and the mechanism of compatibility interaction.

RESULTS

Nine key alkaloids and 7 ginsenosides in Ginseng-Fuzi decoction were simultaneously in-situ monitoring in positive ion mode or negative ion mode respectively. Both types of targeted analytes had satisfactory MS signal response for real-time qualitative and quantitative analysis with high precision (RSD < 14.04%) and low LLODs (0.002 ng/ml-10 ng/ml). Through long-term tracking analysis, the exact detoxification and synergistic effect of Ginseng-Fuzi decoction were confirmed as the concentration of main toxic alkaloids decreased (e.g. the content of mesaconitine has been reduced by about 38%) and the main active monoester alkaloids increased obviously. More importantly, the possible molecular mechanism of the detoxification effect of Ginseng compatibility was revealed for the first time, which was the nucleophilic substitution reaction of diester alkaloids catalyzed by fatty acids.

CONCLUSION

This study revealed the exact effect of co-decoction of Ginseng and Fuzi at the molecular level and the chemical reaction mechanism of fatty acid-catalyzed degradation of toxic diester-type alkaloids. The comprehensive multi-component real-time monitoring strategy for complex traditional medicine compounds developed and implemented here has important demonstration significance for revealing the scientific connotation of the compatibility of compound traditional medicine.

Molecular differentiation of Panax notoginseng grown under different conditions by internal extractive electrospray ionization mass spectrometry and multivariate analysis

Panax notoginseng is a highly valuable and widely used herb in traditional Chinese medicine. The quality and efficacy of Panax notoginseng grown under different conditions can greatly vary due to the differences in chemical composition. The analysis of chemical composition in Panax notoginseng typically involves various experimental steps including extraction, chromatographic separation and characterization, which can be time- and labor-consuming. Therefore, the efficient quality assessment and control of Panax notoginseng requires the development of more rapid methods for the chemical characterization and classification of Panax notoginseng. In this study, a method based on internal extractive electrospray ionization mass spectrometry (iEESI-MS) was developed to characterize chemical components of Panax notoginseng samples under different growth conditions (e.g., place of origin, soil quality, growth season) at the speed of 0.5 min per sample, without sample pretreatment and chromatographic separation. A total of 35 chemical components, including sugars, saponins, organic acids, etc., were identified in Panax notoginseng samples. Clear separation was observed in the multivariate analysis of the iEESI-MS data from Panax notoginseng samples grown under different conditions. The difference in the content of sucrose, fructose, Rg1, Rf, Rb1, Noto-R1, malonyl-Rb1, malonyl-Rg1, malonyl-Rf, Rd, Re, linoleic acid, palmitic acid and malic acid can be used as key characteristic indicators to discriminate origin, commercial specifications, and cultivation conditions of Panax notoginseng samples. The results of our study indicate the high power of iEESI-MS for the rapid molecular characterization and classification of Panax notoginseng under different growth conditions, which can be used for the quality assessment of traditional herbal medicines as well as in pharmaceutical and clinical analysis.

Chemical-activity-based quality marker screening strategy for Viscum articulatum

Viscum articulatum Burm. f. is a parasitic plant rich in flavonoids, triterpenoids, and catechins and has a high nutritional value. It has been reported that consuming V. articulatum can prevent cardiac diseases. In this study, six bioactive compounds, including catechins, triterpenoids, and phenylpropanoid glycosides, were determined in alcohol extracts of the plant using HPLC. The anti-inflammatory and antioxidant activities of three catechins, two triterpenoids, and three combination drugs were measured in cardiomyocytes, and the results showed that the anti-inflammatory activity was significantly enhanced while retaining strong antioxidant activity when epicatechin and ursolic acid were used in combination. The main quality markers epicatechin and ursolic acid were screened based on the specificity of the genuine herb and a potent synergistic effect, and the lowest limitation contents of V. articulatum which could discriminate it from some other taxonomically similar materials were accordingly determined. This self-built lowest limitation content of the two screened quality markers could quickly and accurately reflect the efficacy in terms of chemical composition and reverse the disorderly market use of nongenuine herbs or confusing species for adulteration. This study is of some significance for market regulation, drug development, and clinical medication.

Cardiac efficacy and toxicity of aconitine: A new frontier for the ancient poison

Aconitine (AC) is well-known as the main toxic ingredient and active compound of Aconitum species, of which several aconites are essential herbal medicines of Traditional Chinese Medicine (TCM) and widely applied to treat diverse diseases for their excellent anti-inflammatory, analgesic, and cardiotonic effects. However, the cardiotoxicity and neurotoxicity of AC attracted a lot of attention and made it a favorite botanic poison in history. Nowadays, the narrow therapeutic window of AC limits the clinical application of AC-containing herbal medicines; overdosing on AC always induces ventricular tachyarrhythmia and heart arrest, both of which are potentially lethal. But the underlying cardiotoxic mechanisms remained chaos. Recently, beyond its cardiotoxic effects, emerging evidence shows that low doses of AC or its metabolites could generate cardioprotective effects and are necessary to aconite's clinical efficacy. Consistent with TCM's theory that even toxic substances are powerful medicines, AC thus could not be simply identified as a toxicant or a drug. To prevent cardiotoxicity while digging the unique value of AC in cardiac pharmacology, there exists a huge urge to better know the characteristic of AC being a cardiotoxic agent or a potential heart drug. Here, this article reviews the advances of AC metabolism and focuses on the latest mechanistic findings of cardiac efficacy and toxicity of this aconite alkaloid or its metabolites. We also discuss how to prevent AC-related cardiotoxicity, as well as the issues before the development of AC-based medicines that should be solved, to provide new insight into the paradoxical nature of this ancient poison.

Quality tracing evaluation strategies of compatible materials in Aconitum proprietary Chinese medicines

The proprietary Chinese medicine (PCM) has become a significant supplement of modern medicine. Nevertheless, the absence of quality control standard of compatible materials in PCM has led to serious adulteration, which has an extremely bad effect on safety of drug use and clinical efficacy. Here, a quality tracing evaluation strategy of compatible materials in 32 Aconitum proprietary Chinese medicines (APCMs) was established, including data normalization, model development, model verification, and unknown prescription cracking. The model was delimited based on the weighted content of total 9 key alkaloids in 24 APCMs, which were 5.65-57.10 μg/g for extract medicines and 42.62-380.61 μg/g for powder medicines. Three newly published commercial APCMs, including Wangbi Tablet, Wangbi Granule, and Fengshigutong Capsule, were used to verify its reliability and the results proved to be positive. Moreover, a novel prescription cracking approach was proposed to decode the content of each material in five unknown prescriptions including Yaoxitong Capsule, Tongrendahuoluo Pill, Xinbao Pill, Dahuoluo Capsule, and Mugua Pill. Ultimately, the single or two compatible Aconitum materials in APCMs was successfully decoded and the processed level of the materials were effectively judged. This study for the first time established a practical strategy for supervision and cracking of compatible materials in PCMs and is of great significance to improve the quality control of PCMs.