Neutral fragment filtering for rapid identification of new diester-diterpenoid alkaloids in roots of Aconitum carmichaeli by ultra-high-pressure liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry

Metabolite Profiling Analysis of the Tongmai Sini Decoction in Rats after Oral Administration through UHPLC-Q-Exactive-MS/MS

Tongmai Sini decoction (TSD), the classical prescriptions of traditional Chinese medicine, consisting of three commonly used herbal medicines, has been widely applied for the treatment of myocardial infarction and heart failure. However, the absorbed components and their metabolism in vivo of TSD still remain unknown. In this study, a reliable and effective method using ultra-performance liquid chromatography coupled with hybrid quadrupole-Orbitrap mass spectrometry (UHPLC-Q-Exactive-MS/MS) was employed to identify prototype components and metabolites in vivo (rat plasma and urine). Combined with mass defect filtering (MDF), dynamic background subtraction (DBS), and neutral loss filtering (NLF) data-mining tools, a total of thirty-two major compounds were selected and investigated for their metabolism in vivo. As a result, a total of 82 prototype compounds were identified or tentatively characterized in vivo, including 41 alkaloids, 35 phenolic compounds, 6 saponins. Meanwhile, A total of 65 metabolites (40 alkaloids and 25 phenolic compounds) were tentatively identified. The metabolic reactions were mainly hydrogenation, demethylation, hydroxylation, hydration, methylation, deoxylation, and sulfation. These findings will be beneficial for an in-depth understanding of the pharmacological mechanism and pharmacodynamic substance basis of TSD.

Deciphering in vivo metabolic profile and pharmacological mechanisms of Jitongning Tablet for the treatment of Ankylosing spondylitis

Jitongning tablet (JTNT) is a Traditional Chinese Medicine (TCM) prescription used for the treatment of Ankylosing spondylitis (AS). Currently, it is in phase II clinical trial (NCT03932019) for patients with active axial Spondyloarthritis (axSpA), showing great promise for the treatment of AS. However, the potential material basis and the underlying mechanisms for JTNT to treat AS remain elusive. Here, we performed UPLC-Q-TOF-MS to determine the in vivo metabolic profile of JTNT in rats and conducted in vivo studies including acetic acid-induced writhing, hot plate models, and collagen-induced arthritis (CIA) in rats to evaluate and validate the analgesic and anti-inflammatory effects of JTNT, two main symptoms for AS. Additionally, network pharmacology combined with molecular docking was performed to investigate the potential underlying mechanisms. As a result, a total of 116 xenobiotics were identified from the plasma, urine, and brain tissues of rats after oral administration of JTN extracts. Pharmacological evaluation revealed that fractions JTN-3 and JTN-4 exerted significant analgesic activities by reducing the number of writhes in an acetic acid-induced writhing mice model. JTN extract also exerted excellent therapeutic effects in the CIA model by ameliorating paw edema and decreasing systemic manifestation of inflammation and the level of circulating immune complex (CIC) and interferon γ (IFN-γ). Fractions of JTN extract, especially JTN-2 and JTN-4, on the other hand, ameliorated the secondary lesions caused by chicken type II collagen (CII) to a certain extent. Further, network pharmacology combined with molecular docking suggested crucial roles of inflammation and immune-related genes such as MAPK1, MAPK14, NOS3, and RELA in the treatment of AS by JTNT. In conclusion, our studies suggest that the isoquinoline and diterpenoid alkaloids from Corydalis Rhizoma and Aconiti Radix Cocta, along with coumarins from Angelicae Pubescentis Radix, may be the main bioactive components, and the AS treatment mechanism may mainly involve immune regulation of JTNT. These results help clarify the potential material basis and underlying mechanisms of JTNT for the treatment of AS, facilitating the broad application of this TCM in clinical practice.

Spatial distribution and comparative analysis of Aconitum alkaloids in Fuzi using DESI-MSI and UHPLC-QTOF-MS

Aconitum L. poisoning is a major type of poisoning caused by herbal medicines in many countries. However, despite its toxicity, Aconitum L. is still used because of its therapeutic value. Fuzi, the lateral root of Aconitum L., is one of the most important pharmacological parts. It is necessary for rational medication to figure out the types and contents of toxic Aconitum alkaloids (AAs) in Fuzi and its processed products. The present study aims to investigate the spatial distribution of toxic AAs in Fuzi and the quantification of AAs in various processing products through mass spectrometry methods. In this study, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was used to directly image the sections of raw Fuzi. The results showed a high content of diester alkaloids (DAs) and a relatively uniform distribution in the sections, while the content of monoester alkaloids (MAs) was low and uneven in the sections, distributed in the cortex, epidermis, vascular column, and other parts of the tissues. The content of non-ester alkaloids (NAs) was relatively minimum, and most of the NAs were distributed in the vascular column and the tightly connected cortex of the tissue. To further investigate the difference between raw and processed Fuzi, 60 known compounds were identified using UHPLC-QTOF-MS. The total contents of alkaloids in 7 processed Fuzi were lower than that in Shengfupian (SFP). Paofupian (PFP), Paotianxiong (PTX), Paofupian (PFP*), Danfupian (DFP), and Shufupian (SFP*) were the least similar. Zhengfupian (ZFP) and Chaofupian (CFP) had significantly reduced toxicity and increased efficacy compared with other processed products because the contents of active alkaloids in other processed products were also reduced. Understanding the distribution of metabolites and the composition changes after processing can guide users and herbal manufacturers to carefully choose the relatively safe and better therapeutic species of Fuzi. The information gathered from this study can contribute towards the improved and effective management of therapeutically important, nonetheless toxic, drugs such as Aconitum L.

Unveiling Dynamic Changes of Chemical Constituents in Raw and Processed Fuzi With Different Steaming Time Points Using Desorption Electrospray Ionization Mass Spectrometry Imaging Combined With Metabolomics

Fuzi is a famous toxic traditional herbal medicine, which has long been used for the treatment of various diseases in China and many other Asian countries because of its extraordinary pharmacological activities and high toxicity. Different processing methods to attenuate the toxicity of Fuzi are important for its safe clinical use. In this study, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) with a metabolomics-combined multivariate statistical analysis approach was applied to investigate a series of Aconitum alkaloids and explore potential metabolic markers to understand the differences between raw and processed Fuzi with different steaming time points. Moreover, the selected metabolic markers were visualized by DESI-MSI, and six index alkaloids’ contents were determined through HPLC. The results indicated visible differences among raw and processed Fuzi with different steaming times, and 4.0 h is the proper time for toxicity attenuation and efficacy reservation. A total of 42 metabolic markers were identified to discriminate raw Fuzi and those steamed for 4.0 and 8.0 h, which were clearly visualized in DESI-MSI. The transformation from diester-diterpenoid alkaloids to monoester-diterpenoid alkaloids and then to non-esterified diterpene alkaloids through hydrolysis is the major toxicity attenuation process during steaming. DESI-MSI combined with metabolomics provides an efficient method to visualize the changeable rules and screen the metabolic markers of Aconitum alkaloids during steaming. The wide application of this technique could help identify markers and reveal the possible chemical transition mechanism in the “Paozhi” processes of Fuzi. It also provides an efficient and easy way to quality control and ensures the safety of Fuzi and other toxic traditional Chinese medicine.

Applying Four-Step Characteristic Ion Filtering with HPLC-Q-Exactive MS/MS Spectrometer Approach for Rapid Compound Structures Characterization and Major Representative Components Quantification in Modified Tabusen-2 Decoction

Modified Tabusen-2 decoction (MTBD) is traditional Chinese Mongolia medicine, mainly used to treat osteoporosis. However, the precise material basis of this prescription is not yet fully elucidated. Herein, we establish an HPLC-Q-Exactive MS/MS spectrometer method with four-step characteristic ion filtering (FSCIF) strategy to quickly and effectively identify the structural features of MTBD and determine the representative compounds content. The FSCIF strategy included database establishment, characteristic ions summarization, neutral loss fragments screening, and secondary mass spectrum fragment matching four steps. By using this strategy, a total of 143 compounds were unambiguously or tentatively annotated, including 5 compounds which were first reported in MTBD. Nineteen representative components were simultaneously quantified with the HPLC-Q-Exactive MS/MS spectrometer, and it is suitable for eight batches of MTBD. Methodology analysis showed that the assay method had good repeatability, accuracy, and stability. The method established above was successfully applied to assess the quality of MTBD extracts. Collectively, our findings enhance our molecular understanding of the MTBD formulation and will allow us to control its quality in a better way. At the same time, this study can promote the development and utilization of ethnic medicine.

Insight into chemical basis of traditional Chinese medicine based on the state-of-the-art techniques of liquid chromatography-mass spectrometry

Traditional Chinese medicine (TCM) has been an indispensable source of drugs for curing various human diseases. However, the inherent chemical diversity and complexity of TCM restricted the safety and efficacy of its usage. Over the past few decades, the combination of liquid chromatography with mass spectrometry has contributed greatly to the TCM qualitative analysis. And novel approaches have been continuously introduced to improve the analytical performance, including both the data acquisition methods to generate a large and informative dataset, and the data post-processing tools to extract the structure-related MS information. Furthermore, the fast-developing computer techniques and big data analytics have markedly enriched the data processing tools, bringing benefits of high efficiency and accuracy. To provide an up-to-date review of the latest techniques on the TCM qualitative analysis, multiple data-independent acquisition methods and data-dependent acquisition methods (precursor ion list, dynamic exclusion, mass tag, precursor ion scan, neutral loss scan, and multiple reaction monitoring) and post-processing techniques (mass defect filtering, diagnostic ion filtering, neutral loss filtering, mass spectral trees similarity filter, molecular networking, statistical analysis, database matching, etc.) were summarized and categorized. Applications of each technique and integrated analytical strategies were highlighted, discussion and future perspectives were proposed as well.

A comprehensive quality evaluation of Fuzi and its processed product through integration of UPLC-QTOF/MS combined MS/MS-based mass spectral molecular networking with multivariate statistical analysis and HPLC-MS/MS

ETHNOPHARMACOLOGICAL RELEVANCE

Aconiti Lateralis Radix Praeparata (the Chinese name is Fuzi, FZ), the lateral or daughter root of Aconitum carmichaelii Debx. (Ranunculaceae), is a controversial traditional Chinese medicine (TCM) that is universally distributed and applied in many countries, such as China, Japan, Korea, and India. FZ can be used to treat various diseases, including rheumatic fever, rheumatism, painful joints, syncope, collapse, bronchial asthma, some endocrinal disorders, etc. However, quality control and assessment of FZ are challenging due to its obvious and high toxicological risks, and only its processed products are allowed to be used clinically according to the relative safety regulations. Consequently, it is necessary to analyze the whole chemical composition and the dynamic changes of FZ before and after processing. Addressing the changes in the chemical substance of raw and processed products is a way to reduce toxicity.

AIM OF THE STUDY

In this article, the whole chemical composition of FZ is analyzed, the differences between raw and processed FZ are evaluated, and possible factors that influence the reduced toxicity of processed FZ are explained from the perspective of its chemical composition using qualitative and quantitative analysis methods.

MATERIALS AND METHODS

A novel strategy of multiple data collection and processing based on ultra-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) method in the positive ion mode, together with Global Natural Product Social Molecular Networking (GNPS) and multivariate statistical analysis, was established to systematically identify the chemical constituents of FZ and comprehensively investigate the chemical markers that can be used to differentiate FZ processed with vinegar and honey from its raw product. Combined with the qualitative analysis results, 12 components, including 8 chemical marker compounds and 4 toxicity components, were quantitatively analyzed by using high-performance liquid chromatography equipped with triple-quadrupole mass spectrometry (HPLC-MS/MS).

RESULTS

Using the molecular networking (MN) analysis method, a total of 145 compounds were identified, of which 13 were identified using reference compounds. Seventy seven chemical markers were also detected between raw and processed FZ. The identification results of the chemical markers were also verified by orthogonal partial least squares discriminant analysis (OPLS-DA). The quantitative results indicated that the contents of 12 important components all decreased, especially diester-diterpenoid alkaloids (DDAs), after processing.

CONCLUSION

The decrease of toxicity of FZ after processing is closely related to the changes in its chemical composition. The method developed in this study is a comprehensive analysis technique for quality assessment of FZ, and this study provides a useful and quick strategy to characterize chemical compounds of TCM and explore the different chemical markers between raw and processed Chinese herbal medicine.

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.

An integrated strategy based on characteristic fragment filter supplemented by multivariate statistical analysis in multi-stage mass spectrometry chromatograms for the large-scale detection and identification of natural plant-derived components in rat: The rhubarb case

An integrated strategy based on characteristic fragment filter (CFF) supplemented by multivariate statistical analysis (MSA) for MSⁿ chromatograms [(CFF)s MSA] was proposed for the large-scale detection of natural plant-derived ingredients in vivo. To prove the practicability of this [(CFF)s MSA] strategy, rhubarb was taken as an example. First, representative authentic standards of homologous components contained in rhubarb were chosen, from which the fragmentation rules and chemical characteristic fragments (CCFs) were proposed. Second, the metabolic pathways of the representative compounds were deciphered, and the metabolic characteristic fragments (MCFs) of each family of compounds were acquired. Third, combined with CCFs and MCFs, a CFF method was established. Finally, MSA was used to supplement the xenobiotics missed by the CFF method. In our research, 274 compounds were detected in rhubarb, and 298 ingredients were identified in vivo after oral administration. The results demonstrated that this integrated strategy could comprehensively screen for plant-derived compounds in vivo.

Comprehensive characterization of multiple components and metabolites of Xiaojin Capsule based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

Xiaojin Capsule, a classic traditional Chinese medicine formula, has been used to treat mammary cancer, thyroid nodules, and hyperplasia of the mammary glands. However, its systematic chemical information remained unclear, which hindered the interpretation of the pharmacology and the mechanism of action of this drug. In this research, an ultra high performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry method was developed to identify the complicated components and metabolites of Xiaojin Capsule. Two acquisition modes, including the MS^Energy mode and fast data directed acquisition mode, were utilized for chemical profiling. As a result, 156 compounds were unambiguously or tentatively identified by comparing their retention times and mass spectrometry data with those of reference standards or literature. After the oral administration of Xiaojin Capsule, 53 constituents, including 24 prototype compounds and 29 metabolites, were detected in rat plasma. The obtained results were beneficial for a better understanding of the therapeutic basis of Xiaojin Capsule. A high-resolution and efficient separation method was firstly established for systematically characterizing the compounds of Xiaojin Capsule and the associated metabolites in vivo, which could be helpful for quality control and pharmacokinetic studies of this medicine.

Identification, synthesis and biological activity of alkyl-guanidine oligomers as potent antibacterial agents

In the last two decades, the repertoire of clinically effective antibacterials is shrinking due to the rapidly increasing of multi-drug-resistant pathogenic bacteria. New chemical classes with innovative mode of action are required to prevent a return to the pre-antibiotic era. We have recently reported the identification of a series of linear guanidine derivatives and their antibacterial properties. A batch of a promising candidate for optimization studies (compound 1) turned out to be a mixture containing two unknown species with a better biological activity than the pure compound. This serendipitous discovery led us to investigate the chemical nature of the unknown components of the mixture. Through MS analysis coupled with design and synthesis we found that the components were spontaneously generated oligomers of the original compound. Preliminary biological evaluations eventually confirmed the broad-spectrum antibacterial activity of this new family of molecules. Interestingly the symmetric dimeric derivative (2) exhibited the best profile and it was selected as lead compound for further studies.

Identification of Oxygenated Fatty Acid as a Side Chain of Lipo-Alkaloids in Aconitum carmichaelii by UHPLC-Q-TOF-MS and a Database

Lipo-alkaloid is a kind of C19-norditerpenoid alkaloid usually found in Aconitum species. Structurally, they contain an aconitane skeleton and one or two fatty acid moieties of 3–25 carbon chains with 1–6 unsaturated degrees. Analysis of the lipo-alkaloids in roots of Aconitum carmichaelii resulted in the isolation of six known pure lipo-alkaloids (A1–A6) and a lipo-alkaloid mixture (A7). The mixture shared the same aconitane skeleton of 14-benzoylmesaconine, but their side chains were determined to be 9-hydroxy-octadecadienoic acid, 13-hydroxy-octadecadienoic acid and 10-hydroxy-octadecadienoic acid, respectively, by MS/MS analysis after alkaline hydrolysis. To our knowledge, this is the first time of the reporting of the oxygenated fatty acids as the side chains in naturally-occurring lipo-alkaloids. In order to identify more lipo-alkaloids, a compound database was established based on various combinations between the aconitane skeleton and the fatty acid chain, and then, the identification of lipo-alkaloids was conducted using the database, UHPLC-Q-TOF-MS and MS/MS. Finally, 148 lipo-alkaloids were identified from A. carmichaelii after intensive MS/MS analysis, including 93 potential new compounds and 38 compounds with oxygenated fatty acid moieties.

Study on the Alkaloids in Tibetan Medicine Aconitum pendulum Busch by HPLC-MSn Combined with Column Chromatography

A rapid, convenient and effective identification method of alkaloids was established and an attempt on isolating and analyzing the alkaloids in Aconitum pendulum Busch was conducted successfully. In this article, four high-content components including deoxyaconitine, benzoylaconine, aconine and neoline were isolated by using column chromatography. HPLC-MS(n)was employed to deduce the regulations of fragmentation of diterpenoid alkaloids which displayed a characteristic behavior of loss of CO(28u), CH3COOH(60u), CH3OH(32u), H2O(18u) and C6H5COOH(122u). Then, according to fragmentation regulation of mass spectrometry, 42 alkaloids were found inA. pendulum Among them, 38 compounds were identified and 29 alkaloids were reported for the first time for this herb. Therefore, this means that HPLC-MS(n)combined with column chromatography could work as an effective and reliable tool for rapid identification of the chemical components of herbal medicine.

Fragmentation study of aminoalcohol-diterpenoid alkaloids by electrospray ionization time-of-flight mass spectrometry

RATIONALE

Aminoalcohol-diterpenoid alkaloids were found to be a group of cardioactive substances in the lateral roots of Aconitum carmichaeli Debx. Studies on the fragmentation behaviors and features of these alkaloids in mass spectrometry would be important for their structural identification and in vivo metabolic research, which has not received much attention thus far.

METHODS

In this study, the fragmentation behaviors of 14 aminoalcohol-diterpenoid alkaloids were investigated by utilizing high-resolution time-of-flight tandem mass spectrometry. By analysis of the obtained MS(2) data, we summarized the fragmentation features of the corresponding alkaloids under different collision energy.

RESULTS

The dissociation of functional groups from the skeleton was observed as the main fragmentation way in electrospray ionization (ESI) mode. The order of fragmentation sites was C1/C3 > C16 > C15 > C6 > N, with loss of one or more CH3OH, H2O, C2H4 (substituent on N atom) or CO (at C15 ) groups.

CONCLUSIONS

The first systematic investigations on the fragmentation of aminoalcohol-diterpenoid alkaloids are described in this paper, setting the stage for an in-depth identification and study of the corresponding components in complex systems.

Use, history, and liquid chromatography/mass spectrometry chemical analysis of Aconitum

Aconitum and its products have been used in Asia for centuries to treat various ailments, including arthritis, gout, cancer, and inflammation. In general, their preparations and dispensing have been restricted to qualified folk medicine healers due to their low safety index and reported toxicity. In the past few decades, official guidelines have been introduced in Asian pharmacopeias to control Aconitum herbal products. However, these guidelines were based on primitive analytical techniques for the determination of the whole Aconitum alkaloids and were unable to distinguish between toxic and nontoxic components. Recent advances in analytical techniques, especially high performance liquid chromatography (HPLC) and electrophoresis coupled with highly sensitive detectors, allowed rapid and accurate determination of Aconitum secondary metabolites. Reports focusing on liquid chromatography/mass spectrometry analysis of Aconitum and its herbal products are discussed in the current review. This review can be used by the health liquid chromatography/mass spectrometry regulatory authorities for updating pharmacopeial guidelines of Aconitum and its herbal products.

Ion tree-based structure elucidation of acetophenone dimers (AtA) from Acronychia pedunculata and their identification in extracts by liquid chromatography electrospray ionization LTQ-Orbitrap mass spectrometry

Acronychia-type acetophenones (AtA) is a chemical group of compounds of important structural and biological interest, abundant in Acronychia species. However, there are no data available for their characterization using mass spectrometry. In the current work, AtA have been investigated by multistage high resolution mass spectrometry and both electrospray ionization and atmospheric pressure chemical ionization, in positive and negative mode, were utilized for their structure elucidation and identification. The analysis of AtA using a linear ion trap-Orbitrap analyzer enabled the structural determination of key fragment ions and cleavages, which can be used for the structural characterization thereof. A systematic nomenclature based on protonated and deprotonated fragment ions under collision-induced dissociation conditions and decision trees for the structural determination of AtA are proposed. Furthermore, taking advantage of the characteristic fragmentation patterns, a selective Ultra High Performance Liquid Chromatography Electrospray Ionization multistage Mass Spectrometry (UHPLC-ESI(-)-MS(n)) method was developed and successfully applied for the dereplication of known AtA and the identification of potentially new ones in Acronychia extracts. Despite the structure similarity and the presence of isomers, accurate characterization of known and unknown AtA derivatives was possible.

Simultaneous determination of aconite alkaloids and ginsenosides using online solid phase extraction hyphenated with polarity switching ultra-high performance liquid chromatography coupled with tandem mass spectrometry

Simultaneous determination of ten aconite alkaloids and thirteen ginsenosides using online solid phase extraction hyphenated with polarity switching ultra-high performance liquid chromatography coupled with tandem mass spectrometry.

RECENT ADVANCES IN ULTRA-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR THE ANALYSIS OF TRADITIONAL CHINESE MEDICINE

Traditional Chinese medicine has been widely used for the prevention and treatment of various diseases for thousands of years in China. Ultra-high performance liquid chromatography (UHPLC) is a relatively new technique offering new possibilities. This paper reviews recent developments in UHPLC in the separation and identification, fingerprinting, quantification, and metabolism of traditional Chinese medicine. Recently, the combination of UHPLC with MS has improved the efficiency of the analysis of these materials.

Characterization of the herb-derived components in rats following oral administration of Carthamus tinctorius extract by extracting diagnostic fragment ions (DFIs) in the MSn chromatograms

An E(DFI)MSⁿCs-based strategy was proposed to rapidly detect and identify the in vivo components derived from the extract of Carthamus tinctorius using LC-IT-TOF-MSⁿ.