Dynamic Enhancer DNA Methylation as Basis for Transcriptional and Cellular Heterogeneity of ESCs.

Variable levels of DNA methylation have been reported at tissue-specific differential methylation regions (DMRs) overlapping enhancers, including super-enhancers (SEs) associated with key cell identity genes, but the mechanisms responsible for this intriguing behavior are not well understood. We used allele-specific reporters at the endogenous Sox2 and Mir290 SEs in embryonic stem cells and found that the allelic DNA methylation state is dynamically switching, resulting in cell-to-cell heterogeneity. Dynamic DNA methylation is driven by the balance between DNA methyltransferases and transcription factor binding on one side and co-regulated with the Mediator complex recruitment and H3K27ac level changes at regulatory elements on the other side. DNA methylation at the Sox2 and the Mir290 SEs is independently regulated and has distinct consequences on the cellular differentiation state. Dynamic allele-specific DNA methylation at the two SEs was also seen at different stages in preimplantation embryos, revealing that methylation heterogeneity occurs in vivo.

Metabolic profiling identifies Qrich2 as a novel glutamine sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm.

In our prior investigation, we discerned loss-of-function variants within the gene encoding glutamine-rich protein 2 (QRICH2) in two consanguineous families, leading to various morphological abnormalities in sperm flagella and male infertility. The Qrich2 knockout (KO) in mice also exhibits multiple morphological abnormalities of the flagella (MMAF) phenotype with a significantly decreased sperm motility. However, how ORICH2 regulates the formation of sperm flagella remains unclear. Abnormal glutamylation levels of tubulin cause dysplastic microtubules and flagella, eventually resulting in the decline of sperm motility and male infertility. In the current study, by further analyzing the Qrich2 KO mouse sperm, we found a reduced glutamylation level and instability of tubulin in Qrich2 KO mouse sperm flagella. In addition, we found that the amino acid metabolism was dysregulated in both testes and sperm, leading to the accumulated glutamine (Gln) and reduced glutamate (Glu) concentrations, and disorderly expressed genes responsible for Gln/Glu metabolism. Interestingly, mice fed with diets devoid of Gln/Glu phenocopied the Qrich2 KO mice. Furthermore, we identified several mitochondrial marker proteins that could not be correctly localized in sperm flagella, which might be responsible for the reduced mitochondrial function contributing to the reduced sperm motility in Qrich2 KO mice. Our study reveals a crucial role of a normal Gln/Glu metabolism in maintaining the structural stability of the microtubules in sperm flagella by regulating the glutamylation levels of the tubulin and identifies Qrich2 as a possible novel Gln sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm.

UCHL-3 as a potential biomarker of ovarian cancer.

OBJECTIVE: This study explored promising prognostic and immune therapeutic candidate biomarkers for OC and determined the expression, prognostic value, and immune effects of UCHL3. METHODS: UCHL3 expression and clinical data were investigated using bioinformatic analysis. CCK8 and transwell assays were conducted to evaluate the impact of UCHL3 on proliferation and migration, and the effects of UCHL3 were further validated in a mouse model. Univariate and least absolute shrinkage and selection operator regression analyses were performed to construct a novel UCHL3-related prognostic risk model. Gene set enrichment analysis (GSEA) and immune analysis were performed to identify the significantly involved functions of UCHL3. Finally, bioinformatic analysis and immunohistochemistry were performed to explore the effect of UCHL3 on chemotherapy. RESULTS: UCHL3 expression was upregulated and associated with worse overall survival (OS) in OC. UCHL3 depletion repressed cell proliferation and migration both in vitro and in vivo. Furthermore, 237 genes were differentially expressed between the high and low UCHL3 expression groups. Subsequently, a UCHL3-related prognostic signature was built based on six prognostic genes (PI3, TFAP2B, MUC7, PSMA2, PIK3C2G, and NME1). Independent prognostic analysis suggested that age, tumor mutational burden, and RiskScore can be used as independent prognostic factors. The immune infiltration analysis and GSEA suggested that UCHL3 expression was related to the immune response. In addition, UCHL3 expression was higher in platinum-resistant OC patients than in platinum-sensitive patients. UCHL3 overexpression was associated with poorer OS. CONCLUSION: UCHL3 overexpression contributes to aggressive progression, poor survival, and chemoresistance in OC. Therefore, UCHL3 may be a candidate prognostic biomarker and potential target for controlling progression and platinum resistance in OC.

Quantitative comparison of bile acid glucuronides sub-metabolome between intrahepatic cholestasis and healthy pregnant women.

Because of the pathological indication and the physiological functions, bile acids (BAs) have occupied the research hotspot in recent decades. Although extensive efforts have been paid onto BAs sub-metabolome characterization, as the subfamily, BA glucuronides (gluA-BAs) profile is seldom concerned. Here, we made efforts to develop a LC-MS/MS program enabling quantitative gluA-BAs sub-metabolome characterization and to explore the differential species in serum between intrahepatic cholestasis of pregnancy (ICP) patients and healthy subjects. To gain as many authentic gluA-BAs as possible, liver microsomes from humans, rats, and mice were deployed to conjugate glucuronyl group to authentic BAs through in vitro incubation. Eighty gluA-BAs were captured and subsequently served as authentic compounds to correlate MS/MS spectral behaviors to structural features using squared energy-resolved MS program. Optimal collision energy (OCE) of [M-H]->[M-H-176.1]- was jointly administrated by [M-H]- mass and glucuronidation site, and identical exciting energies corresponding to 50% survival rate of 1st-generation fragment ion (EE50) were observed merely when the aglycone of a gluA-BA was consistent with the suspected structure. Through integrating high-resolution m/z, OCE, and EE50 information to identify gluA-BAs in a BAs pool, 97 ones were found and identified, and further, quantitative program was built for all annotated gluA-BAs by assigning OCEs to [M-H]->[M-H-176.1]- ion transitions. Quantitative gluA-BAs sub-metabolome of ICP was different from that of the healthy group. More GCDCA-3-G, GDCA-3-G, TCDCA-7-G, TDCA-3-G, and T-ß-MCA-3-G were distributed in the ICP group. Above all, this study not only offered a promising analytical tool for in-depth gluA-BAs sub-metabolome characterization, but also clarified gluA-BAs allowing the differentiation of ICP and healthy subjects.

A loss-of-function variant in ZCWPW1 causes human male infertility with sperm head defect and high DNA fragmentation.

BACKGROUND: Male infertility is a global health issue. The more causative genes related to human male infertility should be further explored. The essential role of Zcwpw1 in male mouse fertility has been established and the role of ZCWPW1 in human reproduction needs further investigation to verify. METHODS: An infertile man with oligoasthenoteratozoospermia phenotype and his parents were recruited from West China Second University Hospital, Sichuan University. A total of 200 healthy Han Chinese volunteers without any evidence of infertility were recruited as normal controls, while an additional 150 infertile individuals were included to assess the prevalence of ZCWPW1 variants in a sporadic male sterile population. The causative gene variant was identified by Whole-exome sequencing and Sanger sequencing. The phenotype of the oligoasthenoteratozoospermia was determined by Papanicolaou staining, immunofluorescence staining and electron microscope. In-vitro experiments, western blot and in-silicon analysis were applied to assess the pathogenicity of the identified variant. Additionally, we examined the influence of the variant on the DNA fragmentation and DNA repair capability by Sperm Chromatin Dispersion and Neutral Comet Assay. RESULTS: The proband exhibits a phenotype of oligoasthenoteratozoospermia, his spermatozoa show head defects by semen examination, Papanicolaou staining and electron microscope assays. Whole-exome sequencing and Sanger sequencing found the proband carries a homozygous ZCWPW1 variant (c.1064C > T, p. P355L). Immunofluorescence analysis shows a significant decrease in ZCWPW1 expression in the proband's sperm. By exogenous expression with ZCWPW1 mutant plasmid in vitro, the obvious declined expression of ZCWPW1 with the mutation is validated in HEK293T. After being treated by hydroxyurea, MUT-ZCWPW1 transfected cells and empty vector transfected cells have a higher level of γ-H2AX, increased tail DNA and reduced H3K9ac level than WT-ZCWPW1 transfected cells. Furthermore, the Sperm Chromatin Dispersion assay revealed the proband's spermatozoa have high DNA fragmentation. CONCLUSIONS: It is the first report that a novel homozygous missense mutation in ZCWPW1 caused human male infertility with sperm head defects and high DNA fragmentation. This finding enriches the gene variant spectrum and etiology of oligoasthenoteratozoospermia.

Gastroprotective 2-(2-phenylethyl)chromone-sesquiterpene hybrids from the resinous wood of Aquilaria sinensis (Lour.) Gilg.

Six previously unprecedented 2-(2-phenylethyl)chromone-sesquiterpene hybrids, aquisinenins A-F (1 - 6), were isolated from the resinous wood of Aquilaria sinensis by a LC-MS-guided fractionation procedure. Their structures were determined by extensive spectroscopic analysis (1D and 2D NMR, UV, IR, and HRMS) and experimental and computed ECD data. Compounds 1 - 6 were rare dimeric 2-(2-phenylethyl)chromone-sesquiterpene derivatives featuring 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone hybridized with different sesquiterpene (eudesmane/guaiane type) moieties via ester bond. Furthermore, all the isolated compounds were evaluated for their protective effects on taurocholic acid (TCA)-induced GES-1 cell injury. The most effective aquisinenin F (6) was used to elucidate the involved mechanism on protection against TCA-induced gastric mucosal damage. Our results indicated that 6 protected against gastric mucosal cell insult by downregulation of the ER stress triggered by TCA.

Integrated strategy facilitates rapid in-depth chemome characterization of traditional Chinese medicine prescriptions: Shengbai oral liquid as a case.

Chemome characterization is the prerequisite for either therapeutic mechanism clarification or quality control of traditional Chinese medicine prescriptions (TCMPs). Liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) currently serves as the most popular analytical tool; however, chemome characterization is still challenged by MS/MS spectral acquisition and post-acquisition data processing. Here, an integrated strategy was proposed for in-depth chemome clarification of Shengbai oral liquid (SBOL). Gas phase ion fractionation with staggered mass ranges was demonstrated to be the superior acquisition method regarding MS2 spectrum coverage in this study, and narrower mass range further advanced coverage. To facilitate information extraction, all ingredient materials were measured in parallel to form an in-house library, where each MS1 -MS2 item generated a square mass-to-charge ratio (m/z) frame to capture the tagged identity and each chemical family produced a pentagon frame for mass defect features to accomplish chemical analogs-targeted quasi-molecular ion extraction. Square m/z frame imprinting captured 355 identities, while mass defect frames extracted 275 compounds. Attributing to comprehensive MS2 spectrum acquisition and efficient data processing, 355 components were captured and tentatively identified, resulting in a clarified chemical composition for SBOL. Therefore, the proposed strategy should be meaningful for the chemome characterization of TCMPs.

Characterization of Metabolic Correlations of Ursodeoxycholic Acid with Other Bile Acid Species through In Vitro Sequential Metabolism and Isomer-Focused Identification.

As a first-line agent for cholestasis treatment in a clinic, ursodeoxycholic acid rectifies the perturbed bile acids (BAs) submetabolome in a holistic manner. Considering the endogenous distribution of ursodeoxycholic acid and extensive occurrences of isomeric metabolites, it is challenging to point out whether a given bile acid species is impacted by ursodeoxycholic acid in a direct or indirect manner, thus hindering the therapeutic mechanism clarification. Here, an in-depth exploration of the metabolism pattern of ursodeoxycholic acid was attempted. Sequential metabolism in vitro with enzyme-enriched liver microsomes was implemented to simulate the step-wise metabolism and to capture the metabolically labile intermediates in the absence of endogenous BAs. Squared energy-resolved mass spectrometry (ER2-MS) was utilized to achieve isomeric identification of the conjugated metabolites. As a result, 20 metabolites (M1-M20) in total were observed and confirmatively identified. Of those, eight metabolites were generated by hydroxylation, oxidation, and epimerization, which were further metabolized to nine glucuronides and three sulfates by uridine diphosphate-glycosyltransferases and sulfotransferases, respectively. Regarding a given phase II metabolite, the conjugation sites were correlated with first-generation breakdown graphs corresponding to the linkage fission mediated by collision-induced dissociation, and the structural nuclei were identified by matching second-generation breakdown graphs with the known structures. Together, except for intestinal-bacteria-involved biotransformation, the current study characterized BA species directly influenced by ursodeoxycholic acid administration. Moreover, sequential metabolism in vitro should be a meaningful way of characterizing the metabolic pathways of endogenous substances, and squared energy-resolved mass spectrometry is a legitimate tool for structurally identifying phase II metabolites.

[Chemical constituents of diterpenoids from Boswellia carterii].

This paper explored the chemical constituents of Boswellia carterii by column chromatography on silica gel, Sephadex LH-20, ODS column chromatography, and semi-preparative HPLC. The structures of the compounds were identified by physicochemical properties and spectroscopic data such as infrared radiation(IR), ultra violet(UV), mass spectrometry(MS), and nuclear magnetic resonance(NMR). Seven diterpenoids were isolated and purified from n-hexane of B. carterii. The isolates were identified as(1S,3E,7E,11R,12R)-11-hydroxy-1-isopropyl-4,8,12-trimethyl-15-oxabicyclo[10.2.1]pentadeca-3,7-dien-5-one(1),(1R,3S,4R,7E,11E)-4,8,12,15,15-pentamethyl-14-oxabicyclo[11.2.1]hexadeca-7,11-dien-4-ol(2), incensole(3),(-)-(R)-nephthenol(4), euphraticanoid F(5), dilospirane B(6), and dictyotin C(7). Among them, compounds 1 and 2 were new and their absolute configurations were determined by comparison of the calculated and experimental electronic circular dichroisms(ECDs). Compounds 6 and 7 were obtained from B. carterii for the first time.

Squared Energy-Resolved Mass Spectrometry Advances Quantitative Bile Acid Submetabolome Characterization.

The bile acid (BA) submetabolome can partially reflect either physiological or pathological status of vertebrates. The structural diversity, however, extensively hinders BA submetabolome clarification. Here, efforts were primarily devoted to enhance structural annotation confidences of BAs, in particular the conjugated BAs, through fortifying a new technology, namely, squared energy-resolved mass spectrometry (ER2-MS), to traditional liquid chromatography with tandem mass spectrometry (LC-MS/MS). Because of possessing two tandem-in-space collision cells, namely, q2 and linear ion trap (LIT) chambers, Qtrap-MS was employed as the fit-for-purpose tool to conduct ER2-MS measurements. The first ER-MS was undertaken in a q2 cell to gain first-generation breakdown graphs to disclose conjugation sites via applying the multiple-reaction monitoring (MRM) program, and the second ER-MS was accomplished in a LIT chamber through programming MRM cubed to acquire second-generation breakdown graphs of concerned ions for scaffold characterization. An authentic BA library consisting of commercial BAs together with their in vitro metabolites was built to record a reference breakdown graph set. Moreover, the so-called universal metabolome standard sample that was prepared by pooling diverse BA-enriched matrices was applied for structural deciphering potential evaluation and quasi-quantitative analysis of all detected BAs as well, according to applying a well-defined quasi-content concept. High-confidence structural analysis was achieved for as many as 201 BAs, and significant impacts occurred for the BA submetabolome of HepG2 cells after lithocholic acid treatment. Together, ER2-MS provides a promising tool to promote, although not limited to, LC-MS/MS-based BA-targeted metabolomics.

Glycosylation of Aromatic Glycosides by a Promiscuous Glycosyltransferase UGT71BD1 from Cistanche tubulosa.

Multiple-glycosylated glycosides are a major source of bioactive leads. However, most of the currently reported glycosyltransferases (GTases) mainly catalyze glycosylation of aglycones without sugar group substitution. GTases accepting diverse glycosides as substrates are rarely reported. In this article, a new GTase UGT71BD1 was identified from Cistanche tubulosa, a desert herb plant abundant with various phenylethanoid glycosides (PhGs). Interestingly, UGT71BD1 showed no activity toward the aglycone of PhGs. Instead, it could catalyze the further glycosylation of PhG compounds to produce new phenylethanoid multiglycosylated glycosides, including the natural rarely separated tetraglycoside PhGs. Extensive assays found the unprecedented substrate promiscuity of UGT71BD1 toward diverse glycosides including flavonoid glycosides, stilbene glycosides, and coumarin glycosides, performing further mono- or diglycosylation with efficient conversion rates. Using UGT71BD1, six multiglycosylated glycosides were prepared and structurally identified by NMR spectroscopy. These products showed enhanced pharmacological activities compared with the substrates. Docking, dynamic simulation, and mutagenesis studies identified key residues for UGT71BD1's activity and revealed that the sugar modules in glycosides play crucial roles in substrate recognition, thus partly illuminating the unusual substrate preference of UGT71BD1 toward diverse glycosides. UGT71BD1 could be a potential enzyme tool for glycosylation of diverse glycosides.

Phenolic Glucosides from the Leaves of Vitex negundo var. cannabifolia.

Four new phenolic glucosides, cannabifolins G-J (1-4), together with four known ones (5-8), were isolated from the leaves of Vitex negundo var. cannabifolia. Their structures were established by comprehensive analysis of 1D and 2D NMR data and comparison of their spectroscopic and physical data with the literature values. Compound 7 exhibited weak inhibition of nitric oxide production stimulated by lipopolysaccharide in BV-2 microglial cells with IC50 value of 132.8 µM.

[Rapid chemome characterization of Pien-Tze-Huang by DI-MS/MS~(ALL)].

Pien-Tze-Huang, one of the most famous and widely used Chinese medicinal prescriptions in China, consists of Notoginseng Radix et Rhizoma, Bovis Calculus, Fel Serpentis, and Moschus.The prescription can clear heat and remove toxin, cool blood and resolve blood stasis, and relieve swelling and pain.Characterizing the chemical composition can facilitate the construction of the quality standard and the research on the effective compounds and action mechanism of Pien-Tze-Huang.Therefore, this study used direct infusion(DI)-MS/MS~(ALL) method to rapidly and accurately reveal the chemical composition of Pien-Tze-Huang.The principle of chemical composition profiling of Chinese medicinal prescriptions lies in the MS~1-MS~2 dataset construction, followed by structural annotation based on MS/MS spectra and summarizing of mass fragmentation pathways.MS/MS~(ALL) owns unique mass spectrometric separation ability via applying gas phase fractionation which enables MS~1 ion cohort successively enter the collision cell and acquire MS~2 spectrum for each precursor ion current with a width of m/z=1.Because DI can provide desired measurement time, MS/MS~(ALL) is able to acquire MS~2 spectrum for each compound individually except for the compounds which share identical nominal molecular weight, even isomers.A total of 52 compounds were identified in Pien-Tze-Huang, including 16 saponins, 24 bile acids, 9 fatty acids, 2 saccharides, and 1 other compound.DI-MS/MS~(ALL) can simultaneously identify the compounds with different polarities in a short time, which is superior to LC-MS.This study provides a powerful tool for the rapid chemome profiling of Chinese medicinal prescriptions.

[Sesquiterpenoids from Aquilariae Lignum Resinatum].

Eight sesquiterpenoids were isolated from petroleum ether extract of Aquilariae Lignum Resinatum by various column chromatography techniques including silica gel, ODS, and semi-preparative HPLC. Their structures were identified on the basis of physicochemical properties, UV, IR, MS, and NMR spectroscopic data as(4S,5S,7R,10S)-5,7-dihydroxy-11-en-eudesmane(1),(7R,10S)-eudesma-4-en-11,15-diol(2),(2R,4S,5R,7R)-2-hydroxyeremophila-9,11-dien-8-one(3), 7α-H-9(10)-ene-11,12-epoxy-8-oxoeremophilane(4),(+)-9ß,10ß-epoxyeremophila-11(13)-en(5), 4(14)-eudesmene-8α,11-diol(6), 12,15-dioxo-selina-4,11-dien(7), and 2ß,8 aα-dihydroxy-11-en-eremophilane(8). Compounds 1 and 2 are new compounds, and their absolute configurations were determined by calculating ECD. Compounds 1, 4, and 6-8 could significantly improve taurocholic acid(TCA)-induced gastric mucosal GES-1 cell injury at a concentration of 20 µmol·L~(-1), and the cell protection rates were 23.51%±2.79%, 16.10%±1.25%, 24.45%±4.89%, 17.48%±2.93%, and 21.44%±2.39%, respectively.

[Chemome profiling of Qijiao Shengbai Capsules by UPLC-IT-TOF-MS].

Qijiao Shengbai Capsules(QJ) are a common Miao medicine serving as an adjuvant cancer therapy in clinical practice.QJ consists of seven medicinal materials such as Astragalus membranaceus and Lespedeza buergeri.Its chemical components have not been clarified and the quality control needs to be improved.In this study, LC-IT-TOF-MS was used to comprehensively collect MS~1 and MS~2 fragment information of QJ and rapidly identify the chemical compositions.The chromatographic separation was performed on the Capcell core ADME column(2.1 mm×150 mm, 2.7 µm) with 0.1% formic acid aqueous solution(A) and acetonitrile(B) as mobile phases for gradient elution.High-resolution mass spectrometric information was obtained by scanning in the positive and negative ion ESI modes.A total of 107 compounds were structurally identified according to the deduced MS fragmentation patterns and comparison with standards and data reported in the literature, including 54 flavonoids, 16 phthalides, 13 alkaloids, 12 phenolic acids, 7 saponins, 2 coumarins, 2 condensed tannins, and 1 purine.This study clarified the chemical composition of QJ and provided references for the improvement of its quality standards and the elucidation of its medicinal substances.

Cistanches Herba, from an endangered species to a big brand of Chinese medicine.

Cistanches Herba (CH, Chinese name: Roucongrong), is a very precious, tonic Chinese medicine. Cistanche deserticola and Cistanche tubulosa are the two commonly used species and authenticated in Chinese Pharmacopoeia. Due to the parasitic nature of Cistanche plants, the wild source was once endangered and listed in the Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora. However, after continuously struggling in the past decades, CH has grown up to a big brand of Chinese medicine featured with the cultivation area as 1.26 million mu, the annual output as 6000 tons, and the related industrial output value as more than 20 billion China Yuan, attributing to large-scale cultivation and in-depth phytochemical and pharmacological investigations. Noteworthily, great achievements have reached concerning the research and development of relevant products, such as modern drugs, traditional Chinese medicine prescriptions, and dietary supplements. The current review summarizes the research progresses concerning the distribution and cultivation, phytochemistry, pharmacology, metabolism and product development of CH in the past decades, and the emerging challenges and developing prospects are discussed as well.

Full Collision Energy Ramp-MS2 Spectrum in Structural Analysis Relying on MS/MS.

Albeit frequently being overlooked, MS2 spectrum variation against collision energy (CE) implies auxiliary structural clues for m/z values. Online energy-resolved MS (ER-MS) provides the opportunity to acquire the trajectory of ion intensity against CE for any fragment ion of interest, thus exactly offering the desired momentum to empower the conventional MS2 spectrum at a certain CE forward to a full-CE ramp MS2 spectrum (FCER-MS2). Efforts were made here to construct an FCER-MS2 spectrum and to evaluate its potential toward structural analysis. Flavonoids were employed as a proof of concept. MS2 spectra of 76 compounds were recorded by LC-Q-Exactive-MS, and online ER-MS was subsequently programmed using LC-Qtrap-MS to build a breakdown graph for each obvious fragment ion. After defining the greatest value amongst all regressive apices as 100%, the normalized breakdown graphs comprised an FCER-MS2 spectrum for each compound. The FCER-MS2 spectrum contained the MS2 spectrum at any CE as well as optimal CE (OCE) and maximal relative ion intensity (RIImax) of each fragment ion. Except the pronounced isomeric discrimination potential, either OCE or RIImax reflected certain structural properties, such as aglycone, glycosidic bond, and hydroxy, methoxy, and glycosyl substituents. These rules were subsequently applied for flavonoid-focused characterization of a famous herbal medicine, namely Scutellariae Radix, and high-level structural annotation was accomplished for 75 flavonoids. Above all, the FCER-MS2 spectrum includes m/z, OCEs, and RIImax features, thus facilitating confidence-advanced structural analysis.

Integrated Strategy Drives Direct Infusion-Tandem Mass Spectrometry as an Eligible Tool for Shotgun Pseudo-Targeted Metabolomics of Medicinal Plants.

Direct infusion (DI) has an extraordinary high-throughput advantage. Pseudo-targeted metabolomics (PTM) has been demonstrated integrating the merits of both nontargeted and targeted metabolomics. Herein, we attempted to implant DI into the PTM concept to configure a new strategy allowing shotgun PTM. First, a versatile MS/MSALL program was applied to acquire MS1 and MS2 spectra. Second, online energy-resolved MS (online ER-MS) was conducted to obtain breakdown graph as well as optimal collision energy (OCE) for each ion transition paired by precursor ion and the dominant product ion. Third, selected reaction monitoring (SRM) was responsible to output a quantitative dataset with a constant length. Moreover, breakdown graph also served as orthogonal structural evidence when matching MS2 spectra between DI-MS/MS and an in-house library to strengthen structural annotation confidence. To evaluate and illustrate the utility of the new strategy toward shotgun PTM of medicinal plants, in-depth chemome comparison was conducted within three Cistanche species, all of which are edible medicinal plants and playing essential roles for turning the deserts into the oases. A total of 185 variables participated in the quantitative measurement program. Each diagnostic ion pair was featured with an OCE. Significant species differences occurred, and echinacoside, acteoside, isoacteoside, 2'-acetyl-acteoside, tubuloside B, mannitol, sucrose, betaine, malate, as well as choline were found to be confirmative chemical markers offering primary contributions toward the species discrimination. After cross-validation with LC-MS/MS, DI-MS/MS fortified with the new strategy is an eligible tool for shotgun PTM, beyond Cistanche plants.

Direct Flavonoid-Focused Chemical Comparison among Three Epimedium Plants by Online Liquid Extraction-High Performance Liquid Chromatography-Tandem Mass Spectrometry.

It is usually a tedious task to profile the chemical composition of a given herbal medicine (HM) using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) due to the time-consuming sample preparation and laborious post-acquisition data processing procedures. Even worse, some labile compounds may face degradation risks when exposed to organic solvents for a relatively long period. As one of the most popular HMs, the promising therapeutic benefits of Epimedii Herba (Chinese name: Yinyanghuo) are well defined; however, the chemical profile, and in particular those flavonoids that have been claimed to be responsible for the efficacy, remains largely unknown. Attempts are devoted here to achieve direct LC-MS measurement and efficient post-acquisition data processing, and chemome comparison among three original sources of Epimedii Herba, such as Epimedium sagittatum (Esa), E. pubescens (Epu), and E. koreanum (Eko) was employed to illustrate the strategy utility. A home-made online liquid extraction (OLE) module was introduced at the front of the analytical column to comprehensively transfer the compounds from raw materials onto the LC-MS instrument. A mass defect filtering approach was programmed to efficiently mine the massive LC-MS dataset after which a miniature database was built involving all chemical information of flavonoids from the genus Epimedium to draw a pentagonal frame to rapidly capture potential quasi-molecular ions (mainly [M-H]-). A total of 99 flavonoids (66 in Esa, 84 in Eko, and 66 in Epu) were captured, and structurally annotated by summarizing the mass fragmentation pathways from the mass spectrometric data of authentic compounds and an in-house data library as well. Noteworthily, neutral loss of 144 Da was firstly assigned to the neutral cleavage of rhamnosyl residues. Significant species-differences didn't occur among their chemical patterns. The current study proposed a robust strategy enabling rapid chemical profiling of, but not limited to, HMs.

[Rapid chemome profiling of Cistanche salsa using DI-MS/MS~(ALL)].

The current study aims to rapidly and comprehensively profile the chemical composition of Cistanche salsa using direct infusion coupled with MS/MS~(ALL)(DI-MS/MS~(ALL)). The C. salsa extract was directly imported into electrospray ionization(ESI) source of quadrupole time-of-flight(Q-TOF) mass spectrometer with an infusion pump at a flow rate of 10 µL·min~(-1). Acquisition program was applied under negative ionization polarity to collect one MS~1 spectrum(m/z 50-1 200), followed by 1 150 MS~2 spectra with precursor isolation window(m/z 1) amongst mass range m/z 50-1 200. After each MS~2 spectrum was matched to its precursor ion, putative identification was conducted through matching mass spectral data with literature and database. A total of 31 components were identified from C. salsa, including 9 phenylethanoid glycosides, 2 iridoids, 4 saccharides, 9 organic acids, and 7 other compounds, similar to those from C. tubulosa and C. deserticola. In conclusion, DI-MS/MS~(ALL), a facile and reliable analytical tool, can be employed for qualitative analysis of chemical constituents in C. salsa. The research offers a promising strategy to achieve rapid chemome profiling of herbal medicine and provides an alternative source of Cistanches Herba.