A Strategy Combining Higher Energy C-Trap Dissociation with Neutral Loss- and Product Ion-Based MSn Acquisition for Global Profiling and Structure Annotation of Fatty Acids Conjugates.

Fatty acids conjugates (FACs) are ubiquitous but found in trace amounts in the natural world. They are composed of multiple unknown substructures and side chains. Thus, FACs are difficult to be analyzed by traditional mass spectrometric methods. In this study, an integrated strategy was developed to global profiling and targeted structure annotation of FACs in complex matrix by LTQ Orbitrap. Dicarboxylic acid conjugated bufotoxins (DACBs) in Venenum bufonis (VB) were used as model compounds. The new strategy (abbreviated as HPNA) combined higher-energy C-trap dissociation (HCD) with product ion- (PI), neutral loss- (NL) based MSn (n ≥ 3) acquisition in both positive-ion mode and negative-ion mode. Several advantages are presented. First, various side chains were found under HCD in negative-ion mode, which included both known and unknown side chains. Second, DACBs with multiple side chains were simultaneously detected in one run. Compared with traditional quadrupole-based mass method, it greatly increased analysis throughput. Third, the fragment ions of side chain and steroids substructure could be obtained by PI- and NL-based MSn acquisition, respectively, which greatly increased the accuracy of the structure annotation of DACBs. In all, 78 DACBs have been discovered, of which 68 were new compounds; 25 types of substructure formulas and seven dicarboxylic acid side chains were found, especially five new side chains, including two saturated dicarboxylic acids [(azelaic acid (C9) and sebacic acid (C10)] and three unsaturated dicarboxylic acids (u-C8, u-C9, and u-C10). All these results greatly enriched the structures of DACBs in VB. Graphical Abstract ᅟ.

Venenum Bufonis induces rat neuroinflammation by activiating NF-κB pathway and attenuation of BDNF.

ETHNOPHARMACOLOGICAL RELEVANCE: Venenum Bufonis (VB), also called toad venom, has been widely used in clinic as a cardiotonic, anohyne and antineoplastic agents both in China and other Asian countries. However, its neurotoxicity and cardiotoxicity limit its wide clinical application. Compared with extensive attention attracted with cardiotoxicity, the toxic effect of VB on Central Nervous System (CNS) is much less studied. AIM OF THE RESEARCH: This study was performed to examine the neurotoxicity caused by VB on Sprague Dawley (SD) rats, then to clarify the mechanism in vivo by investigating its action on the neuroinflammation which possibly attributed to the activation of nuclear factor κB (NF-κB) pathway and the attenuation of brain-derived neurotrophic factor (BDNF). MATERIALS AND METHODS: Rats administrated with 0.5% carboxymethyl cellulose sodium salt (CMC-Na) aqueous solution and VB (100mg/kg, 200mg/kg and 400mg/kg) were sacrificed at 2h, 4h, 6h, 8h, 24h and 48h. The brain level of neurotransmitters and their corresponding receptors, pro-inflammatory cytokines, BDNF/TrkB and NF-κB pathway-related proteins were examined, respectively. RESULTS: VB administration induced severe neurologic damage and neuroinflammation, as indicated by the disordered 5-hydroxytryptamine (5-HT), dopamine (DA) and their corresponding receptors, together with the over production of inflammatory cytokines including interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α). VB also notably promoted the expression of p-NF-κBp65, p-IκBα, p-IKKα and p-IKKß and down-regulated the expression of BDNF and TrkB. CONCLUSION: This study demonstrates that VB triggers neurotoxicity which probably is induced by neuroinflammation via activating of NF-κB pathway and attenuating the expression of BDNF.

TXNIP/TRX/NF-κB and MAPK/NF-κB pathways involved in the cardiotoxicity induced by Venenum Bufonis in rats.

Venenum Bufonis (VB) is a widely used traditional medicine with serious cardiotoxic effects. The inflammatory response has been studied to clarify the mechanism of the cardiotoxicity induced by VB for the first time. In the present study, Sprague Dawley (SD) rats, were administered VB (100, 200, and 400 mg/kg) intragastrically, experienced disturbed ECGs (lowered heart rate and elevated ST-segment), increased levels of serum indicators (creatine kinase (CK), creatine kinase isoenzyme-MB (CK-MB), alanine aminotransferase (ALT), aspartate aminotransferase (AST)) and serum interleukin (IL-6, IL-1ß, TNF-α) at 2 h, 4 h, 6 h, 8 h, 24 h, and 48 h, which reflected that an inflammatory response, together with cardiotoxicity, were involved in VB-treated rats. In addition, the elevated serum level of MDA and the down-regulated SOD, CAT, GSH, and GPx levels indicated the appearance of oxidative stress in the VB-treated group. Furthermore, based on the enhanced expression levels of TXNIP, p-NF-κBp65, p-IκBα, p-IKKα, p-IKKß, p-ERK, p-JNK, and p-P38 and the obvious myocardial degeneration, it is proposed that VB-induced cardiotoxicity may promote an inflammatory response through the TXNIP/TRX/NF-κB and MAPK/NF-κB pathways. The observed inflammatory mechanism induced by VB may provide a theoretical reference for the toxic effects and clinical application of VB.

Colon-derived uremic biomarkers induced by the acute toxicity of Kansui radix: A metabolomics study of rat plasma and intestinal contents by UPLC-QTOF-MS(E).

Kansui radix (KR) is a poisonous Chinese herbal medicine recorded in the Chinese Pharmacopoeia, and the acute toxicity obstructs its clinical applications. To explore its acute toxicity mechanism to enhance clinical safety, a metabolomics study based on UPLC-ESI-QTOF-MS(E) was performed. Wistar rats were exposed for 4h to the aqueous and ethyl acetate extracts prepared from KR at a high dose (25g/kg). The contents of six different sections of rat intestine, including the duodenum, jejunum, ileum, cecum, colon, and rectum were collected as samples for the first time, as well as the rat plasma. The interesting results showed that only those rats exposed to the ethyl acetate extract showed a watery diarrhea, similar to the observed acute human toxicity. The identified biomarkers found in the plasma, such as phenol sulfate, indoxyl sulfate, and p-cresol sulfate were significantly perturbed in the rats. These biomarkers are known as colon-derived uremic compounds, which were first reported with respect to KR. The three essential amino acids which produced these biomarkers were only found in the contents of colon and rectum. A hypothesis was proposed that only the colon-derived uremic compounds induced by KR might be responsible for the acute toxicity. Three traditional process methods to reduce the toxicity of KR were compared based on these biomarkers, and different levels of toxicity modulation were observed. These results may be helpful to further understand the mechanism of acute toxicity, and the relevance of the traditional process methods to ameliorate the adverse effects of KR.

An efficient and target-oriented sample enrichment method for preparative separation of minor alkaloids by pH-zone-refining counter-current chromatography.

An efficient and target-oriented sample enrichment method was established to increase the content of the minor alkaloids in crude extract by using the corresponding two-phase solvent system applied in pH-zone-refining counter-current chromatography. The enrichment and separation of seven minor indole alkaloids from Uncaria rhynchophylla (Miq.) Miq. ex Havil(UR) were selected as an example to show the advantage of this method. An optimized two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was used in this study, where triethylamine (TEA) as the retainer and hydrochloric acid (HCl) as the eluter were added at the equimolar of 10mM. Crude alkaloids of UR dissolved in the corresponding upper phase (containing 10mM TEA) were extracted twice with lower phase (containing 10mM TEA) and lower phase (containing 10mM HCl), respectively, the second lower phase extract was subjected to pH-zone-refining CCC separation after alkalization and desalination. Finally, from 10g of crude alkaloids, 4g of refined alkaloids was obtained and the total content of seven target indole alkaloids was increased from 4.64% to 15.78%. Seven indole alkaloids, including 54mg isocorynoxeine, 21mg corynoxeine, 46mg isorhynchophylline, 35mg rhynchophylline, 65mg hirsutine, 51mg hirsuteine and 27mg geissoschizine methylether were all simultaneously separated from 2.5g of refined alkaloids, with the purity of 86.4%, 97.5%, 90.3%, 92.1%, 98.5%, 92.3%, and 92.8%, respectively. The total content and purities of the seven minor indole alkaloids were tested by HPLC and their chemical structures were elucidated by ESI-HRMS and (1)H NMR.

Anti-inflammatory diterpenoids from the root bark of Acanthopanax gracilistylus.

Five new ent-pimarane (1-3, 7, and 8) and three new ent-kaurane diterpenoids (4-6) and a new oleanane triterpene acid (9), together with 22 known compounds, were isolated from the root bark of the medicinal herb Acanthopanax gracilistylus. The structures of 1-9 were established based on the interpretation of high-resolution MS and 1D- and 2D-NMR data. The absolute configurations of 7 and 11 were determined by single-crystal X-ray diffraction and electronic circular dichroism analysis. Compounds 7 and 8 represent rare naturally occurring structures based on the devinyl ent-pimarane skeleton. Compounds 3, 10, 14, 16, and 17 exhibited potent inhibitory effects on the release of interleukin-1ß (IL-1ß), interleukin-8 (IL-8), and tumor necrosis factor (TNF-α) in lipopolysaccharide-stimulated peripheral blood mononuclear cells.

New triterpenic acids from Uncaria rhynchophylla: chemistry, NO-inhibitory activity, and tandem mass spectrometric analysis.

Five new oleanane and ursane type triterpenes, namely uncarinic acids F-J (1-5), together with six known triterpenic acids (6-11) were isolated from the stems and hooks of Uncaria rhynchophylla. Structure elucidation of 1-5 was based on the integrated analyses of high-resolution MS data, 1D ((1)H NMR, (13)C NMR, DEPT) and 2D (HSQC, HMBC, ROESY) NMR spectra. Compounds 4, 10, and 11 exhibited weak inhibitory effects on LPS-induced NO production in RAW264.7 cells (with IC50 1.48, 7.01, and 1.89 µM, respectively) with dexamethasone (IC50 0.04 µM) and quercetin (IC50 0.86 µM) as the positive controls. 19-OH substituted oleanane triterpenic acids (1, 2, 5, 8) were prone to eliminate CH2O3, whereas those ursane-type encompassing 19-OH (3, 6, 7, 9, 4) were featured by preferred cleavage of H2O while performing the negative collision-induced MS/MS fragmentation on an LTQ/Orbitrap mass spectrometer.

Phenanthrenes, 9,10-dihydrophenanthrenes, bibenzyls with their derivatives, and malate or tartrate benzyl ester glucosides from tubers of Cremastra appendiculata.

Eleven previously unknown compounds and 23 known compounds, including 20 phenanthrene or 9,10-dihydrophenanthrene derivatives, five bibenzyls, seven malate or tartrate benzyl ester glucosides, adenosine and gastrodin were isolated from tubers of Cremastra appendiculata. Among the obtained compounds, two are the first isolated dimers with one phenanthrene or bibenzyl unit connected to C-3 of 2,3,4,5-tetrahydro-phenanthro[2,1-b]furan moiety. In addition, 33 of these compounds were evaluated in vitro for their cytotoxic activity against two cancer cell lines. Among the compounds examined, one compound showed moderate cytotoxic activity, while five showed weak cytotoxic activity against the A549 cell line.

Elution-extrusion counter-current chromatography separation of two new benzyl ester glucosides and three other high-polarity compounds from the tubers of Pleione bulbocodioides.

INTRODUCTION: The tubers of Pleione bulbocodioides (Franch.) Rolfe, with gastrodin and benzyl ester glucosides as main components, have been used in traditional Chinese medicine for the treatment of various cancers and bacterial infections. Up to now, their official quality control method is still inadequate, and the difficulty of obtaining these high-polarity compounds is one of the major reasons. OBJECTIVE: To develop a rapid and efficient method for preparative separation of the high-polarity compounds gastrodin and benzyl ester glucosides. METHODS: An optimised solvent system composed of n-butanol:ethanol:water (20:1:20, v/v/v) was applied for the elution-extrusion counter-current chromatography (EECCC) separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase at a flow rate of 1.5 mL/min, a rotation speed of 850 rpm and a temperature of 35°C. RESULTS: Five high-polarity glucosides, including two new compounds, (E)-4-ß-D-glucopyranosyloxycinnamic acid 9-(4-ß-D-glucopyranosyloxybenzyl) ester (4 mg) and (Z)-2-(2-methylpropyl)butenedioic acid bis(4-ß-D-glucopyranosyloxybenzyl) ester (9 mg), and three main components, gastrodin (87 mg), dactylorhin A (60 mg) and militarine (15 mg), with HPLC purities of 95.4%, 96.4%, 91.1%, 97.2% and 95.5% respectively, were yielded from 400 mg of the prepared sample. CONCLUSION: Elution-extrusion counter-current chromatography could be used as a useful tool for the separation of high-polarity compounds such as gastrodin and benzyl ester glucosides and the enrichment of the minor ones.

Simultaneous determination of 24 constituents in Cortex Lycii using high-performance liquid chromatography-triple quadrupole mass spectrometry.

A fast high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry method was developed to determine 24 components including 11 phenolic compounds, 9 phenolic amides, and 4 cyclic peptides in Cortex Lycii. The analytes were quantified by a triple quadrupole instrument in multiple reaction monitoring (MRM) mode. The fragmentation patterns of phenolic amides and cyclic peptides using ESI and collision-induced dissociation (CID) techniques are reported. This assay method was validated with respect to linearity (r(2)>0.9920), precision, repeatability, and accuracy (recovery rate between 93.0 and 105.9% with RSD<4.4%). The analytical results of 28 batches of Cortex Lycii indicated that cyclic peptides and phenolic amides were not only the abundant constituents, but also the characteristic components for Cortex Lycii to distinguish from the adulterants. Principle component analysis (PCA) was used to discriminate samples from different geographical regions of China, and cyclic peptides were considered to be the chemical markers responsible for the classification. The systematic and integrated assessment of Cortex Lycii provides sufficient evidence for the establishment of the quality standard.

Neolignanamides, lignanamides, and other phenolic compounds from the root bark of Lycium chinense.

Seven new neolignanamides (1-7), including two pairs of cis- and trans-isomers, and a new lignanamide (8) were isolated from the EtOAc-soluble fraction of an EtOH extract of the root bark of Lycium chinense, together with 22 known phenolic compounds (9-30), four of which were obtained from the genus Lycium for the first time. Compounds 5, 6, and 7 are unusual dimers having a rare connection mode between the two cinnamic acid amide units, while compounds 6, 7, and 8 are the first naturally occurring dimers derived from two dissimilar cinnamic acid amides. The cinnamic acid amides, neolignanamides, and lignanamides possess moderate radical-scavenging activity against the DPPH (2,2-diphenyl-1-picrylhydrazyl) and superoxide radicals.