High-resolution Electrospray Ionization Mass Research Articles

Novel Diterpenoids Incorporating Rearranged Labdanes from the Chinese Liverwort Anastrophyllum joergensenii and Their Anti-inflammatory Activity.

Liverworts provide valuable ecological services to improve the sustainability of agriculture, encompassing soil health maintenance and natural pest management. Some liverworts have potential applications in medicine and as food additives. Twenty-two novel diterpenoids (anajoerins A-V), of which anajoerins B-G are rearranged labdanes featuring an unprecedented 6/5 fused ring system, were isolated from the Chinese liverwort Anastrophyllum joergensenii Schiffn. The absolute configurations of all compounds were identified based on high-resolution electrospray ionization mass spectroscopy data, NMR spectra, and ECD calculations. Plausible biogenetic pathways for unprecedented rearranged labdanes were proposed. Seven diterpenoids exhibited anti-inflammatory activity by reducing nitric oxide production in LPS-stimulated RAW264.7 murine macrophages in a dose-dependent manner with IC50s between 9.71 and 56.56 μM. All tested compounds showed no cytotoxicity at the tested concentrations. Western blot analyses of NF-κB p65 downregulation showed that anajoerin L could inhibit the NF-κB signaling pathway. Furthermore, anajoerin L also suppressed the secretion of the ConA-induced proinflammatory cytokines IFN-γ, TNF-α, and IL-6.

Unexpected Noremestrin with a Sulfur-Bearing 15-Membered Macrocyclic Lactone from Emericella sp. 1454.

Two previous unreported epipolythiodioxopiperazines of the emestrin family, namely, noremestrin A (1) and secoemestrin E (2), were successfully isolated from the fungal source Emericella sp. 1454. Employing comprehensive spectroscopic techniques, such as high-resolution electrospray ionization mass spectrometry, infrared, and nuclear magnetic resonance (NMR), along with NMR and electronic circular dichroism calculations, the chemical structures of compounds 1 and 2 were elucidated. Particularly noteworthy is the distinctive nature of noremestrin A, representing the inaugural instance of a noremestrin variant incorporating a sulfur-bearing 15-membered macrocyclic lactone moiety. Compounds 1 and 2 exhibited weak cytotoxic activities against the human chronic myelocytic leukemia cell lines MEG-01 and K562.

Aggregation-Induced Emission via the Restriction of the Intramolecular Vibration Mechanism of Pinacol Lanthanide Complexes.

Pinacol lanthanide complexes PyraLn (Ln = Dy and Tb) with the restriction of intramolecular vibration were obtained for the first time via an in situ solvothermal coordination-catalyzed tandem reaction using cheap and simple starting materials, thereby avoiding complex, time-consuming, and expensive conventional organic synthesis strategies. A high-resolution electrospray ionization mass spectrometry (HRESI-MS) analysis confirmed the stability of PyraLn in an organic solution. The formation process of PyraLn was monitored in detail using time-dependent HRESI-MS, which allowed for proposing a mechanism for the formation of pinacol complexes via in situ tandem reactions under one-pot coordination-catalyzed conditions. The PyraLn complexes constructed using a pinacol ligand with a butterfly configuration exhibited distinct aggregation-induced emission (AIE) behavior, with the αAIE value as high as 60.42 according to the AIE titration curve. In addition, the PyraLn complexes in the aggregated state exhibit a rapid photoresponse to various 3d metal ions with low detection limits. These findings provide fast, facile, and high-yield access to dynamic, smart lanthanide complex emissions with bright emission and facilitate the rational construction of molecular machines for artificial intelligence.

Chemical Constituents of the Deep-sea Gammarid Shrimp-Derived Fungus Penicillium citrinum XIA-16.

One new alkaloid, (S)-2-acetamido-4-(2-(methylamino)phenyl)-4-oxobutanoic acid (1), was isolated from the deep-sea-derived Penicillium citrinum XIA-16, together with 25 known compounds including ten polyketones (2-11), eight alkaloids (12-19), six steroids (20-25), and a fatty acid (26). Their planar and relative structures were determined by an analysis of 1D and 2D nuclear magnetic resonance (NMR) as well as high resolution electrospray ionization mass spectroscopy (HR-ESI-MS) data. The absolute configuration of 1 was determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Penicitrinol B (6) significantly inhibited RSL3-induced ferroptosis (EC50 =2.0 μM) by reducing lipid peroxidation and heme oxygenase 1 (HMOX1) expression. Under the concentration of 10 μM, penicitrinol A (7) was able to inhibit cuproptosis with the cell viabilities of 68.2 % compared to the negative control (copper and elesclomol) with the cell viabilities of 14.8 %.

Anti-Wrinkling Effect of 3,4,5-tri-O-caffeoylquinic Acid from the Roots of Nymphoides peltata through MAPK/AP-1, NF-κB, and Nrf2 Signaling in UVB-Irradiated HaCaT Cells.

Nymphoides peltata has been widely used pharmacologically in traditional Chinese medicine to treat heat strangury and polyuria. The aim of this study was to isolate the bioactive components from N. peltata and evaluate their potential use as antioxidant and anti-wrinkle agents. Phytochemical investigation of the methanolic extract of N. peltata roots led to the isolation of 15 compounds (1-15), which were structurally determined as α-spinasterol (1), 3-O-β-D-glucopyranosyl-oleanolic acid 28-O-β-D-glucuronopyranoside (2), 4-hydroxybenzoic acid (3), protocatechuic acid (4), vanillic acid (5), p-coumaric acid (6), caffeic acid (7), ferulic acid (8), neochlorogenic acid (neo-CQA) (9), chlorogenic acid (CQA) (10), cryptochlorogenic acid (crypto-CQA) (11), isochlorogenic acid B (3,4-DCQA) (12), isochlorogenic acid A (3,5-DCQA) (13), isochlorogenic acid C (4,5-DCQA) (14), and 3,4,5-tri-O-caffeoylquinic acid (TCQA) (15). Of these 15 compounds, compound 2 was a new oleanane saponin, the chemical structure of which was characterized by 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data and high-resolution electrospray ionization mass spectrometry (HRESIMS), as well as chemical reaction. Biological evaluation of the isolated compounds revealed that 3,4,5-tri-O-caffeoylquinic acid (TCQA) significantly improved Nrf2 levels in an Nrf2-ARE reporter HaCaT cell screening assay. TCQA was found to potently inhibit the Nrf2/HO-1 pathway and to possess strong anti-wrinkle activity by modulating the MAPK/NF-κB/AP-1 signaling pathway and thus inhibiting MMP-1 synthesis in HaCaT cells exposed to UVB. Our results suggest that TCQA isolated from N. peltata might be useful for developing effective antioxidant and anti-wrinkle agents.

Stereochemistry of aminoacylated cardiolipins and phosphatidylglycerols from bacteria.

Hydrophilic interaction liquid chromatography (HILIC) connected with electrospray high-resolution tandem mass spectrometry (MS) was used for the analysis of unusual amino acid (AA) substituted phosphatidylglycerols (PG) and cardiolipins (CL) in mesophilic and thermophilic bacteria. Individual peaks from the lipid class separation by HILIC were isolated and hydrolyzed to determine the absolute configuration of the aminoacyl side chain. The configuration of the aminoacyl side chain was assigned by indirect liquid chromatography (LC) enantiomer separation after the hydrolysis of the aminoacylated (aminoacyl) lipids using N-(4-nitrophenoxycarbonyl)-l-phenylalanine 2-methoxyethyl ester as chiral derivatizing agent and reversed phase LC-MS for analysis. When two chromatographic methods were combined, less common AAs, such as d-allo-Ile and d-allo-Thr, were identified. The taxonomic classification of bacteria showed that bacteria of the family Bacillaceae (Bacillus and Geobacillus) produce branched-chain AAs, that is, d-allo-Ile, d-Ile, and d-Leu. These AAs were present only in the genera Bacillus and Geobacillus and not in Alicyclobacillus acidoterrestris (family Alicyclobacillaceae). On the contrary, hydroxy AAs, that is, l- and d-Thr, and l- and d-allo-Thr, were identified as aminoacyl-PG and aminoacyl-CL in A. acidoterrestris and were not present in the genera Bacillus and Geobacillus. Therefore, the complete analysis made it possible to identify the stereochemistry of AAs in aminoacyl PGs and CLs and use this fact for chemotaxonomy.

Subplenones A-J: Dimeric Xanthones with Antibacterial Activity from the Endophytic Fungus Subplenodomus sp. CPCC 401465.

Subplenones A-J (1-10), 10 new xanthone dimers, have been isolated and characterized from the endophytic fungus Subplenodomus sp. CPCC 401465, which resides within the Chinese medicinal plant Gentiana straminea. The isolation process was guided by antibacterial assays and molecular-networking-based analyses. The chemical structures of these compounds were elucidated through the interpretation of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESIMS) data. Furthermore, the relative configuration of the compounds was determined using NMR and single-crystal X-ray diffraction analyses, and the absolute configuration was established using electronic circular dichroism calculations. All of the isolated compounds exhibited significant inhibitory activity against Gram-positive bacteria. Notably, compounds 1, 5, and 7 displayed remarkable inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 700698, with a minimum inhibitory concentration (MIC) of 0.25 μg/mL, and against vancomycin-resistant Enterococcus faecium (VRE) ATCC 700221, with MIC values ranging from 0.5 to 1.0 μg/mL.

Analysis of glycosylated cardiolipins from thermophilic bacteria using GC–MS and LC–ESI–MS/MS methods

Unusual glucose-substituted cardiolipins (Glcx-CLs) in three genera of thermophilic bacteria, having more than one glycosidically linked glucose to the hydroxyl of the central glycerol of Glcx-CLs were identified for the first time in thermophilic bacteria of the genera Geobacillus, Meiothermus, and Thermus. The number of glucoses reached up to five units. The structure of glycosidically linked oligosaccharides was determined based on shotgun analysis MS (electrospray high-resolution tandem mass spectrometry), partially methylated alditol acetates were identified by GC–MS, both electron ionization (EI) and positive chemical ionization (PCI), hydrophilic interaction liquid chromatography (HILIC) separation and identification of CLs glycosides by high resolution MS–ESI, and digestion by specific glycosidases.

Ferrous determination in ground and brackish water by high-resolution electrospray ionization mass spectrometry

Generally, methods using nebulizers such as in Electrospray Ionization Mass Spectrometry (ESI-MS) or Induced Coupled Plasma Mass Spectrometry(ICP-MS) for the determination of Fe(II) in seawater are difficult because of the high concentration of salt. In earlier studies, we determined Fe(II) in river water with 1,10-phenanthroline (phen) and measured the complexed species by ESI-MS, but a method to reduce the interference of salts in seawater is lacking. After filtration of water samples with a 0.45 µm membrane on site, the sample was immediately added into a previously prepared solution containing sodium perchlorate (NaClO4) and phen in nitrobenzene (NB). After shaking for 20 min, Fe(II) was extracted into nitrobenzene (NB) with the perchlorate ions. The NB was introduced to an ESI-MS, using a syringe. The Fe(II)-phen complex and perchlorate ions in NB were more stable than in the aqueous solution.Approximately 99.6 % of Fe(II) was extracted into the organic phase. In our previously presented data, Fe(II) was complexed with 1,10-phenanthroline in aqueous solution, and measured by HR-ESI-MS, a standard addition method was used, and a calibration curve was obtained. In this method, the samples were added to 0.025, 0.05, 0.1 and 0.2 Fe(II)/µmol/L and a calibration curve (R2 = 0.993) of the peak intensity was determined by HR-ESI-MS from the total peak areas of [Fe(phen)₂-NB]2+m/z 269.5 and [Fe(phen)3]2+m/z 298.2. In the present study, the concentration of Fe(II) in brackish water containing 1 % salt was determined to be 0.184 ± 0.05 µM, and the total iron concentration was determined by ICP-MS and found to be 0.70 µM. Fe(II)/Fetotal was 26 %, the groundwater sample contained Fe(II) 0.146 ± 0.002 µM, Fetotal was 0.23 ± 0.02 µM, and Fe(II)/Fetotal was 63 %. Groundwater is less sensitive to oxygen and therefore has a higher proportion of Fe(II) to total iron. In brackish water, on the other hand, the proportion of Fe(II) can be higher or lower because it is affected by oxygen supply from the surface and reduction from the bottom sediment. Therefore, the Fe(II) concentration was relatively high, but in brackish water, Fe(II) was low, but Fetotal was high.

Targeted Isolation of N-Acetylcysteine-Containing Angucycline Derivatives from Streptomyces sp. MC16 and Their Antiproliferative Effects.

Liquid chromatography-mass spectrometry (LC-MS/MS)-based molecular networking analysis was applied to Streptomyces sp. MC16. The automatic classification of the MolNetEnhancer module revealed that its major constituent was an angucycline derivative. By targeted isolation of unique clusters in the molecular network, which showed different patterns from typical angucycline compounds, two new N-acetylcysteine-attached angucycline derivatives (1 and 2) were isolated. The structures were elucidated based on intensive NMR analysis and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). All isolated compounds (1-4) were tested for their inhibitory effects on the proliferation of A431, A549, and HeLa cell lines. Antibiotics 100-1 (3) and vineomycinone B2 (4) showed moderate inhibitory effects on these three cell lines with IC50 values ranging from 18.5 to 59.0 μM, while compounds 1 and 2 with an additional N-acetylcysteine residue showed weak inhibitory effects only on the HeLa cell line with IC50 values of 54.7 and 65.2 μM, respectively.

Anti-inflammatory activity via NO production inhibition of compounds from Vietnamese Lycopodium casuarinoides Spring

In our investigation of the methanol extract derived from the aerial parts of Vietnamese Lycopodium casuarinoides Spring, we successfully isolated two novel secondary metabolites: 3β,21α,24-trihydroxyserrat-14-en-29-yl-E-4′-hydroxy-3′-methoxycinnamate (1) and lycocasuarinol A (2), and eight known compounds, namely α-onocerin (3), salcolin A (4), salcolin B (5), (2 R,3 R)-dihydrokaempferol (6), apigenin (7), huperzinine (8), 4-methoxycinnamic acid (9), and (E)-p-coumaric acid (10). The structural elucidation of these compounds was accomplished through high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy techniques. All isolates were tested for their potential to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 cells. Notably, the flavonoids (2 R,3 R)-dihydrokaempferol (6) and apigenin (7) exhibited significant inhibitory activity against NO production, with IC50 values of 3.4 µM and 3.0 µM, respectively. These values surpassed the inhibition observed with the positive control, celastrol. Furthermore, a comparison of the guaiacyl glyceryls salcolin A (4) and salcolin B (5), differing in their threo-β- and erythro-guaiacyl glyceryl moieties, revealed potential structure-activity relationships. These findings suggest that the extract from Lycopodium casuarinoides and its phytochemical constituents hold promise as potential anti-inflammatory agents

Bidesmosidic and monodesmosidic triterpenoid saponins from the grain of Amaranthus hypochondriacus

Five known bidesmosidic triterpenoid saponins (1–5) and their hydrolysates, namely two new monodesmosidic triterpenoid saponins (1′ and 2′) and three known saponins (3′–5′), were isolated from Amaranthus hypochondriacus seeds. The structures of the new compounds were determined using interpreting 1D and 2D nuclear magnetic resonance (NMR) data and high-resolution electrospray ionisation mass spectrometry (HRESI-MS) analyses as 3-O-β-D-glucuronopyranosyl-30-normedicagenic acid (1′) and 3-O-[α-L-rhamnopyranosyl (1 → 3)-β-D-glucuronopyranosyl] bayogenin (2′). For the first time, 5 and 5′ were isolated from Medicago plants as the first examples of glycosides in medicagenic acid from Amaranthus plants. While bidesmosidic saponins showed no cytotoxicity, monodesmosidic saponins, except for 1′, showed moderate cytotoxicity against human cervix adenocarcinoma (HeLa) cells. In addition, monodesmosidic saponins showed anti-fungal activity against the rice blast fungus (Pyricularia oryzae).

Macrosphelides from Antarctic fungus Pseudogymnoascus sp. (strain SF-7351) and their neuroprotective effects on BV2 and HT22 cells

Strategies for reducing inflammation in neurodegenerative diseases have attracted increasing attention. Herein, we discovered and evaluated the neuroprotective potential of fungal metabolites isolated from the Antarctic fungus Pseudogymnoascus sp. (strain SF-7351). The chemical investigation of the EtOAc extract of the fungal strain isolate revealed a novel naturally occurring epi-macrosphelide J (1), a novel secondary metabolite macrosphelide N (2), and three known compounds, namely macrosphelide A (3), macrosphelide B (4), and macrosphelide J (5). Their structures were established unambiguously using spectroscopic methods, such as one-dimensional and two-dimensional nuclear magnetic resonance (1D and 2D-NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and gauge-including atomic orbital (GIAO) NMR chemical shift calculations, with the support of the advanced statistical method DP4+. Among the isolated metabolites, the absolute configuration of epi-macrosphelide J (1) was further confirmed using single-crystal X-ray diffraction analysis. The neuroprotective effects of the isolated metabolites were evaluated in lipopolysaccharide (LPS)-induced BV2 and glutamate-stimulated HT22 cells. Only macrosphelide B (4) displayed substantial protective effects in both BV2 and HT22 cells. Molecular mechanisms underlying this activity were investigated using western blotting and molecular docking studies. Macrosphelide B (4) inhibited the inflammatory response by reducing the nuclear translocation of NF-κB (p65) in LPS-induced BV2 cells and induced the Nrf2/HO-1 signaling pathway in both BV2 and HT22 cells. The neuroprotective effect of macrosphelide B (4) is related to the interaction between Keap1 and p65. These results suggest that macrosphelide B (4), present in the fungus Pseudogymnoascus sp. (strain SF-7351), may serve as a candidate for the treatment of neurodegenerative diseases.

A New Harziane Diterpene, Harziaketal A, and a New Sterol, Trichosterol A, from the Marine-Alga-Epiphytic Trichoderma sp. Z43.

One new diterpene, harziaketal A (1), and one new highly degraded sterol, trichosterol A (2), along with three known compounds, including one diterpene, harzianone (3), and two steroids, (22E,24R)-5α,6α-epoxy-ergosta-8(14),22-dien-3β,7α-diol (4) and isoergokonin B (5), were isolated from the culture of the marine-alga-epiphytic fungus Trichoderma sp. Z43 by silica gel column chromatography (CC), Sephadex LH-20 CC, and preparative thin-layer chromatography (TLC). Their structures and relative configurations were assigned by nuclear magnetic resonance (NMR) and high resolution electrospray ionisation mass spectrometry (HR-ESI-MS) data, and the absolute configuration of 1 was established by X-ray diffraction. Compound 1 features a hemiketal unit situated at the four-membered ring of harziane-type diterpenes for the first time, while 2 represents the rare occurrence of sterols with rings A and B being degraded. Compounds 1 and 2 displayed weak inhibition against the tested phytoplankton (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense) with half maximal inhibitory concentration (IC50 ) ranging from 14 to 53 μg/mL.

Ergosterol and Its Metabolites Induce Ligninolytic Activity in the Lignin-Degrading Fungus Phanerochaete sordida YK-624.

White-rot fungi are the most important group of lignin biodegraders. Phanerochaete sordida YK-624 has higher ligninolytic activity than that of model white-rot fungi. However, the underlying mechanism responsible for lignin degradation by white-rot fungi remains unknown, and the induced compounds isolated from white-rot fungi for lignin degradation have never been studied. In the present study, we tried to screen ligninolytic-inducing compounds produced by P. sordida YK-624. After large-scale incubation of P. sordida YK-624, the culture and mycelium were separated by filtration. After the separation and purification, purified compounds were analyzed by high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance. The sterilized unbleached hardwood kraft pulp was used for the initial evaluation of ligninolytic activity. Ergosterol was isolated and identified and it induced the lignin-degrading activity of this fungus. Moreover, we investigated ergosterol metabolites from P. sordida YK-624, and the ergosterol metabolites ergosta-4,7,22-triene-3,6-dione and ergosta-4,6,8(14),22-tetraen-3-one were identified and then chemically synthesized. These compounds significantly improved the lignin-degrading activity of the fungus. This is the first report on the ligninolytic-inducing compounds produced by white-rot fungi.

Furanonaphthoquinones, Diterpenes, and Flavonoids from Sweet Marjoram and Investigation of Antimicrobial, Bacterial Efflux, and Biofilm Formation Inhibitory Activities.

The chloroform extract of Origanum majorana exhibited high antibacterial and antifungal activities against 12 bacterial and 4 fungal strains; therefore, it was subjected to bioassay-guided isolation to afford six compounds (1-6). The structures were determined via one- and two-dimensional nuclear magnetic spectroscopy and high-resolution electrospray ionization mass spectrometry experiments. The compounds were identified as furanonaphthoquinones [majoranaquinone (1), 2,3-dimethylnaphtho[2,3-b]furan-4,9-dione (2)], diterpenes [19-hydroxyabieta-8,11,13-trien-7-one (3), 13,14-seco-13-oxo-19-hydroxyabieta-8-en-14-al (4)], and flavonoids [sterubin (5) and majoranin (6)]. Compounds 1 and 2 were first obtained from a natural source and compounds 3 and 4 were previously undescribed. Majoranaquinone (1) exhibited a high antibacterial effect against 4 Staphylococcus, 1 Moraxella, and 1 Enterococcus strains (MIC values between 7.8 μM and 1 mM). In the efflux pump inhibition assay, majoranaquinone (1) showed substantial activity in Escherichia coli ATCC 25922 strain. Furthermore, 1 was found to be an effective biofilm formation inhibitor on E. coli ATCC 25922 and E. coli K-12 AG100 bacteria. Our findings proved that bioactivities of majoranaquinone (1) significantly exceed those of the essential oil constituents; therefore, it should also be considered when assessing the antimicrobial effects of O. majorana.

Polyporenic Acids from the Mushroom Buglossoporus quercinus Possess Chemosensitizing and Efflux Pump Inhibitory Activities on Colo 320 Adenocarcinoma Cells.

Polyporenic acids N-R (1-5), five novel 24-methylene lanostane triterpenes along with seven known polyporenic acids (6-12), were identified from the fruiting bodies of Buglossoporus quercinus. The isolation of compounds 1-12 was performed by a combination of multistep flash chromatography and reversed-phase high-performance liquid chromatography (HPLC). The structure determination was carried out by extensive spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) experiments. The isolated fungal metabolites were investigated for their antiproliferative activity in vitro by 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on the resistant Colo 320 human colon adenocarcinoma cell line expressing P-glycoprotein (ABCB1). The lanostane triterpenes exerted moderate antiproliferative activity with IC50 values in the range of 20.7-106.2 μM. A P-glycoprotein efflux pump modulatory test on resistant Colo 320 cells highlighted that fungal metabolites 3, 5, 8, and 10-12 have the ability to inhibit the efflux pump activity of cancer cells. Moreover, the drug interactions of triterpenes with doxorubicin were studied by the checkerboard method. Compounds 3-4, and 7-12 interacted in a synergistic manner, while an outstanding potency was detected for compound 9, which was defined as strong synergism (CI = 0.276). The current study reveals that B. quercinus is a remarkable source of fungal steroids with considerable chemosensitizing activity on cancer cells.

Six New Phenolic Glycosides from the Seeds of Moringa oleifera Lam. and Their α-Glucosidase Inhibitory Activity.

Plant-derived phytochemicals have recently drawn interest in the prevention and treatment of diabetes mellitus (DM). The seeds of Moringa oleifera Lam. are widely used in food and herbal medicine for their health-promoting properties against various diseases, including DM, but many of their effective constituents are still unknown. In this study, 6 new phenolic glycosides, moringaside B-G (1-6), together with 10 known phenolic glycosides (7-16) were isolated from M. oleifera seeds. The structures were elucidated by 1D and 2D NMR spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) data analysis. The absolute configurations of compounds 2 and 3 were determined by electronic circular dichroism (ECD) calculations. Compounds 2 and 3 especially are combined with a 1,3-dioxocyclopentane moiety at the rhamnose group, which are rarely reported in phenolic glycoside backbones. A biosynthetic pathway of 2 and 3 was assumed. Moreover, all the isolated compounds were evaluated for their inhibitory activities against α-glucosidase. Compounds 4 and 16 exhibited marked activities with IC50 values of 382.8 ± 1.42 and 301.4 ± 6.22 μM, and the acarbose was the positive control with an IC50 value of 324.1 ± 4.99 μM. Compound 16 revealed better activity than acarbose.

Determination of Umifenovir and Its Metabolites by High-Performance Liquid Chromatography with Combined Mass Spectrometric Detection

An approach to the highly sensitive and selective determination of the bromine-containing antiviral drug umifenovir (Arbidol) and its metabolites in natural and waste water, activated sludge, and bottom sediments by chromatography-mass spectrometry based on a combination of two techniques– inductively coupled plasma mass spectrometry (ICP MS) and electrospray ionization high-resolution mass spectrometry (ESI HRMS) is developed. Reversed-phase chromatographic separation and detection based on ESI HRMS provide the reliable detection and identification of analytes in complex matrices, while the use of ICP-MS with 79Br signal detection makes it possible to exclude matrix effects and use a single analytical standard for quantitative analysis. The use of solid-phase extraction and pressurized liquid extraction as sample preparation methods made it possible to achieve limits of detection at a level of 0.2 ng/L and 2 µg/kg for liquid and solid samples, respectively. The developed approach was successfully tested in the analysis of real samples. It is shown that the concentrations of analytes in urban wastewaters are in the range 4.4–260 ng/L. The highest concentration (up to 3.7 mg/kg) is characteristic of activated sludge, which acts as an effective sorbent for umifenovir and its transformation products.

Dryoptkirbioside, A New Fructofuranoside glycerol, and Other Constituents from Dryopteris kirbi Hook et Grav Rhizomes.

A new fructofuranoside glycerol, dryoptkirbioside (1), along with fourteen known compounds (2-15), was isolated from the MeOH extract of Dryopteris kirbi rhizomes by silica gel column chromatography, Sephadex LH-20 column chromatography, and semipreparative HPLC. The structure of the new compound was determined by analyses of its spectroscopic data including nuclear magnetic resonance (NMR), and high-resolution electrospray ionisation mass spectrometry (HRESI-MS) and chemical conversions. The n-hexane-soluble portion and the EAFA fraction showed strong activities against lung (A549), breast (MCF-7), and cervical (HeLa) human cancer cell lines (IC50 values ranging from 4.0 to 8.8 µg/mL). Aspidinol P (5) and aspidinol B (6) exhibited moderate to low cytotoxicity on the three cell lines (IC50 values ranging from 20.4 to 58.7 µM). The MeOH extract and n-hexane-soluble portion had excellent activities against Staphylococcus aureus and Bacillus subtilis (MICs 11.7 and 23.4 µg/mL), whereas the EtOAc- and n-BuOH-soluble portions were significantly active on S. aureus (MICs 46.9 and 93.8 µg/mL). The main fractions EAFB, EAFC and nBFB displayed excellent activity against S. aureus (MICs 11.7 and 23.4 µg/mL). Aspidinol B (6) had significant activity, while aspidinol P (5) was moderately active against S. aureus and B. subtilis (MICs 42.0 and 89.5 µM).