Atmospheric Particles Are Major Sources of Aged Anthropogenic Organic Carbon in Marginal Seas.

Deposition of atmospheric particulates is a major pathway for transporting materials from land to the ocean, with important implications for climate and nutrient cycling in the ocean. Here, we report the results of year-round measurements of particulate organic carbon (POC) and black carbon (BC) in atmospheric aerosols collected on Tuoji Island in the coastal Bohai-Yellow Sea of China (2019-2020) and during a cruise in the western North Pacific. Aerosol POC contents ranged from 1.

Identification and quantification of synthetic cannabinoids in "spice-like" herbal mixtures: Update of the German situation for the spring of 2016.

In February 2016, nine "spice-like" products from German language internet shops were analyzed. In total, eight different synthetic cannabinoids were identified by gas chromatography-mass spectrometry (GC-MS), namely THJ-018, THJ-2201, MAB-CHMINACA, 5F-ADB, 5Cl-AKB48 (syn.: 5C-AKB48), 4-pentenyl-AKB48, MDMB-CHMICA and 5F-AB-PINACA.

Structural and quantitative analysis of Equisetum alkaloids.

Equisetum palustre L. is known for its toxicity for livestock. Several studies in the past addressed the isolation and identification of the responsible alkaloids.

Loss of atomic nitrogen from even-electron ions? A study on benzodiazepines.

The fragment spectra of protonated nitro-substituted benzodiazepines show an unusual fragment [M + H - 14] , which is shown by accurate mass measurement to be due to the loss of a nitrogen atom. Our investigations show that this apparent loss of atomic nitrogen is rather an attachment of molecular oxygen to the [M + H - NO ] ion, which is the main fragment ion in these spectra. The oxygen attachment is exothermic, and rate constants have been derived.

Differential expression of secretoglobins in normal ovary and in ovarian carcinoma--overexpression of mammaglobin-1 is linked to tumor progression.

Secretoglobins (SCGB), such as mammaglobin 1 (MGB1, SCGB2A2), mammaglobin 2 (MGB2, SCGB2A1) and lipophilin B (LIPB, SCGB1D2), have been related to carcinogenesis. We profiled expression of MGB1, MGB2 and LIPB in human tissues and ovarian carcinoma and explored the impact of SCGB overexpression on cell proliferation. MGB1, MGB2 and LIPB mRNA are expressed at variable levels in most human tissues and we observed significant bilateral correlations between the different secretoglobins.

Pyrrolizidine alkaloids in the food chain: development, validation, and application of a new HPLC-ESI-MS/MS sum parameter method.

Contamination of food and feed with pyrrolizidine alkaloids is currently discussed as a potential health risk. Here, we report the development of a new HPLC-ESI-MS/MS sum parameter method to quantitate the pyrrolizidine alkaloid content in complex food matrices. The procedure was validated for honey and culinary herbs.

Identification and quantification of synthetic cannabinoids in 'spice-like' herbal mixtures: a snapshot of the German situation in the autumn of 2012.

Synthetic compounds mimicking cannabis-like effects are a recent trend. Currently, these so-called synthetic cannabinoids are the largest and fastest growing class of newly appearing designer drugs. Many national authorities are continuously adapting their regulations to keep pace with the permanently changing variety of compounds.

Synthetic cannabinoids in "spice-like" herbal blends: first appearance of JWH-307 and recurrence of JWH-018 on the German market.

Herbal smoking blends, available on the German market were analyzed and several known synthetic cannabinoids were identified (JWH-122 and JWH-018). In addition, we isolated a new active ingredient by silica gel column chromatography and elucidated the structure by nuclear magnetic resonance (NMR) methods. The compound was identified as JWH-307, a synthetic cannabinoid of the phenyl-pyrrole subclass with known in vitro binding affinities for cannabinoid receptors.

Analysis of synthetic cannabinoids in "spice-like" herbal highs: snapshot of the German market in summer 2011.

In this study, seven commercial "spice-like" products available on the German market were analyzed. They all contained significant amounts of synthetic cannabinoids and had distinctly different compositions of these adulterants. All synthetic cannabinoids were extracted and purified by different chromatographic techniques from the respective product.

Structural identification of SAR-943 metabolites generated by human liver microsomes in vitro using mass spectrometry in combination with analysis of fragmentation patterns.

SAR-943 (32-deoxo rapamycin) is a proliferation signal inhibitor via interaction with the mammalian target of rapamycin (mTOR). Most importantly, SAR-943 has improved chemical stability compared to rapamycin (sirolimus) and is currently under investigation as a drug coated on coronary stents. It was the goal of this study to identify the SAR-943 metabolites generated after incubation with human liver microsomes using high-resolution mass spectrometry (MS) and MS/iontrap (MS(n)) and comparison of fragmentation patterns of the metabolites with those of SAR-943 and other known rapamycin derivatives.

Identification and characterization of JWH-122 used as new ingredient in "Spice-like" herbal incenses.

Recently, several cases across Germany were reported where teenagers were hospitalized showing severe side effects after consumption of a new "Spice-like" herbal incense called "Lava red". The active component of "Lava red", obtained from German internet shops, was isolated by silica gel column chromatography and the structure was elucidated by NMR methods. It is a known N-alkyl-3-(1-naphthoyl)indole (CAS No.

Comparative study on the antiherpetic activity of aqueous and ethanolic extracts derived from Cajanus cajan (L.) Millsp.

Introduction: Aqueous and ethanolic extracts of Cajanus cajan (Fabaceae) were examined in vitro for their antiviral activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2).

Materials And Methods: The antiviral activity was determined using a plaque reduction assay. The cytotoxic concentration (CC50) as well as the inhibitory concentration (IC50) of the extracts was determined from dose-response curves.

The oxygen-independent coproporphyrinogen III oxidase HemN utilizes harderoporphyrinogen as a reaction intermediate during conversion of coproporphyrinogen III to protoporphyrinogen IX.

During heme biosynthesis the oxygen-independent coproporphyrinogen III oxidase HemN catalyzes the oxidative decarboxylation of the two propionate side chains on rings A and B of coproporphyrinogen III to the corresponding vinyl groups to yield protoporphyrinogen IX. Here, the sequence of the two decarboxylation steps during HemN catalysis was investigated. A reaction intermediate of HemN activity was isolated by HPLC analysis and identified as monovinyltripropionic acid porphyrin by mass spectrometry.

The Pseudomonas aeruginosa nirE gene encodes the S-adenosyl-L-methionine-dependent uroporphyrinogen III methyltransferase required for heme d(1) biosynthesis.

Biosynthesis of heme d(1), the essential prosthetic group of the dissimilatory nitrite reductase cytochrome cd(1), requires the methylation of the tetrapyrrole precursor uroporphyrinogen III at positions C-2 and C-7. We produced Pseudomonas aeruginosa NirE, a putative S-adenosyl-L-methionine (SAM)-dependent uroporphyrinogen III methyltransferase, as a recombinant protein in Escherichia coli and purified it to apparent homogeneity by metal chelate and gel filtration chromatography. Analytical gel filtration of purified NirE indicated that the recombinant protein is a homodimer.

Translational regulation of glutathione peroxidase 4 expression through guanine-rich sequence-binding factor 1 is essential for embryonic brain development.

Phospholipid hydroperoxide glutathione peroxidase (GPx4) is a moonlighting selenoprotein, which has been implicated in basic cell functions such as anti-oxidative defense, apoptosis, and gene expression regulation. GPx4-null mice die in utero at midgestation, and developmental retardation of the brain appears to play a major role. We investigated post-transcriptional mechanisms of GPx4 expression regulation and found that the guanine-rich sequence-binding factor 1 (Grsf1) up-regulates GPx4 expression.

Even-electron ions: a systematic study of the neutral species lost in the dissociation of quasi-molecular ions.

The collision-induced dissociations of the even-electron [M + H](+) and/or [M - H](-) ions of 121 model compounds (mainly small aromatic compounds with one to three functional groups) ionized by electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) have been studied using an ion trap instrument, and the results are compared with the literature data. While some functional groups (such as COOH, COOCH(3), SO(3)H in the negative ion mode, or NO(2) in both the positive and negative ion modes) generally promote the loss of neutrals that are characteristic as well as specific, other functional groups (such as COOH in the positive ion mode) give rise to the loss of neutrals that are characteristic, but not specific. Finally, functional groups such as OH and NH(2) in aromatic compounds do not lead to the loss of a neutral that reflects the presence of these substituents.

Assessment and validation of the MS/MS fragmentation patterns of the macrolide immunosuppressant everolimus.

Everolimus (40-O-(2-hydroxyethyl)rapamycin, Certican) is a 31-membered macrolide lactone. In lymphocytes, it inhibits the mammalian target of rapamycin (mTOR) and is used as an immunosuppressant after organ transplantation. Due to its instability in pure organic solvents and insufficient HPLC separation, NMR spectroscopy analysis of its metabolite structures is nearly impossible.

The role of phospholipid hydroperoxide glutathione peroxidase isoforms in murine embryogenesis.

Phospholipid hydroperoxide glutathione peroxidase (GPx4) is a selenocysteine-containing enzyme, and three different isoforms (cytosolic, mitochondrial, and nuclear) originate from the GPx4 gene. Homozygous GPx4-deficient mice die in utero at midgestation, since they fail to initiate gastrulation and do not develop embryonic cavities. To investigate the biological basis for embryonic lethality, we first explored expression of the GPx4 in adult murine brain and found expression of the protein in cerebral neurons.

Structure elucidation of phase II metabolites by tandem mass spectrometry: an overview.

The present paper provides a summary of the collision-induced dissociation of protonated and deprotonated phase II metabolites of drugs and pesticides. This overview is based on published literature and unpublished data from the authors. In particular, glutathione conjugates and their biotransformation products are discussed in detail.

Synthesis of the First 1,3,4-Triphosphole Complex.

Surprisingly selective is the preparation of the novel 1,3,4-triphosphole complex 1 by insertion of a phosphaalkyne into a 1H-diphosphirene complex. NMR spectroscopic experiments and quantum-mechanical calculations indicate a small P-inversion barrier for the σ -phosphorus center in 1 as well as new possibilities of "π-tuning".

Characterization of cytostatically active glycosphingolipids isolated from thioglycollate-elicited murine macrophages.

Two acidic glycosphingolipids (gangliosides) derived from mouse macrophage membranes and separated by thin-layer chromatography have a strong cytostatic effect on human and mouse tumor cells. The structure of the two gangliosides, named M phi G1 and M phi G2, was elucidated by application of physicochemical and immunochemical methods. Gas chromatography and mass spectrometry of M phi G1 and M phi G2 classified them as isomeric monosialogangliosides with ceramide moieties composed of sphingosine as the long-chain base, C16 and C18 fatty acids, respectively, and a lacto-tetraose backbone.

The two facies of pyrrolizidine alkaloids: the role of the tertiary amine and its N-oxide in chemical defense of insects with acquired plant alkaloids.

Larvae of Creatonotos transiens (Lepidoptera, Arctiidae) and Zonocerus variegatus (Orthoptera, Pyrgomorphidae) ingest 14C-labeled senecionine and its N-oxide with the same efficiency but sequester the two tracers exclusively as N-oxide. Larvae of the non-sequestering Spodoptera littoralis eliminate efficiently the ingested alkaloids. During feeding on the two alkaloidal forms transient levels of senecionine (but not of the N-oxide) are built up in the haemolymph of S.