28 research outputs found
Pyrenosetin D, a new pentacyclic decalinoyltetramic acid derivative from the algicolous fungus Pyrenochaetopsis sp. FVE-087
The fungal genus Pyrenochaetopsis is commonly found in soil, terrestrial, and marine environments, however, has received little attention as a source of bioactive secondary metabolites so far. In a recent work, we reported the isolation and characterization of three new anticancer decalinoyltetramic acid derivatives, pyrenosetins AâC, from the Baltic Fucus vesiculosus-derived endophytic fungus Pyrenochaetopsis sp. FVE-001. Herein we report a new pentacyclic decalinoylspirotetramic acid derivative, pyrenosetin D (1), along with two known decalin derivatives wakodecalines A (2) and B (3) from another endophytic strain Pyrenochaetopsis FVE-087 isolated from the same seaweed and showed anticancer activity in initial screenings. The chemical structures of the purified compounds were elucidated by comprehensive analysis of HR-ESIMS, FT-IR, [α]D, 1D and 2D NMR data coupled with DFT calculations of NMR parameters and optical rotation. Compounds 1â3 were evaluated for their anticancer and toxic potentials against the human malignant melanoma cell line (A-375) and the non-cancerous keratinocyte cell line (HaCaT). Pyrenosetin D (1) showed toxicity towards both A-375 and HaCaT cells with IC50 values of 77.5 and 39.3 ”M, respectively, while 2 and 3 were inactive. This is the third chemical study performed on the fungal genus Pyrenochaetopsis and the first report of a pentacyclic decalin ring system from the fungal genus Pyrenochaetopsis
<i>InSpectra</i> - A platform for identifying emerging chemical threats
Non-target analysis (NTA) employing high-resolution mass spectrometry (HRMS) coupled with liquid chromatography is increasingly being used to identify chemicals of biological relevance. HRMS datasets are large and complex making the identification of potentially relevant chemicals extremely challenging. As they are recorded in vendor-specific formats, interpreting them is often reliant on vendor-specific software that may not accommodate advancements in data processing. Here we present InSpectra, a vendor independent automated platform for the systematic detection of newly identified emerging chemical threats. InSpectra is web-based, open-source/access and modular providing highly flexible and extensible NTA and suspect screening workflows. As a cloud-based platform, InSpectra exploits parallel computing and big data archiving capabilities with a focus for sharing and community curation of HRMS data. InSpectra offers a reproducible and transparent approach for the identification, tracking and prioritisation of emerging chemical threats
Deep dive into the chronic toxicity of tyre particle mixtures and their leachates.
This is the final version. Available from Elsevier via the DOI in this record.âŻData Availability:
Data will be made available on request.Particles from the tread of vehicle tyres are a global pollutant, which are emitted into the environment at an approximate rate of 1.4Â kg.year-1 for an average passenger-car. In this study, popular tyre brands were used to generate a tyre tread microparticle mixture. The chronic toxicity of both particles and chemical leachates were compared on a planktonic test species (Daphnia magna). Over 21 days of exposure, pristine tyre tread microparticles were more toxic (LC50 60Â mg.L-1) than chemical lechates alone (LC50 542Â mg.L-1). Microparticles and leachates showed distinct effects on reproduction and morphological development at environmentally relevant concentrations, with dose-dependent uptake of particles visible in the digestive tract. Chemical characterization of leachates revealed a metal predominance of zinc, titanium, and strontium. Of the numerous organic chemicals present, at least 54 were shared across all 5 tyre brands, with many classified to be very toxic. Our results provide a critically needed information on the toxicity of tyre tread particles and the associated chemicals that leach from them to inform future mitigation measures. We conclude that tyre particles are hazardous pollutants of particular concern that are close to or possibly above chronic environmental safety limits in some locations.Natural Environment Research Council (NERC
Per- and polyfluoroalkyl substances (PFAS) in consumer products:Current knowledge and research gaps
While several sources of per- and polyfluoroalkyl substances (PFAS) are known, their use in consumer household products is far less explored. The aim of this study was to provide comprehensive bottom-up analysis of the types and concentrations of PFAS reported in the literature over the past decade. A total of 52 studies revealed 107 PFAS belonging to 15 different categories in 1040 consumer products. The highest number of products tested were from the USA (n = 389) followed by the Czech Republic (n = 111). Mean PFAS concentrations were highest in household firefighting products, followed by textile finishing agents and household chemicals. The highest diversity of PFAS was reported in textiles (72 PFAS). Fluorotelomer alcohol (FTOH), polyfluoroalkyl phosphate esters (PAPs), perfluorocarboxylic acid (PFCA) and perfluorosulfonic acid (PFSA) are the classes of PFAS of high interest. Eight out of 52 studies used High-Resolution Mass Spectrometry techniques. Highlighted knowledge gaps included (i) the development of analytical methods for detecting a range of PFAS in consumer products, (ii) method validation and QA/QC approaches, (iii) application of suspect and non-target analysis, and (iv) an understanding of human exposure risk. This review highlights that the presence of PFAS in consumer products is of concern and remains underexplored
Microbioreactor techniques for the production and spectroscopic characterization of microbial peptides
We have demonstrated that the simple and low-cost microbioreactor can speed up the bioprocessing techniques by using small amount of reagents and very few seed cultures to give results comparable with those obtained from the shake flask. The microbioreactor has the potential of replacing the normal conventional-scale process and offers a high-throughput efficient and analytical technique in addressing some of the challenges encountered in bioprocessing starting that includes bacterial growth and secondary metabolites production targeting the discovery of new antibacterial peptides. In our case studies, we proved that microbes were capable of growing in the microbioreactor and the production of microbial secondary metabolites (i.e., peptides) was detectable in HPLC-DAD-MS. We used QTOF-MS/MS to detect the production of peptides in the microbial culture. The purified peptides were characterized using 1D and 2D NMR, QTOF-MS/MS, and Marfey's analysis
Communicating Confidence of Per- and Polyfluoroalkyl Substance Identification via High-Resolution Mass Spectrometry
[Image: see text] Per- and polyfluoroalkyl substances (PFASs) are important environmental contaminants, yet relatively few analytical reference standards exist for this class. Nontarget analyses performed by means of high-resolution mass spectrometry (HRMS) are increasingly common for the discovery and identification of PFASs in environmental and biological samples. The certainty of PFAS identifications made via HRMS must be communicated through a reliable and harmonized approach. Here, we present a confidence scale along with identification criteria specific to suspect or nontarget analysis of PFASs by means of nontarget HRMS. Confidence levels range from level 1aââConfirmed by Reference Standard,â and level 1bââIndistinguishable from Reference Standard,â to level 5ââExact Masses of Interest,â which are identified by suspect screening or data filtering, two common forms of feature prioritization. This confidence scale is consistent with general criteria for communicating confidence in the identification of small organic molecules by HRMS (e.g., through a match to analytical reference standards, library MS/MS, and/or retention times) but incorporates the specific conventions and tools used in PFAS classification and analysis (e.g., detection of homologous series and specific ranges of mass defects). Our scale clarifies the level of certainty in PFAS identification and, in doing so, facilitates more efficient identification
New PFASs Identified in AFFF Impacted Groundwater by Passive Sampling and Nontarget Analysis
Monitoring contamination from per- and polyfluoroalkyl
substances
(PFASs) in water systems impacted by aqueous film-forming foams (AFFFs)
typically addresses a few known PFAS groups. Given the diversity of
PFASs present in AFFFs, current analytical approaches do not comprehensively
address the range of PFASs present in these systems. A suspect-screening
and nontarget analysis (NTA) approach was developed and applied to
identify novel PFASs in groundwater samples contaminated from historic
AFFF use. A total of 88 PFASs were identified in both passive samplers
and grab samples, and these were dominated by sulfonate derivatives
and sulfonamide-derived precursors. Several ultrashort-chain (USC)
PFASs (â€C3) were detected, 11 reported for the first
time in Australian groundwater. Several transformation products were
identified, including perfluoroalkane sulfonamides (FASAs) and perfluoroalkane
sulfinates (PFASis). Two new PFASs were reported (((perfluorohexyl)sulfonyl)sulfamic
acid; m/z 477.9068 and (E)-1,1,2,2,3,3,4,5,6,7,8,8,8-tridecafluorooct-6-ene-1-sulfonic
acid; m/z 424.9482). This study
highlights that several PFASs are overlooked using standard target
analysis, and therefore, the potential risk from all PFASs present
is likely to be underestimated