A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was ...performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U–13C-labeled FB2 and OTA as internal standards. Mixing 20% isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50% and decreased the ion-suppression with 50–75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.
Introduction
Casearia is an essential source of cytotoxic highly oxidised clerodane diterpenes, in addition to phenolics, flavonoids, and glycoside derivatives. Here we identify ...flavonoid‐3‐O‐glycoside derivatives in the ethyl acetate (EtOAc) fraction of the methanolic extract from leaves C. arborea leaves.
Objective
To characterise the EtOAc phase from the methanolic extract of C. arborea leaves using ultra‐high‐performance liquid chromatography diode array detector high‐resolution tandem mass spectrometry (UHPLC‐DAD‐HRMS/MS) and molecular networking‐based dereplication.
Methodology
We identified compounds not annotated in the GNPS platform by co‐injection of standards in HPLC‐DAD or by isolation and characterisation of the metabolites using nuclear magnetic resonance (NMR) spectroscopy. A workflow on the GNPS platform aided the organisation of spectral data and dereplication by annotations. We subjected the EtOAc phase to HPLC‐DAD analysis using standard compound co‐injection to corroborate the GNPS annotations. We isolated unidentified compounds with semi‐preparative HPLC‐DAD for structural identification using NMR.
Results
We annotated a molecular family of flavonoid‐3‐O‐glycosides in the molecular networking created using the GNPS platform. These included avicularin, cacticin, isoquercitrin, quercitrin, rutin, and a quercetin‐3‐O‐pentoside cluster. We confirmed the annotations with standard compounds using HPLC‐DAD co‐injection analysis, besides identifying quercetin‐3‐O‐robinobioside and kaempferol. We isolated three flavonoid‐3‐O‐pentosides and characterised them using one‐ and two‐dimensional NMR; we identified them as reynoutrin, guaijaverin, and avicularin.
Conclusion
This work describes the isolation of kaempferol and nine known flavonoid‐3‐O‐glycosides from the polar fraction of the methanolic extract (EtOAc) from C. arborea leaves using molecular networking to guide the chromatographic procedures. We identified eight compounds for the first time in Casearia that amplify and reinforce the genus' chemotaxonomy with the presence of glycosylated flavonoids.
Kaempferol and nine flavonoid‐3‐O‐glycosides were isolated from the polar fraction of methanolic extract (EtOAc) from Casearia arborea leaves. Molecular networking‐based dereplication and co‐injection analysis was used to guide the chromatographic procedures. Eight compounds were isolated for the first time in Casearia amplifying the genus’ chemotaxonomy with the presence of glycosylated flavonoids.
Two unusual naphthoquinones, named here as pleonotoquinones A (1) and B (2), were isolated along with two known anthraquinones (3 and 4) via chromatographic separations of an ethyl acetate extract of ...the roots of Pleonotoma jasminifolia. Compounds 1 and 2 are the first examples of quinones bearing a 2-methyloxepine moiety. The compounds were isolated with the aid of mass spectrometry and molecular networking, and their structures were resolved using 1D and 2D NMR and HRESIMS data. The isolated compounds were evaluated for their antiproliferative activity against human cancer cell lines, and compounds 1 and 2 displayed cytotoxicity against human colon cancer HCT116 cells (IC50 = 2.6 μM for compound 1 and IC50 = 4.3 μM for compound 2) and human liver cancer HepG2 cells (IC50 = 1.9 μM for compound 1 and IC50 = 6.4 μM for compound 2).
Glial cells (astrocytes, oligodendrocytes and microglia) are critical for the central nervous system (CNS) in both physiological and pathological conditions. With this in mind, several studies have ...indicated that glial cells play key roles in the development and progression of CNS diseases. In this sense, gliotoxicity can be referred as the cellular, molecular, and neurochemical changes that can mediate toxic effects or ultimately lead to impairment of the ability of glial cells to protect neurons and/or other glial cells. On the other hand, glioprotection is associated with specific responses of glial cells, by which they can protect themselves as well as neurons, resulting in an overall improvement of the CNS functioning. In addition, gliotoxic events, including metabolic stresses, inflammation, excitotoxicity, and oxidative stress, as well as their related mechanisms, are strongly associated with the pathogenesis of neurological, psychiatric and infectious diseases. However, glioprotective molecules can prevent or improve these glial dysfunctions, representing glial cells-targeting therapies. Therefore, this review will provide a brief summary of types and functions of glial cells and point out cellular and molecular mechanisms associated with gliotoxicity and glioprotection, potential glioprotective molecules and their mechanisms, as well as gliotherapy. In summary, we expect to address the relevance of gliotoxicity and glioprotection in the CNS homeostasis and diseases.
Astrocytes may undergo a functional remodeling with aging, acquiring a pro-inflammatory state. In line with this, resveratrol represents an interesting strategy for a healthier brain aging since it ...can improve glial functions. In the present study, we investigated the glioprotective role of resveratrol against lipopolysaccharide (LPS)-induced gliotoxicity in hippocampal aged astrocytes. Astrocyte cultures were obtained from aged rats (365 days old) and challenged in vitro with LPS in the presence of resveratrol. Cultured astrocytes from newborn rats were used as an age comparative for evaluating LPS gliotoxicity. In addition, aged rats were submitted to an acute systemic inflammation with LPS. Hippocampal astrocyte cultures were also obtained from these LPS-stimulated aged animals to further investigate the glioprotective effects of resveratrol in vitro. Overall, our results show that LPS induced a higher inflammatory response in aged astrocytes, compared to newborn astrocytes. Several inflammatory and gene expression alterations promoted by LPS in aged astrocyte cultures were similar in hippocampal tissue from aged animals submitted to in vivo LPS injection, corroborating our in vitro findings. Resveratrol, in turn, presented anti-inflammatory effects in aged astrocyte cultures, which were associated with downregulation of p21 and pro-inflammatory cytokines, Toll-like receptors (TLRs), and nuclear factor κB (NFκB). Resveratrol also improved astroglial functions. Upregulation of sirtuin 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) represent potential molecular mechanisms associated with resveratrol-mediated glioprotection. In summary, our data show that resveratrol can prime aged astrocytes against gliotoxic stimuli, contributing to a healthier brain aging.
Cyclopiamines C (1) and D (2) were isolated from the extract of Penicillium sp. CML 3020, a fungus sourced from an Atlantic Forest soil sample. Their structures and relative configuration were ...determined by 1D and 2D NMR, HRMS, and UV/vis data analysis. Cyclopiamines C and D belong to a small subset of rare spiroindolinone compounds containing an alkyl nitro group and a 4,5-dihydro-1H-pyrrolo3,2,1-ijquinoline-2,6-dione ring system. NMR and MS/HRMS data confirmed the presence of an epoxide unit (C-17–O–C-18) and a hydroxy group at C-5, not observed for their known congeners. Cytotoxic and antimicrobial activities were evaluated.
In addition to seven known alkaloids (2, 6–11) and 1,2,4-trimethoxybenzene (1), three isoquinoline-derived alkaloids (3–5), namely, duguetinine (3), a compound based on an unprecedented ...oxahomoaporphine scaffold, and two new 8-oxohomoaporphine alkaloids, duguesuramine (4) and 11-methoxyduguesuramine (5), and a new asarone-derived phenylpropanoid (10) were isolated from the bark of Duguetia surinamensis. The isolation workflow was guided by HPLC-HRESIMS/MS and molecular networking-based analyses. Twenty-four known alkaloids were dereplicated from the D. surinamensis alkaloid-rich fraction network and were assigned by manual MS/MS interpretation. Their cytotoxic potential was evaluated.
Penicillium meliponae, a recently described and rare species, was isolated as an endophytic fungus from the Amazonian plant Duguetia sthelechantha, and has been proven to be a pigment producer. ...Considering the high productivity of this species and the lack of data on its chemical composition, the present study aimed to characterize the chemical profile of P. meliponae and evaluate the influence of agitation and the use of different culture media. For this purpose, liquid chromatography coupled with mass spectrometry (LC-MS/MS) and molecular networking were used, allowing the identification of 17 azaphilone molecules with sclerotiorin-like skeletons, becoming the first chemical report of this species. In addition, the different production patterns in the tested culture media were indicative that this species is sensitive to changes in the composition of the carbon source and to the presence of agitation. Furthermore, this work contributes to the fragmentation mechanisms of the different possible structural arrangements for azaphilones of the sclerotiorin type and serves as a repository of information on the gas-phase behavior of this type of metabolite in mass spectrometry experiments and will assist future studies aimed at the discovery of azaphilones.
In natural product studies, the purification of metabolites is an important challenge. To accelerate this step, alternatives such as integrated analytical tools should be employed. Based on this, the ...chemical study of
(Rutaceae) was performed using two rapid dereplication strategies:
(Bruker Daltonics
, Bremen, Germany) MS data analysis combined with MS/MS data obtained from the GNPS platform. Through UHPLC-HRMS data, the first approach allowed, from crude fractions, a quick and visual identification of compounds already reported in the
genus. Aside from this, by grouping compounds according to their fragmentation patterns, the second approach enabled the detection of eight molecular families, which presented matches for acridonic alkaloids, phenylacrylamides, and flavonoids. Unrelated compounds for
have been isolated and characterized by NMR experiments, Lansamide I, Lansiumamide B, Lansiumamide C, and
-(2-phenylethyl)cinnamamide.
Phytopathogenic fungi significantly threaten global food security, causing substantial yield and quality losses. Sustainable solutions are urgently needed to combat these agricultural pathogens. This ...study explored the potential of silver (Ag), copper (Cu), and combined Ag/Cu nanoparticles capped with aminolevulinic acid (ALA) as antifungal agents. The nanoparticles (ALAAg, ALACu, and ALAAgCu) were synthesized via photoreduction and characterized using various techniques (UV–Vis, TEM, XRD, Zeta potential). Their antifungal activity against four key plant pathogens (Alternaria grandis, Colletotrichum truncatum, Corynespora cassiicola, and Fusarium oxysporum) was evaluated using poisoned food techniques. Notably, ALAAgCuNPs demonstrated superior antifungal activity compared to a conventional fungicide against two fungal strains. Even at lower concentrations, ALAAgCuNPs exhibited fungistatic effects comparable to those of the control. These promising results suggest the potential of ALAAgCu NPs as a broad-spectrum, potentially eco-friendly alternative for fungal control in plants and seeds. This approach is crucial for ensuring crop health, harvest quality, and food safety.
•The synergic effect of silver and copper in ALA-capped nanoparticles boosts the effectiveness.•ALAAgCu fights common plant pathogens like Fusarium and Alternaria.•ALAAgCu outperforms itraconazole on some strains.•ALAAgCu NPs Blocks Fungal Growth.•Disrupts membranes, damages DNA, and inhibits growth.•ALA-capped nanoparticles Green Alternative for sustainable plant health.
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