Two new phenanthroquinolizidine alkaloids (1: and 2: ) and a new piperidine derivative (3: ) were isolated from the leaves of
aff.
together with 3 known alkaloids: julandine (4: ), cryptopleurine (5: ...), and 1,3,6,6-tetramethyl-5,6,7,8-tetrahydro-isoquinolin-8-one (6: ). Their structures were determined by spectral data analyses including mass spectrometry and 2-dimensional nuclear magnetic resonance data. The absolute configurations of 1: -3: were established by comparison of their experimental circular dichroism data with the calculated electronic circular dichroism spectra. The isolated compounds were evaluated for their cytotoxicity against 4 cancer cell lines: KB (mouth epidermal carcinoma cells), HepG-2 (human liver hepatocellular carcinoma cells), LU-1 (human lung adenocarcinoma cells), and MCF-7 (human breast cancer cells). The new phenanthroquinolizidine pileamartine D (2: ) showed strong and selective proliferation inhibition toward KB and HepG-2 cells with IC
values of 25 and 27 nM, respectively. Pileamartine C (1: ), julandine (4: ), and cryptopleurine (5: ) exhibited cytotoxicity against 4 tested cancer cell lines with IC
values less than 1 µM.
Herein, MgFe2O4-doped TiO2/reduced graphene oxide (MFO-TiO2/rGO) was synthesized via the ultrasound-assisted hydrothermal method and directly used for photodegradation p-nitrophenol from water. The ...characteristics of the catalyst material were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, Scanning electron microscope, Transmission electron microscopy, Energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller specific surface area, thermal gravimetric analysis, and UV–vis spectroscopy. The photodegradation studies via the catalytic recovering property were also investigated with comparing to TiO2/rGO, TiO2, and MFO. The results showed that the MFO and TiO2 nanoparticles were homogeneously distributed on the GO sheet with an average diameter of 5–14 nm. The empirical data indicated a good photocatalytic property under visible light of MFO-TiO2/rGO compared to others with the photodegradation yield 99.53% in 50 min via 40 mg amount of catalysts, 1 mL H2O2 substitution, and a pH of 9. The kinetic studies exhibited that the reaction followed the pseudo-first order with a rate constant of 0.1011 min−1. Besides, it can be easily separated and reused with an insignificant change in photodegradation yield. According to the results, MFO-TiO2/rGO is highly promising for organic contaminant elimination in the effluent for the future wastewater treatment plant.
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Mechanism of p-nitrophenol adsorption and photodegradation.
•MFO-TiO2/rGO nanocomposite was successfully synthesized by the ultrasound-assisted hydrothermal method.•MFO and TiO2 with an average size of 5–14 nm were uniformly distributed on rGO sheets.•MFO-TiO2/rGO shows an extraordinary effect in photodegrading p-nitrophenol form water media.•The amount of H2O2 added, the catalyst dosage and pH has a vital impact on enhancing the photocatalytic property of the material.
Chemical study on marine sponge‐derivated fungus Aspergillus nidulans resulted in the isolation of seven depsidones (1–7) and two macrocyclic peptides (8 and 9). Their chemical structures were ...elucidated by extensive analyses of HRESIMS and NMR spectral data, as well as comparison with the literature. Compound 1 was an undescribed depsidone. All compounds exhibited significant antimicrobial activity (MICs: 2–128 μg/mL) towards at least one of seven microbial strains, including Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, and Candida albicans. Of these, chlorinated depsidones (1–3, and 5) displayed potential antimicrobial activity. Nidulin (2) possessed good activity against tested strains except for S. enterica with MIC values in range of 2–16 μg/mL. Interestingly, undescribed depsidone 1 was selectively bioactive on the Gram‐positive bacteria (MICs: 2–4 μg/mL) and yeast (MIC: 8 μg/mL) but inactivity on the Gram‐negative bacteria (MICs: >256 μg/mL). Macrocyclic peptides, 8 and 9, displayed modest activity against E. faecalis strain with MIC values of 32 and 128 μg/mL, respectively.
Beta-casomorphin peptides including beta-casomorphin 5 (β-CM5) and beta-casomorphin 7 (β-CM7) in raw cow milk were analyzed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Milk ...samples were acidified with HCl followed by centrifuged and cleaned-up using solid-phase extraction (SPE). The eluents were evaporated to dryness and subsequently reconstituted with methanol. Limits of detection (LOD) were 0.32 ng/g for β-CM5 and 0.24 ng/g for β-CM7 and limits of quantification (LOQ) were 1.06 ng/g and 0.69 ng/g for β-CM5 and β-CM7, respectively. Recoveries ranged from 89.7% to 99.4% for β-CM5 and from 96.3% to 98.9% for β-CM7. Intra-day precision was ranged between 7.3% and 22.7% for β-CM5; and 4.5% and 7.3% for β-CM7, meanwhile inter-day precision resulted 7.3%–16.5% for β-CM5 and 9.3%–12.8% for β-CM7. The concentration of β-CM5/7 was analyzed in different milk samples. β-CM7 was detected in 21 out of 30 samples and ranged from 0.76 to 8.41 ng/g milk, while β-CM5 was unequivocally identified in 3 samples, its concentration was 0.4–0.64 ng/g. This is the first report to describe the natural occurrence of β-CM5/7 in raw milk using LC-MS/MS. The present study provides evidence of β-CMs, especially β-CM7 that can be released in raw milk from different breeds.
•High sensitive and selective LC-MS/MS was validated for the determination of β-casomorphin 5/7 in raw milk.•β-casomorphin 5/7 were naturally formed in raw milk collected from different cow breeds.•The levels of β-CM7 ranged from 0.76 to 8.41 ng/g milk, while β-CM5 was from 0.40 to 0.64 ng/g milk.
Microplastics (MPs) are small (< 5 mm) plastic particles that are widely found in marine, freshwater, terrestrial and atmospheric environments. Due to their prevalence and persistence, MPs are ...considered an emerging contaminant of environmental concern. The separation and quantitation of MPs from freshwater sediments is a challenging and critical issue. It is necessary to identify the fate and sources of MPs in the environment, minimise their release and adverse effects. Compared to marine sediments, standardised methods for extracting and estimating the amount of MPs in freshwater sediments are relatively limited. The present study focuses on MP recovery efficiency of four commonly used salt solutions (NaCl, NaI, CaCl
2
and ZnCl
2
) for isolating MPs during the density separation step from freshwater sediment. Known combinations of artificial MP particles (PS, PE, PVC, PET, PP and HDPE) were spiked into standard river sediment. Extraction using NaI, ZnCl
2
and NaCl solutions resulted in higher recovery rates from 37 to 97% compared to the CaCl
2
solution (28–83%) and varied between polymer types. Low-density MPs (PE, HDPE, PP and PS) were more effectively recovered (> 87%) than the denser polymers (PET and PVC: 37 to 88.8%) using NaCl, NaI and ZnCl
2
solutions. However, the effective flotation of ZnCl
2
and NaI solutions is relatively expensive and unsafe to the environment, especially in the context of developing countries. Therefore, considering the efficiency, cost and environmental criteria, NaCl solution was selected. The protocol was then tested by extracting MPs from nine riverine sediment samples from the Red River Delta. Sediments collected from urban rivers were highly polluted by MPs (26,000 MPs items·kg
−1
DW) compared to sediments located downstream. Using a NaCl solution was found to be effective in this case study and might also be used in long-term and large-scale MP monitoring programmes in Vietnam.
Three new lavandulylated flavonoids, (2
,2''
)-6-lavandulyl-7,4'-dimethoxy-5,2'-dihydroxylflavanone (
), (2
,2''
)-6-lavandulyl-5,7,2',4'-tetrahydroxylflavanone (
), and (2''
...)-5'-lavandulyl-2'-methoxy-2,4,4',6'-tetrahydroxylchalcone (
), along with seven known compounds
were isolated from culture broth of
s sp. G248. Their structures were established by spectroscopic data analysis, including 1D and 2D nuclear magnetic resonance (NMR), and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The absolute configurations of
were resolved by comparison of their experimental and calculated electronic circular dichroism spectra. Compounds
exhibited remarkable antimicrobial activity. Whereas, two known compounds
and
exhibited inhibitory activity against
H37Rv with minimum inhibitory concentration (MIC) values of 6.0 µg/mL and 11.1 µg/mL, respectively.
In this study, the zinc oxide-decorated graphitic carbon nitride composite (ZnO/gC3N4 – ZCN) was synthesized for photocatalytic degradation of organic dyes in aqueous media. Particularly, ZnO was ...fabricated by the calcination method with the assistance of Garcinia mangostana pericarp extract as a stabilizer and reducing agent, while graphitic carbon nitride (gC3N4 – CN) was prepared by the calcination method and exfoliated using a strong oxidizer mixture. Characterization results showed ZnO possesses a spherical shape with an average diameter of 30–80 nm and is distributed evenly on the CN sheets. Subsequently, ZCN was subjected to photodegradation towards methylene blue (MB), which indicated that under optimal conditions of 50 mg of catalyst, pH 9, and 10 mg/L of MB concentration, the overall efficiency reached up to 99.16 % after 180 min of visible irradiation. Additionally, ZCN also possesses the degradation ability for other organic dyes, for instance, malachite green (MG) and methyl orange (MO) with an overall efficiency of 96.42 and 57.57 %, respectively. Moreover, the radical scavenging experiments elucidated that the major responsible component for the photodegradation was the photogenerated holes, while other radicals also facilitated the process. Besides, the reusability of the material was excellent as only 10 % of the yield decreased after five cycles. The aforementioned findings reveal the notable potential applications of the ZCN material in the environmental remedial field.
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•The ZnO/gC3N4 composite was biosynthesized with the aid of sonication.•The spherical ZnO distributed evenly on the gC3N4 exfoliation sheet.•The composite exhibited great methylene blue photodegradation under visible light.
Analysis of an antimicrobial extract prepared from the culture broth of the marine-derived actinomycete
Nocardiopsis synnemataformans
(HT06 strain) led to the isolation of a new C-glucoside benzoic ...acid derivative, 4
β
C-glucopyranosyl-3,5-dihydroxy-2-methoxybenzoic acid (
1
), along with eight known compounds, norharman (
2
), (E)-4-(3-hydroxy-4-methoxyphenyl)but-3-en-2-one (
3
), methyl 2,3,4,9-tetrahydro-1H-pyrido3,4-bindole-3-carboxylate (
4
), 1H-indole-3-ethanol (
5
), 4-hydroxy-3-methoxybenzaldehyde (
6
), 3-phenylpropanoic acid (
7
), phloretic acid (
8
), and cinnamic acid (
9
). The antimicrobial activity of all isolated compounds was assayed.
From marine sponge‐associated fungus Hamigera avellanea, thirteen secondary metabolites including a pair of undescribed alkaloid enantiomers (+)‐hamiavemin A (4S) (+)‐1 and (−)‐hamiavemin A (4R) ...(−)‐1. Compound 1 was enantiomers resolved by the Chiralpak AS‐3 column, using a hexane/isopropanol mobile phase. Their structures were determined based on extensive analyses of HR‐ESI‐MS, 1D and 2D NMR spectra. The absolute configuration of (+)‐1 and (−)‐1 were assigned tentatively by ECD calculations. Among the isolates, compound 6 showed strongest antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella enterica, and Candida albicans with the MIC values of 2, 2, 16, 32, 64, and 16 μg/mL, respectively, which were stronger than that of the positive control compound, kanamycin (MIC values ranging from 4 to 128 μg/mL). In addition, compounds 1, 2, and 9 showed moderate cytotoxic activity against three cancer cell lines, HepG2, A549, and MCF‐7 with the IC50 values ranging from 55.35±1.70 to 83.02±2.85 μg/mL.
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