-
International Journal of Molecular... Jul 2020Pyrazolines are five-membered heterocycles possessing two adjacent nitrogens. They have attracted significant attention from organic and medicinal chemists due to their... (Review)
Review
Pyrazolines are five-membered heterocycles possessing two adjacent nitrogens. They have attracted significant attention from organic and medicinal chemists due to their potent biological activities and the numerous possibilities for structural diversification. In the last decade, they have been intensively studied as targets for potential anticancer therapeutics, producing a steady yearly rise in the number of published research articles. Many pyrazoline derivatives have shown remarkable cytotoxic activities in the form of heterocyclic or non-heterocyclic based hybrids, such as with coumarins, triazoles, and steroids. The enormous amount of related literature in the last 5 years prompted us to collect all these published data from screening against cancer cell lines, or protein targets like EGFR and structure activity relationship studies. Therefore, in the present review, a comprehensive account of the compounds containing the pyrazoline nucleus will be provided. The chemical groups and the structural modifications responsible for the activity will be highlighted. Moreover, emphasis will be given on recent examples from the literature and on the work of research groups that have played a key role in the development of this field.
Topics: Antineoplastic Agents; Cell Proliferation; Coumarins; Humans; Molecular Structure; Neoplasms; Nitrogen; Pyrazoles; Steroids; Structure-Activity Relationship; Triazoles
PubMed: 32752126
DOI: 10.3390/ijms21155507 -
The Science of the Total Environment Jul 2021Fate and transport of nitrogen (N) in urban coastal watersheds continues to draw research interest due to serious impacts of N pollution and complexities with N sources...
Fate and transport of nitrogen (N) in urban coastal watersheds continues to draw research interest due to serious impacts of N pollution and complexities with N sources and transport pathways. In this study, we used multiple tracers for source identification of N pollution (N isotope in nitrate and chemical sewage tracers in water) and waters (using isotopes of O and H in water) in a coastal northwest Florida U.S.A. urban bayou fed by two contrasting streams, namely Jackson Creek traversing a dense residential area and Jones Creek flowing mainly through a wetland preserve. Results showed that the slightly higher δN-NO values in Jones Creek and the bayou were insufficient to distinguish N sources; yet the different chemical sewage tracer concentrations (e.g., sucralose, carbamazepine and sulfamethoxazole) clearly demonstrated the major N source from leaking septic tanks in the Jackson Creek sub-basin but not in the Jones Creek sub-basin. The higher concentrations of nitrate, which constituted over 98% of dissolved inorganic N in Jackson Creek, support active nitrification in sandy soils and steep terrain while higher δN-NO and much lower nitrate in Jones Creek are likely associated with denitrification in dense vegetative wetland and riparian zones. Episodic high nitrate concentrations and δO values in Jackson Creek preceded by periods of little rainfall indicated that the creek was sustained by subsurface flow with a steady input of nitrate. This study demonstrated the connection of land use and stormwater runoff generation to the forms of N entering urban waterways, the utility of N sourcing approaches, and the value of watershed-scale assessments for developing strategies to limit N loadings in urban settings.
Topics: Environmental Monitoring; Nitrates; Nitrogen; Nitrogen Isotopes; Rivers; Water Pollutants, Chemical
PubMed: 35185223
DOI: 10.1016/j.scitotenv.2021.145862 -
International Journal of Molecular... Dec 2022The pyrolysis of biomass is an efficient means of utilizing biomass resources. Biomass can be converted into various high-performance chemicals and functional materials...
The pyrolysis of biomass is an efficient means of utilizing biomass resources. Biomass can be converted into various high-performance chemicals and functional materials through pyrolysis. However, current pyrolysis technologies suffer from low conversion rates and single products, so the preparation of nitrogen compounds with high economic value remains a challenge. The walnut shell was soaked in three nitrogen-containing compound solutions before carbonization to produce high-value-added nitrogen-containing chemicals (with a nitrogen content of 59.09%) and biochar for the adsorption of polycyclic aromatic hydrocarbons (PAHs). According to biochar analysis, biochar has a porous structure with a specific surface area of 1161.30 m/g and a high level of rocky desertification. The surface forms a dense pyrrole structure, and the structure produces π-π interactions with naphthalene molecules, exhibiting excellent naphthalene adsorption with a maximum capacity of 214.98 mg/g. This study provides an efficient, rapid, and environmentally friendly method for producing nitrogen-containing chemicals with high-added value and biochar.
Topics: Polycyclic Aromatic Hydrocarbons; Nitrogen; Pyrolysis; Charcoal; Adsorption
PubMed: 36499539
DOI: 10.3390/ijms232315193 -
ELife Feb 2022Whether species coculture can overcome the shortcomings of crop monoculture requires additional study. Here, we show how aquatic animals (i.e. carp, crabs, and softshell...
Whether species coculture can overcome the shortcomings of crop monoculture requires additional study. Here, we show how aquatic animals (i.e. carp, crabs, and softshell turtles) benefit paddy ecosystems when cocultured with rice. Three separate field experiments and three separate mesocosm experiments were conducted. Each experiment included a rice monoculture (RM) treatment and a rice-aquatic animal (RA) coculture treatment; RA included feed addition for aquatic animals. In the field experiments, rice yield was higher with RA than with RM, and RA also produced aquatic animal yields that averaged 0.52-2.57 t ha. Compared to their corresponding RMs, the three RAs had significantly higher apparent nitrogen (N)-use efficiency and lower weed infestation, while soil N contents were stable over time. Dietary reconstruction analysis based on C and N showed that 16.0-50.2% of aquatic animal foods were from naturally occurring organisms in the rice fields. Stable-isotope-labeling (C) in the field experiments indicated that the organic matter decomposition rate was greater with RA than with RM. Isotope N labeling in the mesocosm experiments indicated that rice used 13.0-35.1% of the aquatic animal feed-N. All these results suggest that rice-aquatic animal coculture increases food production, increases N-use efficiency, and maintains soil N content by reducing weeds and promoting decomposition and complementary N use. Our study supports the view that adding species to monocultures may enhance agroecosystem functions.
Topics: Agriculture; Animals; Brachyura; Carps; Ecosystem; Nitrogen; Oryza; Soil; Turtles
PubMed: 35190027
DOI: 10.7554/eLife.73869 -
Proceedings of the National Academy of... Apr 2017Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient...
Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Paul, Minnesota. Lawn fertilizer and pet waste dominated N and P inputs, respectively, underscoring the importance of household actions in influencing urban watershed nutrient budgets. Watersheds retained only 22% of net P inputs versus 80% of net N inputs (watershed area-weighted averages, where net inputs equal inputs minus biomass removal) despite relatively low P inputs. In contrast to many nonurban watersheds that exhibit high P retention, these urban watersheds have high street density that enhanced transport of P-rich materials from landscapes to stormwater. High P exports in storm drainage networks and yard waste resulted in net P losses in some watersheds. Comparisons of the N/P stoichiometry of net inputs versus storm drain exports implicated denitrification or leaching to groundwater as a likely fate for retained N. Thus, these urban watersheds exported high quantities of N and P, but via contrasting pathways: P was exported primarily via stormwater runoff, contributing to surface water degradation, whereas N losses additionally contribute to groundwater pollution. Consequently, N management and P management require different strategies, with N management focusing on reducing watershed inputs and P management also focusing on reducing P movement from vegetated landscapes to streets and storm drains.
Topics: Ecosystem; Environmental Monitoring; Groundwater; Nitrogen; Phosphorus; Water Pollutants, Chemical; Water Pollution
PubMed: 28373560
DOI: 10.1073/pnas.1618536114 -
PloS One 2020As a widespread phytoplankton species, the coccolithophore Gephyrocapsaoceanica has a significant impact on the global biogeochemical cycle through calcium carbonate...
As a widespread phytoplankton species, the coccolithophore Gephyrocapsaoceanica has a significant impact on the global biogeochemical cycle through calcium carbonate precipitation and photosynthesis. As global change continues, marine phytoplankton will experience alterations in multiple parameters, including temperature, pH, CO2, and nitrogen sources, and the interactive effects of these variables should be examined to understand how marine organisms will respond to global change. Here, we show that the specific growth rate of G. oceanica is reduced by elevated CO2 (1000 μatm) in [Formula: see text]-grown cells, while it is increased by high CO2 in [Formula: see text]-grown ones. This difference was related to intracellular metabolic regulation, with decreased cellular particulate organic carbon and particulate organic nitrogen (PON) content in the [Formula: see text] and high CO2 condition compared to the low CO2 condition. In contrast, no significant difference was found between the high and low CO2 levels in [Formula: see text] cultures (p > 0.05). The temperature increase from 20°C to 25°C increased the PON production rate, and the enhancement was more prominent in [Formula: see text] cultures. Enhanced or inhibited particulate inorganic carbon production rate in cells supplied with [Formula: see text] relative to [Formula: see text] was observed, depending on the temperature and CO2 condition. These results suggest that a greater disruption of the organic carbon pump can be expected in response to the combined effects of increased [Formula: see text]/[Formula: see text] ratio, temperature, and CO2 level in the oceans of the future. Additional experiments conducted under nutrient limitation conditions are needed before we can extrapolate our findings to the global oceans.
Topics: Carbon Dioxide; Haptophyta; Nitrogen; Temperature
PubMed: 32649709
DOI: 10.1371/journal.pone.0235755 -
PloS One 2023Nitrogen isotope ratio analysis (δ15N) of animal tissue is widely used in archaeology and palaeoecology to investigate diet and ecological niche. Data interpretations...
Nitrogen isotope ratio analysis (δ15N) of animal tissue is widely used in archaeology and palaeoecology to investigate diet and ecological niche. Data interpretations require an understanding of nitrogen isotope compositions at the base of the food web (baseline δ15N). Significant variation in animal δ15N has been recognised at various spatiotemporal scales and related to changes both in baseline δ15N, linked to environmental and climatic influence on the terrestrial nitrogen cycle, and animal ecology. Isoscapes (models of isotope spatial variation) have proved a useful tool for investigating spatial variability in biogeochemical cycles in present-day marine and terrestrial ecosystems, but so far, their application to palaeo-data has been more limited. Here, we present time-sliced nitrogen isoscapes for late Pleistocene and early Holocene Europe (c. 50,000 to 10,000 years BP) using herbivore collagen δ15N data. This period covers the Last Glacial-Interglacial Transition, during which significant variation in the terrestrial nitrogen cycle occurred. We use generalized linear mixed modelling approaches for interpolation and test models which both include and exclude climate covariate data. Our results show clear changes in spatial gradients of δ15N through time. Prediction of the lowest faunal δ15N values in northern latitudes after, rather than during, the Last Glacial Maximum is consistent with the Late Glacial Nitrogen Excursion (LGNE). We find that including climatic covariate data does not significantly improve model performance. These findings have implications for investigating the drivers of the LGNE, which has been linked to increased landscape moisture and permafrost thaw, and for understanding changing isotopic baselines, which are fundamental for studies investigating diets, niche partitioning, and migration of higher trophic level animals.
Topics: Animals; Nitrogen; Ecosystem; Nitrogen Isotopes; Food Chain; Europe; Carbon Isotopes
PubMed: 36745587
DOI: 10.1371/journal.pone.0268607 -
Chemical Reviews Jun 2020The metallobiochemistry underlying the formation of the inorganic N-N-bond-containing molecules nitrous oxide (NO), dinitrogen (N), and hydrazine (NH) is essential to... (Review)
Review
The metallobiochemistry underlying the formation of the inorganic N-N-bond-containing molecules nitrous oxide (NO), dinitrogen (N), and hydrazine (NH) is essential to the lifestyles of diverse organisms. Similar reactions hold promise as means to use N-based fuels as alternative carbon-free energy sources. This review discusses research efforts to understand the mechanisms underlying biological N-N bond formation in primary metabolism and how the associated reactions are tied to energy transduction and organismal survival. These efforts comprise studies of both natural and engineered metalloenzymes as well as synthetic model complexes.
Topics: Hydrazines; Metalloproteins; Models, Molecular; Nitrogen; Nitrous Oxide
PubMed: 32108471
DOI: 10.1021/acs.chemrev.9b00629 -
Animal : An International Journal of... Aug 2022The difficulty in selecting cattle for higher feed and nitrogen use efficiency (NUE) is an important factor contributing to poor growth and reproductive performance in...
The difficulty in selecting cattle for higher feed and nitrogen use efficiency (NUE) is an important factor contributing to poor growth and reproductive performance in dry-tropics rangelands. Therefore, the objectives were to examine the cattle variation in retaining nitrogen in a protein-deficient diet and the natural abundance of stable isotopes in body tissues as a practical alternative for the detection of more efficient cattle. In experiment 1, feed efficiency parameters were determined in 89 Brahman steers fed a protein-limiting diet for 70 days, followed by 7 days in metabolism crates for total collection of urine and faeces and calculation of nitrogen retention and NUE. The diet-animal fractionation of nitrogen isotopes (ΔN) was quantified in tail hair and plasma proteins using isotope-ratio MS. There was a large variation in growth performance, feed efficiency and nitrogen losses among steers. Quantifying ΔN in tail hair (ΔN) resulted in stronger correlations with feed efficiency and nitrogen metabolism parameters than when quantified in plasma proteins. ΔN was positively correlated with nitrogen losses in urine (r = 0.31, P < 0.01) and faeces (r = 0.25, P = 0.04), leading to a negative correlation with NUE (r = -0.40, P < 0.01). The group of steers with lower ΔN had greater feed efficiency, lower nitrogen losses, and greater NUE. In experiment 2, for evaluation of isotope fraction as a predictor of reproductive performance, 630 Brahman-crossed cows were classified for reproductive performance for 2 years. From this group, 25 cows with poor reproductive performance and 25 cows with good reproductive performance were selected. Tail hair representing 7 months of growth were segmented and analysed for carbon (δC) and nitrogen (δN) isotope enrichment. Reproductive performance was not associated with diet selection, as there was no difference in tail hair δC between groups. However, more productive cows had lower (P < 0.05) tail hair δN during the dry season, indicating differences in N metabolism and possibly lower N losses. In addition, cows with better reproductive performance and, therefore, greater nutrient demands, had similar body condition scores and a tendency (P = 0.09) for higher live weight at the end of the trial. In conclusion, the findings of the present study confirm that nitrogen isotope fractionation in tail hair can be used as a predictor of nitrogen losses, NUE, and reproductive performance of Brahman cattle on low-protein diets.
Topics: Animal Feed; Animals; Blood Proteins; Cattle; Diet; Female; Nitrogen; Nitrogen Isotopes
PubMed: 35688653
DOI: 10.1016/j.animal.2022.100551 -
BMC Biology Sep 2022Nitrogen is considered the most limiting nutrient element for herbivorous insects. To alleviate nitrogen limitation, insects have evolved various symbiotically mediated...
BACKGROUND
Nitrogen is considered the most limiting nutrient element for herbivorous insects. To alleviate nitrogen limitation, insects have evolved various symbiotically mediated strategies that enable them to colonize nitrogen-poor habitats or exploit nitrogen-poor diets. In frugivorous tephritid larvae developing in fruit pulp under nitrogen stress, it remains largely unknown how nitrogen is obtained and larval development is completed.
RESULTS
In this study, we used metagenomics and metatranscriptomics sequencing technologies as well as in vitro verification tests to uncover the mechanism underlying the nitrogen exploitation in the larvae of Bactrocera dorsalis. Our results showed that nitrogenous waste recycling (NWR) could be successfully driven by symbiotic bacteria, including Enterobacterales, Lactobacillales, Orbales, Pseudomonadales, Flavobacteriales, and Bacteroidales. In this process, urea hydrolysis in the larval gut was mainly mediated by Morganella morganii and Klebsiella oxytoca. In addition, core bacteria mediated essential amino acid (arginine excluded) biosynthesis by ammonium assimilation and transamination.
CONCLUSIONS
Symbiotic bacteria contribute to nitrogen transformation in the larvae of B. dorsalis in fruit pulp. Our findings suggest that the pattern of NWR is more likely to be applied by B. dorsalis, and M. morganii, K. oxytoca, and other urease-positive strains play vital roles in hydrolysing nitrogenous waste and providing metabolizable nitrogen for B. dorsalis.
Topics: Animals; Bacteria; Drosophila; Larva; Nitrogen; Symbiosis; Tephritidae
PubMed: 36104720
DOI: 10.1186/s12915-022-01399-9