Protective effect exerted by soil phosphorus on soybean subjected to arsenic and fluoride

Objetive: Arsenic (As) and fluoride (F) are found in groundwater and soils around the world, causing different problems to crops. Because these elements compete against phosphorus (P) in soils and plants, their relationship is complex. The aim of this work was to study the oxidative stress of soybean plants subjected to different concentrations of As and F, and the effect of P.

Methods: The following 10 treatments were carried out in each of two soils with different P content: three As levels (low 10?mg?As?kg^-1, medium 50?mg?As?kg^?1 and high 100?mg As kg^?1), three F levels (low 160?mg?F?kg^?1, medium 250?mg?F?kg^?1 and high 500?mg?F?kg^?1) and three As?+?F levels (same concentrations), and the control treatment (soil with the background As and F concentrations) Lipid peroxidation, chlorophyll, gluthatione contents and antioxidant enzymes activities were determination.

Results: Increased lipid peroxidation and alterations in glutathione content, catalase, superoxide dismutase and peroxidase activities as well as in chlorophyll content revealed that As causes higher oxidative stress in plants grown in soils with low P content.

Conclusion: Stress parameters in F treatments were less affected. Plants grown in soils enriched with P revealed a decrease in the toxic effects caused by As and F.     

Fluoride levels in water and fish from Lake Magadi (Kenya)

Water entering Lake Magadi from a spring contained 73 mg fluoride (F)1^-1, while samples taken 100 and 400 m from the spring were estimated to contain 110 and 140 mg F 1^-1. Evaporation apparently increased the F and salt concentrations to levels at which the common method of F analyses became unreliable, even after dilution. It is recommended to re-examine the very high F levels reported in the saline lakes of Rift Valley. The F levels of Tilapia grahami living in water with about 110 mg F 1^-1 averaged (mg F kg^-1 dry weight): fillet 68, skin 819, gills 1,366 and bones 1,661. The variation was highest in fillet and skin. There was no positive correlation between tissue F levels and fish size (range 3–20 g). It remains uncertain whether the fish bone was saturated at this concentration of F or if some mechanism of elimination hindered higher F accumulation in the skeletal structures.author for correspondenceauthor for correspondence     

In Vivo Quantification of Inflammation in Experimental Autoimmune Encephalomyelitis Rats Using Fluorine-19 Magnetic Resonance Imaging Reveals Immune Cell Recruitment outside the Nervous System

Progress in identifying new therapies for multiple sclerosis (MS) can be accelerated by using imaging biomarkers of disease progression or abatement in model systems. In this study, we evaluate the ability to noninvasively image and quantitate disease pathology using emerging “hot-spot” ¹⁹F MRI methods in an experimental autoimmune encephalomyelitis (EAE) rat, a model of MS. Rats with clinical symptoms of EAE were compared to control rats without EAE, as well as to EAE rats that received daily prophylactic treatments with cyclophosphamide. Perfluorocarbon (PFC) nanoemulsion was injected intravenously, which labels predominately monocytes and macrophages in situ. Analysis of the spin-density weighted ¹⁹F MRI data enabled quantification of the apparent macrophage burden in the central nervous system and other tissues. The in vivo MRI results were confirmed by extremely high-resolution ¹⁹F/¹H magnetic resonance microscopy in excised tissue samples and histopathologic analyses. Additionally, ¹⁹F nuclear magnetic resonance spectroscopy of intact tissue samples was used to assay the PFC biodistribution in EAE and control rats. In vivo hot-spot ¹⁹F signals were detected predominantly in the EAE spinal cord, consistent with the presence of inflammatory infiltrates. Surprising, prominent ¹⁹F hot-spots were observed in bone-marrow cavities adjacent to spinal cord lesions; these were not observed in control animals. Quantitative evaluation of cohorts receiving cyclophosphamide treatment displayed significant reduction in ¹⁹F signal within the spinal cord and bone marrow of EAE rats. Overall, ¹⁹F MRI can be used to quantitatively monitored EAE disease burden, discover unexpected sites of inflammatory activity, and may serve as a sensitive biomarker for the discovery and preclinical assessment of novel MS therapeutic interventions.     

Speciation and legislation

Abstract

The chemical speciation of milks containing trace levels of aluminium defies experimental analysis because of the extremely low concentrations and labile equilibria present. Nevertheless, atomic absorption spectrophotometry data in combination with precisely determined formation constants have been used to construct speciation models simulated using the ECCLES computer program and the Cardiff thermodynamic database.

Formation constants for the Al³⁺-citrate, -succinate, -picolinate, and -malate systems are reported for 37°C and I = 150 mmol dm^?3. Total aluminium concentrations in a range of commercially available bovine milks are given.

In general, the major aluminium species present are charged citrate complexes which present little or no apparent threat to a healthy human as such complexes will not be absorbed through the intestinal walls. However, the importance of phosphate binding is revealed and further studies recommended.     

Nuclear analytical methods for trace element studies in calcified tissues

Various nuclear analytical methods have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the¹⁹F(p, α ψ)¹⁶O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues: enamel, dentine, cementum, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Microprobe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelodentin junction.

     

Effect of the BMPR-II-SMAD3/MRTF pathway on proliferation and migration of ASMCs and the mechanism in asthma

Background

A variety of smooth muscle-specific genes and proteins, including SMAD3, BMPR-II, and MRTF, are involved in airway remodeling in asthma. As a receptor of bone morphogenetic protein (BMP) signaling, BMPR-II has important roles in airway remodeling in asthma. However, the underlying mechanism of BMPR-II in airway smooth muscle cells (ASMCs) in asthma remains incomplete.

Methods

Wistar rats were intraperitoneally injected with ovalbumin antigen suspension and aluminium hydroxide and, stimulated with ovalbumin nebulized inhalation to constructed asthma model. Primary ASMCs were isolated with collagenase I and identified by testing the α-SMA expression. Quantitative polymerase chain reaction (qPCR) and western blot assay were employed to detect the gene expression. CCK8, Transwell and Fluo-4 A assays were introduced to measure the cell viability, migration and intracellular Ca²⁺. Co-Immunoprecipitation (Co-IP) assay was applied to test the interaction among proteins.

Results

First, we observed significant increases in BMPR-II in asthmatic rat model and ASMCs at both the mRNA and protein levels. Second, we observed that silencing of siBMPR-II inhibited proliferation, migratory capacity and intracellular Ca²⁺ concentration in ASMCs. Furthermore, our study demonstrated that siBMPR-II inhibited the Smad3 expression and overexpression promoted the bioactivity of ASMCs. In addition, this study showed that p-Smad3 could interacted with MRTF and siMRTF inhibits the bioactivity of ASMCs. Finally, our results revealed BMPR-II-SMAD3/MRTF pathway affected the bioactivity of ASMCs.

Conclusions

This study indicates that the BMPR-II-SMAD3/MRTF signaling pathway is involved in the process of ASMCs remodeling, providing novel avenues for the identification of new therapeutic modalities.

     

Removal of aluminium from aqueous solution by four wild-type strains of Aspergillus niger

This paper provides a unique comparison of the performance of four wild-type Aspergillus niger strains in remediation of aluminium(III)-contaminated aqueous solutions. The direct fungal aluminium removal via biosorption and bioaccumulation was compared among all fungal strains, including bioaccumulation efficiency during dynamic and static cultivation. Our results indicate that aluminium bioaccumulation by living biomass outperformed biosorption, although biosorption by non-living biomass is a less time-demanding process. Among others, only one strain significantly differed regarding comparison of dynamic and static bioaccumulation. In this case, a significantly higher removal performance was achieved under dynamic cultivation conditions at initial aluminium(III) concentrations over 2.5 mg L⁻¹. Although the fungal sensitivity towards aluminium(III) differed among selected fungal strains, there was no apparent correlation between the strains’ removal performance and their adaptive mechanisms.

     

Polynuclear Aromatic Hydrocarbons (PAH) and Heavy Metals in Dry and Wet Sludge from As-Samra Wastewater Treatment Plant,Jordan

Dry and wet sludge samples were collected from the sewage sludge storage site and primary treatment ponds at As-Samra Wastewater Treatment Ponds in Al Hayshmia, Jordan. The concentrations of polynuclear aromatic hydrocarbons (PAH) and macro- and microelements were determined using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively.

Environmentally relevant concentrations of PAH were detected ranging from 62 μg g^?1 to 70 μg g^?1 for dry sludge and from 35 μg g^?1 to 47 μg g^?1 for wet sludge. These results indicated a potential environmental risk if sewage sludge is reused in Jordan as organic fertilizer without first being treated. The results of the study showed that the sewage sludge samples were contaminated with low levels of heavy metals, as the dry sludge samples were characterized by higher concentrations of most analyzed elements than for wet sludge samples. Still, none of the trace metal concentrations exceeded the threshold concentration levels for agricultural-related sludge.

Unlike many other nutrients found in sludge, the Total Organic Carbon (TOC%) found in dry and wet sludge revealed similar values, at 13.18 percent and 13.29 percent, respectively. The total phosphorus ranged from 0.25% for dry sludge to 0.47% for wet sludge. Total nitrogen varied from 0.80% for wet sludge to 1.01% for the dry sludge samples. The overall nutrients levels are close to those found in the literature. The findings of this study have improved the understanding of sewage sludge characteristics in a semiarid environment.     

Heat-initiated detection for reduced glutathione with 19F NMR probes based on modified gold nanoparticles

For detecting reduced glutathione (GSH) with a ¹⁹F NMR spectroscopy with time-specificity, we developed the probes based on gold nanoparticles modified with the fluorinated groups via the thermally-cleavable linkers. Before the heating treatment with the probe, the maleimide moiety as a binding site with GSH in the probe is inactivated by cycloaddition of furan. At this silent state, the magnitude of ¹⁹F NMR signals from the fluorinated groups was suppressed. By heating for the activation of the probe, the maleimide moiety was produced via retro Diels–Alder reaction, and ¹⁹F NMR signals were observed. From this moment, GSH started the reaction with the probe via Michael addition to the maleimide moiety, leading to the observation of the new peak in ¹⁹F NMR spectra. Finally, the amounts of GSH were determined from the increase of the magnitude of ¹⁹F NMR signals.     

Optimizing <Superscript>19</Superscript>F NMR protein spectroscopy by fractional biosynthetic labeling

In protein NMR experiments which employ nonnative labeling, incomplete enrichment is often associated with inhomogeneous line broadening due to the presence of multiple labeled species. We investigate the merits of fractional enrichment strategies using a monofluorinated phenylalanine species, where resolution is dramatically improved over that achieved by complete enrichment. In NMR studies of calmodulin, a 148 residue calcium binding protein, ¹⁹F and ¹H-¹⁵N HSQC spectra reveal a significant extent of line broadening and the appearance of minor conformers in the presence of complete (>95%) 3-fluorophenylalanine labeling. The effects of varying levels of enrichment of 3-fluorophenylalanine (i.e. between 3 and >95%) were further studied by ¹⁹F and ¹H-¹⁵N HSQC spectra,¹⁵N T₁ and T₂ relaxation measurements, ¹⁹F T₂ relaxation, translational diffusion and heat denaturation experiments via circular dichroism. Our results show that while several properties, including translational diffusion and thermal stability show little variation between non-fluorinated and >95% ¹⁹F labeled samples, ¹⁹F and ¹H-¹⁵N HSQC spectra show significant improvements in line widths and resolution at or below 76% enrichment. Moreover, high levels of fluorination (>80%) appear to increase protein disorder as evidenced by backbone ¹⁵N dynamics. In this study, reasonable signal to noise can be achieved between 60–76% ¹⁹F enrichment, without any detectable perturbations from labeling.     

Microbial decomposition of dissolved organic matter in a hypertrophic pond

Planktonic heterotrophic bacteria in lakes utilize the labile fraction of dissolved organic carbon (DOC), although information about seasonal changes in labile DOC in hypertrophic lakes in terms of absolute amount and relative proportion of the total DOC is still limited. We conducted DOC decomposition experiments using GF/F filtrates in water samples from hypertrophic Furuike Pond, together with monitoring of DOC concentration and bacterial abundance in water samples from the pond, to examine seasonal changes in the amount of labile DOC and growth of bacteria on labile DOC. DOC concentrations fluctuated between 2.7 and 11 mg C l⁻¹, and bacterial abundance fluctuated between 1.5 × 10⁶ and 1.0 × 10⁸ cells ml⁻¹. In the DOC decomposition experiment when grazers of bacteria were removed, small portions of DOC (18% ± 12%) were labile for decomposition by bacteria, and the growth yield of bacteria on labile DOC ranged between 3.3% and 19%. Furthermore, addition of nitrogen to water samples enhanced bacterial growth. Thus, not only labile DOC but also nitrogen limited bacterial growth in the pond. Considering the results in the present study together with those of previous studies, bacterial abundance in Furuike Pond is subjected to bottom-up control, such as by limitation of DOC and nitrogen throughout the year, although top-down control of bacterial abundance such as by grazing is seasonally important. Received: May 1, 2001 / Accepted: July 22, 2001     

Introduction of Fluorine Into the C8 Position of Purine Nucleosides

Abstract

We have synthesized 2-amino-6,8-difluoro-9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)purine (3) from 2-amino-6,8-dichloro-9-(2,3,5-tri-O-acetyl-ß-D-ribofuranosyl)purine (1) in a two-step procedure. The reaction of 3 with anhydrous ammonia in dry 1,2-dimethoxyethane gave 2,8-diamino-6-fluoro-9-(2,3,5-tri-O-acetyl-ß-D-ribofuranosyl)purine (4) in 64.1% yield. Compound 4 was deaminated with t-butylnitrite in tetrahydrofuran to give 2-amino-6-fluoro-9-(2,3,5-tri-O-acetyl-ß-D-ribofuranosyl)purine (6). The ¹H, ¹⁹F, and ¹³C NMR spectral data were determined and evaluated for each of the compounds.     

The bioavailability of26Al-labelled aluminium citrate and aluminium hydroxide in volunteers

A study was undertaken to determine the fraction of ingested aluminium taken up by two male volunteers, following their ingestion of either aluminium citrate or aluminium hydroxide. In addition, the effects of simultaneous citrate ingestion on the gastrointestinal absorption of aluminium from its hydroxide was studied. Volunteers received three oral doses of²⁶Al-labelled aluminium compound in water. The doses were administered directly into the stomach using a paediatric feeding tube. Blood samples were collected from the volunteers at 1, 4 and 24 h after administration, and their daily output of urine and faeces was collected for 6 days. These samples were analysed for their²⁶Al content using either coincidence gamma-counting or accelerator mass spectrometry. The uptake of aluminium was greatest following its administration in the citrate form and was least following intake as the aluminium hydroxide suspension. The co-administration of citrate, with the aluminium hydroxide suspension, was found to enhance the levels of²⁶Al uptake in both volunteers. Using a urinary excretion factor based on the results of previous studies, the fractional aluminium uptake from each of the species was calculated: aluminium citrate, 5.23 × 10^–3; aluminium hydroxide, 1.04 × 10^–4; aluminium hydroxide with citrate, 1.36 × 10^–3.     

Biological monitoring of exposure to low concentrations of benzene in workers at a metallurgical coke production plant: new insights into S-phenylmercapturic acid and urinary benzene

Context: Urinary S-phenylmercapturic acid (SPMA) and benzene (U-Ben) are usually measured at the end of the work shift (ES), although their kinetic of elimination is not clearly known.

Objective: To investigate SPMA and U-Ben elimination 16?h after the ES, in 93 coke production workers exposed to low benzene concentrations.

Materials and methods: Airborne benzene (A-Ben) was measured by passive samplings, while SPMA, U-Ben, methyl-tert-butyl ether (U-MTBE), cotinine (U-Cot) and creatinine were determined on urine samples collected at ES and before the beginning of the next work shift (next BS).

Results: Median A-Ben concentrations were 17.2?µg/m³ in the personal and 34.7?µg/m³ in the stationary samplings. SPMA was always detectable, whereas U-Ben was below the limit of quantification in 26.7% of the ES and 35.6% of the next BS samples, and U-MTBE in more than the 80.0% of the samples. At both the sampling times, SPMA and U-Ben showed a positive dependence on personal A-Ben, as well as on creatinine and U-Cot values.

Discussion and conclusion: SPMA and U-Ben at the next BS were dependent on the exposure to low benzene concentrations suffered in the previous work shift, prompting a reconsideration of the urine sampling time recommended by the American Conference Governmental Industrial Hygienists (ACGIH).     

Quantitative PCR assays to survey the bovine adenovirus levels in environmental samples

Aims: Previous studies suggested bovine adenoviruses (BAdVs) could be used as cattle faecal indicators. The main aim of this study was to survey the levels of BAdV in environmental samples using quantitative polymerase chain reaction (qPCR). Methods and Results: Two qPCR assays were developed to identify and quantify BAdVs in environmental samples. BAdVs were detected in all dairy manure, and in most cases, the sample concentrations were around 10³–10⁴ copies ml^?1. Farm tile drainage samples were also detected, but the concentrations were about 1–3 log₁₀ lower than the BAdV concentrations in the manure samples. The genome equivalent copy (GEC) levels of BAdV and the phage forming unit (PFU) levels of somatic phage in manure samples were comparable. Four of twenty individual cattle faeces were positive with concentrations similar to that found in the manure samples. Sequencing results confirmed the presence of BAdV in the environmental samples, and phylogenetic analysis indicated that BAdV 2 and 4 were the most prevalent serotypes in all the manure samples tested. The qPCR assays developed in this study showed higher sensitivity in detecting BAdV 1 and 2 than the previous published nested assay. Conclusion: The high levels of BAdV in the environmental samples may suggest it could be used for bovine faecal indicator. The significant levels of BAdV in the drainage samples may indicate the potential of surface water pollution by the manure applied to farm fields. Significance and Impact of the Study: This is the first study that reports the quantitative level of BAdV in environmental samples. These results could be useful when it comes to determining whether BAdV could be utilized as a bovine faecal indicator.     

Concentrations of Thirteen Trace Metals in Scales of Three Nototheniid Fishes from Antarctica (James Ross Island,Antarctic Peninsula)

In this study, we assessed concentrations of 13 trace metals in the scales of Notothenia coriiceps, Trematomus bernacchii and Gobionotothen gibberifrons caught off the coast of James Ross Island (Antarctic Peninsula). Overall, our results for scales broadly match those of previous studies using different fish and different organs, with most metals found at trace levels and manganese, aluminium, iron and zinc occurring at high levels in all species. This suggests that scales can serve as a useful, non-invasive bioindicator of long-term contamination in Antarctic fishes. High accumulation of manganese, aluminium, iron and zinc is largely due to high levels in sediments associated with nearby active volcanic sites. Manganese, vanadium and aluminium showed significant positive bioaccumulation in T. bernacchii (along with non-significant positive accumulation of iron, zinc, cobalt and chromium), most likely due to greater dietary specialisation on sediment feeding benthic prey and higher trophic species. Levels of significance in bioaccumulation regressions were strongly affected by large-scale variation in the data, driven largely by individual differences in diet and/or changes in habitat use and sex differences associated with life stage and reproductive status. Increased levels of both airborne deposition and precipitation and meltwater runoff associated with climate change may be further adding to the already high levels of manganese, aluminium, iron and zinc in Antarctic Peninsula sediments. Further long-term studies are encouraged to elucidate mechanisms of uptake (especially for aluminium and iron) and possible intra- and interspecific impacts of climate change on the delicate Antarctic food web.

     

Effects of aluminium on growth and nutrient uptake of small Picea abies and Pinus sylvestris plants

Summary The effects of aluminium concentrations between 0.2 and 30 mM at pH 3.8 ±0.2 on small plants of Norway spruce [(Picea abies (L.) Karst], Scots pine (Pinus sylvestris L.), and Scots pine infected with the ectomycorrhizal fungus Suillus bovinus (L. ex Fr.) O. Kuntze were investigated. The plants were grown at maximum relative growth rate (R_G % day^–1) with free access but very low external concentrations of nutrients. Steady-state conditions with respect to relative growth rate (R_G) and internal nutrient concentrations were achieved before addition of aluminium, which was added as AlCl₃ and/or Al(NO₃)₃. There were reductions in rg at aluminium concentrations of 0.3 mM in spruce, 6 mM in pine and 10 mM in ectomycorrhizal pine, i. e. at aluminium concentrations considerably higher than those normally occurring in the top layer of the mineral soil where most fine roots are found. Nutrient uptake rate per unit root growth rate was calculated for different nutrient elements. The uptake rate of calcium and magnesium was reduced at aluminium concentrations of 0.2 mM (spruce), 1 mM (pine) and 3 mM (ectomycorrhizal pine), without influencing R_g. The results question the validity of the hypothesis of aluminium toxicity to forest tree species at low external concentrations.     

Fluorine-19 magnetic resonance angiography of the mouse

Purpose

To implement and characterize a fluorine-19 (¹⁹F) magnetic resonance imaging (MRI) technique and to test the hypothesis that the ¹⁹F MRI signal in steady state after intravenous injection of a perfluoro-15-crown-5 ether (PCE) emulsion may be exploited for angiography in a pre-clinical in vivo animal study.

Materials and Methods

In vitro at 9.4T, the detection limit of the PCE emulsion at a scan time of 10 min/slice was determined, after which the T₁ and T₂ of PCE in venous blood were measured. Permission from the local animal use committee was obtained for all animal experiments. 12 µl/g of PCE emulsion was intravenously injected in 11 mice. Gradient echo ¹H and ¹⁹F images were obtained at identical anatomical levels. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were determined for 33 vessels in both the ¹⁹F and ¹H images, which was followed by vessel tracking to determine the vessel conspicuity for both modalities.

Results

In vitro, the detection limit was ∼400 µM, while the ¹⁹F T₁ and T₂ were 1350±40 and 25±2 ms. The ¹⁹F MR angiograms selectively visualized the vasculature (and the liver parenchyma over time) while precisely coregistering with the ¹H images. Due to the lower SNR of ¹⁹F compared to ¹H (17±8 vs. 83±49, p<0.001), the ¹⁹F CNR was also lower at 15±8 vs. 52±35 (p<0.001). Vessel tracking demonstrated a significantly higher vessel sharpness in the ¹⁹F images (66±11 vs. 56±12, p = 0.002).

Conclusion

¹⁹F magnetic resonance angiography of intravenously administered perfluorocarbon emulsions is feasible for a selective and exclusive visualization of the vasculature in vivo.     

Systematic comparison of two novel,thiol-reactive prosthetic groups for <Superscript>18</Superscript>F labeling of peptides and proteins with the acylation agent succinimidyl-4-[<Superscript>18</Superscript>F]fluorobenzoate ([<Superscript>18</Superscript>F]SFB)

A systematic comparison of 4-[¹⁸F]fluorobenzaldehyde-O-(2-{2-[2-(pyrrol-2,5-dione-1-yl)ethoxy]-ethoxy}-ethyl)oxime ([¹⁸F]FBOM) and 4-[¹⁸F]fluorobenzaldehyde-O-[6-(2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-hexyl]oxime ([¹⁸F]FBAM) as prosthetic groups for the mild and efficient ¹⁸F labeling of cysteine-containing peptides and proteins with the amine-group reactive acylation agent, succinimidyl-4-[¹⁸F]fluorobenzoate ([¹⁸F]SFB), is described. All three prosthetic groups were prepared in a remotely controlled synthesis module. Synthesis of [¹⁸F]FBOM and [¹⁸F]FBAM was accomplished via oxime formation through reaction of appropriate aminooxy-functionalized labeling precursors with 4-[¹⁸F]fluorobenzaldehyde. The obtained radiochemical yields were 19% ([¹⁸F]FBOM) and 29% ([¹⁸F]FBAM), respectively. Radiolabeling involving [¹⁸F]FBAM and [¹⁸F]FBOM was exemplified by the reaction with cysteine-containing tripeptide glutathione (GSH), a cysteine-containing dimeric neurotensin derivative, and human native low-density lipoprotein (nLDL) as model compounds. Radiolabeling with the acylation agent [¹⁸F]SFB was carried out using a dimeric neurotensin derivative and nLDL. Both thiol-group reactive prosthetic groups show significantly better labeling efficiencies for the peptides in comparison with the acylation agent [¹⁸F]SFB. The obtained results demonstrate that [¹⁸F]FBOM is especially suited for the labeling of hydrophilic cysteine-containing peptides, whereas [¹⁸F]FBAM shows superior labeling performance for higher molecular weight compounds as exemplified for nLDL apolipoprotein constituents. However, the acylation agent [¹⁸F]SFB is the preferred prosthetic group for labeling nLDL under physiological conditions.