Contamination of Apple Fruit with Diphenylamine During Storage

Apple fruit are treatmented with diphenylamine (DPA) in the form of a postharvest dip to prevent the development of storage scald. However, DPA residues have been detected on apples not treated with DPA, which is problematic in markets where DPA residues are not acceptable. The objective of this study was to identify sources of DPA contamination and evaluate the effectiveness of ozone to reduce contamination. Concentrations of DPA in the atmosphere of commercial storage rooms was monitored during the storage season and the adsorption of DPA onto wood and plastic bin material, plastic bin liners, foam insulation, and apple fruit was assessed. DPA was sampled from headspace with solid phase micro extraction using 65 μm polyacrylate micro fibers and analyzed using GC-MS. The effectiveness of gaseous treatments of 300 and 800 ppb ozone to reduce DPA contamination on apple fruit and bin material was also determined. DPA was found to volatilize from treated apples and bins into the storage room air, where it was adsorbed onto storage room walls, bins, bin liners and other fruit. DPA was found in the atmosphere of storage rooms containing apples that were not treated with DPA. Wood and plastic bin material, bin liners, and foam insulation all had a high affinity for DPA and were determined to be potential sources of contamination. Ozone reacted with DPA and following gaseous ozone treatments, off-gassing of DPA from wood and plastic bin material and bin liners was reduced. However, ozone was not effective in removing all DPA in contaminated materials and was ineffective in removing DPA from contaminated apples. Due to the pervasive and persistent nature of DPA, fruit should be handled and stored in facilities where DPA is not used to prevent contamination of fruit.

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A method to detect diphenylamine contamination of apple fruit and storages using headspace solid phase micro-extraction and gas chromatography/mass spectroscopy

Food Chemistry ◽

10.1016/j.foodchem.2014.03.099 ◽

2014 ◽

Vol 160 ◽

pp. 255-259 ◽

Cited By ~ 9

Author(s):

Jun Song ◽

Charles F. Forney ◽

Michael A. Jordan

Keyword(s):

Gas Chromatography ◽

Mass Spectroscopy ◽

Solid Phase ◽

Apple Fruit ◽

Solid Phase Micro Extraction ◽

Gas Chromatography Mass Spectroscopy

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Volatile Profiles of Decaying Apple Fruit

HortScience ◽

10.21273/hortsci.32.3.458e ◽

1997 ◽

Vol 32 (3) ◽

pp. 458E-458

Author(s):

N.A. Mir ◽

R.M. Beaudry

Keyword(s):

Formic Acid ◽

Solid Phase ◽

Apple Fruit ◽

Solid Phase Micro Extraction ◽

Volatile Profile ◽

Volatile Collection ◽

Glass Tubes ◽

Volatile Profiles ◽

Flow Through ◽

Volatile Aroma

The changes in volatile-aroma of Penicillium expansium and Botrytis cinerea fungi and apple fruit inoculated with these fungi were studied using GC-MS. A specially designed chamber with raised end glass tubes with access ports fitted with Teflon-lined septa was used to determine the volatile profile for fungi on agar. Inoculated fruit were placed in glass flow-through chambers similarly fitted with sampling ports. Volatile collection from fruits or fungi was accomplished using solid phase micro-extraction (SPME) device (Supelco, Inc.). In fungi-inoculated fruits, volatiles not produced by uninfected fruit included formic acid, 2-cyano acetamide; 1-hydroxy-2-propanone, and 1-1-diethoxy-2-propanone, which were initially detected 6 hr after inoculation. These new volatiles are suggested to be synthesized specifically by the action of fungi on fruits as they were not detected from fungi that were grown on agar or bruised fruits. In general, esters, alcohols, aldehydes, ketones, acids, and hydrocarbons other than α-farnesene declined in fungi infected fruits.

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Synthesis and Screening of A DNA-Encoded Library of Non-Peptidic Macrocycles

10.26434/chemrxiv.13490151.v1 ◽

2020 ◽

Author(s):

Eric Koesema ◽

Animesh Roy ◽

Nicholas G. Paciaroni ◽

Thomas Kodadek

Keyword(s):

Solid Phase Synthesis ◽

Solid Phase ◽

Cell Permeability ◽

Phase Synthesis ◽

Protein Ligands ◽

High Affinity ◽

Scaffold Diversity

There is considerable interest in the development of libraries of non-peptidic macrocycles as a source of ligands for difficult targets. We report here the solid-phase synthesis of a DNA-encoded library of several hundred thousand thioether-linked macrocycles. The library was designed to be highly diverse with respect to backbone scaffold diversity and to minimize the number of amide N-H bonds, which compromise cell permeability. The utility of the library as a source of protein ligands is demonstrated through the isolation of compounds that bind streptavidin, a model target, with high affinity.

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Water quality. Determination of volatile organic compounds in water. Method using headspace solid-phase micro-extraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS)

10.3403/30261807 ◽

2016 ◽

Keyword(s):

Mass Spectrometry ◽

Water Quality ◽

Gas Chromatography ◽

Volatile Organic Compounds ◽

Organic Compounds ◽

Solid Phase ◽

Gas Chromatography Mass Spectrometry ◽

Solid Phase Micro Extraction ◽

Volatile Organic

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Impact of Estrogens Present in Environment on Health and Welfare of Animals

Animals ◽

10.3390/ani11072152 ◽

2021 ◽

Vol 11 (7) ◽

pp. 2152

Author(s):

Konrad Wojnarowski ◽

Paweł Podobiński ◽

Paulina Cholewińska ◽

Jakub Smoliński ◽

Karolina Dorobisz

Keyword(s):

Environmental Impact ◽

Environmental Pollution ◽

Animal Welfare ◽

Environmental Contamination ◽

Physiological Condition ◽

Negative Consequences ◽

Natural Processes ◽

Neoplastic Processes ◽

Potential Sources ◽

Sources Of Contamination

Nowadays, there is a growing interest in environmental pollution; however, knowledge about this aspect is growing at an insufficient pace. There are many potential sources of environmental contamination, including sex hormones—especially estrogens. The analyzed literature shows that estrone (E1), estradiol (E2), estriol (E3), and synthetic ethinyloestradiol (EE2) are the most significant in terms of environmental impact. Potential sources of contamination are, among others, livestock farms, slaughterhouses, and large urban agglomerations. Estrogens occurring in the environment can negatively affect the organisms, such as animals, through phenomena such as feminization, dysregulation of natural processes related to reproduction, lowering the physiological condition of the organisms, disturbances in the regulation of both proapoptotic and anti-apoptotic processes, and even the occurrence of neoplastic processes thus drastically decreasing animal welfare. Unfortunately, the amount of research conducted on the negative consequences of their impact on animal organisms is many times smaller than that of humans, despite the great richness and diversity of the fauna. Therefore, there is a need for further research to help fill the gaps in our knowledge.

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Design of PSMA ligands with modifications at the inhibitor part: an approach to reduce the salivary gland uptake of radiolabeled PSMA inhibitors?

EJNMMI Radiopharmacy and Chemistry ◽

10.1186/s41181-021-00124-1 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Veronika Barbara Felber ◽

Manuel Amando Valentin ◽

Hans-Jürgen Wester

Keyword(s):

Salivary Gland ◽

Solid Phase ◽

Solid Phase Peptide Synthesis ◽

In Vivo Studies ◽

Tumor Xenograft ◽

Tumor Uptake ◽

Lncap Cells ◽

High Affinity

Abstract Aim To investigate whether modifications of prostate-specific membrane antigen (PSMA)-targeted radiolabeled urea-based inhibitors could reduce salivary gland uptake and thus improve tumor-to-salivary gland ratios, several analogs of a high affinity PSMA ligand were synthesized and evaluated in in vitro and in vivo studies. Methods Binding motifs were synthesized ‘on-resin’ or, when not practicable, in solution. Peptide chain elongations were performed according to optimized standard protocols via solid-phase peptide synthesis. In vitro experiments were performed using PSMA+ LNCaP cells. In vivo studies as well as μSPECT/CT scans were conducted with male LNCaP tumor xenograft-bearing CB17-SCID mice. Results PSMA ligands with A) modifications within the central Zn2+-binding unit, B) proinhibitor motifs and C) substituents & bioisosteres of the P1′-γ-carboxylic acid were synthesized and evaluated. Modifications within the central Zn2+-binding unit of PSMA-10 (Glu-urea-Glu) provided three compounds. Thereof, only natLu-carbamate I (natLu-3) exhibited high affinity (IC50 = 7.1 ± 0.7 nM), but low tumor uptake (5.31 ± 0.94% ID/g, 1 h p.i. and 1.20 ± 0.55% ID/g, 24 h p.i.). All proinhibitor motif-based ligands (three in total) exhibited low binding affinities (> 1 μM), no notable internalization and very low tumor uptake (< 0.50% ID/g). In addition, four compounds with P1′-ɣ-carboxylate substituents were developed and evaluated. Thereof, only tetrazole derivative natLu-11 revealed high affinity (IC50 = 16.4 ± 3.8 nM), but also this inhibitor showed low tumor uptake (3.40 ± 0.63% ID/g, 1 h p.i. and 0.68 ± 0.16% ID/g, 24 h p.i.). Salivary gland uptake in mice remained at an equally low level for all compounds (between 0.02 ± 0.00% ID/g and 0.09 ± 0.03% ID/g), wherefore apparent tumor-to-submandibular gland and tumor-to-parotid gland ratios for the modified peptides were distinctly lower (factor 8–45) than for [177Lu]Lu-PSMA-10 at 24 h p.i. Conclusions The investigated compounds could not compete with the in vivo characteristics of the EuE-based PSMA inhibitor [177Lu]Lu-PSMA-10. Although two derivatives (3 and 11) were found to exhibit high affinities towards LNCaP cells, tumor uptake at 24 h p.i. was considerably low, while uptake in salivary glands remained unaffected. Optimization of the established animal model should be envisaged to enable a clear identification of PSMA-targeting radioligands with improved tumor-to-salivary gland ratios in future studies.

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