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1.
Int J Mol Sci ; 24(13)2023 Jun 27.
Article in English | MEDLINE | ID: mdl-37445897

ABSTRACT

The use of alternative energy sources, such as microwaves (MW) or ultrasounds (US), and their mutual cross-combination have been widely described in the literature in the development of new synthetic methodologies in organic and medicinal chemistry. In this review, our attention is focused on representative examples, reported in the literature in the year range 2013-2023 of selected N-containing bicyclic heterocycles, with the aim to highlight the advantages of microwave- and ultrasound-assisted organic synthesis.


Subject(s)
Microwaves , Nitrogen , Chemistry Techniques, Synthetic , Ultrasonography , Chemistry, Pharmaceutical
2.
J Dairy Sci ; 104(5): 5125-5132, 2021 May.
Article in English | MEDLINE | ID: mdl-33685697

ABSTRACT

Bisphenol A (BPA) as a chemical hazard may enter the milk chain during primary production at the farm and, successively, during milk processing at a dairy company. To identify the potential pathways that play a role in the occurrence of BPA, a monitoring model for risk assessment based on the identification of the hazards at each stage of milk processing was investigated. Milk samples were analyzed using liquid chromatography with fluorescence detection. Quantifiable levels were detected in samples obtained from the raw milk storage tank, pasteurized milk from the storage tank, and packaged milk. The highest BPA contamination levels were detected in raw milk from the storage tank (mean 0.265 µg/L). Despite the fact that dietary exposure levels were below the temporary daily intake, BPA may have adverse effects, particularly for vulnerable population groups. New monitoring programs involving each stage of milk processing should therefore be applied.


Subject(s)
Benzhydryl Compounds , Milk , Animals , Benzhydryl Compounds/analysis , Food Contamination/analysis , Milk/chemistry , Phenols/analysis , Risk Assessment
3.
Arch Pharm (Weinheim) ; 354(5): e2000414, 2021 May.
Article in English | MEDLINE | ID: mdl-33543794

ABSTRACT

A new series of norbornene and exo-N-hydroxy-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximide derivatives was prepared, and their affinities to the 5-HT1A , 5-HT2A , and 5-HT2C receptors were evaluated and compared with a previously synthesized series of derivatives characterized by the same nuclei, to identify selective ligands for the subtype receptors. Arylpiperazines represent one of the most important classes of 5-HT1A R ligands, and the research of new derivatives has been focused on the modification of one or more portions of this pharmacophore. The combination of structural elements (heterocyclic nucleus, hydroxyalkyl chain, and 4-substituted piperazine), known to be critical for the affinity to 5-HT1A receptors, and the proper selection of substituents resulted in compounds with high specificity and affinity toward serotoninergic receptors. The most active compounds were selected for further in vivo assays to determine their functional activity. Finally, to rationalize the obtained results, molecular docking studies were performed. The results of the pharmacological studies showed that 3e, 4j, and 4n were the most active and promising derivatives for the serotonin receptor considered in this study.


Subject(s)
Molecular Docking Simulation , Piperazine/pharmacology , Receptors, Serotonin/metabolism , Animals , Dose-Response Relationship, Drug , Ligands , Male , Molecular Structure , Piperazine/chemical synthesis , Piperazine/chemistry , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship
4.
J Environ Sci Health B ; 53(2): 116-120, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-29172986

ABSTRACT

A simple and sensitive validated analytical method based on liquid chromatography coupled to tandem fluorescence (FD) and ultraviolet (UV) spectrophotometry was applied to monitor the presence of bisphenol A and bisphenol S in plastic baby bottles marketed in Italy. The limits of detection (LOD) were 3.75 ng mL-1 and 80.00 ng mL-1, and those of quantification (LOQ) were 12.51 ng mL-1 and 260.00 ng mL-1 for BPA (FD detection) and for BPS (UV detection), respectively. BPA was found in only four samples, two samples undergone to microwave heating and two samples undergone to bottle warmer heating either at 40°C or at 80°C. Although the quantities of leached BPA were well below the reference dose for daily intake established by the European Food Safety Authority (EFSA) (4.0 µg kg-1 bw/day), the release of BPA and BPS from these plastic materials should be carefully considered by the government authorities to increase people's awareness on this issue and to protect the most vulnerable population group.


Subject(s)
Benzhydryl Compounds/analysis , Food Contamination/analysis , Food Packaging , Milk/chemistry , Phenols/analysis , Sulfones/analysis , Animals , Chromatography, Liquid/methods , Fluorescence , Humans , Infant , Italy , Limit of Detection , Microwaves , Plastics/chemistry , Spectrophotometry, Ultraviolet/methods
5.
Food Chem ; 442: 138498, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38245984

ABSTRACT

Residue levels of seven pesticides were analyzed in thirty-five samples of Extra Virgin Olive Oil to assess the health risk of consuming Italian oils correlated with the presence of these pesticides. An in-house analytical procedure was developed and validated, consisting of a specific dispersive solid-phase extraction using the QuEChERS technique and a qualitative-quantitative analysis using liquid chromatography coupled with tandem mass spectrometry. Thirty-four percent of the samples were contaminated with pesticide residues; in the concentration range of 0.53-0.56 ng/mL for imazalil, 1.11-1.56 ng/mL for acetamiprid-N-desmethyl, 1.28-1.46 ng/mL for clothianidin, 0.94-1.49 ng/mL for thiacloprid, 1.08-4.64 ng/mL for dinotefuran, 0.42-1.47 ng/mL for thiamethoxam, 0.42-6.14 ng/mL for imidacloprid). Risk assessment was evaluated using the hazard quotient, hazard index, and Pesticide Residue Intake Model by EFSA. All hazard indices confirmed that the concentrations of pesticides detected in the oil samples did not represent a short or long-term risk for consumers' health.


Subject(s)
Pesticide Residues , Pesticides , Pesticide Residues/analysis , Olive Oil/chemistry , Tandem Mass Spectrometry/methods , Chromatography, Liquid , Liquid Chromatography-Mass Spectrometry , Pesticides/analysis , Risk Assessment
6.
Pharmaceuticals (Basel) ; 17(3)2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38543094

ABSTRACT

D-galactose, a simple natural compound, has been investigated as a powerful scaffold for drug delivery, diagnostics, and theranostics due to its distinctive properties and interactions with specific cell receptors. In the field of drug delivery, galactose functions as a ligand to selectively target cells expressing galactose receptors, such as hepatocytes, macrophages, and specific cancer cells. The direct attachment of galactose to the main drug or to drug-loaded nanoparticles or liposomes enhances cellular uptake, thereby improving drug delivery to the intended target cells. Galactose has also been found to be useful in diagnostics. Specifically, diagnostic tests based on galactose, such as the galactose elimination capacity test, are utilized to evaluate liver function and assess liver disease as well as hepatic functional reserve. Additionally, galactose-based theranostic agents can be designed by combining drug delivery and diagnostic capabilities. This review is an update of our previous review concerning the broad spectrum of possibilities for exploiting D-galactose as a vector for prodrug design and the synthetic strategies that allow its realization, jointly in diagnostics and theranostics, to highlight the versatility of this interesting vector.

7.
Food Chem ; 416: 135642, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-36871506

ABSTRACT

The levels of bisphenol A (BPA), bisphenol B (BPB), bisphenol F (BPF) and bisphenol S (BPS) were monitored in twenty-three samples of canned legumes from popular brands marketed in Italy. BPB, BPS and BPF were not detected in any samples, while BPA was found in 91 % of the samples in the concentration range 1.51-21.22 ng/mL. The risk associated with the human exposure to BPA was categorized using the Rapid Assessment of Contaminant Exposure (RACE) tool promoted by the European Food Safety Authority (EFSA). The results showed that there is no risk for any of the population groups when the current TDI value for BPA of 4 µg/kg bw/day was used as toxicological reference point. In contrast, using the new TDI value for BPA of 0.04 ng/kg bw/day, proposed by EFSA in December 2021, the existing risk was found to be real for all population groups.


Subject(s)
Fabaceae , Humans , Vegetables , Benzhydryl Compounds/analysis
8.
Article in English | MEDLINE | ID: mdl-35947373

ABSTRACT

The concern for human exposure to bisphenol A (BPA) has led to the introduction of other bisphenols to be used as substitutes in industrial processes. These compounds show activity similar to BPA as endocrine disruptors and could be already widespread both in the environment and in food. To monitor their possible occurrence in the food chain, an analytical method based on affinity chromatography clean-up and UHPLC coupled to tandem mass spectrometry detection was developed and in-house validated according to European law, for simultaneous determination of 17 bisphenols in milk and blood serum from bovine and buffalo, in drinking water and in feed. The analytical performance parameters of the method for these matrices were determined. The results showed satisfactory precision in terms of relative standard deviation (3.3%-21.4%), overall good trueness as mean percentage recoveries (77.0%-119.4%), with the only exception of bisphenol PH and bisphenol S in milk and BPA diglycidyl ether in serum. The high specificity and sensitivity of the method allowed us to determine the analytes at very low concentrations, that is, 0.01-1.0 ng/mL in water, 0.1-2.0 ng/mL in milk, 0.01-1.0 ng/g in blood serum and 1.0-10.0 ng/g in feed.


Subject(s)
Drinking Water , Endocrine Disruptors , Animals , Benzhydryl Compounds/analysis , Cattle , Chromatography, High Pressure Liquid/methods , Drinking Water/analysis , Endocrine Disruptors/analysis , Humans , Milk/chemistry , Phenols , Serum/chemistry , Tandem Mass Spectrometry/methods
9.
Foods ; 11(23)2022 Nov 29.
Article in English | MEDLINE | ID: mdl-36496660

ABSTRACT

The consumption of plant-based beverages as an alternative to cow's milk has recently gained vast attention worldwide. The aim of this work is to monitor the intake of Bisphenol A (BPA), Bisphenol B (BPB) and Bisphenol S (BPS) in the Italian population through the consumption of these foodstuffs. Specifically, the development and validation of an analytical procedure for the quantitative determination of the analytes by liquid chromatography coupled to tandem mass spectrometry was reported. Thirty-four samples of plant-based beverages (soya, coconut, almond, oats and rice) of popular brands marketed in Italy were analyzed. BPA was found in 32% of the samples, while BPB was found in 3% of the samples. The risk assessment using the Rapid Assessment of Contaminant Exposure (RACE) tool demonstrated that there was no risk for all population groups, when using the current Tolerable Daily Intake (TDI) of 4 ng/kg body weight (bw)/day as a toxicological reference point. In contrast, using the new temporary TDI of 0.04 ng/kg bw/day, the existing risk was found to be real for all population groups. If this value were to become final, even more attention would have to be paid to the possible presence of BPA in food to protect consumer health.

10.
Pharmaceuticals (Basel) ; 15(5)2022 Apr 29.
Article in English | MEDLINE | ID: mdl-35631377

ABSTRACT

Carbohydrates are one of the most abundant and important classes of biomolecules. The variety in their structures makes them valuable carriers that can improve the pharmaceutical phase, pharmacokinetics and pharmacodynamics of well-known drugs. D-galactose is a simple, naturally occurring monosaccharide sugar that has been extensively studied for use as a carrier and has proven to be valuable in this role. With the aim of validating the galactose-prodrug approach, we have investigated the galactosylated prodrugs ibuprofen, ketoprofen, flurbiprofen and indomethacin, which we have named IbuGAL, OkyGAL, FluGAL and IndoGAL, respectively. Their physicochemical profiles in terms of lipophilicity, solubility and chemical stability have been evaluated at different physiological pH values, as have human serum stability and serum protein binding. Ex vivo intestinal permeation experiments were performed to provide preliminary insights into the oral bioavailability of the galactosylated prodrugs. Finally, their anti-inflammatory, analgesic and ulcerogenic activities were investigated in vivo in mice after oral treatment. The present results, taken together with those of previous studies, undoubtedly validate the galactosylated prodrug strategy as a problem-solving technique that can overcome the disadvantages of NSAIDs.

11.
Biomed Chromatogr ; 25(12): 1315-8, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21308706

ABSTRACT

A method for the determination of dimethyl fumarate (DMF) in desiccant and antimould sachets, employed for protecting consumer products from humidity and mould, has been developed. The method is based on a solid-liquid extraction followed by HPLC-UV analysis. The method was validated with respect to recovery, linearity, limits of detection and quantitation and precision. The recovery was 98%. The correlation coefficient value (r) was equal to 0.94. Both intra- and inter-day precisions were studied at several concentration levels, being satisfactory in all cases (RSD < 5). Limits of detection and quantification values were in the low microgram per gram level, thus allowing the determination of DMF at concentrations below the limit established (0.1 mg/kg) by the recent EU Directive (Decision 2009/251/EC). The proposed procedure was applied for the determination of the target compound in 41 desiccant and antimould samples. DMF was detected in 39.0% of samples and its content in many samples exceeded the legal limits. The results of our analysis highlight the high risk of exposure to this powerful allergic sensitizer for consumers.


Subject(s)
Antifungal Agents/analysis , Chromatography, Reverse-Phase/methods , Fumarates/analysis , Hygroscopic Agents/analysis , Antifungal Agents/isolation & purification , Chromatography, High Pressure Liquid , Dimethyl Fumarate , Fumarates/isolation & purification , Hygroscopic Agents/isolation & purification , Product Packaging/standards , Reproducibility of Results , Sensitivity and Specificity , Solid Phase Extraction/methods
12.
Food Chem Toxicol ; 154: 112334, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34118346

ABSTRACT

The occurrence of analogues of bisphenol A (BPA), including bisphenol F(BPF) in milk is still not well known. BPF may enter the milk chain at the farm and during milk processing at the dairy company. This study identified the main BPF contamination pathways using a monitoring model based on the identification of the hazard at three stages along the dairy chain: raw milk from the storage tank, pasteurized milk from the storage tank, and cardboard packaged milk. Quantitative analysis was performed by high-performance liquid chromatography with fluorometric detection (HPLC/FD) system. BPF was detected in all analysed stages (from

Subject(s)
Benzhydryl Compounds/analysis , Endocrine Disruptors/analysis , Food Contamination/analysis , Milk/chemistry , Phenols/analysis , Animals , Food Handling , Food Packaging , Food Safety , Humans , Pasteurization , Risk Assessment
13.
Pharmaceuticals (Basel) ; 14(11)2021 Nov 11.
Article in English | MEDLINE | ID: mdl-34832931

ABSTRACT

In our previous studies, a ketorolac-galactose conjugate (ketogal) showed prolonged anti-inflammatory and analgesic activity, causing less gastric ulcerogenic effect and renal toxicity than its parent drug ketorolac. In order to demonstrate the safer profile of ketogal compared to ketorolac, histopathological changes in the small intestine and liver using three staining techniques before and after repeated oral administration in mice with ketorolac or an equimolecular dose of its galactosylated prodrug ketogal were assessed. Cytotoxicity and oxidative stress parameters were evaluated and compared in ketorolac- and ketogal-treated Human Primary Colonic Epithelial cells at different concentrations and incubation times. Evidence of mitochondrial oxidative stress was found after ketorolac treatment; this was attributable to altered mitochondrial membrane depolarization and oxidative stress parameters. No mitochondrial damage was observed after ketogal treatment. In ketorolac-treated mice, severe subepithelial vacuolation and erosion with inflammatory infiltrates and edematous area in the intestinal tissues were noted, as well as alterations in sinusoidal spaces and hepatocytes with foamy cytoplasm. In contrast, treatment with ketogal provided a significant improvement in the morphology of both organs. The prodrug clearly demonstrated a safer profile than its parent drug both in vitro and ex vivo, confirming that ketogal is a strategic alternative to ketorolac.

14.
Antioxidants (Basel) ; 9(8)2020 Aug 05.
Article in English | MEDLINE | ID: mdl-32764410

ABSTRACT

Currently, there is a growing interest in screening and quantifying antioxidants from biological samples in the quest for natural and effective antioxidants to combat free radical-related pathological complications. Antioxidant assays play a crucial role in high-throughput and cost-effective assessment of antioxidant capacities of natural products such as medicinal plants and food samples. However, several investigators have expressed concerns about the reliability of existing in vitro assays. Such concerns arise mainly from the poor correlation between in vitro and in vivo results. In addition, in vitro assays have the problem of reproducibility. To date, antioxidant capacities are measured using a panel of assays whereby each assay has its own advantages and limitations. This unparalleled review hotly disputes on in vitro antioxidant assays and elaborates on the chemistry behind each assay with the aim to point out respective principles/concepts. The following critical questions are also addressed: (1) What make antioxidant assays coloured? (2) What is the reason for working at a particular wavelength? (3) What are the advantages and limitations of each assay? and (4) Why is a particular colour observed in antioxidant-oxidant chemical reactions? Furthermore, this review details the chemical mechanism of reactions that occur in each assay together with a colour ribbon to illustrate changes in colour. The review ends with a critical conclusion on existing assays and suggests constructive improvements on how to develop an adequate and universal antioxidant assay.

15.
Article in English | MEDLINE | ID: mdl-31490737

ABSTRACT

The monitoring of the contamination levels of bisphenol A (BPA) and its congeners bisphenol B (BPB) and bisphenol F (BPF) in foodstuffs is a necessary process for assessment of consumers' risk. After development and validation of a method using Strata® C18-E cartridge cleanup with detection by liquid chromatography coupled to tandem mass spectrometry, forty-six samples of fruit juices, sold on Italian markets, have been analysed to assess the concentration of BPA, BPB and BPF. BPB and BPF were not detected in any samples, BPA was found in 33 % of the samples. The observed levels ranged from 0.50 ng mL-1 to 2.85 ng mL-1. Potential Daily Intakes (PDI) of BPA for Italian populations were calculated by the budget method model. PDIs ranged from 0.012 to 0.285 µg kg-1 bw day-1. None of the calculated values exceeded the current temporary TDI of 4 µg kg-1 bw day-1.


Subject(s)
Benzhydryl Compounds/analysis , Food Contamination/analysis , Fruit and Vegetable Juices/analysis , Phenols/analysis , Chromatography, Liquid , Italy , Tandem Mass Spectrometry
16.
J Med Chem ; 50(7): 1458-64, 2007 Apr 05.
Article in English | MEDLINE | ID: mdl-17348636

ABSTRACT

A42 is a chimera peptide consisting of Galphas(374-394)C379A--the 21-mer C terminus of the Galphas protein, able of adenosine inhibitory activity--and penetratin--the 16 residue fragment, derived from the homeodomain of the Drosophila transcription factor Antennapedia. A42 is able to cross cell membranes and to inhibit A2A and A2B adenosine and beta-adrenergic receptor stimulated camps (D'Ursi et al. Mol. Pharmacol. 2006, 69, 727-36). Here we present an extensive biophysical study of A42 in different membrane mimetics, with the objective to evaluate the molecular mechanisms which promote the membrane permeation. Fluorescence, CD, and NMR data were acquired in the presence of negatively charged and zwitterionic sodium dodecyl sulfate and dodecylphosphocholine surfactants. To validate the spectroscopic results in a larger scale, fluorescence microscopy experiments were performed on negatively charged and zwitterionic dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine vesicles. Our results show that the internalization of A42 is mainly driven by electrostatic interactions, hydrophobic interactions playing only a secondary, sinergistic role. The distribution of the charges along the molecule has an important role, highlighting that internalization is a process which requires a specific matching of peptide and membrane properties.


Subject(s)
Carrier Proteins/chemistry , GTP-Binding Protein alpha Subunits, Gs/chemistry , Membranes, Artificial , Peptide Fragments/chemistry , Proteins/chemistry , Cell-Penetrating Peptides , Circular Dichroism , Fluorescence , Hydrophobic and Hydrophilic Interactions , Magnetic Resonance Spectroscopy , Micelles , Microscopy, Fluorescence , Models, Molecular , Peptides , Permeability , Phosphorylcholine/analogs & derivatives , Sodium Dodecyl Sulfate , Static Electricity , Surface-Active Agents
17.
Chemosphere ; 184: 467-472, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28622644

ABSTRACT

The study compared the profile of 14 polycyclic aromatic hydrocarbons, frequently occurred in food, in milk (N = 22) and meat/fish based (N = 18) baby foods available on the Italian market. PAH total levels, markers (Regulation EC/835/2011) and carcinogenic PAHs were determined by high- performance liquid chromatography with fluorescence detector (HPLC-FD). The average of total PAHs was 52.25 µg kg-1 in milk and 11.82 µg kg-1 in meat/fish based baby foods. The levels of PAH markers were higher than the permissible EU limits of 1 µg kg-1 in 18.2% and 77.7% milk, and 5.6% and 44.4% meat/fish based baby foods. Milk based samples showed significant higher values (P < 0.05) of carcinogenic and possible carcinogenic hydrocarbons than meat/fish based products. The Margins of Exposure (MOE) value of milk based baby food samples indicated a potential concern for consumer health. Monitoring programs, and good agriculture and manufacture practices should be recommended.


Subject(s)
Food Contamination/analysis , Infant Food/analysis , Meat/analysis , Milk/chemistry , Polycyclic Aromatic Hydrocarbons/analysis , Animals , Carcinogens/analysis , Chromatography, High Pressure Liquid/methods , Fishes , Humans , Infant , Infant, Newborn , Italy , Meat Products/analysis
18.
Food Chem Toxicol ; 83: 68-75, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26070504

ABSTRACT

Monitoring of food contamination from bisphenols is a necessary process for the consumers' risk assessment. A method for the quali-quantitative analysis of Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol A Diglycidyl Ether (BADGE), and Bisphenol F Diglycidyl Ether (BFDGE), by liquid chromatography with fluorescence detection (LC-FD), was performed and validated for their determination in 33 samples of tuna fish, canned in either oil or aqueous medium. Samples were collected in Italian markets. Tuna and the correspondent preservation medium were analyzed separately. Detected levels of bisphenols ranged from 19.1 to 187.0 ng/g in tuna matrix and from 6.3 to 66.9 ng/mL in oil medium. No bisphenols were found in aqueous medium. At least one of the analytes was found in 83% of the tuna samples in oil medium, whereas tuna samples in aqueous medium showed BPA alone in 67% of samples. 21% of the oil medium samples resulted positive for at least one bisphenol. On the basis of measured concentrations and general daily ingestion rate of canned tuna fish, the probable daily intake of BPA for Italian population was calculated.


Subject(s)
Benzhydryl Compounds/analysis , Endocrine Disruptors/analysis , Environmental Pollutants/analysis , Food Contamination , Food, Preserved/analysis , Phenols/analysis , Seafood/analysis , Tuna , Animals , Benzhydryl Compounds/toxicity , Chromatography, High Pressure Liquid , Dietary Fats, Unsaturated/analysis , Dietary Fats, Unsaturated/economics , Endocrine Disruptors/toxicity , Environmental Pollutants/toxicity , Epoxy Compounds/analysis , Epoxy Compounds/toxicity , Food Inspection/methods , Food, Preserved/economics , Humans , Italy , Limit of Detection , Phenols/toxicity , Plant Oils/chemistry , Plant Oils/economics , Reproducibility of Results , Seafood/economics , Spectrometry, Fluorescence , Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry
19.
Food Chem ; 178: 149-55, 2015 Jul 01.
Article in English | MEDLINE | ID: mdl-25704695

ABSTRACT

Since cereals are raw materials for production of beer and beer-based drinks, the occurrence mycotoxins in 154 beer samples was topic of investigation in this study. The analyses were conducted using QuEChERS extraction and gas chromatography-tandem mass spectrometry determination. The analytical method showed recoveries for vast majority of analytes ranged from 70% to 110%, relative standard deviations lower than 15% and limits of detection from 0.05 to 8 µg/L. A significant incidence of HT-2 toxin and deoxynivalenol (DON) were found in 9.1% and 59.7% of total samples, respectively. The exposure of European population to mycotoxins through beer consumption was assessed. No toxicological concern was associated to mycotoxins exposure for average beer consumers. Despite that, for heavy beer drinkers, the contribution of this commodity to the daily intake is not negligible, approaching or even exceeding the safety levels.


Subject(s)
Beer/analysis , Food Contamination/analysis , Mycotoxins/analysis , Gas Chromatography-Mass Spectrometry , Humans , Mycotoxins/administration & dosage , T-2 Toxin/analogs & derivatives , T-2 Toxin/analysis , Tandem Mass Spectrometry , Trichothecenes/analysis
20.
J Med Chem ; 45(4): 762-9, 2002 Feb 14.
Article in English | MEDLINE | ID: mdl-11831889

ABSTRACT

CCK-15, a peptide derived from the 115-membered CCK preprohormone, was the object of a comparative conformational analysis by NMR spectroscopy and molecular modeling methods. NMR data in several solvents demonstrate that the propensity of the peptide to fold into a helical conformation is intrinsic, not merely a consequence of the interaction with phosphatidylcholine micelles or with a putative receptor, as suggested by a previous study on CCK-8 (Pellegrini, M.; Mierke, D. Biochemistry 1999, 38, 14775-14783.). The prevailing CCK-15 conformer in a mixture 1,1,1,3,3,3-hexafluoroacetone/water reveals that the residues common to CCK-15 and CCK-8 assume very similar conformations. Our CCK-15 structure is consistent with the model of receptor interaction proposed by Pellegrini and Mierke and discloses possible novel interactions that involve a larger area of the putative receptor. The consensus structure between CCK-15 and CCK-8 shows a good superposition of the side chains of residues 12-14 with crucial moieties of two non-peptidic CCK-A antagonists.


Subject(s)
Acetone/analogs & derivatives , Cholecystokinin/chemistry , Peptide Fragments/chemistry , Receptors, Cholecystokinin/chemistry , Circular Dichroism , Dimethyl Sulfoxide , Fluorocarbons , Magnetic Resonance Spectroscopy , Micelles , Models, Molecular , Protein Structure, Secondary , Receptor, Cholecystokinin A , Solutions , Solvents , Water
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