Residue Determination in Honey

The use of antibiotics to fight bacterial and fungal honeybee diseases is documented since 1940s. Although at present in some countries certain antibiotics are authorized in apiculture, only few law systems provide maximum residue limits in honey. In addition, residues of worldwide banned antibiotics such as chloramphenicol, nitrofurans and nitroimidazoles have been frequently found. Therefore, the availability of reliable analytical methods able to detect concentrations at few parts per billions is fundamental. After a general overview of the available sample treatment strategies and analytical techniques, the most significantly published methods are discussed. Aminoglycosides and, to a lesser extent, tetracyclines are the more difficult classes to analyse. The current trends are the development of multiclass procedures and of micro-extraction techniques to improve the cost-effectiveness of residues control in the globalization era

Pharmacokinetics of cannabidiol following single oral and oral transmucosal administration in dogs

IntroductionIn the last few years, different formulations containing cannabidiol (CBD) were tested with regard to its efficacy on chronic pain, refractory epilepsy, anxiety, aggressive behavior and atopic dermatitis in dogs. CBD is generally administered orally, but its low bioavailability, probably due to a first-pass metabolism, represents a great limitation. The aim of this study was to evaluate if CBD bioavailability increases after oral transmucosal administration (OTM) compared to oral treatment.MethodsTwelve dogs diagnosed with mild chronic pain were enrolled in the study and treated once orally or OTM (6 dogs/group) with a pure CBD in oil formulation at a dosing rate of 1 mg/kg b.w. At prefixed time points, blood samples were collected to define CBD plasma concentrations vs. time profiles, and the main pharmacokinetics parameters were obtained by non-compartmental model.ResultsCBD Cmax, Tmax, terminal half-life and AUC0 − t were 206.77 ± 167 and 200.33 ± 158.33 ng/mL, 2.17 ± 0.98 and 1.92 ± 1.11 h, 2.67 ± 0.53 and 2.62 ± 0.64 h, 647.51 ± 453.17, and 536.05 ± 370.21 h*ng/mL, following oral and OTM administration, respectively. No significant difference in pharmacokinetic parameters were observed between treatments.DiscussionThe OTM administration did not increase cannabidiol bioavailability compared to oral treatment. The almost perfectly superimposable mean plasma concentrations of cannabidiol following the two treatments suggests that CBD is not able to be adsorbed by the oral mucosa or that its absorption is very scarce, and that CBD is swallowed and absorbed in the gastrointestinal tract

Distribution of Transferable Antibiotic Resistance Genes in Laboratory-Reared Edible Mealworms (Tenebrio molitor L.)

In the present study, the distribution of antibiotic resistance genes in laboratory-reared fresh mealworm larvae (Tenebrio molitor L.), their feeding substrates (carrots and wheatmeal), and frass was assessed. Microbial counts on selective media added with antibiotics highlighted the presence of lactic acid bacteria resistant to ampicillin and vancomycin and, more specifically, enterococci resistant to the latter antibiotic. Moreover, staphylococci resistant to gentamicin, erythromycin, tetracycline, and vancomycin were detected. Enterobacteriaceae resistant to ampicillin and gentamicin were also found, together with Pseudomonadaceae resistant to gentamicin. Some of the genes coding for resistance to macrolide-lincosamide-streptogramin B (MLSB) [erm(A), erm(C)], vancomycin [vanA, vanB], tetracycline [tet(O)], and β-lactams [mecA and blaZ] were absent in all of the samples. For the feeding substrates, organic wheatmeal was positive for tet(S) and tet(K), whereas no AR genes were detected in organic carrots. The genes tet(M), tet(K), and tet(S) were detected in both mealworms and frass, whereas gene aac-aph, coding for resistance to amynoglicosides was exclusively detected in frass. No residues for any of the 64 antibiotics belonging to 10 different drug classes were found in either the organic wheatmeal or carrots. Based on the overall results, the contribution of feed to the occurrence of antibiotic resistance (AR) genes and/or antibiotic-resistant microorganisms in mealworm larvae was hypothesized together with vertical transmission via insect egg smearing

3-hydroxy-L-kynurenamine is an immunomodulatory biogenic amine

Tryptophan catabolism is a major metabolic pathway utilized by several professional and non-professional antigen presenting cells to maintain immunological tolerance. Here we report that 3-hydroxy-l-kynurenamine (3-HKA) is a biogenic amine produced via an alternative pathway of tryptophan metabolism. In vitro, 3-HKA has an anti-inflammatory profile by inhibiting the IFN-gamma mediated STAT1/NF-kappa Beta pathway in both mouse and human dendritic cells (DCs) with a consequent decrease in the release of pro-inflammatory chemokines and cytokines, most notably TNF, IL-6, and IL12p70. 3-HKA has protective effects in an experimental mouse model of psoriasis by decreasing skin thickness, erythema, scaling and fissuring, reducing TNF, IL-1 beta, IFN-gamma, and IL-17 production, and inhibiting generation of effector CD8(+) T cells. Similarly, in a mouse model of nephrotoxic nephritis, besides reducing inflammatory cytokines, 3-HKA improves proteinuria and serum urea nitrogen, overall ameliorating immune-mediated glomerulonephritis and renal dysfunction. Overall, we propose that this biogenic amine is a crucial component of tryptophan-mediated immune tolerance. 3-hydroxy-L-kynurenamine (3-HKA) is a metabolite deriving from a lateral pathway of tryptophan catabolism. Here the authors identify 3-HKA as a biogenic amine and show it has anti-inflammatory properties that can protect mice against psoriasis and nephrotoxic nephritis.Peer reviewe

Stereoselective synthesis of 3-(ethoxycarbonyl)-4-hydroxy-5-(1-hydroxyalkyl)-2-isoxazoline 2-oxides by reaction of 2,3-epoxy aldehydes and ethyl nitroacetate on alumina surface

Treatment of racemic 2,3-epoxy aldehydes and ethyl nitroacetate with alumina affords title compounds through a nitroaldol reaction—cyclization process. While in the case of 3-trans-monosubstituted substrates, C4,C5-trans and cis isomers (dr = 1.5) with C5,C6-anti configuration are obtained, 3-cis-monosubstituted 2,3-epoxy aldehydes give C4,C5-trans and cis derivatives with a much higher diastereoselectivity (dr > 20) and C5,C6-syn configuration. 5-Exo cyclization occurs also when 2,3-epoxy aldehydes are 2-substituted

Single‐Step Synthesis of Dehydroalanine Derivatives via a Brønsted Acid‐Catalyzed Multicomponent Reaction

A single-step practical synthesis of dehydroalanine (Dha) derivatives from commercially available starting materials is reported. The approach comprises a Brønsted acid-catalyzed three-component condensation reaction of pyruvic acid, an alcohol/thiol, and an amide/carbamate. This protocol provided access to several Dha derivatives, including a novel chiral version modified with diverse functional groups, which might be useful for further transformations in the construction of more complex molecules

Determination of Perfluorinated and Polyfluorinated Alkyl Substances (PFASs) in PM₁₀ Samples: Analytical Method, Seasonal Trends, and Implications for Urban Air Quality in the City of Terni (Central Italy)

A quantitative analytical method for PFAS determination in airborne particulate matter (PM) has been developed using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS), allowing for the determination of 33 compounds. The procedure was applied to ambient PM10 with limits of quantification for PFAS in the fg m−3 range. PM10 samples collected during a year-long campaign conducted in an urban site in Umbria (Central Italy) have been characterized for their PFAS content. Among the seven detected PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the most abundant compounds. Furthermore, this work allowed us to obtain the first seasonal trend of airborne PFASs in Central Italy. Seasonal trend analysis shows that PFAS concentration in the atmosphere peaks in summertime. A comparison with trends of other relevant primary and secondary air pollutants determined at the sampling site suggests a secondary nature of the observed PFAS, which are formed in the atmosphere directly from gaseous precursors and can contribute to worsen the urban air quality in summertime

Dietary Administration of Olive Mill Wastewater Extract Reduces Campylobacter spp. Prevalence in Broiler Chickens

Food wastes are sources of compounds that can be used as natural additives in the food and feed industry. The olive oil industry produces two main wastes: aqueous waste (olive mill wastewater) and solid waste (pomace or olive cake). These by-products are rich in phenols, which are antioxidant and antimicrobial compounds able to inhibit or delay the growth of several bacteria in vitro. The dietary effect of both olive mill wastewater polyphenolic extract (OMWPE) and dehydrated olive cake (DOC) on the prevalence of Campylobacter spp. in broiler chickens was investigated. A commercial basal diet was supplemented with either OMWPE- or DOC-enriched maize at two dosages (low: 16%; high: 33%). The prevalence of Campylobacter spp. shedding was evaluated at 21, 35, and 49 days of age. The prevalence of Campylobacter spp. differed among groups only at 49 days of age. Both OMWPE groups showed a lower (p < 0.05) prevalence compared to the control group. The odds ratio evaluation showed that the higher dose of OMWPE reduced the possibility of shedding 11-fold compared to the control group (p < 0.001). These results highlight the potential use of olive by-products against Campylobacter spp. in poultry

Optimized one-pot derivatization and enantioseparation of cysteine: Application to the study of a dietary supplement

Cysteine is a sulfur-containing amino acid which plays an outstanding role in many biological pathways in mammals. The analysis and quantification of native cysteine remains a critical issue due to its highly reactive thiol group evolving to the disulfide cystine derivative through oxidation reaction. Aimed at improving the derivative stability, cysteine was labelled with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), which reacts with both amino and thiol groups. The derivatization was optimized and the chemical identity of the reaction product was assessed via high-resolution mass spectrometry. The NBD-cysteine derivative resulted stable for 10 days. This derivative was enantioresolved (α and RS equal to 1.25 and 2.70, respectively) thanks to a (R,R)-Whelk-O1 phase with the following chromatographic setting: eluent, MeOH/water-90/10 (v/v) with 15 mM ammonium formate ( 6.0); column temperature, 35 °C; flow rate, 1.0 mL/min. The developed method was validated following the ICH guidelines and applied for the quality control of a L-cysteine containing dietary supplement

Determination of macrocyclic lactones in food and feed

<div><p>A confirmatory high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) was developed and validated for the simultaneous determination of the following anti-parasitic veterinary drugs in foodstuffs (liver, muscle and milk) and feed: abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin. Samples were extracted, purified and analysed by HPLC-FLD after prior derivatisation of analytes with <i>N</i>-methylimidazole, trifluoracetic anhydride and acetic acid to produce stable fluorescent derivatives. Recoveries were in the range of 73–98% (liver), 82–93% (muscle), 77–84% (milk), and 93–110% (feed). In all matrices the coefficients of variation for repeatability and intra-laboratory reproducibility were satisfactory. For emamectin in liver the worst method performance was observed. As this multi-analyte method fully met the required criteria and applicability both to food and feed, it has been successfully applied in National Control Plans in food and feed.</p></div