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Recently, as the interest in cannabidiol (CBD) has grown due to its therapeutic potential, e-cigarette liquids containing CBD have proliferated on the market. Typically, e-liquids contain variable concentrations of CBD (from 2 mg∙mL−1 to 20 mg∙mL−1) in propylene glycol or 70:30 propylene glycol:glycerol mixture and are eventually flavored with food-grade flavors. In this work, carried out by a GC-MS analysis of the condensed smoke produced by a real e-cig, we have demonstrated the actual amount of CBD that can survive the smoking process, and we found that negligible amounts of THCs are formed during the smoking process (i.e., the amount formed was 9-THC is around 2.5 mg (smoked or ingested per os), it is reasonable to conclude that accidental THC intoxication is unlikely, which is a very important issue from a forensic point of view, as in some court cases the use of e-cig liquids containing CBD has been argued as being the source of THC intoxication. Furthermore, all the other cannabinoids considered in this study and potentially derived from CBD thermal degradation have concentrations below the instrumental LOD.

The oxidation of alcohols to the corresponding carbonyl derivatives has been realized under photoelectrochemical conditions in the presence of tetrabutylammonium decatungstate (TBADT) as the homogeneous photocatalyst. The protocol can be applied to both primary and secondary, benzylic and aliphatic alcohols. The desired products are obtained selectively, skipping the need for purposely added chemical oxidants. An in‐depth study of photoelectrochemical conditions revealed that the protocol works best under amperostatic conditions in an undivided electrochemical cell irradiated with a 390 nm LED lamp. The comparison with analogous electrochemical and chemical oxidant‐promoted photocatalytic transformations demonstrates the superior efficiency and selectivity of the hereby reported photoelectrochemical conditions. [ABSTRACT FROM AUTHOR]

In the present work, we describe the electrochemical behaviour of two opioids structurally related to aroyl amides of forensic interest, namely U-47700 and AH-7921. The data obtained allowed for the mise-au-point of a voltammetric determination protocol, that relies on differential pulse voltammetry (DPV) at a glassy carbon electrode in ethanol/0.1 M lithium perchlorate/0.10 M 2,6-lutidine. To apply the method to the analysis of real samples (urines), a clean-up and a preconcentration strategy by solid phase extraction (SPE) using the adsorbent Florisil have been developed. LOQ of 0.2 μg·mL−1 in urine samples with an enrichment factor of 20 and linear range from 5 to 150 μg·mL−1 were obtained.

Identifying the composition and the physical characteristics of the bullet that generated a specific hole in the victim's clothes or skin may be crucial in shooting incident reconstructions. In forensics, chemographic tests are routinely conducted to visualize lead, copper, or nitrite deposits around entrance holes with the aim of confirming a projectile impact or estimating the shooting distance. A quantitative chemical analysis of the particles collected from the periphery of an entrance hole is required for identifying the type of passing bullet. In real cases, such analysis would be affected by the possible cross-contributions of both inorganic residue from the discharged ammunition primer and metallic fragments from previous rounds projected from the gun barrel. The actual contribution of the sole bullet to the composition of the inorganic residue deposited on target is then hardly distinguishable. In the present study, the deposits left by three different copper/zinc jacketed bullets on targets were analysed by inductively coupled plasma optical emission spectrometry and by X-ray fluorescence spectrometry. To reduce any possible source of contamination, a heavy metal free primer mixture and a brand new pistol were used. Elements of interest were quantified varying the shooting distances with the aim of identifying different bullet contributions to the inorganic residue on targets.

Four melanin polymers prepared from different precursors (5,6‐dihydroxyindole, 5,6‐dihydroxyindole 2‐carboxylic acid, 1,8‐dihydroxynaphthalene and dopamine) have been adopted as photocatalysts in the reductive dehalogenation of a series of model α‐halogen carbonyl derivatives. The best performing melanin was that obtained from 5,6‐dihydroxyindole 2‐carboxylic acid, which allowed to dehalogenate efficiently both bromomalonate esters and phenacyl bromide; on the other hand, chloromalonate esters were almost unreactive under the same reaction conditions. Electrochemical and control experiments enabled to elucidate the reaction mechanism, demonstrating the key role of electrons as charge carriers in the observed photocatalytic process. [ABSTRACT FROM AUTHOR]

Neuromelanin (NM) accumulates in catecholamine long-lived brain neurons that are lost in neurodegenerative diseases. NM is a complex substance made of melanic, peptide and lipid components. NM formation is a natural protective process since toxic endogenous metabolites are removed during its formation and as it binds excess metals and xenobiotics. However, disturbances of NM synthesis and function could be toxic. Here, we review recent knowledge on NM formation, toxic mechanisms involving NM, go over NM binding substances and suggest experimental models that can help identifying xenobiotic modulators of NM formation or function. Given the high likelihood of a central NM role in age-related human neurodegenerative diseases such as Parkinson’s and Alzheimer’s, resembling such diseases using animal models that do not form NM to a high degree, e.g., mice or rats, may not be optimal. Rather, use of animal models (i.e., sheep and goats) that better resemble human brain aging in terms of NM formation, as well as using human NM forming stem cellbased in vitro (e.g., mid-brain organoids) models can be more suitable. Toxicants could also be identified during chemical synthesis of NM in the test tube.

Neuromelanins are compounds accumulating in neurons of human and animal brain during aging, with neurons of substantia nigra and locus coeruleus having the highest levels of neuromelanins. These compounds have melanic, lipid, peptide, and inorganic components and are contained inside special autolysosomes. Neuromelanins can participate in neuroprotective or toxic processes occurring in Parkinson's disease according to cellular environment. Their synthesis depends on the concentration of cytosolic catechols and is a protective process since it prevents the toxic accumulation of catechols‐derived reactive compounds. Neuromelanins can be neuroprotective also by binding reactive/toxic metals to produce stable and non‐toxic complexes. Extraneuronal neuromelanin released by dying dopamine neurons in Parkinson's disease activates microglia which generate reactive oxygen species, reactive nitrogen species, and proinflammatory molecules, thus producing still neuroinflammation and neuronal death. Synthetic neuromelanins have been prepared with melanic, protein structure, and metal content closely mimicking the natural brain pigment, and these models are also able to activate microglia. Neuromelanins have different structure, synthesis, cellular/subcellular distribution, and role than melanins of hair, skin, and other tissues. The main common aspect between brain neuromelanin and peripheral melanin is the presence of eumelanin and/or pheomelanin moieties in their structure. [ABSTRACT FROM AUTHOR]

Water‐soluble melanin‐protein‐Fe/Cu conjugates derived from norepinephrine and fibrillar β‐lactoglobulin are reliable models for neuromelanin (NM) of human brain locus coeruleus. Both iron and copper promote catecholamine oxidation and exhibit strong tendency to remain coupled in oligonuclear aggregates. The Fe‐Cu clusters are EPR silent and affect the 1H NMR spectra of the conjugates through a specific sequence of signals. Derivatives containing only Fe or Cu exhibit different NMR patterns. The EPR spectra show weak signals of paramagnetic FeIII in conjugates containing Fe or mixed Fe‐Cu sites due to small amounts of mononuclear centers. The latter derivatives exhibit EPR signals for isolated CuII centers. These features parallel the EPR behavior of NM from locus coeruleus. The spectral data indicate that FeIII is bound to the melanic fraction, whereas CuII is bound on the protein fibrils, suggesting that the Fe‐Cu clusters occur at the interface between the two components of the synthetic NMs. [ABSTRACT FROM AUTHOR]

Dopamine (DA) is the most important catecholamine in the brain, as it is the most abundant and the precursor of other neurotransmitters. Degeneration of nigrostriatal neurons of substantia nigra pars compacta in Parkinson's disease represents the best-studied link between DA neurotransmission and neuropathology. Catecholamines are reactive molecules that are handled through complex control and transport systems. Under normal conditions, small amounts of cytosolic DA are converted to neuromelanin in a stepwise process involving melanization of peptides and proteins. However, excessive cytosolic or extraneuronal DA can give rise to nonselective protein modifications. These reactions involve DA oxidation to quinone species and depend on the presence of redox-active transition metal ions such as iron and copper. Other oxidized DA metabolites likely participate in post-translational protein modification. Thus, protein-quinone modification is a heterogeneous process involving multiple DA-derived residues that produce structural and conformational changes of proteins and can lead to aggregation and inactivation of the modified proteins., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can activate microglia with consequent neurodegeneration, typical of Parkinson's disease (PD). Synthetic analogues of NM were prepared to develop a PD model reproducing the neuropathological conditions of the disease. Soluble melanin-protein conjugates were obtained by melanization of fibrillated β-lactoglobulin (fLG). The melanic portion of the conjugates contains either eumelanic (EufLG) or mixed eumelanic/pheomelanic composition (PheofLG), the latter better simulating natural NMs. In addition, the conjugates can be loaded with controlled amounts of iron. Upon melanization, PheofLG-Fe conjugates maintain the amyloid cross-β protein core as the only structurally organized element, similarly to human NMs. The similarity in composition and structural organization with the natural pigment is reflected by the ability of synthetic NMs to activate microglia, showing potential of the novel conjugates to model NM induced neuroinflammation. Thus, synthetic NM/microglia constitute a new model to develop anti-Parkinson drugs.