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Molecules

Molecules is a leading international, peer-reviewed, open access journal of chemistry published semimonthly online by MDPI.
Indexed in PubMed | Quartile Ranking JCR - Q2 (Biochemistry and Molecular Biology | Chemistry, Multidisciplinary)

All Articles (62,553)

Magnetotactic bacteria (MTB) have attracted interest in recent years, mainly due to their natural ability to form intracellular magnetic nanocrystals with potential for biomedical and environmental applications. In this study, we focused on the morphological analysis of the Paramagnetospirillum magnetotacticum MS-1 strain, trying to keep the bacteria as close to their natural state as possible. An important element of this work is the use of untreated bacterial cells, without conductive coating or chemical fixation, using a simple and low-cost support. This choice was made intentionally to avoid changes induced by metallization and to allow direct observation of characteristics that may be relevant in applications where the interaction of the bacteria with the environment plays an important role, such as biosensors. In addition, the analysis was performed on a bacterial suspension stored for approximately 10 months at 4 °C to assess whether the morphology specific to the MS-1 strain is maintained over time. The obtained results show that the general cell morphology and magnetosome organization can be clearly and reproducibly observed even after long-term storage. Without attempting to replace studies based on conventional sample preparation methods, this work provides a complementary perspective and suggests that magnetotactic bacteria may represent a natural and effective alternative to synthetic magnetic nanoparticles, with potential applications in the biomedical and environmental fields.

12 January 2026

SEM (A) and STEM (B) imaging of an untreated copper-based TEM grid.

Nucleophilic ring-opening of bis(oxiranes), containing several reactive centers, can be used to elaborate straightforward atom-economy and stereoselective approaches to polyfunctionalized compounds. In the present work, ring-opening of cis- and trans-diastereomers of a spirocyclic bis(oxirane), containing a cyclooctane core (namely, 1,8-dioxadispiro[2.3.2.3]dodecane), upon treatment with various amines, was studied. Trans-isomer afforded aminoalcohols with 9-oxabicyclo[3.3.1]nonane moiety, formed via domino-process, including opening of an oxirane ring followed by intramolecular cyclization. Ring-opening of cis-isomer gave aminosubstituted cis-cyclooctane-1,5-diols, derived from independent reaction of two oxirane moieties. Activation of oxirane rings by the addition of LiClO4, acting as a Lewis acid, allowed the involvement of a number of primary and secondary aliphatic amines as well as aniline derivatives in the reaction. Scope and limitations of the reaction were studied and a series of aminoalcohols with a 9-oxabicyclo[3.3.1]nonane core and symmetric diaminodiols with a cyclooctane core were obtained.

12 January 2026

Examples of bioactive compounds containing aminoalcohol scaffolds.

Selenium-enriched yeast is considered the most bioavailable dietary form of this trace element. It is already authorised for use in food and feed, making it a key vehicle for closing nutritional Se gaps worldwide. Understanding how selenium accumulation reshapes the amino-acid balance of yeast biomass is crucial for diet-related health benefits and optimising biotechnological processes that rely on high-quality microbial protein. The effect of selenium on yeast amino-acid metabolism is an important area of research due to its potential applications in biotechnology and functional food production. In the presented work, changes in the amino acid profile and protein quality in Saccharomyces cerevisiae ATCC 7090 and Rhodotorula glutinis CCY 20-2-26 cells grown in the presence of different selenium concentrations (0–40 mg Se4+/L) for 24 and 48 h were analyzed. The amino acid content was assessed, and the Chemical Score (CS) and adjusted Essential Amino Acid Index (EAAI) were determined. The results showed that moderate selenium concentrations (2–10 mg Se4+/L after 24 h) promoted the accumulation of essential amino acids, such as lysine (53.3 mg/g) and valine (38.0 mg/g) in S. cerevisiae and lysine (42.8 mg/g) and valine (41.6 mg/g) in R. glutinis. High values of protein quality indices were also obtained under the same conditions—CS exceeding 200% and adjusted EAAI reaching 1.71 for S. cerevisiae and 2.05 for R. glutinis. It is worth noting, however, that EAAI was presented without methionine and tryptophan. In turn, higher selenium concentrations and longer cultivation time decreased these parameters, especially in the case of S. cerevisiae. The obtained data confirm that R. glutinis may be a promising source of high-quality protein in selenium-enriched products.

12 January 2026

Heatmap of Pearson correlations between amino acid concentrations in S. cerevisiae biomass and selenium content over time. Asterisks indicate statistically significant correlations (p-value < 0.05).

Synthetic cannabinoids (SCs) are a rapidly developing kind of novel psychoactive substance, frequently associated with acute intoxication and public health concerns. This study aimed to elucidate and compare the phase I metabolic pathways of two structurally related SCs, 5F-ADB-PINACA and 5F-ADBICA, using in vitro and in vivo models. Temporal metabolic profiling was performed to identify potential signature metabolites. Temporal abundance patterns and correlation cluster analysis of metabolites were analyzed to determine metabolite biomarkers. The two SCs were incubated with pooled human liver microsomes for 24 h and were also evaluated in vivo in zebrafish. Metabolite profiles were characterized using UHPLC-QE Orbitrap-MS. HLM analysis identified 21 5F-ADB-PINACA metabolites and 28 5F-ADBICA metabolites. Metabolites of 5F-ADBICA were detected for the first time in vitro and in a zebrafish model. Zebrafish studies confirmed the presence of all key metabolites observed in HLM. Comparative analysis of their metabolic pathways revealed differences in metabolism driven by structural differences between the indazole and indole cores. This is the first time that correlation analysis has been used in the temporal metabolic profiling of SCs. This study comprehensively characterized the metabolism of 5F-ADB-PINACA and 5F-ADBICA, identifying M13 (hydrolytic defluorination) as a potential metabolite biomarker for 5F-ADB-PINACA and M19 (hydrolytic defluorination) as a potential metabolite biomarker for 5F-ADBICA. The metabolic reactions of the main metabolites of the two synthetic cannabinoids are consistent. However, their metabolic processes (i.e., the overall metabolic pathways and temporal progression of these reactions) are different, which illustrates the metabolic similarity of structurally similar synthetic cannabinoids and the impact of different structures on the metabolic processes.

12 January 2026

The 21 metabolites and predicted metabolic ways of 5F-ADB-PINACA. (The metabolites highlighted in red were detected in zebrafish).

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Molecules - ISSN 1420-3049