Chimia

Journal: Chimia

Abbreviation

Chimia

Publisher

Swiss Chemical Society

ISSN

0009-4293
2673-2424

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Publications 1 - 10 of 709

Esterification Product Protection Strategies for Direct and Selective Methane Conversion
Blankenship, Andrea; Ravi, Manoj; van Bokhoven, Jeroen A. (2021)
Chimia
A scale-flexible process for the direct and selective oxidation of methane to primary oxygenates is of great interest, however, a commercially feasible approach has yet to be realized due to a number of challenges. Low product yields imposed by a well-established selectivity-conversion limit are particularly burdensome for direct methane-to-methanol chemistry. One strategy that has emerged to break out of this limit is the in situ esterification of produced methanol to the more oxidation-resistant methyl ester. However, these methaneto-methyl-ester approaches still elude commercialization despite their unprecedented high yields. Herein, we outline some of the key barriers that hinder the commercial prospects of this otherwise promising route for highyield direct catalytic methane conversion, including extremely corrosive reagents, homogeneous catalysts, and inviable oxidants. We then highlight directions to address these challenges while maintaining the characteristic high performance of these systems. These discussions support the efficacy of product protection strategies for the direct, selective oxidation of methane and encourage future work in developing creative solutions to merge this promising chemistry with more practical industrial requirements.
Three Bronze Medals for Switzerland at the 45th International Chemistry Olympiad in Moscow, Russia
Wicky, Basile; Keller, Sebastian F.; Meier, Lucia D.; et al. (2013)
Chimia
A team of four students from Swiss high schools, selected in a national competition and accompanied by their mentors, represented their country at the 45th International Chemistry Olympiad (IChO) held in July 2013 in Moscow, Russia. The exceptional performances of Patrik Willi, Boris Stolz and Mario De Capitani in both practical and theoretical chemistry were rewarded by three bronze medals at the international level, reflecting their efforts during the year-long preparation prior to the competition.
Non-Oxidative Coupling of Methane: Interplay of Catalyst Interface and Gas Phase Mechanisms
Zhang, Seraphine B.X.Y.; Copéret, Christophe (2023)
Chimia
Non-oxidative coupling of methane (NOCM) is a sought-after reaction that has been studied for de-cades. Harsh reaction conditions (T >800 degrees C) in the face of limited catalyst stability lead to rapid catalyst deactiva-tion and strong coking, preventing application thus far. Recent reports have shown the significance of an interplay of catalyst nature and reaction conditions, whereas metal carbides have prevailed to play a crucial role which involves incorporation of carbidic carbon in C2Hx and aromatic products. This perspective gives an overview of proposed mechanistic pathways and considerations about experiment conditions in order to foster a rational catalyst design platform for NOCM.
Steps toward experimental detection of molecular parity violation in CHFBrI
Albert, S.; Albert, Karen K.; Bauerecker, S.; et al. (2008)
Chimia
Inhibition of Extracellular Enzymes Exposed to Cyanopeptides
Egli, Christine M.; Naturni, Regiane S.; Jones, Martin R.; et al. (2020)
Chimia
Harmful cyanobacterial blooms in freshwater ecosystems produce bioactive secondary metabolites including cyanopeptides that pose ecological and human health risks. Only adverse effects of one class of cyanopeptides, microcystins, have been studied extensively and have consequently been included in water quality assessments. Inhibition is a commonly observed effect for enzymes exposed to cyanopeptides and has mostly been investigated for human biologically relevant model enzymes. Here, we investigated the inhibition of ubiquitous aquatic enzymes by cyanobacterial metabolites. Hydrolytic enzymes are utilized in the metabolism of aquatic organisms and extracellularly by heterotrophic bacteria to obtain assimilable substrates. The ubiquitous occurrence of hydrolytic enzymes leads to the co-occurrence with cyanopeptides especially during cyanobacterial blooms. Bacterial leucine aminopeptidase and alkaline phosphatase were exposed to cyanopeptide extracts of different cyanobacterial strains ( Microcystis aeruginosa wild type and microcystin-free mutant, Planktothrix rubescens) and purified cyanopeptides. We observed inhibition of aminopeptidase and phosphatase upon exposure, especially to the apolar fractions of the cyanobacterial extracts. Exposure to the dominant cyanopeptides in these extracts confirmed that purified microcystins, aerucyclamide A and cyanopeptolin A inhibit the aminopeptidase in the low mg L–1 range while the phosphatase was less affected. Inhibition of aquatic enzymes can reduce the turnover of nutrients and carbon substrates and may also impair metabolic functions of grazing organisms.
Chemigenetic Approaches for the Development of Fluorescent Biosensors for Biological Imaging
Dressler , Elias; Frei, Michelle (2025)
Chimia
Fluorescent biosensors are essential for probing analyte dynamics and enzyme activities with high spatial and temporal resolution in living cells by functional microscopy. Recently hybrid, or so called chemigenetic, biosensors have emerged, that integrate the strengths of synthetic fluorophores - such as spectral diversity, high brightness and photostability - with the specificity and sensitivity of genetically encoded sensing units. Beyond enhancing optical performance, synthetic chemistry can also expand the repertoire of sensing units themselves, creating opportunities for novel biosensor designs sensing previously inaccessible analytes. In this review, we summarize the protein-labeling strategies used in chemigenetic biosensor design with particular emphasis on self-labeling protein tags. We further discuss biosensor design principles, representative applications, and emerging advances that highlight the growing impact of chemigenetic biosensors in functional microscopy.
Bio-Based Approaches for Selective Cyclization
Moore, Eléonore; Fraley, Amy E. (2025)
Chimia
Cyclic natural products offer important, unique scaffolds and functionalities for the pharmaceutical industry. They are produced by enzymes catalyzing a wide range of cyclization reactions. This large family of enzymes creates distinctive cyclic structures via a variety of mechanisms naturally evolved for selectivity. In this review, we aim to present an overview of these natural catalysts, the therapeutic compounds for which they are involved in the production, as well as engineering efforts to tune them for anthropogenic needs in human medicine. Biochemical methodologies commonly used for the discovery and engineering of enzymes will also be highlighted, with an emphasis on enzymatic terpene cyclization and Pictet-Spengler-type cyclization.
On Paper Diagnostics: A Brief History and Future Perspectives
Khosla, Nathan K.; Demello, Andrew J.; Richards, Daniel A. (2025)
Chimia
For centuries, diagnostic technologies have played a key role in medicine. Effective diagnostics can help clinicians identify the presence and extent of disease in their patients, as well as their general health. Precipitated by advances in biochemistry, chemistry, and engineering, the 20th and 21st centuries have witnessed rapid advancement in diagnostic technologies. However, these improvements have brought increased complexity and a corresponding move towards more centralized and specialized laboratories. This has led to significant healthcare disparities between high- and low/middle-income regions. However, with the introduction of paper-based diagnostics this paradigm has begun to shift, with new assay formats designed for point-of-care (PoC) or athome use. By leveraging innovations from multiple fields, these paper-based tests can translate complex assay procedures into easy-to-use, single-step tests for the end user. In this review, we summarize the interdisciplinary beginnings of paper-based diagnostics, detailing their development through market introduction and commercial successes, and discuss the current state-of-the-art. Finally, we highlight areas for improvement and propose pathways that could enable increasingly complex chemistries to be performed on simple paper-based devices.
Chemical Tools for Monitoring and Targeting Collagen Cross-linking
Deen, Matthew C.; Boll, Linus B.; Wennemers, Helma (2024)
Chimia
The formation of collagen, the most abundant protein in mammals, is vital for the integrity of skin, tendons, and tissue in essentially any organ. Excessive collagen formation is, however, characteristic of fibrotic and malignant diseases, which include major global health issues. The diagnosis of abnormal collagen production and deposition is, therefore, critical for disease prognosis and helps guide treatment decisions. Here, we summarize our research on the development of tailored tools for monitoring and targeting excessive collagen crosslinking. We anticipate these tools will provide a deep understanding at the molecular level of collagen formation in normal and disease conditions with applications in imaging and disease treatment.
Nanoscale tungstates
Michailovsky, Alexej; Grunwaldt, Jan-Dierk; Baiker, Alfons; et al. (2006)
Chimia

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