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Crustaceans are particularly sensitive to copper toxicity, and although the downstream effects of increased copper exposure on the metabolome are often postulated and observed, they are rarely measured. To perform absolute quantification of hydrophilic small-molecule metabolites in the hemolymph of the crustacean Cancer borealis, we derivatized targeted metabolites related to copper toxicity using in-house-developed isotopic N,N-dimethyl leucine (iDiLeu) tags. Selected analytes were pooled at previously determined concentrations to serve as internal standards, and a calibration curve was generated. The sample loss was minimized by optimizing the derivatization-assisted sample cleanup using dispersive liquid–liquid microextraction (DLLME) and hydrophilic–lipophilic balancing (HLB). Calibration curves were then used for the absolute quantification of metabolites of interest following 30 min, 1 h, and 2 h exposures to 10 µM CuCl2. We found that glutamic acid was downregulated after 2 h of copper exposure, which may disrupt cellular metabolism and increase oxidative stress in crustaceans. These changes could have significant impacts on crustacean populations and the ecosystems they support. 

We establish that a complete, natural hormonal environment (hemolymph) increases the likelihood of a neuropeptide activating the gastric mill (chewing) rhythm in the crab stomatogastric ganglion (STG). The similar action of a higher neuropeptide concentration in saline, its comparable desensitizing effect to that of neuropeptide plus hemolymph on subsequent neuropeptide applications, and the absence of that neuropeptide in hemolymph suggest one or more distinct hormones act to enhance the effectiveness of the applied peptide. 

Synthetic biology aims to expand the genetic code by increasing cellular information storage and retrieval. A recent advance is the dTAT1-dNaM unnatural base pair, which is more photo- and thermostable than dTPT3-dNaM while maintaining high efficiency and fidelity in vitro and in vivo. However, the photophysics and cytotoxicity behavior of dTAT1 under UV light have not been investigated. We demonstrate that dTAT1 populates the triplet state upon 390 nm excitation but exhibits minimal cytotoxicity in cells. Analysis of reactive oxygen species indicates that dTAT1 produces a low singlet oxygen quantum yield of 17% while it generates superoxide, a less harmful reactive oxygen species. Its triplet lifetime is 2.7 times shorter than that of dTPT3, contributing to its lower photocytotoxicity. These findings highlight the potential of dTAT1 for safe genetic code expansion and therapeutic applications, providing valuable insights for designing next-generation unnatural nucleosides with minimal impact on cellular health. 

ABSTRACT Lipids, indispensable yet structurally intricate biomolecules, serve as critical regulators of cellular function and disease progression. Conventional lipidomics, constrained by limited resolution for isomeric and low‐abundance species, has been transformed by ion mobility‐mass spectrometry (IM‐MS). This technology augments analytical power through enhanced orthogonal separation, collision cross‐section (CCS)‐based identification, and improved sensitivity. This review examines the transformative advances in IM‐MS‐driven lipidomics, focusing on three major pillars: (1) a critical evaluation of leading ion mobility spectrometry (IMS) platforms, emphasizing innovative instrument geometries and breakthroughs in resolving lipid isomers; (2) an exploration of lipid CCS databases and predictive frameworks, spotlighting computational modeling and machine learning strategies that synergize experimental data with molecular representations for high‐confidence lipid annotation; (3) emerging multi‐dimensional lipidomics workflows integrating CCS with liquid chromatography‐MS/MS to boost identification and depth, alongside mass spectrometry imaging for spatially resolved lipidomics. By unifying cutting‐edge instrumentation, computational advances, and biological insights, this review outlines a roadmap for leveraging IM‐MS to unravel lipidome complexity, catalyzing biomarker discovery and precision medicine innovation.