Chemistry Commons^™

Postharvest Application Of Thiol Compounds Affects Surface Browning And Antioxidant Activity Of Fresh-Cut Potatoes, İnci Cerit, Annalise Pfaff, Nuran Ercal, Omca Demirkol

Chemistry Faculty Research & Creative Works

The aim of this study was to compare the effects of sodium metabisulphite and the thiol compounds, glutathione (GSH), L-cysteine (CYS), and N-acetylcysteine (NAC), on the enzymatic browning, antioxidant activities, total phenolic, and ascorbic acid content of potatoes after 1, 24, and 48 hr. Three different concentrations (0.5%, 1.0%, and 2.0%) of each thiol compound were tested. While sulphite solution inhibited polyphenol oxidase as expected, NAC and CYS also decreased its activity. CYS-treated samples exhibited the highest residual thiol content, while the amount of residual thiol in GSH-treated samples was the lowest. The 2.0% NAC and 2.0% CYS solutions were …

Computational And Pharmacological Evaluation Of Carveol For Antidiabetic Potential, Muhammad Shabir Ahmed, Arif Ullah Khan, Lina Tariq Al Kury, Fawad Ali Shah

All Works

© Copyright © 2020 Ahmed, Khan, Kury and Shah. Background: Carveol is a natural drug product present in the essential oils of orange peel, dill, and caraway seeds. The seed oil of Carum Carvi has been reported to be antioxidant, anti-inflammatory, anti-hyperlipidemic, antidiabetic, and hepatoprotective. Methods: The antidiabetic potential of carveol was investigated by employing in-vitro, in-vivo, and in-silico approaches. Moreover, alpha-amylase inhibitory assay and an alloxan-induced diabetes model were used for in-vitro and in-vivo analysis, respectively. Results: Carveol showed its maximum energy values (≥ -7 Kcal/mol) against sodium-glucose co-transporter, aldose reductase, and sucrose-isomaltase intestinal, whereas it exhibited intermediate energy …

In Silico Investigation Of First-Pass Effect On Selected Small Molecule Excipients And Structural Dynamics Of P-Glycoprotein, Toluwase Hezekiah Fatoki, Omodele Ibraheem, Oladoja A. Awofisayo, Abiodun Samuel Oyedele, Olapade Samuel Akinlolu

Chemistry Student Research

In this study, the interaction of selected pharmaceutical excipients on the function of P-glycoprotein (P-gp) and activity of 6 cytochrome P450 (CYP) isoforms were computationally investigated. At binding free energy cut-off value of −5.0 kcal/mol, the result showed possible modulatory or inhibitory effect by cethyl alcohol on CPY3A4 and P-gp; cetyltrimethyl-ammonium bromide (CTAB) on CYP1A2 and P-gp; dibutyl sebacate on CYP2C9, CYP2E1, and P-gp; sodium caprylate on CYP1A2 and CYP3A4; while most of the tested excipients have good interaction with the cytochromes and P-gp. The predicted pharmacokinetics provided possible inhibitors of the CYPs and P-gp and suggested that aspartame and …

Carborane‐Containing Matrix Metalloprotease (Mmp) Ligands As Candidates For Boron Neutron‐Capture Therapy (Bnct), Marlon R. Lutz Jr, Sebastian Flieger, Andre Colorina, John Wozny, Narayan S. Hosmane, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

Based on the previously reported potent and selective sulfone hydroxamate inhibitors SC‐76276, SC‐78080 (SD‐2590), and SC‐77964, potent MMP inhibitors have been designed and synthesized to append a boron‐rich carborane cluster by employing click chemistry to target tumor cells that are known to upregulate gelatinases. Docking against MMP‐2 suggests binding involving the hydroxamate zinc‐binding group, key H‐bonds by the sulfone moiety with the peptide backbone residues Leu82 and Leu83, and a hydrophobic interaction with the deep P1’ pocket. The more potent of the two triazole regioisomers exhibits an IC50 of 3.7 nM versus MMP‐2 and IC50 of 46 nM versus MMP‐9.

Tactviz: A Vmd Plugin For Tactile Visualization Of Protein Structures, Olivia R. Shaw, Jodi A. Hadden-Perilla

Journal of Science Education for Students with Disabilities

Scientific disciplines spanning biology, biochemistry, and biophysics involve the study of proteins and their functions. Visualization of protein structures represents a barrier to education and research in these disciplines for students who are blind or visually impaired. Here, we present a software plugin for readily producing variable-height tactile graphics of proteins using the free biomolecular visualization software Visual Molecular Dynamics (VMD) and protein structure data that is publicly available through the Protein Data Bank. Our method also supports interactive tactile visualization of proteins with VMD on electronic refreshable tactile display devices. Employing our method in an academic laboratory has enabled …

Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo

Journal of Science Education for Students with Disabilities

This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.

The Nitrogen Budget Of Laboratory-Simulated Western Us Wildfires During The Firex 2016 Fire Lab Study, James M. Roberts, Chelsea E. Stockwell, Robert J. Yokelson, Joost De Gouw, Yong Liu, Vanessa Selimovic, Abigail R. Koss, Kanako Sekimoto, Matthew M. Coggon, Bin Yuan, Kyle J. Zarzana, Steven S. Brown, Cristina Santin, Stefan H. Doerr, Carsten Warneke

Chemistry and Biochemistry Faculty Publications

Reactive nitrogen (Nr, defined as all nitrogencontaining compounds except for N2 and N2O) is one of the most important classes of compounds emitted from wildfire, as Nr impacts both atmospheric oxidation processes and particle formation chemistry. In addition, several Nr compounds can contribute to health impacts from wildfires. Understanding the impacts of wildfire on the atmosphere requires a thorough description of Nr emissions. Total reactive nitrogen was measured by catalytic conversion to NO and detection by NO-O3 chemiluminescence together with individual Nr species during a series of laboratory fires of fuels characteristic of western US wildfires, conducted as part of …

The Development Of A New Entry Point Into Enantiomerically Enriched Sulfinyl Derivatives, Jessica Shaw

Theses and Dissertations

Optical probes may be used as reliable tools for detecting and imagining the inside of cells for medical diagnostics. Among available options, the use of thiol probes is of interest as thiols are present in nearly all cells and their levels are tightly regulated, thus any variation is associated with disease. A proper thiol bioimaging probe must have a thiol cleavage group/reactive group and a fluorophore. It is found that novel sulfinate aryl ester (phenoxysulfinate esters) probes selectively cleave thiols at physiological pH and show much promise as effective tools for bioimaging.

In this context, the synthesis of the related …

Analysis Of Temperature-Dependent H/D Exchange Mass Spectrometry Experiments., Nastaran N Tajoddin, Lars Konermann

Chemistry Publications

H/D exchange (HDX) mass spectrometry (MS) is a widely used technique for interrogating protein structure and dynamics. Backbone HDX is mediated by opening/closing (unfolding/refolding) fluctuations. In traditional HDX-MS, proteins are incubated in D₂O as a function of time at constant temperature (T). There is an urgent need to complement this traditional approach with experiments that probe proteins in a T-dependent fashion, e.g., for assessing the stability of therapeutic antibodies. A key problem with such studies is the absence of strategies for interpreting HDX-MS data in the context of T-dependent protein dynamics. Specifically, it has …

Phosphonium Versus Ammonium Compact Polyelectrolyte Complex Networks With Alginate-Comparing Their Properties And Cargo Encapsulation., Tristan D. Harrison, Alexandre J. Salmon, John R. De Bruyn, Paul J. Ragogna, Elizabeth R. Gillies

Chemistry Publications

Phosphonium and ammonium polymers can be combined with polyanions to form polyelectrolyte complex (PEC) networks, with potential application in self-healing materials and drug delivery vehicles. While various structures and compositions have been explored, to the best of our knowledge, analogous ammonium and phosphonium networks have not been directly compared to evaluate the effects of phosphorus versus nitrogen cations on the network properties. In this study, we prepared PECs from sodium alginate and poly[triethyl(4-vinylbenzyl)phosphonium chloride], poly[triethyl(4-vinylbenzyl)ammonium chloride], poly[tri(

1,1,2,2,2,3,3,3-Octa­Carbonyl-1,1,2,3-Tetra­Kis­(1,3,5-Tri­Aza-7-Phosphatri­Cyclo­[3.3.1.13,7]Decane-Κp)-Triangulo-Triosmium(0), David M. Marolf, Kristen L. Brehm, Vincent M. Lynch, Gregory Powell

Chemistry and Biochemistry

The title compound, [Os3(C6H12N3P)4(CO)8], crystallizes in the orthorhombic space group Pbca with Z = 8. The molecule consists of a triangular triosmium(0) core surrounded by eight carbonyl ligands and four 1,3,5-triaza-7-phosphatri- cyclo[3.3.1.13,7]decane (or PTA) ligands. One Os atom is coordinated by two PTA ligands and two CO ligands, while the other two Os atoms are each bonded to a single PTA ligand and three CO ligands. There is a small disorder associated with the Os3 unit so that a minor orientation has an occupancy of 2.17 (4)%. The title compound represents the first structurally characterized triangular Os3 carbonyl cluster with …

Light-Addressable Electrochemical Sensing With Electrodeposited N-Silicon/Gold Nanoparticle Schottky Junctions, Irina M. Terrero Rodríguez, Alexandra J. Borrill, Katherine J. Schaffer, Jocelyn B. Hernandez, Glen D. O'Neil

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Light-addressable electrochemical sensors (LAESs) are a class of sensors that use light to activate an electrochemical reaction on the surface of a semiconducting photoelectrode. Here, we investigate semiconductor/metal (Schottky) junctions formed between n-type Si and Au nanoparticles as light-addressable electrochemical sensors. To demonstrate this concept, we prepared n-Si/Au nanoparticle Schottky junctions by electrodeposition and characterized them using scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. We found that the sensors behaved almost identically to Au disk electrodes for the oxidation of an outer-sphere redox couple (ferrocene methanol) and two inner-sphere redox couples (potassium ferrocyanide and dopamine). In buffered dopamine …

Plasma And Serum Proteins Bound To Nanoceria: Insights Into Pathways By Which Nanoceria May Exert Its Beneficial And Deleterious Effects In Vivo, D. Allan Butterfield, Binghui Wang, Peng Wu, Sarita S. Hardas, Jason M. Unrine, Eric A. Grulke, Jian Cai, Jon B. Klein, William M. Pierce, Robert A. Yokel, Rukhsana Sultana

Chemistry Faculty Publications

Nanoceria (CeO2, cerium oxide nanoparticles) is proposed as a therapeutic for multiple disorders. In blood, nanoceria becomes protein-coated, changing its surface properties to yield a different presentation to cells. There is little information on the interaction of nanoceria with blood proteins. The current study is the first to report the proteomics identification of plasma and serum proteins adsorbed to nanoceria. The results identify a number of plasma and serum proteins interacting with nanoceria, proteins whose normal activities regulate numerous cell functions: antioxidant/detoxification, energy regulation, lipoproteins, signaling, complement, immune function, coagulation, iron homeostasis, proteolysis, inflammation, protein folding, protease inhibition, adhesion, protein/RNA …

Detection Of The Thietane Precursor In The Uva Formation Of The Dna 6-4 Photoadduct, Luis A. Ortiz-Rodríguez, Christian Reichardt, Sean J. Hoehn, Carlos E. Crespo-Hernández

Faculty Scholarship

Notwithstanding the central biological role of the (6-4) photoadduct in the induction of skin cancer by sunlight, crucial mechanistic details about its formation have evaded characterization despite efforts spanning more than half a century. 4-Thiothymidine (4tT) has been widely used as an important model system to study its mechanism of formation, but the excited-state precursor, the intermediate species, and the time scale leading to the formation of the (6-4) photoadduct have remained elusive. Herein, steady-state and time-resolved spectroscopic techniques are combined with new and reported quantum-chemical calculations to demonstrate the excited state leading to the formation of the thietane intermediate, …

Comparison Of Accelerated Solvent Extraction (Ase) And Energized Dispersive Guided Extraction (Edge) For The Analysis Of Pesticides In Leaves, Ashlie D. Kinross, Kimberly J. Hageman, William J. Doucette, Alexandria L. Foster

Chemistry and Biochemistry Faculty Publications

Various techniques have been evaluated for the extraction and cleanup of pesticides from environmental samples. In this work, a Selective Pressurized Liquid Extraction (SPLE) method for pesticides was developed using a Thermo Fisher Scientific Accelerated Solvent Extraction (ASE) system. This instrument was compared to the newly introduced (2017) extraction instrument, the Energized Dispersive Guided Extraction (EDGE) system, which combines Pressurized Liquid Extraction (PLE) and dispersive Solid Phase Extraction (dSPE). We first optimized the SPLE method using the ASE instrument for pesticide extraction from alfalfa leaves using layers of Florisil and graphitized carbon black (GCB) downstream of the leaf homogenate in …

A Chemical Investigation Of Three Antarctic Tunicates Of The Genus Synoicum, Sofia Kokkaliari

USF Tampa Graduate Theses and Dissertations

Marine invertebrates, mainly sponges, tunicates and corals, have in the past few decades attracted the interest of the scientific community in regard to their secondary metabolites and their potential as leads in drug discovery. The genus Synoicum is comprised of multiple organisms found in both deep and shallow waters, tropical and cold environments around the world. The majority of the members of this genus that have been investigated can be found in shallow tropical waters due to the ease of accessing and collecting them. Of the cold environments, Antarctica is a representative of the environments where members of the Synoicum …

Chemical Investigation Of Floridian Mangrove Endophytes And Antarctic Marine Organisms, Bingjie Yang

USF Tampa Graduate Theses and Dissertations

Nature creates diseases and illnesses for mankind, however, nature also provides therapeutics by making biological systems produce secondary metabolites. Although the secondary metabolites originally play roles in chemical defense or evolution, researchers have been working on them for drug discovery. Plants, fungi and marine organisms have been mostly explored by natural products chemists over the century and contributed most drugs to the market. With the increasing need of new drugs resulting from drug resistance and pathogen evolution, the natural products area has been focused on developing innovative methodologies to achieve higher efficiency of isolating new bioactive compounds.

This dissertation herein …

Small Molecule Analog Studies Of Paramagnetic Dmso Reductase Enzyme Family Intermediates, Khadanand Kc

Chemistry and Chemical Biology ETDs

Pyranopterin molybdenum and tungsten enzymes are expressed in numerous organisms from all domains of life. These enzymes catalyze a variety of atom, hydride, and electron transfer reactions. The enzymes are of great importance in the biogeochemical cycles of nitrogen, carbon, and sulfur. In recent years, chemists have investigated applications for some of these enzymes as industrial biocatalysts. The dimethylsulfoxide reductase (DMSOr) enzyme family is the broadest family of pyranopterin Mo enzymes. The first coordination sphere of the Mo or W-containing active site for each member of this family is made up of 4 sulfur donors from the two pyranopterin dithiolenes …

Global Atmospheric Budget Of Acetone: Air-Sea Exchange And The Contribution To Hydroxyl Radicals, Siyuan Wang, Eric C. Apel, Rebecca H. Schwantes, Kelvin H. Bates, Daniel J. Jacob, Emily V. Fischer, Rebecca S. Hornbrook, Alan J. Hills, Louisa K. Emmons, Laura L. Pan, Shawn Honomichl, Simone Tilmes, Jean‐François Lamarque, Mingxi Yang, Christa A. Marandino, E. S. Saltzman, Warren J. De Bruyn, Sohiko Kameyama, Hiroshi Tanimoto, Yuko Omori, Samuel R. Hall, Kirk Ullmann, Thomas B. Ryerson, Chelsea R. Thompson, Jeff Peischl, Bruce C. Daube, Róisín Commane, Kathryn Mckain, Colm Sweeney, Alexander B. Thames, David O. Miller, William H. Brune, Glenn S. Diskin, Joshua P. Digangi, Steven C. Wofsy

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Acetone is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere. The oceans impose a strong control on atmospheric acetone, yet the oceanic fluxes of acetone remain poorly constrained. In this work, the global budget of acetone is evaluated using two global models: CAM‐chem and GEOS‐Chem. CAM‐chem uses an online air‐sea exchange framework to calculate the bidirectional oceanic acetone fluxes, which is coupled to a data‐oriented machine‐learning approach. The machine‐learning algorithm is trained using a global suite of seawater acetone measurements. GEOS‐Chem uses a fixed surface seawater concentration of acetone to calculate the oceanic fluxes. Both …

Solvation Structures And Dynamics Of Small Molecules: Experimental And Computational Studies Using Carbonyl Vibrational Modes As Probe, Xiaoliu Zhang

LSU Doctoral Dissertations

Solutions are ubiquitous in both the global environment and the human body, and play a significant role in scientific research and industrial production. The structures and dynamics of solutions have been studied for centuries. However, conventional experimental methods, whose intrinsic measuring time is on the order of nanoseconds to microseconds, could not detect the fast dynamics taking place in the solution on the timescale of femto- and pico-second. In this dissertation, the ultrafast two-dimensional infrared (2DIR) spectroscopy was applied to characterize the structure and dynamics in three different types of solutions on the sub-picosecond timescale. Linear Fourier transform infrared spectroscopy …

(S)-2-[(4-Fluoro­Phen­Yl)Formamido]-3-Phenyl­Propanoic Acid, Kathleen Lee, Luke Turner, Cynthia Powell, Eric W. Reinheimer

Chemistry and Biochemistry

No abstract provided.

Phosphorylation Of Adp-Glucose Pyrophosphorylase During Wheat Seeds Development, Danisa M. L. Ferrero, Claudia V. Piattoni, Matías D. Asencion Diez, Bruno E. Rojas, Matías D. Hartman, Miguel A. Ballicora, Alberto A. Iglesias

Chemistry: Faculty Publications and Other Works

Starch is the dominant reserve polysaccharide accumulated in the seed of grasses (like wheat). It is the most common carbohydrate in the human diet and a material applied to the bioplastics and biofuels industry. Hence, the complete understanding of starch metabolism is critical to design rational strategies to improve its allocation in plant reserve tissues. ADP-glucose pyrophosphorylase (ADP-Glc PPase) catalyzes the key (regulated) step in the synthetic starch pathway. The enzyme comprises a small (S) and a large (L) subunit forming an S2L2 heterotetramer, which is allosterically regulated by orthophosphate, fructose-6P, and 3P-glycerate. ADP-Glc PPase was found in a phosphorylated …

Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates

LSU Master's Theses

Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …

Allosteric Regulation At The Crossroads Of New Technologies: Multiscale Modeling, Networks, And Machine Learning, Gennady M. Verkhivker, Steve Agajanian, Guang Hu, Peng Tao

Mathematics, Physics, and Computer Science Faculty Articles and Research

Allosteric regulation is a common mechanism employed by complex biomolecular systems for regulation of activity and adaptability in the cellular environment, serving as an effective molecular tool for cellular communication. As an intrinsic but elusive property, allostery is a ubiquitous phenomenon where binding or disturbing of a distal site in a protein can functionally control its activity and is considered as the “second secret of life.” The fundamental biological importance and complexity of these processes require a multi-faceted platform of synergistically integrated approaches for prediction and characterization of allosteric functional states, atomistic reconstruction of allosteric regulatory mechanisms and discovery of …

Mapping Gadolinium Contrast In A Complex Ionic And Photosynthesis Environment Of Pineapple By Near-Infrared And X-Ray Imaging, Subhendra Sarkar, Zoya Vinokur, Chen Xu, Tetiana Soloviova, Amina Shahbaz, Aldona Gjoni

Publications and Research

This work explores the diffusivity of a lanthanide complex, Eovist (Gadolinium-Ethoxy Benzyl Diethylenetriamine pentaacetate) that is stable in neutral media but is not in acidic environment. In the current work an acidic fruit model like pineapple that is rich in transition metals was used and a possible transmetallation reaction among Eovist and transition metal complexes was tested using X-ray imaging. Another goal of this work was to perturb the usual and the unusual photosynthesis systems that pineapple has maintained for millions of years during the evolution of circadian genes for efficient water conservation by dark photosynthesis. To detect such photosynthesis …

Chemist Table: A Tool For Designing Or Modifying Instruction For A Systems Thinking Approach In Chemistry Education, Sarah York, Marykay Orgill

Chemistry and Biochemistry Faculty Research

Recently, there have been calls to integrate systems thinking approaches into chemistry education in order to strengthen students’ conceptual understanding, build their problem-solving capabilities, and prepare them to make informed, ethical decisions about globally relevant issues, such as sustainability. Unfortunately, implementation of systems thinking approaches in chemistry classrooms currently poses challenges. Exemplar systems thinking materials with a STEM focus are limited, particularly at the tertiary level. Moreover, the science education community has yet to agree upon a systems thinking definition or develop a comprehensive list of systems thinking skills that students should develop. Thus, a current priority for the advancement …

Guar Gum Based Hydrogel Matrices As Low-Cost Biomaterials For Bone Tissue Engineering, Anil Parameswaran Thankam

Theses and Dissertations

Hydrogels have existed for more than half a century, and today they have many applications including tissue engineering. We have synthesized hydrogel scaffolds based on low cost and biodegradable polymer like hydroxypropyl guar (HPG) and applying them for bone tissue engineering. We have fabricated hydrogel matrices without any toxic chemical crosslinker to avoid possible toxicity in fabrication. We followed two methods of fabrication for HPG based hydrogels. One is via physical crosslinking, by simply mixing poly(vinyl alcohol) (PVA) with HPG and the other one is grafting poly(vinyl caprolactam) (PNVCL) on HPG via radical polymerization. For the first method, we developed …

Analytic Gradients For State-Averaged Multiconfiguration Pair-Density Functional Theory, Thais R. Scott, Matthew R. Hermes, Andrew M. Sand, Meagan S. Oakley, Donald G. Truhlar, Laura Gagliardi

Scholarship and Professional Work - LAS

Analytic gradients are important for efficient calculations of stationary points on potential energy surfaces, for interpreting spectroscopic observations, and for efficient direct dynamics simulations. For excited electronic states, as are involved in UV–Vis spectroscopy and photochemistry, analytic gradients are readily available and often affordable for calculations using a state-averaged complete active space self-consistent-field (SA-CASSCF) wave function. However, in most cases, a post-SA-CASSCF step is necessary for quantitative accuracy, and such calculations are often too expensive if carried out by perturbation theory or configuration interaction. In this work, we present the analytic gradients for multiconfiguration pair-density functional theory based on SA-CASSCF …

Collaborative Research: Mechanism And Target Recognition Of Protein Arginine Methyltransferases (Prmts), Joan Hevel

Funded Research Records

No abstract provided.

Observation Of The Low-Frequency Spectrum Of The Water Trimer As A Sensitive Test Of The Water-Trimer Potential And The Dipole-Moment Surface, Raffael Schwan, Chen Qu, Devendra Mani, Nitish Pal, Gerhard Schwaab, Joel M. Bowman, Gregory S. Tschumper, Martina Havenith

Faculty and Student Publications

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. Intermolecular interactions in bulk water are dominated by pairwise and non-pairwise cooperative interactions. While accurate descriptions of the pairwise interactions are available and can be tested by precise low-frequency spectra of the water dimer up to 550 cm−1, the same does not hold for the three-body interactions. Here, we report the first comprehensive spectrum of the water trimer in the frequency region from 70 to 620 cm−1 using helium-nanodroplet isolation and free-electron lasers. By comparison to accompanying high-level quantum calculations, the experimentally observed intermolecular bands can be assigned. …