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Nature Nov 2023Optimum protein function and biochemical activity critically depends on water availability because solvent thermodynamics drive protein folding and macromolecular...
Optimum protein function and biochemical activity critically depends on water availability because solvent thermodynamics drive protein folding and macromolecular interactions. Reciprocally, macromolecules restrict the movement of 'structured' water molecules within their hydration layers, reducing the available 'free' bulk solvent and therefore the total thermodynamic potential energy of water, or water potential. Here, within concentrated macromolecular solutions such as the cytosol, we found that modest changes in temperature greatly affect the water potential, and are counteracted by opposing changes in osmotic strength. This duality of temperature and osmotic strength enables simple manipulations of solvent thermodynamics to prevent cell death after extreme cold or heat shock. Physiologically, cells must sustain their activity against fluctuating temperature, pressure and osmotic strength, which impact water availability within seconds. Yet, established mechanisms of water homeostasis act over much slower timescales; we therefore postulated the existence of a rapid compensatory response. We find that this function is performed by water potential-driven changes in macromolecular assembly, particularly biomolecular condensation of intrinsically disordered proteins. The formation and dissolution of biomolecular condensates liberates and captures free water, respectively, quickly counteracting thermal or osmotic perturbations of water potential, which is consequently robustly buffered in the cytoplasm. Our results indicate that biomolecular condensation constitutes an intrinsic biophysical feedback response that rapidly compensates for intracellular osmotic and thermal fluctuations. We suggest that preserving water availability within the concentrated cytosol is an overlooked evolutionary driver of protein (dis)order and function.
Topics: Cell Death; Cytosol; Homeostasis; Macromolecular Substances; Osmolar Concentration; Pressure; Proteins; Solvents; Temperature; Thermodynamics; Time Factors; Water
PubMed: 37853127
DOI: 10.1038/s41586-023-06626-z -
Molecules (Basel, Switzerland) Nov 2023This review presents a description of the available data from the literature on the electrochemical properties of flavonoids. The emphasis has been placed on the... (Review)
Review
This review presents a description of the available data from the literature on the electrochemical properties of flavonoids. The emphasis has been placed on the mechanism of oxidation processes and an attempt was made to find a general relation between the observed reaction paths and the structure of flavonoids. Regardless of the solvent used, three potential regions related to flavonoid structures are characteristic of the occurrence of their electrochemical oxidation. The potential values depend on the solvent used. In the less positive potential region, flavonoids, which have an dihydroxy moiety, are reversibly oxidized to corresponding -quinones. The -quinones, if they possess a C3 hydroxyl group, react with water to form a benzofuranone derivative (). In the second potential region, () is irreversibly oxidized. In this potential region, some flavonoids without an dihydroxy moiety can also be oxidized to the corresponding -quinone methides. The oxidation of the hydroxyl groups located in ring A, which are not in the position, occurs in the third potential region at the most positive values. Some discrepancies in the reported reaction mechanisms have been indicated, and this is a good starting point for further investigations.
Topics: Flavonoids; Electrochemistry; Oxidation-Reduction; Solvents
PubMed: 38005343
DOI: 10.3390/molecules28227618 -
Biomolecules Dec 2023Collagen is a triple-helical protein unique to the extracellular matrix, conferring rigidity and stability to tissues such as bone and tendon. For the [(PPG)10]3...
Collagen is a triple-helical protein unique to the extracellular matrix, conferring rigidity and stability to tissues such as bone and tendon. For the [(PPG)10]3 collagen-mimetic peptide at room temperature, our molecular dynamics simulations show that these properties result in a remarkably ordered first hydration layer of water molecules hydrogen bonded to the backbone carbonyl (bb-CO) oxygen atoms. This originates from the following observations. The radius of gyration attests that the PPG triplets are organized along a straight line, so that all triplets (excepting the ends) are equivalent. The solvent-accessible surface area (SASA) for the bb-CO oxygens shows a repetitive regularity for every triplet. This leads to water occupancy of the bb-CO sites following a similar regularity. In the crystal-phase X-ray data, as well as in our 100 K simulations, we observe a 0-2-1 water occupancy in the P-P-G triplet. Surprisingly, a similar (0-1.7-1) regularity is maintained in the liquid phase, in spite of the sub-nsec water exchange rates, because the bb-CO sites rarely remain vacant. The manifested ordered first-shell water molecules are expected to produce a cylindrical electrostatic potential around the peptide, to be investigated in future work.
Topics: Peptides; Water; Solvents; Chemical Phenomena; Collagen
PubMed: 38136615
DOI: 10.3390/biom13121744 -
Nature Communications Jun 2023Optical clearing with high-refractive-index (high-n) reagents is essential for 3D tissue imaging. However, the current liquid-based clearing condition and dye...
Optical clearing with high-refractive-index (high-n) reagents is essential for 3D tissue imaging. However, the current liquid-based clearing condition and dye environment suffer from solvent evaporation and photobleaching, causing difficulties in maintaining the tissue optical and fluorescent features. Here, using the Gladstone-Dale equation [(n-1)/density=constant] as a design concept, we develop a solid (solvent-free) high-n acrylamide-based copolymer to embed mouse and human tissues for clearing and imaging. In the solid state, the fluorescent dye-labeled tissue matrices are filled and packed with the high-n copolymer, minimizing scattering in in-depth imaging and dye fading. This transparent, liquid-free condition provides a friendly tissue and cellular environment to facilitate high/super-resolution 3D imaging, preservation, transfer, and sharing among laboratories to investigate the morphologies of interest in experimental and clinical conditions.
Topics: Mice; Humans; Animals; Imaging, Three-Dimensional; Solvents; Fluorescent Dyes; Acrylamide; Optical Imaging
PubMed: 37296117
DOI: 10.1038/s41467-023-39082-4 -
International Journal of Molecular... Aug 2023Cellulose is produced industrially by the kraft and sulfite processes. The evolution of these technologies in biorefineries is driven by the need to obtain greater added... (Review)
Review
Cellulose is produced industrially by the kraft and sulfite processes. The evolution of these technologies in biorefineries is driven by the need to obtain greater added value through the efficient use of raw materials and energy. In this field, organosolv technologies (and within them, those using liquid phases made up of water and one partly miscible organic solvent, known as "biphasic fractionation" in reference to the number of liquid phases) represent an alternative that is receiving increasing interest. This study considers basic aspects of the composition of lignocellulosic materials, describes the fundamentals of industrial cellulose pulp production processes, introduces the organosolv methods, and comprehensively reviews published results on organosolv fractionation based on the use of media containing water and an immiscible solvent (1-butanol, 1-pentanol or 2-methyltetrahydrofuran). Special attention is devoted to aspects related to cellulose recovery and fractionation selectivity, measured through the amount and composition of the treated solids.
Topics: Cellulose; Lignin; Solvents; Water; Technology; Biomass
PubMed: 37569779
DOI: 10.3390/ijms241512404 -
Applied Microbiology and Biotechnology Feb 2024In recent years, microbial carotenoids have emerged as a promising alternative for the pharmaceutical and food industries, particularly in promoting human health due to... (Review)
Review
In recent years, microbial carotenoids have emerged as a promising alternative for the pharmaceutical and food industries, particularly in promoting human health due to their potent antioxidant and antimicrobial properties. Microbial carotenoids, particularly those produced by yeast, bacteria, and microalgae, are synthesized intracellularly, requiring the use of solvents for their effective extraction and recovery. The conventional use of toxic volatile organic solvents (VOCs) like hexane, petroleum ether, and dimethyl sulfoxide in the extraction of microbial carotenoids has been common. However, ongoing research is introducing innovative, non-toxic, environmentally friendly tailor-made solvents, such as ionic liquids (IL) and deep eutectic solvents (DES), indicating a new era of cleaner and biocompatible technologies. This review aims to highlight recent advancements in utilizing IL and DES for obtaining carotenoids from microorganisms. Additionally, we explore the utilization of in silico tools designed to determine the solubilities of microbial carotenoids in tailor-made DES and ILs. This presents a promising alternative for the scientific community, potentially reducing the need for extensive experimental screening of solvents for the recovery of microbial carotenoids in the separation processing. According to our expert perspective, both IL and DES exhibit a plethora of exceptional attributes for the recovery of microbial carotenoids. Nevertheless, the current employment of these solvents for recovery of carotenoids is restricted to scientific exploration, as their feasibility for practical application in industrial settings has yet to be conclusively demonstrated. KEY POINTS: • ILs and DES share many tailoring properties for the recovery of microbial carotenoids • The use of ILs and DES for microbial carotenoid extraction remains driven by scientific curiosity. • The economic feasibility of ILs and DES is yet to be demonstrated in industrial applications.
Topics: Humans; Solvents; Carotenoids; Ionic Liquids; Antioxidants; Dimethyl Sulfoxide
PubMed: 38400930
DOI: 10.1007/s00253-024-13049-x -
Analytica Chimica Acta Sep 2023In this work, a novel solvent-free microfluidic method based liquid phase microextraction has been proposed for the first time. A comprehensive study of liquid phase...
In this work, a novel solvent-free microfluidic method based liquid phase microextraction has been proposed for the first time. A comprehensive study of liquid phase microextraction (LPME) and electromembrane extraction (EME) implemented in microfluidic formats has been carried out to investigate the efficiency of biodegradable membranes (such as agarose) without organic solvent to develop fully environmental microfluidic methods. For this study, non-polar and polar basic compounds (five) were selected as model analytes and different agarose membrane compositions were synthesized and tested with and without organic solvent (solvent-free). Under optimal experimental conditions, the extraction efficiencies obtained using solvent-free LPME-chip devices were similar to the ones obtained using solvent-free EME-chip devices at very low voltages (0.25 V), however, LPME microfluidic format was selected due to its simplicity. The proposed green microfluidic device was successfully applied in urine samples with recoveries between 80 and 93% for all analytes and relative standard deviation below 7% for all analytes. Results were compared with experiments previously conducted using conventional (polypropylene) membranes, observing that solvent-free microfluidic systems based on biodegradable solid support materials have proven to be an attractive alternative and offered the same advantages in terms of membrane stability allowing consecutive extractions compared to supported liquid membranes (SLM) microfluidic methods.
Topics: Solvents; Liquid Phase Microextraction; Sepharose; Lab-On-A-Chip Devices; Microfluidics; Membranes, Artificial
PubMed: 37455082
DOI: 10.1016/j.aca.2023.341572 -
Accounts of Chemical Research Sep 2023Mass spectrometry (MS) is one of the most widely used technologies in the chemical sciences. With applications spanning the monitoring of reaction products, the... (Review)
Review
Mass spectrometry (MS) is one of the most widely used technologies in the chemical sciences. With applications spanning the monitoring of reaction products, the identification of disease biomarkers, and the measurement of thermodynamic parameters and aspects of structural biology, MS is well established as a universal analytical tool applicable to small compounds as well as large molecular complexes. Regardless of the application, the generation of gas-phase ions from neutral compounds is a key step in any MS experiment. However, this ionization step was for many years limited to high-energy approaches that required gas-phase analytes and thus it was restricted to volatile samples. Over the last few decades, new methodologies have been developed to address this limitation and facilitate ionization of biological molecules. Electrospray ionization (ESI) is the most broadly used of these methods, as it facilitates the ionization of intact polar compounds from solution. Twenty years ago, our group reported a new ionization method that uses a charged solvent spray to impact a surface, generating ions from rather than just and doing so directly in the ambient environment with no vacuum requirements and little to no sample preparation. This method was termed desorption electrospray ionization (DESI), and it initiated a new field that would come to be known as ambient mass spectrometry. The simplicity and wide applicability of the DESI technology—and the tens of ambient ionization methods developed subsequently—revolutionized the MS analysis of complex materials for their organic components, especially for applications. This Account describes the history of DESI, starting with the development of the technique from early electrosonic spray ionization (ESSI) experimental observations as well as the studies leading to the understanding of its mechanism as a “droplet pick-up” phenomenon involving sequential events (, thin film formation, solid–liquid extraction, secondary droplet generation, and ESI-like ionization from these droplets). We also overview the developments and applications of the technology that have been demonstrated by our group during the last two decades. In particular, we describe (i) the use of DESI for tissue imaging, one of its more significant applications to date, and its extension to intraoperative clinical diagnosis; (ii) the integration of the technology with portable instrumentation for analysis, especially when coupled with tandem mass spectrometry (MS/MS); (iii) the use of DESI microdroplets as microvessels to accelerate organic reactions by orders of magnitude compared to those in bulk solution; and (iv) the combination of all these capabilities for automated high-throughput experiments aimed at accelerating drug discovery.
Topics: Drug Discovery; Pentaerythritol Tetranitrate; Solvents; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry
PubMed: 37671799
DOI: 10.1021/acs.accounts.3c00382 -
Journal of Chromatography. A Jul 2024Previous in vitro toxicological assessments have demonstrated that almost no mutagenic and genotoxic activities in electronic cigarette (e-cigarette) and heated tobacco...
Previous in vitro toxicological assessments have demonstrated that almost no mutagenic and genotoxic activities in electronic cigarette (e-cigarette) and heated tobacco product (HTP) aerosols were detected even at the maximum recommended concentration. To accurately compare the toxicity levels between cigarette smoke and e-cigarette or HTP aerosols, higher exposure concentrations increasing the possibility to detect toxicity in in vitro tests are necessary, while avoiding solvent-induced toxicity. This study aimed to develop a solvent-free extraction method to obtain concentrated aerosol extracts for improved toxicological evaluation. Our novel approach involved squeezing several Cambridge filter pads, which collected aerosol constituents, in closed containers to achieve solvent-free extraction with comparable efficiency to the conventional method using organic solvents. The optimized squeezing method yielded extracts with concentrations approximately 10 times higher than those obtained in conventional extraction methods. Yield comparison of various constituents, such as flavoring compounds, in e-cigarette aerosol extracts revealed similar extraction efficiencies between the squeezing and conventional methods. However, the extraction efficiency for constituents with high log P values, predominantly found in HTP aerosol extracts, was unacceptably low using the squeezing method. In addition, solvent-free centrifuging, another type of extraction method, exhibited unsatisfactory results for even e-cigarette aerosols compared with the conventional method. Our findings suggest that the solvent-free squeezing method is suitable for extracting aerosol collected mass from e-cigarette aerosol but not from HTP aerosol. We anticipate that the solvent-free squeezing method will contribute to a deeper understanding of toxicological differences between e-cigarettes and conventional combustible cigarettes.
Topics: Aerosols; Electronic Nicotine Delivery Systems; Tobacco Products; Hot Temperature; Solvents; Chemical Fractionation; Flavoring Agents; Gas Chromatography-Mass Spectrometry
PubMed: 38776605
DOI: 10.1016/j.chroma.2024.465009 -
ACS Applied Bio Materials Aug 2023This paper reports on the production of electro-spun nanofibers from softwood Kraft lignin without the need for polymer blending and/or chemical modification....
This paper reports on the production of electro-spun nanofibers from softwood Kraft lignin without the need for polymer blending and/or chemical modification. Commercially available softwood Kraft lignin was fractionated using acetone. The acetone-soluble lignin (AcSL) had an ash content of 0.06 wt %, a weight average molecular weight of 4250 g·mol along with the polydispersity index of 1.73. The corresponding values for as-received lignin (ARL) were 1.20 wt %, 6000 g·mol, and 2.22, respectively. The AcS was dissolved in a binary solvent consisting of acetone, and dimethyl sulfoxide (2:1, v/v) was selected for dissolving the AcSL. Conventional and custom-designed grounded electrode configurations were used to produce electro-spun neat lignin fibers that were randomly oriented or highly aligned, respectively. The diameter of the electro-spun fibers ranged from 1.12 to 1.46 μm. After vacuum drying at 140 °C for 6 h to remove the solvents and oxidation at 250 °C, the fibers were carbonized at 1000, 1200, and 1500 °C for 1 h. The carbonized fibers were unfused and void-free with an average diameter of 500 nm. Raman spectroscopy, scanning electron microscopy, and image analysis were used to characterize the carbonized fibers.
Topics: Solvents; Lignin; Acetone; Chemical Fractionation
PubMed: 37523247
DOI: 10.1021/acsabm.3c00278