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Frontiers in Chemistry 2023Photochromic fluorescent proteins (FPs) have proved to be indispensable luminous probes for sophisticated and advanced bioimaging techniques. Among them, an interplay...
Photochromic fluorescent proteins (FPs) have proved to be indispensable luminous probes for sophisticated and advanced bioimaging techniques. Among them, an interplay between photoswitching and photoconversion has only been observed in a limited subset of Kaede-like FPs that show potential for discovering the key mechanistic steps during green-to-red photoconversion. Various spectroscopic techniques including femtosecond stimulated Raman spectroscopy (FSRS), X-ray crystallography, and femtosecond transient absorption were employed on a set of five related FPs with varying photoconversion and photoswitching efficiencies. A 3-methyl-histidine chromophore derivative, incorporated through amber suppression using orthogonal aminoacyl tRNA synthetase/tRNA pairs, displays more dynamic photoswitching but greatly reduced photoconversion the least-evolved ancestor (LEA). Excitation-dependent measurements of the green anionic chromophore reveal that the varying photoswitching efficiencies arise from both the initial transient dynamics of the bright state and the final -like photoswitched state, with an exocyclic bridge H-rocking motion playing an active role during the excited-state energy dissipation. This investigation establishes a close-knit feedback loop between spectroscopic characterization and protein engineering, which may be especially beneficial to develop more versatile FPs with targeted mutations and enhanced functionalities, such as photoconvertible FPs that also feature photoswitching properties.
PubMed: 38144887
DOI: 10.3389/fchem.2023.1328081 -
STAR Protocols Dec 2023Homoallenic alcohols are versatile building blocks to access complex molecules in synthetic chemistry. We present a protocol for accessing homoallenic alcohols by an...
Homoallenic alcohols are versatile building blocks to access complex molecules in synthetic chemistry. We present a protocol for accessing homoallenic alcohols by an allenyl radical-involved radical-polar crossover process. We describe steps for preparing solvents and the photoreactor and synthesizing 5-methyl-1-phenyl-3-tosylhexa-3,4-dien-1-ol 3 in 85% yield. In addition, 5-methyl-1-phenyl-3-tosylhexa-3,4-dien-1-ol 3 has been successfully synthesized in 2-mmol scale. This protocol is also applicable to the synthesis of homoallenic amides. For complete details on the use and execution of this protocol, please refer to Wei et al. (2023)..
Topics: Alcohols; Alkenes; Amides
PubMed: 37756157
DOI: 10.1016/j.xpro.2023.102598 -
Scientific Reports Dec 2023Nanobiotechnology is a unique class of multiphase and recently become a branch of contemporary science and a paradigm shift in material research. One of the two main...
Nanobiotechnology is a unique class of multiphase and recently become a branch of contemporary science and a paradigm shift in material research. One of the two main problems facing the field of nanomaterial synthesis is the discovery of new natural resources for the biological production of metal nanoparticles and the absence of knowledge about the chemical composition of bio-source required for synthesis and the chemical process or mechanism behind the production of metal nanoparticles presents the second difficulty. We reported template-free green synthesized copper oxide nanoparticles using Tribulus terrestris seed natural extract without any isolation process. XRD, TEM, SEM, UV-Vis, DLS, zeta potential, and BET evaluated the synthesized metal nanoparticle. The TEM analysis confirmed that the CuO NPs are well dispersed and almost round in shape with an average size of 58 nm. EDAX confirms that copper is the prominent metal present in the nanomaterial. The greener fabricated copper oxide nanoparticle was employed to degrade methyl orange dye, almost 84% of methyl orange was degraded within 120 min. The outcomes demonstrated the nanomaterial's effective breakdown of contaminants, highlighting their potential for environmental rehabilitation. The electrochemical investigation of the CuO NPs was utilized for supercapacitor application. An appreciable value of specific capacitance is 369 F/g specific capacitances with 96.4% capacitance retention after 6000 cycles. Overall, the results of the current study show that the biologically produced copper oxide nanoparticles have intriguing uses as photocatalysts for treating water contaminants and are suitable for energy storage devices.
Topics: Copper; Tribulus; Nanoparticles; Metal Nanoparticles; Oxides; Seeds; Plant Extracts; Spectroscopy, Fourier Transform Infrared
PubMed: 38110542
DOI: 10.1038/s41598-023-49706-w -
ACS Omega Aug 2023Graphene oxide (GO) is a conventional yet vital precursor for the synthesis of porous graphene (PG). Several strong oxidizing agents such as potassium permanganate and...
Graphene oxide (GO) is a conventional yet vital precursor for the synthesis of porous graphene (PG). Several strong oxidizing agents such as potassium permanganate and perchlorates are typically used for oxidization of graphite. However, they expose toxic reactants/products that harm the environment. Therefore, a greener approach is desperately needed to oxidize and exfoliate graphite. This study reports for the first time on successful oxidation of graphite by ferrate(VI) compounds via an encapsulation approach. By further reducing GO prepared from this near green route with vitamin C, PG anticipated by many highly important and expanding areas such as water treatment could be readily achieved. X-ray diffraction (XRD), Fourier transform infrared (FTIR) and UV-vis spectroscopy, and scanning electronic microscopy (SEM) along with energy-dispersive spectroscopy confirmed the high yield of GO from the oxidation of graphite. Raman spectroscopy, XRD, and TEM confirmed the formation of high-quality few-layered PG from the reduction of as-prepared GO. The above results demonstrated the practicality of using encapsulated ferrate(VI) compounds to realize green oxidation of graphite and resolve the paradox about the oxidation capability of ferrate(VI). To further illustrate its potential for the removal of emerging and crucial contaminants from water, as-prepared PG was further examined against the contaminants of methyl orange (MeO) dye and ibuprofen (IBU). Taken together, the results revealed that more than 90% removal efficiency could be achieved at a high PG dosage against MeO and IBU. This ground-breaking greener approach opens the door to risk-free, extensive graphene environmental applications.
PubMed: 37599955
DOI: 10.1021/acsomega.3c03812 -
Molecules (Basel, Switzerland) Nov 2023Volatile organic compounds (VOCs) and flavor characteristics of Tratt. (RR) and (RS) were analyzed using headspace solid-phase microextraction coupled with gas...
Volatile organic compounds (VOCs) and flavor characteristics of Tratt. (RR) and (RS) were analyzed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The flavor network was constructed by combining relative odor activity values (ROAVs), and the signature differential flavor components were screened using orthogonal partial least squares discriminant analysis (OPLS-DA) and random forest (RF). The results showed that 61 VOCs were detected in both RR and RS: 48 in RR, and 26 in RS. There were six key flavor components (ROAVs ≥ 1) in RR, namely nonanal, ethyl butanoate, ethyl hexanoate, ()-3-hexen-1-yl acetate, ethyl caprylate, and styrene, among which ethyl butanoate had the highest contribution, whereas there were eight key flavor components (ROAVs ≥ 1) in RS, namely 2-nonanol, ()-2-hexenal, nonanal, methyl salicylate, β-ocimene, caryophyllene, α-ionone, and styrene, among which nonanal contributed the most to RS. The flavor of RR is primarily fruity, sweet, green banana, and waxy, while the flavor of RS is primarily sweet and floral. In addition, OPLS-DA and RF suggested that ()-2-hexenal, ethyl caprylate, β-ocimene, and ethyl butanoate could be the signature differential flavor components for distinguishing between RR and RS. In this study, the differences in VOCs between RR and RS were analyzed to provide a basis for further development and utilization.
Topics: Gas Chromatography-Mass Spectrometry; Rosa; Solid Phase Microextraction; Odorants; Volatile Organic Compounds; Styrenes
PubMed: 38067608
DOI: 10.3390/molecules28237879 -
Discover Nano Apr 2024Titanium dioxide nanoparticles (TiO-NPs) are a promising anode material for Lithium-ion batteries (LIBs) due to their good rate capability, low cost, non-toxicity,...
Titanium dioxide nanoparticles (TiO-NPs) are a promising anode material for Lithium-ion batteries (LIBs) due to their good rate capability, low cost, non-toxicity, excellent structural stability, extended cycle life, and low volumetric change (∼4%) during the Li insertion/de-insertion process. In the present paper, anatase TiO-NPs with an average particle size of ~ 12 nm were synthesized via a green synthesis route using Beta vulgaris (Beetroot) extract, and the synthesized TiO-NPs were evaluated as anode material in LIBs. Furthermore, we employed an aqueous binder (1:1 mixture of carboxy methyl cellulose and styrene butadiene) for electrode processing, making the process cost-effective and environmentally friendly. The results revealed that the Li/TiO half-cells delivered an initial discharge capacity of 209.7 mAh g and exhibited superior rate capability (149 mAh g at 20 C) and cycling performances. Even at the 5C rate, the material retained a capacity of 82.2% at the end of 100 cycles. The synthesis route of TiO-NPs and the aqueous binder-based electrode processing described in the present work are facile, green, and low-cost and are thus practically beneficial for producing low-cost and high-performance anodes for advanced LIBs.
PubMed: 38632188
DOI: 10.1186/s11671-024-04010-y -
Bioinorganic Chemistry and Applications 2023Organotin complexes were prepared through a one-pot reaction with three components by reacting thiosemicarbazide or 4-methyl-3-thiosemicarbazide or...
Organotin complexes were prepared through a one-pot reaction with three components by reacting thiosemicarbazide or 4-methyl-3-thiosemicarbazide or 4-phenylthiosemicarbazide, dehydroacetic acid (DHA) and dibutyl, diphenyl, dicyclohexyl, and bis[(trimethylsilyl)methyl]tin(IV) oxides; all complexes were characterized by infrared (IR), ultraviolet-visible (UV-vis), mass spectrometry (MS), and nuclear magnetic resonance (NMR) spectroscopy. The Sn NMR revealed chemical shifts corresponding to a pentacoordinated environment in solution. The X-ray crystallography of the two complexes evidenced the formation of monomeric complexes with a pentacoordinated geometry around tin via three donor atoms from the ligand, the sulfur of the thiol, the nitrogen of the imine group, and the oxygen of the pyran ring. The geometries of the five-coordinated complexes (BuSnL3), (PhSnL3), and (CySnL3) acid were intermediate between square pyramidal and trigonal bipyramidal, and complex (BuSnL1) adopted a bipyramidal trigonal geometry (BPT). The sulforhodamine B assay assessed the cytotoxicity of organotin(IV) complexes against the MDA-MB-231 and MCF-7 (human mammary adenocarcinoma) cell lines and one normal COS-7 (African green monkey kidney fibroblast). The IC values evidenced a significant antiproliferative effect on cancer cells; the complexes were more potent than the positive cisplatin control and the corresponding ligands, dehydroacetic acid thiosemicarbazone (), dehydroacetic acid-N(4)-methylthiosemicarbazone (), and dehydroacetic acid-N(4)-phenylthiosemicarbazone (). The IC values also indicated that the organotin(IV) complexes were more cytotoxic against the triple-negative breast cell line MDA-MB-231 than MCF-7, inducing significant morphological alterations. The interactions of organotin(IV) (PhSnL1), (CySnL1), and (((CH)SiCH)SnL1) were evaluated with ss-DNA by fluorescence; intensity changes of the fluorescence were indicative of the displacement of ethidium bromide (EB), confirming the interaction of the organotin(IV) complexes with ss-DNA; the results showed a DNA binding affinity. The thermodynamic parameters obtained through isothermal titration calorimetry showed that the interaction of (PhSnL1), with ss-ADN, was exothermic. Molecular docking studies also demonstrated that the organotin(IV) complexes were intercalated in DNA by conventional hydrogen bonds, carbon-hydrogen bonds, and -alkyl interactions. These complexes furthermore showed a greater affinity towards DNA than cisplatin.
PubMed: 37920233
DOI: 10.1155/2023/7901843 -
RSC Advances Jan 2024A green and sustainable metal-free, additive-free olefination approach is proposed for the facile synthesis of various unsaturated -heteroazaarenes from simple...
A green and sustainable metal-free, additive-free olefination approach is proposed for the facile synthesis of various unsaturated -heteroazaarenes from simple methyl-substituted heteroarenes and amines. The developed protocol employs only air as the sole oxidant and provides a useful strategy for obtaining various -selective conjugated heterocyclic olefins. This provides a useful strategy for application in generating grams of a variety of unsaturated -heteroazaarenes (up to 20.33 grams) and the synthetic imaging agents of STB-8 (2.40 gram) with high regioselectivity in one pot.
PubMed: 38304557
DOI: 10.1039/d4ra00189c -
The Journal of Organic Chemistry Oct 2023When generated in a mass spectrometer bridged bicyclic 1,3-dioxenium ions derived from 4--acylgalactopyranosyl, donors can be observed by infrared spectroscopy at...
Stereodirecting Effect of Esters at the 4-Position of Galacto- and Glucopyranosyl Donors: Effect of 4--Methylation on Side-Chain Conformation and Donor Reactivity, and Influence of Concentration and Stoichiometry on Distal Group Participation.
When generated in a mass spectrometer bridged bicyclic 1,3-dioxenium ions derived from 4--acylgalactopyranosyl, donors can be observed by infrared spectroscopy at cryogenic temperatures, but they are not seen in the solution phase in contrast to the fused bicyclic 1,3-dioxalenium ions of neighboring group participation. The inclusion of a 4--methyl group into a 4--benzoyl galactopyranosyl donor enables nuclear magnetic resonance observation of the bicyclic ion arising from participation by the distal ester, with the methyl group influence attributed to ester ground state conformation destabilization. We show that a 4--methyl group also influences the side-chain conformation, enforcing a conformation in gluco and galactopyranosides. Competition experiments reveal that the 4--methyl group has only a minor influence on the rate of reaction of 4--benzoyl or 4--benzyl-galacto and glucopyranosyl donors and, consequently, that participation by the distal ester does not result in kinetic acceleration (anchimeric assistance). We demonstrate that the stereoselectivity of the 4--benzoyl-4--methyl galactopyranosyl donor depends on reaction concentration and additive (diphenyl sulfoxide) stoichiometry and hence that participation by the distal ester is a borderline phenomenon in competition with standard glycosylation mechanisms. An analysis of a recent paper affirming participation by a remote pivalate ester is presented with alternative explanations for the observed phenomena.
PubMed: 37677151
DOI: 10.1021/acs.joc.3c01496 -
Molecules (Basel, Switzerland) Jul 2023Organic thioethers play an important role in the discovery of drugs and natural products. However, the green synthesis of organic sulfide compounds remains a challenging...
Organic thioethers play an important role in the discovery of drugs and natural products. However, the green synthesis of organic sulfide compounds remains a challenging task. The convenient and efficient synthesis of 5-alkoxy-3-halo-4-methylthio-2(5)-furanones from DMSO is performed via the mediation of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), affording a facile route for the sulfur-functionalization of 3,4-dihalo-2(5)-furanones under transition metal-free conditions. This new approach has demonstrated the functionalization of non-aromatic C-X-type halides with unique structures containing C-X, C-O, C=O and C=C bonds. Compared with traditional synthesis methods using transition metal catalysts with ligands, this reaction has many advantages, such as the lower temperature, the shorter reaction time, the wide substrate range and good functional group tolerance. Notably, DMSO plays multiple roles, and is simultaneously used as an odorless methylthiolating reagent and safe solvent.
PubMed: 37570605
DOI: 10.3390/molecules28155635