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1.
Zhongguo Yi Liao Qi Xie Za Zhi ; 48(3): 343-345, 2024 May 30.
Artigo em Chinês | MEDLINE | ID: mdl-38863106

RESUMO

From the perspective of the performance evaluation, concerns of the range of pathogens, establishment of enterprise reference material, reaction system study and analytical performances evaluation of central nervous system infection pathogen metagenome sequencing reagent are briefly described, including study methods and quality control requirements. This study is intended to increase the research and development efficiency of products, and contribute to the development of associated industry.


Assuntos
Infecções do Sistema Nervoso Central , Metagenoma , Infecções do Sistema Nervoso Central/microbiologia , Controle de Qualidade , Indicadores e Reagentes
2.
Zhongguo Yi Liao Qi Xie Za Zhi ; 48(3): 339-342, 2024 May 30.
Artigo em Chinês | MEDLINE | ID: mdl-38863105

RESUMO

As an important part of the Big Health Industry, in vitro diagnostic(IVD) reagents play a vital role in the prevention, diagnosis and treatment of diseases. In recent years, especially after the novel coronavirus infection, IVD industry has developed rapidly in China, but it still cannot meet the needs of clinical use. By conducting desk research, expert interview, manufacturer survey and hospital survey, this study analyzed the development status of IVD industry in Shanghai, summarized the problems encountered in the high-quality development from the aspects of raw materials, innovation ability, and clinical trials, etc., and proposed recommendations for promoting the high-quality innovation and development of IVD industry in Shanghai.


Assuntos
Indicadores e Reagentes , China , Humanos , COVID-19
3.
Zhongguo Yi Liao Qi Xie Za Zhi ; 48(3): 315-318, 2024 May 30.
Artigo em Chinês | MEDLINE | ID: mdl-38863100

RESUMO

The management of in vitro diagnostic (IVD) reagents in hospitals often faces issues such as the lack of a unified coding system, unclear consumption patterns, and unknown cost-to-income ratios. It is necessary to employ information systems to achieve comprehensive, detailed, and traceable management of IVD reagents. An information management system for IVD reagents based on unique coding is introduced, which integrates admission, acceptance, and consumption processes through unique codes. The system calculates the income per experimental item based on the consumption of IVD reagents and the charge for each experimental item. The system enhances the efficiency of the IVD reagent supply chain management and promotes detailed oversight of IVD reagent usage.


Assuntos
Indicadores e Reagentes , Sistemas de Informação Administrativa , Administração de Materiais no Hospital
4.
Biomed Microdevices ; 26(3): 28, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38825594

RESUMO

Microfluidic-based point-of-care diagnostics offer several unique advantages over existing bioanalytical solutions, such as automation, miniaturisation, and integration of sensors to rapidly detect on-site specific biomarkers. It is important to highlight that a microfluidic POC system needs to perform a number of steps, including sample preparation, nucleic acid extraction, amplification, and detection. Each of these stages involves mixing and elution to go from sample to result. To address these complex sample preparation procedures, a vast number of different approaches have been developed to solve the problem of reagent storage and delivery. However, to date, no universal method has been proposed that can be applied as a working solution for all cases. Herein, both current self-contained (stored within the chip) and off-chip (stored in a separate device and brought together at the point of use) are reviewed, and their merits and limitations are discussed. This review focuses on reagent storage devices that could be integrated with microfluidic devices, discussing further issues or merits of these storage solutions in two different sections: direct on-chip storage and external storage with their application devices. Furthermore, the different microvalves and micropumps are considered to provide guidelines for designing appropriate integrated microfluidic point-of-care devices.


Assuntos
Dispositivos Lab-On-A-Chip , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Indicadores e Reagentes/química , Desenho de Equipamento
5.
Org Biomol Chem ; 22(22): 4420-4435, 2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38775347

RESUMO

Over past decades, chiral amides and peptides have emerged as powerful and versatile compounds due to their various biological activities and interesting molecular architectures. Although some chiral condensation reagents have been applied successfully for their synthesis, the introduction of racemization-free methods of amino acid activation have shown lots of advantages in terms of their low cost and low toxicity. In this review, advancements in amide and peptide synthesis using racemization-free coupling reagents over the last 10 years are summarized. Various racemization-free coupling reagents have been applied in the synthesis of enantioselective amides and peptides, including ynamides, allenones, HSi[OCH(CF3)2]3, Ta(OMe)5, Nb(OEt)5, Ta(OEt)5, TCFH-NMI, water-removable ynamides, DBAA, DATB, o-NosylOXY, TCBOXY, Boc-Oxyma, NDTP, 9-silafluorenyl dichlorides, the Mukaiyama reagent, EDC and T3P. The racemization-free reagents described in this review provide an alternative greener option for the asymmetric synthesis of chiral amides and peptides. We hope that this review will inspire further studies and developments in this field.


Assuntos
Amidas , Peptídeos , Amidas/química , Amidas/síntese química , Peptídeos/química , Peptídeos/síntese química , Estereoisomerismo , Técnicas de Química Sintética/métodos , Indicadores e Reagentes/química , Estrutura Molecular
6.
Top Curr Chem (Cham) ; 382(2): 15, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38703255

RESUMO

Aligned with the increasing importance of bioorthogonal chemistry has been an increasing demand for more potent, affordable, multifunctional, and programmable bioorthogonal reagents. More advanced synthetic chemistry techniques, including transition-metal-catalyzed cross-coupling reactions, C-H activation, photoinduced chemistry, and continuous flow chemistry, have been employed in synthesizing novel bioorthogonal reagents for universal purposes. We discuss herein recent developments regarding the synthesis of popular bioorthogonal reagents, with a focus on s-tetrazines, 1,2,4-triazines, trans-cyclooctenes, cyclooctynes, hetero-cycloheptynes, and -trans-cycloheptenes. This review aims to summarize and discuss the most representative synthetic approaches of these reagents and their derivatives that are useful in bioorthogonal chemistry. The preparation of these molecules and their derivatives utilizes both classical approaches as well as the latest organic chemistry methodologies.


Assuntos
Ciclo-Octanos , Triazinas , Triazinas/química , Triazinas/síntese química , Ciclo-Octanos/química , Ciclo-Octanos/síntese química , Alcinos/química , Alcinos/síntese química , Catálise , Indicadores e Reagentes/química , Estrutura Molecular
7.
Vet Immunol Immunopathol ; 272: 110769, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38703558

RESUMO

There are extensive immunological reagents available for laboratory rodents and humans. However, for veterinary species there is a need for expansion of immunological toolkits, with this especially evident for marine mammals, such as cetaceans. In addition to their use in a research setting, immune assays could be employed to monitor the health status of cetaceans and serve as an adjunct to available diagnostic tests. Such development of specific and sensitive immune assays will enhance the proper care and stewardship of wild and managed cetacean populations. Our goal is to provide immune reagents and immune assays for the research community, clinicians, and others involved in care of bottlenose dolphins. This review will provide an update on our development of a bottlenose dolphin immunological toolkit. The future availability and continued development of these reagents is critical for improving wild and managed bottlenose dolphin population health through enhanced assessment of their responses to alterations in the marine environment, including pathogens, and improve our ability to monitor their status following vaccination.


Assuntos
Golfinho Nariz-de-Garrafa , Animais , Golfinho Nariz-de-Garrafa/imunologia , Indicadores e Reagentes
8.
Nature ; 629(8010): 98-104, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38693411

RESUMO

Photobiocatalysis-where light is used to expand the reactivity of an enzyme-has recently emerged as a powerful strategy to develop chemistries that are new to nature. These systems have shown potential in asymmetric radical reactions that have long eluded small-molecule catalysts1. So far, unnatural photobiocatalytic reactions are limited to overall reductive and redox-neutral processes2-9. Here we report photobiocatalytic asymmetric sp3-sp3 oxidative cross-coupling between organoboron reagents and amino acids. This reaction requires the cooperative use of engineered pyridoxal biocatalysts, photoredox catalysts and an oxidizing agent. We repurpose a family of pyridoxal-5'-phosphate-dependent enzymes, threonine aldolases10-12, for the α-C-H functionalization of glycine and α-branched amino acid substrates by a radical mechanism, giving rise to a range of α-tri- and tetrasubstituted non-canonical amino acids 13-15 possessing up to two contiguous stereocentres. Directed evolution of pyridoxal radical enzymes allowed primary and secondary radical precursors, including benzyl, allyl and alkylboron reagents, to be coupled in an enantio- and diastereocontrolled fashion. Cooperative photoredox-pyridoxal biocatalysis provides a platform for sp3-sp3 oxidative coupling16, permitting the stereoselective, intermolecular free-radical transformations that are unknown to chemistry or biology.


Assuntos
Aminoácidos , Biocatálise , Acoplamento Oxidativo , Processos Fotoquímicos , Aminoácidos/biossíntese , Aminoácidos/química , Aminoácidos/metabolismo , Biocatálise/efeitos da radiação , Evolução Molecular Direcionada , Radicais Livres/química , Radicais Livres/metabolismo , Glicina/química , Glicina/metabolismo , Glicina Hidroximetiltransferase/metabolismo , Glicina Hidroximetiltransferase/química , Indicadores e Reagentes , Luz , Acoplamento Oxidativo/efeitos da radiação , Fosfato de Piridoxal/metabolismo , Estereoisomerismo , Aminoácidos de Cadeia Ramificada/química , Aminoácidos de Cadeia Ramificada/metabolismo
9.
Top Curr Chem (Cham) ; 382(2): 12, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589598

RESUMO

Organoselenium compounds have been the subject of extensive research since the discovery of the biologically active compound ebselen. Ebselen has recently been found to show activity against the main protease of the virus responsible for COVID-19. Other organoselenium compounds are also well-known for their diverse biological activities, with such compounds exhibiting interesting physical properties relevant to the fields of electronics, materials, and polymer chemistry. In addition, the incorporation of selenium into various organic molecules has garnered significant attention due to the potential of selenium to enhance the biological activity of these molecules, particularly in conjunction with bioactive heterocycles. Iodine and iodine-based reagents play a prominent role in the synthesis of organoselenium compounds, being valued for their cost-effectiveness, non-toxicity, and ease of handling. These reagents efficiently selenylate a broad range of organic substrates, encompassing alkenes, alkynes, and cyclic, aromatic, and heterocyclic molecules. They serve as catalysts, additives, inducers, and oxidizing agents, facilitating the introduction of different functional groups at alternate positions in the molecules, thereby allowing for regioselective and stereoselective approaches. Specific iodine reagents and their combinations can be tailored to follow the desired reaction pathways. Here, we present a comprehensive review of the progress in the selenylation of organic molecules using iodine reagents over the past decade, with a focus on reaction patterns, solvent effects, heating, microwave, and ultrasonic conditions. Detailed discussions on mechanistic aspects, such as electrophilic, nucleophilic, radical, electrochemical, and ring expansion reactions via selenylation, multiselenylation, and difunctionalization, are included. The review also highlights the formation of various cyclic, heterocyclic, and heteroarenes resulting from the in situ generation of selenium intermediates, encompassing cyclic ketones, cyclic ethers, cyclic lactones, selenophenes, chromones, pyrazolines, pyrrolidines, piperidines, indolines, oxazolines, isooxazolines, lactones, dihydrofurans, and isoxazolidines. To enhance the reader's interest, the review is structured into different sections covering the selenylation of aliphatic sp2/sp carbon and cyclic sp2 carbon, and then is further subdivided into various heterocyclic molecules.


Assuntos
Iodo , Isoindóis , Compostos Organosselênicos , Selênio , Iodo/química , Indicadores e Reagentes , Compostos Organosselênicos/química , Lactonas/química , Carbono
10.
ACS Sens ; 9(4): 2075-2082, 2024 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-38557006

RESUMO

Wearable sweat sensors have achieved rapid development since they hold great potential in personalized health monitoring. However, a typical difficulty in practical processes is the control of working conditions for biorecognition elements, e.g., pH level and ionic strength in sweat may decrease the affinity between analytes and recognition elements. Here, we developed a wearable sensing device for cortisol detection in sweat using an aptamer as the recognition element. The device integrated functions of sweat collection, reagent prestorage, and signal conversion. Especially, the components of prestored reagents were optimized according to the inherent characteristics of sweat samples and electrodes, which allowed us to keep optimal conditions for aptamers. The sweat samples were transferred from the inlet of the device to the reagent prestored chamber, and the dry preserved reagents were rehydrated with sweat and then arrived at the aptamer-modified electrodes. Sweat samples of volunteers were analyzed by the wearable sensing device, and the results showed a good correlation with those of the ELISA kit. We believe that this convenient and reliable wearable sensing device has significant potential in self-health monitoring.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Hidrocortisona , Suor , Dispositivos Eletrônicos Vestíveis , Suor/química , Hidrocortisona/análise , Humanos , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Eletrodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Indicadores e Reagentes/química
11.
RNA ; 30(7): 901-919, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38670632

RESUMO

A key to understanding the roles of RNA in regulating gene expression is knowing their structures in vivo. One way to obtain this information is through probing the structures of RNA with chemicals. To probe RNA structure directly in cells, membrane-permeable reagents that modify the Watson-Crick (WC) face of unpaired nucleotides can be used. Although dimethyl sulfate (DMS) has led to substantial insight into RNA structure, it has limited nucleotide specificity in vivo, with WC face reactivity only at adenine (A) and cytosine (C) at neutral pH. The reagent 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) was recently shown to modify the WC face of guanine (G) and uracil (U). Although useful at lower concentrations in experiments that measure chemical modifications by reverse transcription (RT) stops, at higher concentrations necessary for detection by mutational profiling (MaP), EDC treatment leads to degradation of RNA. Here, we demonstrate EDC-stimulated degradation of RNA in Gram-negative and Gram-positive bacteria. In an attempt to overcome these limitations, we developed a new carbodiimide reagent, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide methiodide (ETC), which we show specifically modifies unpaired Gs and Us in vivo without substantial degradation of RNA. We establish ETC as a probe for MaP and optimize the RT conditions and computational analysis in Escherichia coli Importantly, we demonstrate the utility of ETC as a probe for improving RNA structure prediction both alone and with DMS.


Assuntos
Guanina , Conformação de Ácido Nucleico , Ésteres do Ácido Sulfúrico , Uracila , Ésteres do Ácido Sulfúrico/química , Uracila/química , Uracila/análogos & derivados , Uracila/metabolismo , Guanina/química , Guanina/metabolismo , RNA/química , RNA/genética , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Carbodi-Imidas/química , RNA Bacteriano/química , RNA Bacteriano/genética , Estabilidade de RNA , Indicadores e Reagentes/química
12.
Anal Chem ; 96(15): 5815-5823, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38575144

RESUMO

Microfluidic techniques are widely applied in biomolecular analysis and disease diagnostic assays. While the volume of the sample that is directly used in such assays is often only femto-to microliters, the "dead volume" of solutions supplied in syringes and tubing can be much larger, even up to milliliters, increasing overall reagent use and making analysis significantly more expensive. To reduce the difficulty and cost, we designed a new chip using a low volume solution for analysis and applied it to obtain real-time data for protein-protein interaction measurements. The chip takes advantage of air/aqueous two-phase droplet flow, on-chip rapid mixing within milliseconds, and a droplet capture method, that ultimately requires only 2 µL of reagent solution. The interaction is analyzed by particle diffusometry, a nonintrusive and precise optical detection method to analyze the properties of microparticle diffusion in solution. Herein, we demonstrate on-chip characterization of human immunodeficiency virus p24 antibody-antigen protein binding kinetics imaged via fluorescence microscopy and analyzed by PD. The measured kon and koff are 1 × 106 M-1 s-1 and 3.3 × 10-4 s-1, respectively, and agree with independent measurement via biolayer interferometry and previously calculated p24-antibody binding kinetics. This new microfluidic chip and the protein-protein interaction analysis method can also be applied in other fields that require low-volume solutions to perform accurate measurement, analysis, and detection.


Assuntos
Técnicas Analíticas Microfluídicas , Microfluídica , Humanos , Cinética , Difusão , Indicadores e Reagentes , Técnicas Analíticas Microfluídicas/métodos
13.
Forensic Sci Int ; 358: 112018, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38581824

RESUMO

A number of solvents, (Solstice PF, Opteon SF33 and Amolea AS-300), are compared to the recommended carrier solvent of HFE7100 for the ninhydrin and 1,2-indandione formulations. As the supply of HFE7100 will cease by the end of 2025, suitable alternatives are required in the short-term to ensure the detection of latent fingermarks on porous surfaces is still effective. Although these solvents, with the exception of Amolea AS-300, are classified as per- and polyfluoroalkyl substances (PFAS); they are not classed as hazardous. The alternatives in this study have a low global warming potential and atmospheric lifetime and are volatile, non-flammable and non-ozone depleting, in addition to other desirable properties such as a high wetting-index. During Phase 2 trials with deposited fingermarks, HFE7100 provided the best performing results followed by Opteon SF33, Solstice PF and Amolea AS-300. A significant difference with a negligible effect size was observed for ninhydrin formulations (p-value 0.00179; ε2 0.00418) while a significant difference with a weak effect size was observed for 1,2-indanedione formulations (p-value 2.095 ×10-10; ε2 0.0167). Furthermore, HFE7100 provided the least ink diffusion and the brightest 1,2-indanedione luminosity (significant difference with a moderate effect size p-value 1.772 ×10-13; ε2 0.0434) but the HFE formulation turned cloudy more quickly and needed regular replacements. Phase 3 pseudo-operational trials of 100 porous items followed a similar trend whereby HFE7100 formulations detected the highest number of marks followed by Opteon SF33 and Solstice PF. Although HFE7100 is still the best performing carrier solvent, this study demonstrates that, in the short-term, Opteon SF33 and Solstice PF may have potential as non-flammable replacement carrier solvents while developing the long-term goal of solvent-less methods.


Assuntos
Dermatoglifia , Indanos , Indicadores e Reagentes , Ninidrina , Solventes , Humanos , Solventes/química , Indanos/química
14.
Talanta ; 275: 126084, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38608344

RESUMO

The 5-nitro-2-furaldehyde (5-NF) is an aldehyde aromatic organic compound that has been envisaged as an alternative marker for detecting nitrofurazone treatment abuse and to avoid the false positive results induced by the semicarbazide. Analyzing 5-NF presents challenges, and its derivatization reaction with hydrazine reagents is required to enhance the capability of its detection and its identification. This study aims at developping an analytical method for 5-NF determination in trout muscle samples based on chemical derivatization prior to analysis by liquid chromatography-tandem mass spectrometry. Four commercially available hydrazine reagents, namely: N,N-Dimethylhydrazine (DMH), 4-Hydrazinobenzoic acid (HBA), 2,4-Dichlorophenylhydrazine (2,4-DCPH) and 2,6-Dichlorophenylhydrazine (2,6-DCPH) were proposed for the first time as derivatizing reagents in the analysis of 5-NF. The derivatization reaction was simultaneously performed along with the extraction method in acidic condition using ultrasonic assistance and followed by liquid extraction using acetonitrile. The efficiency of the chemical reaction with 5-NF was examined and the reaction conditions including the concentration of hydrochloric acid, pH, temperature, reaction time and the concentration of the derivatizing reagents were optimized. Experiments with fortified samples demonstrated that 2,4-DCPH derivatizing reagent at 20 mM for 20 min of ultrasonic treatment under acidic condition (pH 4) gave an effective sample derivatization method for 5-NF analysis. Under the optimized conditions, the calibration curves were linear from 0.25 to 2 µg kg-1 with coefficient of determination >0.99. The recoveries ranged from 89 % to 116 % and precision was less than 13 %. The limit of detection and quantification were 0.1 and 0.2 µg kg-1, respectively.


Assuntos
Músculos , Espectrometria de Massas em Tandem , Truta , Espectrometria de Massas em Tandem/métodos , Animais , Cromatografia Líquida/métodos , Músculos/química , Furaldeído/análogos & derivados , Furaldeído/análise , Furaldeído/química , Limite de Detecção , Indicadores e Reagentes/química , Hidrazinas/química
16.
J Cosmet Dermatol ; 23(6): 2231-2239, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38576192

RESUMO

BACKGROUND: Pigment Red 53 is a dangerous synthetic dye that is often added to cosmetics, even though its use in cosmetic products has been prohibited because of possible impacts on health. Faster and more sensitive detection of Pigment Red 53 is needed for onsite analysis to protect the community from illegal cosmetics that contain the dye. Indicator color charts are a kind of analytical method that can be used to detect Pigment Red 53 in cosmetic products, including lipstick, rouge, and eyeshadow. Such charts are practical, fast, and can be used for onsite analysis. METHODS: In this study, an indicator for Pigment Red 53 detection was obtained through a reagent reaction that caused a specific color change. An indicator color chart was then produced by setting out in paper form the series of colors which resulted from the reaction of specific chemical reagents and Pigment Red 53 solutions at concentrations of 10, 20, 40, 60, 80, and 100 ppm. RESULTS: The testing results showed that the indicator color chart may be used as an initial screening method for the detection of Pigment Red 53 in cosmetic products with a detectable minimum concentration of 10 ppm. Out of nine samples, only one (Eyeshadow 3) tested positive for Pigment Red 53. Further analysis was carried out on the indicator color chart and the results showed good agreement with TLC and UV-Vis spectrophotometry methods. CONCLUSION: The results reported in this paper demonstrate that the indicator color chart is a good prospective method for onsite analysis to detect Pigment Red 53 in cosmetic samples, with a lower detection limit compared to polymer-based indicators.


Assuntos
Corantes , Cosméticos , Cosméticos/química , Cosméticos/análise , Indonésia , Humanos , Corantes/análise , Cor , Colorimetria/métodos , Compostos Azo/análise , Compostos Azo/química , Indicadores e Reagentes/química
17.
Nature ; 627(8004): 680-687, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38448587

RESUMO

Methods for selective covalent modification of amino acids on proteins can enable a diverse array of applications, spanning probes and modulators of protein function to proteomics1-3. Owing to their high nucleophilicity, cysteine and lysine residues are the most common points of attachment for protein bioconjugation chemistry through acid-base reactivity3,4. Here we report a redox-based strategy for bioconjugation of tryptophan, the rarest amino acid, using oxaziridine reagents that mimic oxidative cyclization reactions in indole-based alkaloid biosynthetic pathways to achieve highly efficient and specific tryptophan labelling. We establish the broad use of this method, termed tryptophan chemical ligation by cyclization (Trp-CLiC), for selectively appending payloads to tryptophan residues on peptides and proteins with reaction rates that rival traditional click reactions and enabling global profiling of hyper-reactive tryptophan sites across whole proteomes. Notably, these reagents reveal a systematic map of tryptophan residues that participate in cation-π interactions, including functional sites that can regulate protein-mediated phase-separation processes.


Assuntos
Cátions , Ciclização , Indicadores e Reagentes , Proteínas , Triptofano , Cátions/química , Indicadores e Reagentes/química , Oxirredução , Proteoma/química , Triptofano/química , Peptídeos/química , Química Click , Proteínas/química
18.
J Histochem Cytochem ; 72(4): 233-243, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38553997

RESUMO

Xylene is the commonest clearing agent even though it is hazardous and costly. This study evaluated the clearing properties of coconut oil as an alternative cost-effective clearing agent for histological processes. Ten (10) prostate samples fixed in formalin were taken and each one was cut into 4 before randomly separating them into four groups (A, B, C and D). Tissues were subjected to ascending grades of alcohol for dehydration. Group A was cleared in xylene and Groups B, C, and D were cleared at varying times of 1hr 30mins, 3hrs, and 4hrs in coconut oil respectively before embedding, sectioning, and staining were carried out. Gross and histological features were compared. Results indicated a significant shrinkage in coconut oil-treated specimen compared with the xylene-treated specimen and only the tissues cleared in coconut oil for 4hrs were as rigid as the tissues cleared in xylene (p > 0.05). No significant difference was found in either of the sections when checked for cellular details and staining quality (p > 0.999). Coconut oil is an efficient substitute for xylene in prostate tissues with a minimum clearing time of 4hrs, as it is environmentally friendly and less expensive, but causes significant shrinkage to prostate tissue.


Assuntos
Formaldeído , Xilenos , Óleo de Coco , Xilenos/química , Coloração e Rotulagem , Indicadores e Reagentes
19.
Acc Chem Res ; 57(6): 855-869, 2024 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-38452397

RESUMO

Since the pioneering work of Curtius and Fischer, chemical peptide synthesis has witnessed a century's development and evolved into a routine technology. However, it is far from perfect. In particular, it is challenged by sustainable development because the state-of-the-art of peptide synthesis heavily relies on legacy reagents and technologies developed before the establishment of green chemistry. Over the past three decades, a broad range of efforts have been made for greening peptide synthesis, among which peptide synthesis using unprotected amino acid represents an ideal and promising strategy because it does not require protection and deprotection steps. Unfortunately, C → N peptide synthesis employing unprotected amino acids has been plagued by undesired polymerization, while N → C inverse peptide synthesis with unprotected amino acids is retarded by severe racemization/epimerization owing to the iterative activation and aminolysis of high racemization/epimerization susceptible peptidyl acids. Consequently, there is an urgent need to develop innovative coupling reagents and strategies with novel mechanisms that can address the long-standing notorious racemization/epimerization issue of peptide synthesis.This Account will describe our efforts in discovery of ynamide coupling reagents and their application in greening peptide synthesis. Over an eight-year journey, ynamide coupling reagents have evolved into a class of general coupling reagents for both amide and ester bond formation. In particular, the superiority of ynamide coupling reagents in suppressing racemization/epimerization enabled them to be effective for peptide fragment condensation, and head-to-tail cyclization, as well as precise incorporation of thioamide substitutions into peptide backbones. The first practical inverse peptide synthesis using unprotected amino acids was successfully accomplished by harnessing such features and taking advantage of a transient protection strategy. Ynamide coupling reagent-mediated ester bond formation enabled efficient intermolecular esterification and macrolactonization with preservation of α-chirality and the configuration of the conjugated α,ß-C-C double bond. To make ynamide coupling reagents readily available with reasonable cost and convenience, we have developed a scalable one-step synthetic method from cheap starting materials. Furthermore, a water-removable ynamide coupling reagent was developed, offering a column-free purification of the target coupling product. In addition, the recycle of ynamide coupling reagent was accomplished, thereby paving the way for their sustainable industrial application.As such, this Account presents the whole story of the origin, mechanistic insights, preparation, synthetic applications, and recycle of ynamide coupling reagents with a perspective that highlights their future impact on peptide synthesis.


Assuntos
Amidas , Peptídeos , Indicadores e Reagentes , Peptídeos/química , Amidas/química , Aminoácidos/química , Ésteres
20.
Chem Soc Rev ; 53(9): 4607-4647, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38525675

RESUMO

Alcohol is ubiquitous with unparalleled structural diversity and thus has wide applications as a native functional group in organic synthesis. It is highly prevalent among biomolecules and offers promising opportunities for the development of chemical libraries. Over the last decade, alcohol has been extensively used as an environmentally friendly chemical for numerous organic transformations. In this review, we collectively discuss the utilisation of alcohol from 2015 to 2023 in various organic transformations and their application toward intermediates of drugs, drug derivatives and natural product-like molecules. Notable features discussed are as follows: (i) sustainable approaches for C-X alkylation (X = C, N, or O) including O-phosphorylation of alcohols, (ii) newer strategies using methanol as a methylating reagent, (iii) allylation of alkenes and alkynes including allylic trifluoromethylations, (iv) alkenylation of N-heterocycles, ketones, sulfones, and ylides towards the synthesis of drug-like molecules, (v) cyclisation and annulation to pharmaceutically active molecules, and (vi) coupling of alcohols with aryl halides or triflates, aryl cyanide and olefins to access drug-like molecules. We summarise the synthesis of over 100 drugs via several approaches, where alcohol was used as one of the potential coupling partners. Additionally, a library of molecules consisting over 60 fatty acids or steroid motifs is documented for late-stage functionalisation including the challenges and opportunities for harnessing alcohols as renewable resources.


Assuntos
Álcoois , Álcoois/química , Álcoois/síntese química , Preparações Farmacêuticas/química , Preparações Farmacêuticas/síntese química , Produtos Biológicos/química , Produtos Biológicos/síntese química , Indicadores e Reagentes/química , Alquilação , Estrutura Molecular , Alcenos/química , Alcenos/síntese química , Química Verde
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