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1.
Chemistry ; 30(40): e202400537, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38703390

RESUMO

With the popularization of 5G technology and artificial intelligence, thermally conductive epoxies with self-healing ability will be widely used in flexible electronic materials. Although many compounds containing both performances have been synthesized, there is little systematic theory to explain the coordination mechanism. In this paper, alkyl chains of different lengths were introduced to epoxies to discuss the thermally conductive, the self-healing performance, and the synergistic effect. A series of electronic-grade biphenyl epoxies (4,4'-bis(oxiran-2-ylmethoxy)-1,1'-biphenyl (1), 4,4'-bis(2-(oxiran-2-yl)ethoxy)-1,1'-biphenyl (2), 4,4'-bis(3-(oxiran-2-yl)propoxy)-1,1'-biphenyl (3), and 4,4'-bis(4-(oxiran-2-yl)butoxy)-1,1'-biphenyl (4) were synthesized and characterized. Furthermore, they were cured with decanedioic acid to produce polymers. Results showed that alkyl chains can both affect the two properties, and the epoxies suitable for specific application scenarios can be prepared by adjusting the length of alkyl chains. In terms of thermal conductivity, compound 1 was a most promising material. However, compound 4 was expected to be utilized in flexible electronic devices because of its acceptable thermal conductivity, self-healing ability, transparency, and flexibility.

2.
Chemistry ; 30(6): e202302904, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-37936501

RESUMO

A highly enantioselective Mannich reaction of biphenyl-bridged seven-membered cyclic N-sulfonylimines with methyl alkyl ketones is disclosed in this study. The reaction was performed under organocatalysis by using a quinine-derived primary amine as the catalyst in combination with a Brønsted acid as the co-catalyst. High yields (up to 89 %) and excellent enantioselectivities (up to 97 % ee) were observed. For methyl alkyl ketones containing a larger alkyl substituent, specific regioselective addition to the C=N bond is favored at the methyl group. On the contrary, ketones containing a smaller alkyl substituent or hydroxyacetone substrates gave major syn selective Mannich products at the methylene group.

3.
Crit Rev Toxicol ; 54(2): 92-122, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38363552

RESUMO

Polychlorinated biphenyls (PCBs) are persistent organic toxicants derived from legacy pollution sources and their formation as inadvertent byproducts of some current manufacturing processes. Metabolism of PCBs is often a critical component in their toxicity, and relevant metabolic pathways usually include their initial oxidation to form hydroxylated polychlorinated biphenyls (OH-PCBs). Subsequent sulfation of OH-PCBs was originally thought to be primarily a means of detoxication; however, there is strong evidence that it may also contribute to toxicities associated with PCBs and OH-PCBs. These contributions include either the direct interaction of PCB sulfates with receptors or their serving as a localized precursor for OH-PCBs. The formation of PCB sulfates is catalyzed by cytosolic sulfotransferases, and, when transported into the serum, these metabolites may be retained, taken up by other tissues, and subjected to hydrolysis catalyzed by intracellular sulfatase(s) to regenerate OH-PCBs. Dynamic cycling between PCB sulfates and OH-PCBs may lead to further metabolic activation of the resulting OH-PCBs. Ultimate toxic endpoints of such processes may include endocrine disruption, neurotoxicities, and many others that are associated with exposures to PCBs and OH-PCBs. This review highlights the current understanding of the complex roles that PCB sulfates can have in the toxicities of PCBs and OH-PCBs and research on the varied mechanisms that control these roles.


Assuntos
Bifenilos Policlorados , Bifenilos Policlorados/toxicidade , Bifenilos Policlorados/metabolismo , Hidroxilação , Sulfatos/toxicidade , Sulfatos/metabolismo , Poluição Ambiental , Substâncias Perigosas
4.
Environ Sci Technol ; 58(8): 3895-3907, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38356175

RESUMO

Volatilization of lower-chlorinated polychlorinated biphenyls (LC-PCBs) from sediment poses health threats to nearby communities and ecosystems. Biodegradation combined with black carbon (BC) materials is an emerging bioaugmentation approach to remove PCBs from sediment, but development of aerobic biofilms on BC for long-term, sustained LC-PCBs remediation is poorly understood. This work aimed to characterize the cell enrichment and activity of biphenyl- and benzoate-grown Paraburkholderia xenovorans strain LB400 on various BCs. Biphenyl dioxygenase gene (bphA) abundance on four BC types demonstrated corn kernel biochar hosted at least 4 orders of magnitude more attached cells per gram than other feedstocks, and microscopic imaging revealed the attached live cell fraction was >1.5× more on corn kernel biochar than GAC. BC characteristics (i.e., sorption potential, pore size, pH) appear to contribute to cell attachment differences. Reverse transcription qPCR indicated that BC feedstocks significantly influenced bphA expression in attached cells. The bphA transcript-per-gene ratio of attached cells was >10-fold more than suspended cells, confirmed by transcriptomics. RNA-seq also demonstrated significant upregulation of biphenyl and benzoate degradation pathways on attached cells, as well as revealing biofilm formation potential/cell-cell communication pathways. These novel findings demonstrate aerobic PCB-degrading cell abundance and activity could be tuned by adjusting BC feedstocks/attributes to improve LC-PCBs biodegradation potential.


Assuntos
Compostos de Bifenilo , Burkholderiaceae , Carvão Vegetal , Bifenilos Policlorados , Benzoatos , Biodegradação Ambiental , Carbono , Ecossistema , Bifenilos Policlorados/metabolismo , Dioxigenases/química , Dioxigenases/metabolismo
5.
Bioorg Chem ; 146: 107280, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479131

RESUMO

Ten new compounds, including three pairs of diarylcyclopentenone enantiomers (±) talaromycesins A-C (1-3) and four biphenyl derivatives talaromycesins D-G (4-7), along with four known compounds (8-11), were isolated from the fungus Talaromyces adpressus. Their structures were determined by analyses of extensive NMR spectroscopic and HRESIMS data, and their absolute configurations were elucidated by the dimolybdenum tetraacetate [Mo2(AcO)4]-induced ECD spectra, X-ray crystallographic studies, and ECD calculations. These new compounds were evaluated for their immunosuppressive activities for the first time, and compound 7 probably exerted liver-protective and anti-inflammatory effects on Con A-induced AIH by decreasing the levels of inflammatory cytokines, modulating immune homeostasis, and decreasing hepatocyte apoptosis, which may become a potential drug for the treatment of autoimmune diseases.


Assuntos
Talaromyces , Espectroscopia de Ressonância Magnética , Talaromyces/química , Compostos de Bifenilo , Estrutura Molecular
6.
Bioorg Chem ; 146: 107291, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38521011

RESUMO

Hyaluronidase is a promising target in drug discovery, given its overexpression in a range of physiological and pathological processes, including tumor migration, skin aging, sagging, and wrinkling, as well as inflammation and bacterial infections. In this study, to identify novel hyaluronidase inhibitors, we applied click chemistry for the modular synthesis of 370 triazoles in 96-well plates, starting with biphenyl azide. Utilizing an optimized turbidimetric screening assay in microplates, we identified Fmoc-containing triazoles 5 and 6, as well as quinoline-containing triazoles 15 and 16, as highly effective hyaluronidase inhibitors. Subsequent research indicated that these triazoles potentially interact with a novel binding site of hyaluronidase. Notably, these inhibitors displayed minimal cytotoxicity and showed promising anti-inflammatory effects in LPS-stimulated macrophages. Remarkably, compound 6 significantly reduced NO release by 74 % at a concentration of 20 µM.


Assuntos
Compostos de Bifenilo , Hialuronoglucosaminidase , Triazóis , Triazóis/química , Química Click , Sítios de Ligação
7.
Bioorg Chem ; 148: 107433, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38754311

RESUMO

Second-generation AR antagonists, such as enzalutamide, are the primary therapeutic agents for advanced prostate cancer. However, the development of both primary and secondary drug resistance leads to treatment failures and patient mortality. Bifunctional agents that simultaneously antagonize and degrade AR block the AR signaling pathway more completely and exhibit excellent antiproliferative activity against wild-type and drug-resistant prostate cancer cells. Here, we reported the discovery and optimization of a series of biphenyl derivatives as androgen receptor antagonists and degraders. These biphenyl derivatives exhibited potent antiproliferative activity against LNCaP and 22Rv1 cells. Our discoveries enrich the diversity of small molecule AR degraders and offer insights for the development of novel AR degraders for the treatment of enzalutamide-resistant prostate cancer.


Assuntos
Antagonistas de Receptores de Andrógenos , Antineoplásicos , Benzamidas , Compostos de Bifenilo , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Nitrilas , Feniltioidantoína , Neoplasias da Próstata , Receptores Androgênicos , Humanos , Masculino , Benzamidas/farmacologia , Benzamidas/química , Benzamidas/síntese química , Nitrilas/química , Nitrilas/farmacologia , Feniltioidantoína/farmacologia , Feniltioidantoína/análogos & derivados , Feniltioidantoína/química , Compostos de Bifenilo/farmacologia , Compostos de Bifenilo/antagonistas & inibidores , Receptores Androgênicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Relação Estrutura-Atividade , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Neoplasias da Próstata/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Estrutura Molecular , Antagonistas de Receptores de Andrógenos/farmacologia , Antagonistas de Receptores de Andrógenos/química , Antagonistas de Receptores de Andrógenos/síntese química , Antagonistas de Receptores de Andrógenos/uso terapêutico , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Relação Dose-Resposta a Droga , Linhagem Celular Tumoral
8.
Bioorg Chem ; 146: 107263, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38492493

RESUMO

The aberrant activation of NLRP3 inflammasome has been observed in various human diseases. Targeting the NLRP3 protein with small molecule inhibitors shows immense potential as an effective strategy for disease intervention. Herein, a series of novel biphenyl-sulfonamide NLRP3 inflammasome inhibitors were designed and synthesized. The representative compound H28 was identified as potent and specific NLRP3 inflammasome inhibitor with IC50 values of 0.57 µM. Preliminary mechanistic studies have revealed that compound H28 exhibits direct binding to the NLRP3 protein (KD: 1.15 µM), effectively inhibiting the assembly and activation of the NLRP3 inflammasome. The results in a mouse acute peritonitis model revealed that H28 effectively inhibit the NLRP3 inflammasome pathway, demonstrating their anti-inflammatory properties. Our findings strongly support the further development of H28 as potential lead compound for treating NLRP3-related diseases.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Camundongos , Animais , Humanos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Compostos de Bifenilo , Sulfonamidas/farmacologia , Sulfanilamida , Camundongos Endogâmicos C57BL
9.
Environ Res ; : 120081, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39343341

RESUMO

Exposure to polychlorinated biphenyls (PCBs) remains a potential human health risk due to their persistence in the environment, despite a global ban on their production. Understanding the composition of PCB mixtures is essential for the application of a mixtures-based approach to assessing health risks of PCB exposure. This work represents the most extensive effort to date to compile and make publicly available the PCB congener profiles for mixtures with toxicological data, providing a foundation for understanding toxicological potency of PCB mixtures in the environment. We identified published congener profiles across 29 commercial and simulated environmental PCB mixtures, including various Aroclors, Phenoclors, Clophens, and Kanechlors, among others. A total of 117 references containing 401 distinct complete or partial tabularized profiles were found. Aroclor 1254 had the most published profiles, with 79 unique datasets characterizing multiple mixture lots. In contrast, no congener-specific composition data were identified for Fenclors, Clophen C, or Pyralenes. Eighty-seven of the most complete and clearly reported profiles underwent a detailed extraction of the congener data, PCB mixture source, and analytical methods. Challenges encountered during data extraction included congener coelutions, incomplete methods reporting, and inconsistencies in PCB nomenclature. These factors complicate data visualization, comparisons across datasets, and use of the data in subsequent analyses. Where possible, we have converted profiles to the same units and congener numbering convention to allow for easier comparison. The extracted data are publicly available online as interactive visuals and as a downloadable Microsoft Excel® workbook. This dataset provides researchers with an overview of the current PCB mixture profile landscape that can serve as a tool to support efforts to minimize the health impacts of environmental PCB exposure, including the exploration of links between mixture composition and toxicity and the identification of the most efficient and effective remediation strategies at contaminated sites.

10.
Plant Cell Rep ; 43(3): 62, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38336832

RESUMO

KEY MESSAGE: Yeast extract-induced oxidative stress in Sorbus aucuparia suspension cells leads to the biosynthesis of various hormones, which activates specific signaling pathways that augments biphenyl phytoalexin production. Pathogen incursions pose a significant threat to crop yield and can have a pronounced effect on agricultural productivity and food security. Biphenyl phytoalexins are a specialized group of secondary metabolites that are mainly biosynthesized by Pyrinae plants as a defense mechanism against various pathogens. Despite previous research demonstrating that biphenyl phytoalexin production increased dramatically in Sorbus aucuparia suspension cells (SASCs) treated with yeast extract (YE), the underlying mechanisms remain poorly understood. To address this gap, we conducted an in-depth, multi-omics analysis of transcriptome, proteome, and metabolite (including biphenyl phytoalexins and phytohormones) dynamics in SASCs exposed to YE. Our results indicated that exposure to YE-induced oxidative stress in SASCs, leading to the biosynthesis of a range of hormones, including jasmonic acid (JA), jasmonic acid isoleucine (JA-ILE), gibberellin A4 (GA4), indole-3-carboxylic acid (ICA), and indole-3-acetic acid (IAA). These hormones activated specific signaling pathways that promoted phenylpropanoid biosynthesis and augmented biphenyl phytoalexin production. Moreover, reactive oxygen species (ROS) generated during this process also acted as signaling molecules, amplifying the phenylpropanoid biosynthesis cascade through activation of the mitogen-activated protein kinase (MAPK) pathway. Key genes involved in these signaling pathways included SaBIS1, SaBIS2, SaBIS3, SaPAL, SaB4H, SaOMT, SaUGT1, SaLOX2, SaPR1, SaCHIB1, SaCHIB2 and SaCHIB3. Collectively, this study provided intensive insights into biphenyl phytoalexin accumulation in YE-treated SASCs, which would inform the development of more efficient disease-resistance strategies in economically significant cultivars.


Assuntos
Compostos de Bifenilo , Ciclopentanos , Oxilipinas , Sesquiterpenos , Sorbus , Fitoalexinas , Sorbus/genética , Sorbus/metabolismo , Multiômica , Estresse Oxidativo , Hormônios/metabolismo , Sesquiterpenos/metabolismo
11.
Phytochem Anal ; 35(5): 1142-1151, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38558474

RESUMO

INTRODUCTION: Gomisin is a natural dibenzo cyclooctene lignan, which is mainly derived from the family Magnoliaceae. It has anti-inflammatory, antioxidant, anti-tumor, anti-aging, and hypoglycemic effects. Gomisins play important roles as medicines, nutraceuticals, food additives, and cosmetics. OBJECTIVE: The objective of this study is to establish a micellar electrokinetic chromatography (MEKC) method for simultaneous separation and determination of seven biphenyl cyclooctene lignans (Gomisin D, E, G, H, J, N, and O) in Schisandra chinensis and its preparations. METHODS: The method was optimized by studying the effects of the main parameters on the separation. The method has been validated and successfully applied to the determination of seven Gomisins in S. chinensis and its preparations. RESULTS: In the separation system, the running buffer was composed of 20 mM Na2HPO4, 8.0 mM sodium dodecyl sulfate (SDS), 11% (v/v) methanol, and 6.0% (v/v) ethanol. A diode array detector was used with a detection wavelength of 230 nm, a separation voltage of 17 kV, and an operating temperature of 25°C. Under this condition, the seven analytes were separated at baseline within 20 min, and a good linear relationship was obtained with correlation coefficient ranging from 0.9919 to 0.9992. The limit of detection (LOD, S/N = 3) and the limit of quantification (LOQ, S/N = 10) ranged from 0.8 to 0.9 µg/mL and from 2.6 to 3.0 µg/mL, respectively. The recovery rate was between 99.1% and 102.5%. CONCLUSION: The experimental results indicated that this method is suitable for the separation and determination of seven Schisandra biphenyl cyclooctene lignan compounds in real samples. At the same time, it provides an effective reference for the quality control of S. chinensis and its preparations.


Assuntos
Cromatografia Capilar Eletrocinética Micelar , Ciclo-Octanos , Lignanas , Schisandra , Solventes , Lignanas/análise , Schisandra/química , Cromatografia Capilar Eletrocinética Micelar/métodos , Solventes/química , Ciclo-Octanos/análise , Ciclo-Octanos/química , Reprodutibilidade dos Testes , Limite de Detecção , Compostos de Bifenilo/química
12.
J Environ Manage ; 357: 120803, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38569268

RESUMO

Resuscitation promoting factors (Rpfs), known for their anti-dormancy cytokine properties, have been extensively investigated in the medical field. Although the Rpf from Micrococcus luteus has been successfully utilized to resuscitate and stimulate microbial populations for the degradation of polychlorinated biphenyls (PCBs), the presence of indigenous Rpf homologs in PCB-contaminated soils has not been established. In this study, the distribution characteristics of rpf-like genes and indigenous strain capable of producing Rpf in PCB-contaminated soils were explored. The results revealed the widespread presence of Rpf-like domains and their associated genes, particularly in close association with heavy metals and PCBs. The rpf-like genes were predominantly found in Proteobacteria and displayed a positive correlation with genes involved in PCB degradation and viable but non-culturable (VBNC) formation. Notably, the recombinant Rpf-Ac protein derived from the indigenous strain Achromobacter sp. HR2 exhibited muralytic activity and demonstrated significant efficacy in resuscitating the growth of VBNC cells, while also stimulating the growth of normal cells. These findings shed light on the prevalent presence of Rpf homologs in PCB-contaminated soils and their potential to resuscitate functional populations in the VBNC state, thereby enhancing in situ bioremediation.


Assuntos
Bifenilos Policlorados , Biodegradação Ambiental , Solo
13.
Molecules ; 29(11)2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38893290

RESUMO

Herbicides are useful tools for managing weeds and promoting food production and sustainable agriculture. In this study, we report on the development of a novel class of lipophilic pyrimidine-biphenyl (PMB) herbicides. Firstly, three PMBs, Ia, IIa, and IIIa, were rationally designed via a scaffold hopping strategy and were determined to inhibit acetohydroxyacid synthase (AHAS). Computational simulation was carried out to investigate the molecular basis for the efficiency of PMBs against AHAS. With a rational binding mode, and the highest in vitro as well as in vivo potency, Ia was identified as a preferable hit. Furthermore, these integrated analyses guided the design of eighteen new PMBs, which were synthesized via a one-step Suzuki-Miyaura cross-coupling reaction. These new PMBs, Iba-ic, were more effective in post-emergence control of grass weeds compared with Ia. Interestingly, six of the PMBs displayed 98-100% inhibition in the control of grass weeds at 750 g ai/ha. Remarkably, Ica exhibited ≥ 80% control against grass weeds at 187.5 g ai/ha. Overall, our comprehensive and systematic investigation revealed that a structurally distinct class of lipophilic PMB herbicides, which pair excellent herbicidal activities with new interactions with AHAS, represent a noteworthy development in the pursuit of sustainable weed control solutions.


Assuntos
Herbicidas , Pirimidinas , Herbicidas/química , Herbicidas/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Acetolactato Sintase/antagonistas & inibidores , Acetolactato Sintase/metabolismo , Acetolactato Sintase/química , Compostos de Bifenilo/química , Compostos de Bifenilo/antagonistas & inibidores , Simulação de Acoplamento Molecular , Plantas Daninhas/efeitos dos fármacos , Relação Estrutura-Atividade , Estrutura Molecular
14.
Angew Chem Int Ed Engl ; 63(29): e202400143, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38698663

RESUMO

The chemistry of quinone methides formed in situ has been flourishing in recent years. In sharp contrast, the development and utilization of biphenyl quinone methides are rare. In this study, we achieved a remote stereocontrolled 1,12-conjugate addition of biphenyl quinone methides formed in situ for the first time. In the presence of a suitable chiral phosphoric acid, alkynyl biphenyl quinone methides were generated from α-[4-(4-hydroxyphenyl)phenyl]propargyl alcohols, followed by enantioselective 1,12-conjugate addition with indole-2-carboxylates. The strategy enabled the alcohols to serve as efficient allenylation reagents, providing practical access to a broad range of axially chiral allenes bearing a (1,1'-biphenyl)-4-ol unit, which were previously less accessible. Combined with control experiments, density functional theory calculations shed light on the reaction mechanism, indicating that enantioselectivity originates from the nucleophilic addition of alkynyl biphenyl quinone methides. Notably, not only the presence of biphenyl quinone methides as versatile intermediates was confirmed but also organocatalytic enantioselective 1,12-addition was established.

15.
Bioorg Med Chem ; 88-89: 117336, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37209638

RESUMO

As oncogene c-MYC is abnormally expressed during TNBC pathogenesis, stabilizing its promoter G-quadruplex (G4), which may thus inhibit c-MYC expression and promote DNA damage, may be a potential anti-TNBC strategy. However, large quantities of potential G4-forming sites exist in the human genome, which represents a potential drug selectivity problem. In order to achieve better recognition for c-MYC G4, we herein presented a new approach of designing small-molecule ligands by linking tandem aromatic rings with the c-MYC G4 selective binding motifs. Thus, a series of non-fused, conformation-tunable imidazole-biphenyl analogs were designed and synthesized. Among them, the optimal ligand appeared more effective on stabilizing c-MYC G4 than other types of G4s possibly through an adaptive, multi-site binding mode involved of end-stacking, groove-binding and loop-interacting. Then, the optimal ligand exerted good inhibitory activity on c-MYC expression and induced remarkable DNA damage, leading to the occurrence of G2/M phase arrest, apoptosis and autophagy. Furthermore, the optimal ligand exhibited potent antitumor effects in a TNBC xenograft tumor model. To sum up, this work offers new insights for the development of selective c-MYC G4 ligands against TNBC.


Assuntos
Antineoplásicos , Quadruplex G , Neoplasias de Mama Triplo Negativas , Humanos , Antineoplásicos/química , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Ligantes , Proteínas Proto-Oncogênicas c-myc/genética , Imidazóis/farmacologia
16.
Environ Res ; 220: 115148, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36580985

RESUMO

Assessing health outcomes associated with exposure to polychlorinated biphenyls (PCBs) is important given their persistent and ubiquitous nature. PCBs are classified as a Group 1 carcinogen, but the full range of potential noncancer health effects from exposure to PCBs has not been systematically summarized and evaluated. We used systematic review methods to identify and screen the literature using combined manual review and machine learning approaches. A protocol was developed that describes the literature search strategy and Populations, Exposures, Comparators, and Outcomes (PECO) criteria used to facilitate subsequent screening and categorization of literature into a systematic evidence map of PCB exposure and noncancer health endpoints across 15 organs/systems. A comprehensive literature search yielded 62,599 records. After electronic prioritization steps, 17,037 studies were manually screened at the title and abstract level. An additional 900 studies identified by experts or supplemental searches were also included. After full-text screening of 3889 references, 1586 studies met the PECO criteria. Relevant study details such as the endpoints assessed, exposure duration, and species were extracted into literature summary tables. This review compiles and organizes the human and mammalian studies from these tables into an evidence map for noncancer health endpoints and PCB mixture exposure to identify areas of robust research as well as areas of uncertainty that would benefit from future investigation. Summary data are available online as interactive visuals with downloadable metadata. Sufficient research is available to inform PCB hazard assessments for most organs/systems, but the amount of data to inform associations with specific endpoints differs. Furthermore, despite many years of research, sparse data exist for inhalation and dermal exposures, which are highly relevant human exposure routes. This evidence map provides a foundation for future systematic reviews and noncancer hazard assessments of PCB mixtures and for strategic planning of research to inform areas of greater uncertainty.


Assuntos
Bifenilos Policlorados , Animais , Humanos , Carcinógenos , Mamíferos , Bifenilos Policlorados/toxicidade , Incerteza
17.
Chirality ; 35(9): 549-561, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36951009

RESUMO

Soai's asymmetric autocatalysis represents a highly remarkable example for spontaneous symmetry breaking and enantioselective amplification in the enantioselective alkylation of pyrimidine-5-carbaldehydes to the corresponding chiral pyrimidine alcohols. Recently, zinc hemiacetalate complexes, formed from pyrimidine-5-carbaldehydes and the chiral product alcohol, were identified by in situ high-resolution mass spectrometric measurements as highly active transient asymmetric catalysts in this autocatalytic transformation. To study the formation of such hemiacetals and their stereodynamic properties, we focused on the synthesis of coumarin homolog biaryl systems with carbaldehyde and alcohol substituents. Such systems are able to form hemiacetals by intramolecular cyclization. An interesting feature of the substituted biaryl backbone is that tropos and atropos systems can be obtained, enabling or disabling the intramolecular cyclization to hemiacetals. Biaryl structures with various functional groups were synthesized, and the equilibrium and stereodynamics between the closed and open structures were investigated by dynamic enantioselective HPLC (DHPLC). The enantiomerization barriers ΔGǂ and activation parameters ΔHǂ and ΔSǂ were determined from temperature dependent kinetic measurements.

18.
J Enzyme Inhib Med Chem ; 38(1): 2230388, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37439326

RESUMO

Recent studies on biphenyl-containing compounds, a type of PD-1/PD-L1 blocker which binds to PD-L1 and induces dimerisation, have focussed on its immune function. Herein, 10 novel biphenyl derivatives were designed and synthesised. The results of the CCK-8 showed that compounds have different anti-tumour activities for tumour cells in the absence of T cells. Particularly, 12j-4 can significantly induce the apoptosis of MDA-MB-231 cells (IC50 = 2.68 ± 0.27 µM). In further studies, 12j-4 has been shown to prevent the phosphorylation of AKT by binding to cytoplasmic PD-L1, which induces apoptosis in MDA-MB-231 cells through non-immune pathways. The inhibition of AKT phosphorylation restores the activity of GSK-3ß, ultimately resulting in the degradation of PD-L1. Besides, in vivo study indicated that 12j-4 repressed tumour growth in nude mice. As these biphenyls exert their anti-tumour effects mainly through non-immune pathways, they are worthy of further study as PD-L1 inhibitors.


Assuntos
Compostos de Bifenilo , Neoplasias da Mama , Proteínas Proto-Oncogênicas c-akt , Animais , Camundongos , Antígeno B7-H1 , Glicogênio Sintase Quinase 3 beta , Camundongos Nus , Neoplasias da Mama/tratamento farmacológico , Compostos de Bifenilo/farmacologia
19.
Biomed Chromatogr ; 37(4): e5580, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36609857

RESUMO

A nonsteroidal drug called flurbiprofen (FBN) has analgesic, anti-inflammatory and antipyretic activity. Currently the determination of FBN in cataplasm does not have any pharmacopeial method. However, the drug substance, tablet and ophthalmic solution formulations do have pharmacopeial methods. The development and validation of an accurate, precise and stability-indicating analytical method for the determination of FBN in cataplasm formulations is reported. The gradient method was employed for the quantification of FBN in the presence of internal standards such as biphenyl. A nonpolar separation phase (C18 , 250 × 4.6 mm, 5 µm Inertsil column; GL Sciences) was used. The optimal flow rate, column oven temperature, injection volume and detector wavelengths were 1.0 ml/min, 40°C, 20 µl and 245 nm, respectively. Mobile phase A was a mixture of water and glacial acetic acid (30:1 v/v) pH adjusted to 2.20 with glacial acetic acid or 1 m NaOH; mobile phase B was methanol (100%). The gradient elution program was [time (min)/% B]: 5/60, 20/70, 25/70, 30/60 and 40/60. The obtained RSDs for the precision and intermediate precision were 0.7 and 0.5%. The percentage recovery ranged from 99.2 to 100.4%. The linear regression coefficient >0.9996 indicates that all peak responses were linear with the concentration. The sample and standard solutions were stable for up to 24 h on the benchtop and in the refrigerator. The critical peaks were well separated from the generated peaks owing to forced degradation, including diluent and placebo peaks. The method validation data and quality by design-based robustness study results indicate that the developed method is robust and fit for routine use in the quality control laboratory. The proposed method is specific, accurate and precise, and the quality by design utilized the first method for the determination of FBN in cataplasm formulations. Transdermal patches and gels have low extraction capacity and this method is applicable for quantification.


Assuntos
Flurbiprofeno , Cromatografia Líquida de Alta Pressão/métodos , Ácido Acético , Estabilidade de Medicamentos , Cromatografia Líquida
20.
J Asian Nat Prod Res ; 25(11): 1076-1084, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37724355

RESUMO

The investigation of chemical constituents from the rhizomes of Ruscus aculeatus resulted in the isolation of two new biphenyl derivatives, aculebiphenyls A and B (1-2), together with two known analogs (3-4). Their chemical structures were elucidated based on extensive spectroscopic interpretation and HR-ESI-MS analysis. Compounds 3-4 were isolated from the Ruscus genus for the first time. The isolated compounds were tested for anti-inflammatory activities and antibacterial activities. Compound 1 exhibited significant inhibitory effects on LPS-induced NO production and COX-2 with IC50 values of 10.8 µM and 0.4 µM. Compound 1 also significantly down-regulated the levels of inflammatory cytokines IL-1ß, IL-6, and TNF-α. Compound 1 showed moderate antibacterial activities.


Assuntos
Ruscus , Ruscus/química , Rizoma , Antibacterianos/farmacologia
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