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4.
Angew Chem Int Ed Engl ; : e202406845, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38687326

Consecutive photoinduced electron transfer (ConPET) is a powerful and atom-economical protocol to overcome the limitations of the intrinsic redox potential of visible light-absorbing photosensitizers, thereby considerably improving the substrate and reaction types. Likely because such an exothermic single-electron transfer (SET) process usually does not require the aid of chiral catalysts, resulting in an inevitable racemic background reaction, notably, no enantioselective manifolds have been reported. Herein, we report on the viability of cooperative ConPET and chiral hydrogen-bonding catalysis for the [3 + 2] photocycloaddition of cyclopropyl ketones with vinylazaarenes. In addition to enabling the first use of olefins that preferentially interact with chiral catalysts, this catalysis platform paves the way for the efficient synthesis of pharmaceutically and synthetically important cyclopentyl ketones functionalized by azaarenes with high yields, ees and dr. The robust capacity of the method can be further highlighted by the low loading of the chiral catalyst (1.0 mol%), the good compatibility of both 2-azaarene and 3-pyridine-based olefins, and the successful concurrent construction of three stereocenters on cyclpentane rings involving an elusive but important all-carbon quaternary.

5.
Cureus ; 16(4): e58081, 2024 Apr.
Article En | MEDLINE | ID: mdl-38616979

Purpose This study delves into the epidemiology of high-risk human papillomavirus (HR-HPV) infection and its link to precancerous lesions among perimenopausal (40-59 years) and elderly (60-65 years) women in a Chinese county with a notably high incidence of cervical cancer. By uniquely focusing on these age groups in underdeveloped regions, the research aims to offer novel strategies for the management and prevention of cervical cancer. It seeks to inform targeted interventions and public health policies that could significantly benefit women at heightened risk for HPV, addressing a critical gap in current prevention efforts in economically disadvantaged communities. Methods This observational study was conducted at the Maternal and Child Health and Family Planning Service Centre in Lueyang County, from September 2021 to January 2022. It assessed 2008 women aged 40-65 for HPV screening, with 342 undergoing further cytological examination. The study evaluated the prevalence of HPV infection across different age groups and risk categories. It utilized a questionnaire to collect participants' basic information, health behaviors, and other relevant data to analyze factors influencing HR-HPV infection. Statistical analyses comprised chi-square tests, trend analysis, logistic regression, and multiple imputation techniques to address missing data. Results The prevalence of HR-HPV infection among women aged 40-65 years in Lueyang County was 18.43%. Older women exhibited a higher incidence of HPV infection, abnormal ThinPrep Cytology Test (TCT) results (Shaanxi Fu'an Biotechnology Co. Ltd., Baoji City, China), and low/high-grade squamous intraepithelial lesions (LSIL/HSIL) (P<0.05). The most prevalent HR-HPV genotypes in the overall, perimenopausal, and elderly groups were HPV-52, -53, and -58; HPV-52, -53, and -16; and HPV-58, -52, and -53, respectively. The prevalent HR-HPV genotypes in the abnormal The Bethesda System (TBS) results were HPV-16, -52, -33, -58; -16, -52, -58; and-16, -33, and -52. HPV-16, -18, -33 prevalence increased with increasing lesion severity (P<0.05). In this study, factors affecting HR-HPV in the three age groups were found to be mainly related to sexual behavior and education level, including history of lower genital tract diseases, multiple pregnancies, contraceptive methods without tubal ligation, age at first marriage greater than 18 years, never washing the vulva after sex, abstinence from sex, education level of junior high school or above, and spouse's education level of high school or above. Conclusions These findings suggest that the elevated rate of abnormal TBS in the older age group may be attributed to the higher prevalence of persistent infection-prone HR-HPV genotypes (HPV-58, -52, and-53), multiple infections, and potent oncogenic HR-HPV genotypes (HPV-16 and -33). Additionally, the higher HR-HPV prevalence in older patients may be related to lower education attainment, reduced screening rate, and limited condom usage. Therefore, strategies targeting perimenopausal and older women should prioritize enhancing health awareness, increasing screening rates, and encouraging condom utilization.

6.
Nat Chem ; 2024 Apr 02.
Article En | MEDLINE | ID: mdl-38565977

Visible-light-driven photoredox catalysis is known to be a powerful tool for organic synthesis. Its occurrence critically depends on the twice exothermic single-electron transfer processes of photosensitizers, which are governed by the redox properties of the species involved. Hence, the inherently narrow range of redox potentials of photosensitizers inevitably constrains their further availability. Sensitization-initiated electron transfer has recently been found to effectively overcome this substantial challenge. However, feasible and practical strategies for designing such complicated catalytic systems are rather scarce. Herein we report an elaborate dual-catalyst platform, with dicyanopyrazine as a visible light photosensitizer and a pyrenyl-incorporated chiral phosphoric acid as a co-sensitizer, and we demonstrate the applicability of this sensitization-initiated electron transfer strategy in an asymmetric formal de Mayo-type reaction. The catalysis platform enables otherwise thermodynamically unfavourable electron transfer processes to close the redox cycle and allows for precise access to valuable enantioenriched 1,5-diketones with a wide substrate range.

7.
bioRxiv ; 2024 Feb 29.
Article En | MEDLINE | ID: mdl-38464254

Eukaryotic chromosome segregation requires kinetochores, multi-megadalton protein machines that assemble on the centromeres of chromosomes and mediate attachments to dynamic spindle microtubules. Kinetochores are built from numerous complexes, and understanding how they are arranged is key to understanding how kinetochores perform their multiple functions. However, an integrated understanding of kinetochore architecture has not yet been established. To address this, we purified functional, native kinetochores from Kluyveromyces marxianus and examined them by electron microscopy, cryo-electron tomography and atomic force microscopy. The kinetochores are extremely large, flexible assemblies that exhibit features consistent with prior models. We assigned kinetochore polarity by visualizing their interactions with microtubules and locating the microtubule binder Ndc80c. This work shows that isolated kinetochores are more dynamic and complex than what might be anticipated based on the known structures of recombinant subassemblies, and provides the foundation to study the global architecture and functions of kinetochores at a structural level.

8.
J Am Chem Soc ; 146(12): 8372-8380, 2024 Mar 27.
Article En | MEDLINE | ID: mdl-38499472

Here we present a highly enantioselective [2π + 2σ] photocycloaddition of bicyclo[1.1.0]butanes (BCBs). The reaction uses a variety of vinylazaarenes as partners and is catalyzed by a polycyclic aromatic hydrocarbon (PAH)-containing chiral phosphoric acid as a bifunctional chiral photosensitizer. A wide array of pharmaceutically important bicyclo[2.1.1]hexane (BCH) derivatives have been synthesized with high yields, enantioselectivity, and diastereoselectivity. In addition to the diverse 1-ketocarbonyl-3-substituted BCBs, α/ß-substituted vinylazaarenes are compatible with such an unprecedented photoredox catalytic pathway, resulting in the successful assembly of an all-carbon quaternary stereocenter or two adjacent tertiary stereocenters on the product.

10.
Talanta ; 274: 125991, 2024 Jul 01.
Article En | MEDLINE | ID: mdl-38547836

Numerous photothermal agents (PTAs) require high-intensity and long-duration laser excitation for photothermal therapy (PTT), resulting in light damage to healthy skin and tissue as well as limiting their biomedical applications. Integrating desirable near-infrared (NIR) absorption and high photothermal conversion efficiency (PCE) into a single small-molecule PTA is an important prerequisite for realizing efficient PTT, but is a serious challenge. Herein, through molecular engineering strategy, an acceptor-donor-acceptor (A-D-A) type PTA (ADA3) was readily developed for 808 nm laser-driving photothermal imaging and PTT of tumor. Theoretical calculations and experiment results show molecular engineering strategy is significant in regulating the structure and energy gap of PTAs, so as to effectively induce a narrow band gap for NIR absorption and further optimize photothermal properties. ADA3 possesses molar extinction coefficient of 3.1 × 104 M-1 cm-1 at 808 nm, followed being assembled into nanoparticles, ADA3-NPs show high PCE of 80.3%. In vivo experiments indicate that ADA3-NPs have excellent antitumor capability under one-time, low-intensity and short-duration (808 nm, 330 mW/cm2, 3 min) laser irradiation. Therefore, this work definitely exemplifies the enormous potential of molecular engineering strategy and provides an effective method for developing small-molecule PTAs.


Infrared Rays , Photothermal Therapy , Humans , Animals , Mice , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Nanoparticles/chemistry , Mice, Inbred BALB C , Cell Survival/drug effects , Female , Neoplasms/therapy , Cell Proliferation/drug effects
11.
Adv Healthc Mater ; : e2400201, 2024 Mar 22.
Article En | MEDLINE | ID: mdl-38519419

Photothermal agents (PTAs) with desirable near-infrared (NIR) absorption and excellent photothermal conversion efficiency (PCE) are ideal candidates for cancer treatment. However, numerous PTAs still require high-intensity and long-duration laser irradiation to completely ablate the tumor during the photothermal therapy (PTT) process, resulting in light damage to healthy skin and tissue as well as limiting their biomedical applications. Integrating intense NIR absorption and high PCE into a single small-molecule PTA is an important prerequisite for realizing efficient PTT, but is a serious challenge. Herein, a series of donor-acceptor type PTAs (CC1 to NC4) are designed through a molecular engineering strategy. Theoretical calculations and experimental results show that the NIR absorption and photothermal effect from CC1 to NC4 are significantly enhanced as expected. Notably, NC4 nanoparticles exhibit intense NIR absorption, superhigh PCE of up to 88.9% for PTT, photoacoustic imaging and photothermal imaging, and effective reactive oxygen species generation for photodynamic therapy (PDT). The superior PTT/PDT synergistic phototherapeutic efficacy is well demonstrated by the complete elimination of tumor in vivo upon one-time, low-intensity, and short-duration laser irradiation (808 nm, 330 mW cm-2, and 3 min). This work provides a valuable guideline for rational design of PTAs for cancer phototherapy.

12.
Chemistry ; 30(24): e202304056, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38379208

3-Indole-3-one is a key intermediate in the synthesis of many drugs and plays an important role in synthetic chemistry and biochemistry. A new method for synthesizing trifluoromethylated 3-indoleketones by Pd(0)-catalyzed carbonylation was introduced. In the absence of additives, 1-chloro-3,3,3-trifluoropropyl (an inexpensive and environmentally friendly synthetic block of trifluoromethyl) reacts with indole and carbon monoxide to generate trifluoromethylindole ketones with good yields, regioselectivity, and chemical selectivity; furthermore, the products exhibit strong resistance to basic functional groups, such as alkynes, aldehydes, and esters. In addition to the conversion of indole compounds into corresponding products, pyrrole and heteroindole may be suitable for corresponding chemical transformations. This study provides a synthetic method for the further construction of trifluoromethylated 3-indole ketones.

13.
Adv Sci (Weinh) ; 11(12): e2307773, 2024 Mar.
Article En | MEDLINE | ID: mdl-38233152

An unprecedented enantioselective protonation reaction enabled by photoredox catalytic radical coupling is developed. Under cooperative dicynopyrazine-derived chromophore (DPZ) as a photosensitizer and a chiral phosphoric acid catalyst, and Hantzsch ester as a sacrificial reductant, the transformations between α-substituted enones and cyanoazaarenes or 2-(chloromethyl)azaaren-1-iums can proceed a tandem reduction, radical coupling, and enantioselective protonation process efficiently. Two classes of pharmaceutically important enantioenriched azaarene variants, which contain a synthetically versatile ketone-substituted tertiary carbon stereocenter at the ß- or γ-position of the azaarenes, are synthesized with high yields and ees.

14.
J Org Chem ; 89(4): 2238-2246, 2024 Feb 16.
Article En | MEDLINE | ID: mdl-38296256

Visible-light-induced regioselective cascade radical cyclization of α-bromocarbonyls for the synthesis of benzazepine derivatives is described. In the presence of fac-Ir(ppy)3 (2.0 mol %) as a photocatalyst, 2,6-lutidine as a base, and dichloromethane as a solvent, the reactions proceed smoothly to afford seven-membered rings in good yields. This protocol features a broad substrate scope, excellent functional group tolerance, and mild reaction conditions. Preliminary mechanistic studies reveal that the generation of the α-carbon radical is more prone to react with the 1,1-diphenylethylene tethered acrylamide to generate the stable seven-membered heterocycle.

17.
Infect Drug Resist ; 16: 7155-7163, 2023.
Article En | MEDLINE | ID: mdl-38023398

Background: Currently, there is no single test indicator for diagnosing periprosthetic joint infection (PJI) with an acceptable level of sensitivity. Therefore, ratio indicators have been introduced to improve the accuracy of diagnostic algorithms. Platelet count /mean platelet volume (PMR) is reported to be a potential PJI diagnostic biomarker, but its clinical value for diagnosing PJI is still uncertain. This study aims to provide additional evidence to support the effectiveness of PMR in accurately diagnosing PJI. Methods: This study recruited 116 patients with PJI and 137 patients with aseptic loosening, divided them into PJI group and AL group. Collect subjects' preoperative laboratory indicators such as ESR, CRP, PLT, MPV, etc. The area under the curve (AUC) was calculated by plotting the receiver operating characteristic (ROC) curve to determine the diagnostic efficacy of PMR. Results: ESR, CRP, PLT, and PLT/MPV were significantly increased in the PJI group, while MPV levels were decreased (both P< 0.001). The AUC of the PMR was 0.752, and the optimal cut-off value for diagnosing chronic PJI was determined to be 27.8 based on the Youden index. The sensitivity and specificity for diagnosing PJI were 79.3% and 47.9%, respectively, with a positive predictive value of 68.27%, a negative predictive value of 69.80%, and a diagnostic odds ratio of 4.97. The AUC (0.752) of the ratio biomarker was lower than that of ESR (0.825) and CRP (0.900). After predictive model calculation, the combination of PMR, CRP, and ESR had an AUC value of 0.910, with a sensitivity of 84.5% and a specificity of 84.7%, showing good discriminative ability. Conclusion: Compared with traditional biomarkers ESR and CRP, the value of the PMR for diagnosing PJI is not significant, but it can be used as an auxiliary indicator for PJI diagnosis in combination with other indicators (P<0.001).

18.
J Org Chem ; 88(23): 16556-16565, 2023 Dec 01.
Article En | MEDLINE | ID: mdl-37971950

Herein, an N-heterocyclic carbene (NHC)-catalyzed tandem cyclization/addition/cyclization reaction of 2-isocyanobiaryls and α-bromo-N-cinnamylamides for the synthesis of 2-pyrrolidinone-functionalized phenanthridines is developed. This protocol features a radical cascade process, broad substrate scope, and good functional group compatibility under metal- and oxidant-free reaction conditions.

20.
Nat Commun ; 14(1): 5063, 2023 08 21.
Article En | MEDLINE | ID: mdl-37604828

Specificity remains a major challenge to current therapeutic strategies for cancer. Mutation associated neoantigens (MANAs) are products of genetic alterations, making them highly specific therapeutic targets. MANAs are HLA-presented (pHLA) peptides derived from intracellular mutant proteins that are otherwise inaccessible to antibody-based therapeutics. Here, we describe the cryo-EM structure of an antibody-MANA pHLA complex. Specifically, we determine a TCR mimic (TCRm) antibody bound to its MANA target, the KRASG12V peptide presented by HLA-A*03:01. Hydrophobic residues appear to account for the specificity of the mutant G12V residue. We also determine the structure of the wild-type G12 peptide bound to HLA-A*03:01, using X-ray crystallography. Based on these structures, we perform screens to validate the key residues required for peptide specificity. These experiments led us to a model for discrimination between the mutant and the wild-type peptides presented on HLA-A*03:01 based exclusively on hydrophobic interactions.


Antibodies , Proto-Oncogene Proteins p21(ras) , Proto-Oncogene Proteins p21(ras)/genetics , Recognition, Psychology , Hydrophobic and Hydrophilic Interactions , HLA-A Antigens/genetics
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