Search

A new narrowband thermally activated delayed fluorescence emitter, PhCzBN-PO, was developed by incorporating the diphenylphosphine oxide (DPPO) group into a multi-resonance core. The unique properties of DPPO enabled PhCzBN-PO to achieve pure green emission and a nonplanar structure. The resulting electroluminescent devices achieved high external quantum efficiencies up to 32.4% with extremely low efficiency roll-off and pure-green emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.24, 0.67). [ABSTRACT FROM AUTHOR]

1,4‐BN‐doped polycyclic aromatic hydrocarbons (PAHs) have emerged as very promising emitters in organic light‐emitting diodes (OLEDs) due to their narrowband emission spectra that may find application in high‐definition displays. While considerable research has focused on investigating the properties of these materials, less attention has been placed on their synthetic methodology. Here we developed an efficient synthetic method for 1,4‐BN‐doped PAHs, which enables sustainable production of narrowband organic emitting materials. By strategically introducing substituents, such as methyl, tert‐butyl, phenyl, and chloride, at the C5 position of the 1,3‐benzenediamine substrates, we achieved remarkable regioselective borylation in the para‐position of the substituted moiety. This approach facilitated the synthesis of a diverse range of 1,4‐BN‐doped PAHs emitters with good yields and exceptional regioselectivity. The synthetic method demonstrated excellent scalability for large‐scale production and enabled late‐stage transformation of the borylated products. Mechanistic investigations provided valuable insights into the pivotal roles of electron effect and steric hindrance effect in achieving highly efficient regioselective borylation. Moreover, the outstanding device performance of the synthesized compounds 10 b and 6 z, underscores the practicality and significance of the developed method. [ABSTRACT FROM AUTHOR]

The development of blue thermally activated delayed fluorescence (TADF) emitters that can simultaneously achieve narrowband emission, high efficiency, and low efficiency roll-off in organic light-emitting diodes (OLEDs) remains a significant challenge. In this study, we present the successful design and synthesis of a series of TADF emitters by directly incorporating an electron donor into a boron/nitrogen/oxygen ternary doped multiple resonance (MR) skeleton. By carefully manipulating the donor strength, we were able to induce a long-range charge transfer triplet state to accelerate the reverse intersystem crossing (RISC) process. Meanwhile, the MR character of the first singlet excited state was preserved. As a result, the optimized emitter not only maintained the intrinsically excellent properties of the MR-TADF skeleton, such as deep-blue emission and high photoluminescence quantum yield of up to 89%, but also achieved a high RISC rate constant of 1.9 × 105 s−1. The corresponding deep-blue device exhibited a maximum external quantum efficiency (EQEmax) of 28.7%, with a full width at half maximum (FWHM) of only 36 nm and CIE coordinates approaching the NTSC blue standard. This study presents a simple yet effective approach for constructing high-performance deep-blue emitters for wide-color-gamut OLED displays. [ABSTRACT FROM AUTHOR]

Background: Lymphocyte-activation gene 3 (LAG-3), a checkpoint molecule contributing to immune suppressive microenvironment, is regarded as a promising target in cancer treatment. SHR-1802 is a novel anti-LAG-3 monoclonal antibody. Objectives: To evaluate the safety, tolerability, pharmacokinetics, and antitumor activity of SHR-1802. Design: A phase I dose-escalation and expansion trial of SHR-1802 in patients with advanced solid tumors. Methods: Patients with confirmed advanced solid tumors who failed previous standard-of-care or for whom no effective therapy was available were enrolled to receive SHR-1802 once every 21-day cycle. Dose escalation was performed in an accelerated titration design followed by a 3 + 3 scheme at escalating doses from 0.3 to 10 mg/kg. On the basis of results from dose-escalation phase, one or two dose levels were expanded to establish the recommended phase II dose (RP2D). The primary end points were dose-limiting toxicity (DLT) and RP2D. Results: Between 01 July 2020, and 07 September 2021, 28 patients were enrolled. No DLTs were observed, and all doses investigated were well tolerated. Treatment-related adverse events occurred in 20 patients (71.4%), all grade 1 or 2, with the most common ones being anemia (14.3%), asthenia (14.3%), electrocardiogram QT prolonged (14.3%), followed by increased blood fibrinogen (10.7%), infusion-related reaction (10.7%), and hypoalbuminemia (10.7%). No adverse event-related discontinuation occurred. Three patients died from adverse events, but none of the deaths were deemed related to study treatment. SHR-1802 exposure enhanced with the increasing doses in a greater than dose-proportional manner over the investigated dose range. The disease control rate was 32.0% (95% CI 14.9%–53.5%). The median progression-free survival was 2.0 months (95% CI 1.2–6.1). Conclusions: SHR-1802 demonstrated a tolerable safety profile and preliminary antitumor activity in patients with advanced solid tumors. Further studies with larger sample size and in combination forms are warranted for future clinical application. Registration ClinicalTrials.gov: NCT04414150 [ABSTRACT FROM AUTHOR]

Reported herein is a chemical method for the direct resolution of unprotected racemic β-substituted-β-amino acids (β³-AAs) that uses specially designed, stable, and recyclable α- methylproline-derived chiral ligands. The versatility of this methodology is unmatched by biocatalytic approaches. The method shows a broad synthetic generality for various aryl- or alkyl-substituted β³-AAs, and the new nonracemizable ligands can be accessed readily. Furthermore, the presented method produces an excellent stereochemical outcome and has a fully recyclable source of chirality, and the reaction conditions are operationally simple and convenient. The procedure has also been successfully applied to the scalable synthesis of the anti- HIV drug maraviroc. [ABSTRACT FROM AUTHOR]

Structurally simple and inexpensive chiral tridentate ligands were employed for substantially advancing the purely chemical dynamic kinetic resolution (DKR) of unprotected racemic tailor-made α-amino acids (TM-α-AAs), enabling the first DKR of TM-α-AAs bearing tertiary alkyl chains as well as multiple unprotected functional groups. Owing to the operationally convenient conditions, virtually complete stereoselectivity, and full recyclability of the source of chirality, this method should find wide applications for the preparation of TM-α-AAs, especially on large scale. [ABSTRACT FROM AUTHOR]

Reported herein is the first purely chemical method for the dynamic kinetic resolution (DKR) of unprotected racemic α-amino acids (α-AAs), a method which can rival the economic efficiency of the enzymatic reactions. The DKR reaction principle can be readily applied for S/R interconversions of α-AAs, the methodological versatility of which is unmatched by biocatalytic approaches. The presented process features a virtually complete stereochemical outcome, fully recyclable source of chirality, and operationally simple and convenient reaction conditions, thus allowing its ready scalability. A quite unique and novel mode of the thermodynamic control over the stereochemical outcome, including an exciting interplay between axial, helical, and central elements of chirality is proposed. [ABSTRACT FROM AUTHOR]

The purely chemical dynamic kinetic resolution of α‐amino acids bearing tertiary alkyl chains and multiple unprotected functional groups is based on the enantioselective formation of nickel(II) complexes and their disassembly under convenient conditions. In their Communication on page 12918 ff., H. Liu, V. A. Soloshonok et al. show that the specially designed chiral ligands can be easily recycled while the target amino acids are isolated in good yields and excellent enantioselectivities. [ABSTRACT FROM AUTHOR]

Die rein chemische dynamische kinetische Racematspaltung von α ‐ Aminosäuren mit tertiären Alkylketten und unterschiedlichsten funktionellen Gruppen basiert auf der enantioselektiven Bildung eines Nickel(II) ‐ Komplexes und dessen Hydrolyse. In der Zuschrift auf S. 13110 ff. zeigen H. Liu, V. A. Soloshonok et al., dass die hierfür entwickelten Liganden leicht wiederverwendet werden können, während die gewünschten Aminosäuren in guten Ausbeuten und mit exzellenter Enantioselektivität isoliert wurden. [ABSTRACT FROM AUTHOR]

Saposhnikovia divaricata is an authentic Chinese herbal medicine in Northeast China named Guanfangfeng, which is made from very high-quality plants for sufficient efficacy. However, leaf spot causes a very large reduction in the yield and quality of S. divaricata in Shuangyashan (46.58°N, 131.28°E), Northeast China. A total of 18 isolates were isolated from the diseased leaves of S. divaricata , following Koch's postulates, and identified as Fusarium acuminatum based on morphological, molecular biological, and phylogenetic tree analyses. To the authors' knowledge, this is the first report of F. acuminatum causing S. divaricata leaf spot in China. F. acuminatum infected perilla and mung beans but not foxtail millet, peanuts, wheat, peas, rye, red beans, or sorghum. Susceptibility assessment of F. acuminatum to fungicides using the mycelial growth rate method showed that isolates of F. acuminatum were most sensitive to prochloraz, with effective concentration values of 0.0005413 to 0.0009523 μg/ml. In the two field experiments, the average control efficacy of prochloraz at 0.450 g/liter on S. divaricata leaf spot caused by F. acuminatum was 75.42%. Therefore, nonhost plant rotation or intercropping with suitable chemical fungicides may be used to control S. divaricata leaf spot. This study's results provide a theoretical basis for controlling S. divaricata leaf spot and will facilitate the development of effective disease management programs., Competing Interests: The author(s) declare no conflict of interest.

White clover ( Trifolium repens L.) is an excellent quality forage legume species with superior planting efficiency, which reduces the cost of artificial weeding and nitrogen fertilizer inputs, and has feeding and economic value. However, from June to September 2022, severe stem rot affected the yield and quality of white clover crops in Harbin, Heilongjiang Province, China. The aim of this study was to identify the causative agents of the disease. Overall, Colletotrichum truncatum (6 isolates) and C. destructivum (10 isolates) were obtained from rotten white clover stems and identified based on morpho-molecular characteristics and phylogenetic analyses. Pathogenicity tests of the isolates revealed that C. destructivum had a higher pathogenicity to white clover than C. truncatum . In addition, all isolates were highly pathogenic to broad bean, fodder soybean, soybean, pak choi, and chickpea, were pathogenic to mint, and did not infect corn, wheat, or cilantro. C. destructivum and C. truncatum isolates were very sensitive to tebuconazole and pyraclostrobin, with EC 50 values of 0.54 to 0.70 μg/ml and 0.42 to 0.62 μg/ml, respectively, efficacies ranging between 93.2 to 94.9% and 90.2 to 95.2% at 600 μg/ml and 450 μg/ml, respectively, and EC 90 values of 1.88 to 13.36 μg/ml and 1.32 to 23.39 μg/ml, respectively. Therefore, intercropping of host and nonhost plants and chemicals can be considered to control stem rot in white clover. These results provide a basis for controlling C. destructivum and C. truncatum in white clover in China., Competing Interests: The author(s) declare no conflict of interest.

1,4-BN-doped polycyclic aromatic hydrocarbons (PAHs) have emerged as very promising emitters in organic light-emitting diodes (OLEDs) due to their narrowband emission spectra that may find application in high-definition displays. While considerable research has focused on investigating the properties of these materials, less attention has been placed on their synthetic methodology. Here we developed an efficient synthetic method for 1,4-BN-doped PAHs, which enables sustainable production of narrowband organic emitting materials. By strategically introducing substituents, such as methyl, tert-butyl, phenyl, and chloride, at the C5 position of the 1,3-benzenediamine substrates, we achieved remarkable regioselective borylation in the para-position of the substituted moiety. This approach facilitated the synthesis of a diverse range of 1,4-BN-doped PAHs emitters with good yields and exceptional regioselectivity. The synthetic method demonstrated excellent scalability for large-scale production and enabled late-stage transformation of the borylated products. Mechanistic investigations provided valuable insights into the pivotal roles of electron effect and steric hindrance effect in achieving highly efficient regioselective borylation. Moreover, the outstanding device performance of the synthesized compounds 10 b and 6 z, underscores the practicality and significance of the developed method., (© 2024 Wiley‐VCH GmbH.)

Background: The combination of immune-checkpoint inhibitors and antiangiogenic agents can synergistically modulate the tumor microenvironment and represents a promising treatment option. Here, we evaluated the efficacy and safety of camrelizumab plus famitinib (a receptor tyrosine kinase inhibitor) as a first-line treatment for advanced or metastatic NSCLC patients with a programmed death ligand-1 (PD-L1) tumor proportion score (TPS) of ≥1%, in an open-label, multicenter, phase 2 basket trial., Methods: Eligible patients received camrelizumab (200 mg once every 3 weeks via intravenous infusion) plus oral famitinib at an initial dose of 20 mg once daily. The primary endpoint was the objective response rate (ORR), as assessed by the investigator per Response Evaluation Criteria in Solid Tumors V.1.1. Key secondary endpoints included disease control rate (DCR), duration of respons, progression-free survival (PFS), overall survival (OS), 12-month OS rate, and safety profile., Results: Of the enrolled 41 patients, 21 (51.2%) had a PD-L1 TPS of 1-49%. As of the cut-off date on June 22, 2022, the combination regimen of camrelizumab and famitinib achieved an ORR of 53.7% (95% CI 37.4% to 69.3%) and a DCR of 92.7% (95% CI 80.1% to 98.5%). The median PFS was 16.6 months (95% CI 8.3 to not reached), and OS data were not yet mature, with an estimated 12-month OS rate of 76.8% (95% CI 60.0% to 87.3%). The most common treatment-related adverse events of grade 3 or higher included hypertension (22.0%), increased alanine aminotransferase (12.2%), decreased neutrophil count (9.8%), proteinuria (7.3%), decrease platelet count (7.3%), and hypokalemia (7.3%). One (2.4%) patient died from grade 5 hemoptysis, which was considered possibly related to the study treatment by the investigator., Conclusion: Camrelizumab plus famitinib demonstrated promising antitumor activity in advanced or metastatic NSCLC patients and had an acceptable safety profile. These findings suggest that this combination regimen could be an alternative therapeutic option and warrant further investigation., Trial Registration Number: NCT04346381., Competing Interests: Competing interests: HD, SW, and XY report being employed by Jiangsu Hengrui Pharmaceuticals. The remaining authors declare no other competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: We assessed the efficacy and safety of camrelizumab [an anti-programmed death (PD-1) mAb] plus apatinib (a VEGFR-2 tyrosine kinase inhibitor) in patients with advanced hepatocellular carcinoma (HCC)., Patients and Methods: This nonrandomized, open-label, multicenter, phase II study enrolled patients with advanced HCC who were treatment-naïve or refractory/intolerant to first-line targeted therapy. Patients received intravenous camrelizumab 200 mg (for bodyweight ≥50 kg) or 3 mg/kg (for bodyweight <50 kg) every 2 weeks plus oral apatinib 250 mg daily. The primary endpoint was objective response rate (ORR) assessed by an independent review committee (IRC) per RECIST v1.1., Results: Seventy patients in the first-line setting and 120 patients in the second-line setting were enrolled. As of January 10, 2020, the ORR was 34.3% [24/70; 95% confidence interval (CI), 23.3-46.6] in the first-line and 22.5% (27/120; 95% CI, 15.4-31.0) in the second-line cohort per IRC. Median progression-free survival in both cohorts was 5.7 months (95% CI, 5.4-7.4) and 5.5 months (95% CI, 3.7-5.6), respectively. The 12-month survival rate was 74.7% (95% CI, 62.5-83.5) and 68.2% (95% CI, 59.0-75.7), respectively. Grade ≥3 treatment-related adverse events (TRAE) were reported in 147 (77.4%) of 190 patients, with the most common being hypertension (34.2%). Serious TRAEs occurred in 55 (28.9%) patients. Two (1.1%) treatment-related deaths occurred., Conclusions: Camrelizumab combined with apatinib showed promising efficacy and manageable safety in patients with advanced HCC in both the first-line and second-line setting. It might represent a novel treatment option for these patients. See related commentary by Pinato et al., p. 908 ., (©2020 American Association for Cancer Research.)

We report the first purely chemical method for the resolution of C, N-unprotected racemic α-substituted β-amino acids (β 2 -AAs) using thermodynamically stable and recyclable chiral proline-derived ligands. The ligands and racemic β 2 -AAs along with Ni(II) could form a pair of Ni(II) complex diastereoisomers with a desirable diastereoselectivity (dr up to 91:9). Enantiomerically pure C, N-unprotected β 2 -AAs could be obtained by simple hydrolysis of an isolated favored Ni(II) complex. The method featured unique versatility compared with enzymatic approaches and characterized by its broad synthetic generality, good stereochemical outcome, and mild reaction conditions, thus making it a powerful supplement in the field of chemical resolution of β 2 -AAs.

Hepatitis C is a current pandemic liver disease caused by the hepatitis C virus (HCV) with high morbidity and mortality. Recently, the direct-acting antiviral agents (DAAs) targeting HCV NS3/4A, NS5A and NS5B have become the most effective therapies against HCV infection in the clinical treatment. Among them, the second-generation of NS3/4A inhibitors have emerged as the mainstay of the DAA therapies, which are derived from the peptide substrate of NS3/4A protease and modified with various tailor-made amino acids in order to achieve high sustained virologic response (SVR) against HCV. This review summarizes sixteen examples of the second-generation of HCV NS3/4A inhibitors, mainly focusing on the clinical application, structure development, structure-activity relationship (SAR) and their synthesis., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Unnatural (R)-α-amino acids (α-AAs) are in growing demand in the biomedical research and pharmaceutical industries. In this work, we present development of a purely chemical approach for preparation of (R)-α-AAs via (S)-to-(R)-interconversion of natural and tailor-made (S)-α-AAs. The method can be used on free, unprotected α-AAs and features a remarkable structural generality including substrates bearing tertiary alkyl chains and reactive functional groups. These attractive characteristics, combined with simplicity of reaction conditions and virtually complete stereochemical outcome, constitute a true methodological advance in this area, rivaling previously reported chemical and biocatalytic approaches.

Structurally simple and inexpensive chiral tridentate ligands were employed for substantially advancing the purely chemical dynamic kinetic resolution (DKR) of unprotected racemic tailor-made α-amino acids (TM-α-AAs), enabling the first DKR of TM-α-AAs bearing tertiary alkyl chains as well as multiple unprotected functional groups. Owing to the operationally convenient conditions, virtually complete stereoselectivity, and full recyclability of the source of chirality, this method should find wide applications for the preparation of TM-α-AAs, especially on large scale., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Described here is an advanced, general method for purely chemical dynamic thermodynamic resolution and S/R interconversion of unprotected tailor-made α-amino acids (α-AAs) through intermediate formation of the corresponding nickel(II)-chelated Schiff bases. The method features virtually complete stereochemical outcome, broad substrate generality (35 examples), and operationally convenient conditions allowing for large-scale preparation of the target α-AAs in enantiomerically pure form. Furthermore, the new type of nonracemizable axially chiral ligands can be quantitatively recycled and reused, rendering the whole process economically and synthetically attractive.

Reported herein is the first purely chemical method for the dynamic kinetic resolution (DKR) of unprotected racemic α-amino acids (α-AAs), a method which can rival the economic efficiency of the enzymatic reactions. The DKR reaction principle can be readily applied for S/R interconversions of α-AAs, the methodological versatility of which is unmatched by biocatalytic approaches. The presented process features a virtually complete stereochemical outcome, fully recyclable source of chirality, and operationally simple and convenient reaction conditions, thus allowing its ready scalability. A quite unique and novel mode of the thermodynamic control over the stereochemical outcome, including an exciting interplay between axial, helical, and central elements of chirality is proposed., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A simple and novel furanyl acryl conjugated coumarin fluorophore was designed as an effective thioredoxin reductase (TrxR)-responding fluorescent probe by an activity-guided approach. Basically, the α,β-unsaturated ketone moiety in the probe structure could quench the fluorescence of the coumarin, but upon the covalent modification of TrxR, a significant fluorescence could be generated, which has been confirmed to be obviously selective over Trx, GSH, Cys and DTT.