Enantioselective Construction of β-Substituted γ-Lactone through Catalytic Asymmetric Oshima-Utimoto Reaction: Divergent Total Syntheses of (-)-Podophyllotoxin and Its Eleven Congeners.

We report the first highly enantioselective Oshima-Utimoto reaction, which is combined with subsequent one-pot oxidation to construct synthetically important enantioenriched β-substituted γ-lactones with high enantioselectivity (up to 97% ee) from two chemical feedstocks (allylic alcohols and vinyl ethers). Significantly, the absolute configuration of chiral β-substituted γ-lactones can be precisely controlled by strategically selecting - or -allylic alcohol substrates, thereby providing an alternative access to both enantiomers of chiral γ-lactones. Capitalizing on this catalytic asymmetric transformation as a key step, we have achieved a concise and stereodivergent total synthesis of the natural aryltetralin lignan drug (-)-podophyllotoxin and its 11 structural congeners in only 6-8 steps from commercial materials through the combination of chemical and chemoenzymatic strategies.

Epidemiological, etiological, and serological characteristics of hand, foot, and mouth disease in Guizhou Province, Southwest China, from 2008 to 2023.

Background: Hand, foot, and mouth disease (HFMD) is caused by more than 20 different enteroviruses (EVs). The predominant EV serotypes of HFMD have been continuously changing in recent years. Guizhou Province has reported higher rates of severe and fatal cases of HFMD.

SPA-PNN ligand for the kinetic resolution of carbocyclic and heterocyclic spiranes by asymmetric hydrogenation.

The chiral carbocyclic and heterocyclic spirane scaffolds are widely present in natural products and pharmaceutical molecules. Efficient, concise, and enantioenriched synthesis of these structures is a significant objective in both academic and industrial fields. Here, we design and synthesize a series of chiral SPA-PNN ligands, which are used to kinetically resolve racemic spirocyclic 1,3-diketones and their analogs via Ir-catalyzed asymmetric direct hydrogenation to afford the corresponding chiral spirocyclic 1,3-diketones and chiral hydroxyspiroketones.

Single-cell and spatial analyses of the GDF family in tumors, with a focus on the prognostic and biological role of GDF15 in hepatocellular carcinoma.

Growth differentiation factors (GDFs) are a subfamily of the TGF-β superfamily whose expression increases in response to cellular stress and disease. Despite emerging cell- or animal-based evidence supporting an association between the GDF subfamily and cancer, systematic pan-cancer analyses of the GDF subfamily based on single-cell and spatial transcriptomes remains unavailable. In this study, we performed a comprehensive analysis of the GDF subfamily in 33 cancers, including expression, diagnosis, methylation, prognostic value, immune infiltration analysis, and potential biological pathways.

Diploidization in a wild rice allopolyploid is both episodic and gradual.

Polyploid organisms evolve from their initial doubled genomic condition through a number of processes collectively termed diploidization, whose tempo and mode remain poorly understood mainly due to the difficulty of discriminating de novo evolution subsequent to polyploidy from variation inherited from progenitors. Here, we generated chromosome-scale genome assemblies for the wild rice allopolyploid and its two diploid progenitors, and , and employed a population genomic approach to investigate the diploidization process in at the sequence and transcriptomic level. We show that this wild rice allopolyploid originated around 0.

Nonlinear Hysteresis Parameter Identification of Piezoelectric Actuators Using an Improved Gray Wolf Optimizer with Logistic Chaos Initialization and a Levy Flight Variant.

Piezoelectric tilt mirrors are crucial components of precision optical systems. However, the intrinsic hysteretic nonlinearity of the piezoelectric actuator severely restricts the control accuracy of these mirrors and the overall performance of the optical system. This paper proposes an improved Gray Wolf Optimization (GWO) algorithm for high-accuracy identification of hysteresis model parameters based on the Bouc-Wen (BW) differential equation.

Catalytic Enantioselective α-Ethynylation of Oxindoles: Total Synthesis of (-)-Corynoxine, (-)-Isorhynchophylline, (-)-Aspidospermidine, and (-)-Limaspermidine.

The all-carbon quaternary stereogenic center of oxindoles is a crucial structural element of a broad spectrum of indole alkaloids, imparting these molecules with rigid three-dimensional configurations essential for their biological activities. Here, we present a catalytic asymmetric α-ethynylation reaction of oxindoles taking advantage of the catalysis of a spiropyrrolidine amide (SPA) triazolium. This transformation enables the enantioselective construction of the C3 quaternary carbon stereocenter of oxindoles while introducing a versatile ethynyl functionality.

Engineering the regulation strategy of active sites to explore the intrinsic mechanism over single‑atom catalysts in electrocatalysis.

The development of efficient and sustainable energy sources is a crucial strategy for addressing energy and environmental crises, with a particular focus on high-performance catalysts. Single-atom catalysts (SACs) have attracted significant attention because of their exceptionally high atom utilization efficiency and outstanding selectivity, offering broad application prospects in energy development and chemical production. This review systematically summarizes the latest research progress on SACs in five key electrochemical reactions: hydrogen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, nitrogen reduction reaction, and oxygen evolution reaction.

In-depth insight into structure-reactivity/regioselectivity relationship of Lewis acid catalyzed cascade 4πe-cyclization/dicycloexpansion reaction.

The Lewis acid-catalyzed tittle reaction of 1,3-dicycloalkenlidine ketones is recognized as so far the shortest and most effective 1-step method for construction of angular tricyclic scaffolds, which are extensively found in bioactive terpenoids. Here, a further kinetic study of this reaction with 30 reaction examples is carried out using in situ IR technology and DFT calculation. That enables the creation of well-fitted linear relationships of lnk/(ΔG/T), ΔG/ΔG, ln(k/k)/σ, reflecting the structure's effect on reactivity/selectivity, and validating the reaction mechanism.

One-pot Nazarov cyclization/oxidative 1,2-carbon rearrangement/Ritter reaction to access 5-quaternary-4-amidocyclopent-2-enones and 2-quaternary-3-amidoindanones.

A one-pot Nazarov cyclization/oxidative 1,2-carbon rearrangement/Ritter reaction has been explored for the first time, facilitating the synthesis of the unprecedented 2,3-disubstituted-5-quaternary-4-amidocyclopent-2-enone and 2-quaternary-3-amidoindanones. This transformation features convenient operation, good yields (up to 70%), and good to excellent diastereoselectivity (up to 20 : 1). The proposed reaction mechanism is supported by some experimental results.

Catalytic Asymmetric 1,4-Hydrocarbonation of 1,3-Enynes via Photoredox/Cobalt/Chromium Triple Catalysis.

A synergistic photoredox/cobalt/chromium triple catalysis system for regioselective, enantioselective, and diastereoselective 1,4-hydrocarbonation of readily available 1,3-enyne precursors was explored, providing a modular synthetic platform for various trisubstituted axially chiral allenes bearing an extra central chirality. The protocol features a broad substrate scope, good functional group tolerance, excellent selectivity, and mild reaction conditions. Furthermore, a possible reaction mechanism is proposed based on numerous control experiments and density functional theory calculations.

Phenological and morphological variations of Oryza rufipogon and O. nivara in Sri Lanka and their evolutionary implications.

Phenological and morphological variation are widely viewed as a pivotal driver of ecological adaptation and speciation. Here, we investigate variation patterns of flowering phenology and morphological traits within and between O. rufipogon and O.

CCC pincer Ru complex-catalyzed C-H vinylation/6π-E-cyclization of aldimines for constructing 4-pyrido[1,2-]pyrimidines.

An unusual cascade C-H activation, vinylation and 6π-electrocyclization of 2-pyridyl aldimines with vinyl bromides/triflates was achieved using catalysis with a unique CCC pincer NHC-Ru(iii) complex (Cat B). This reaction was found to enable a rapid and diverse synthesis of polycyclic 4-pyrido[1,2-]pyrimidine derivatives in mostly good to high yields, and with a broad substrate scope. A mechanistic study suggested the formation of a semi-opened Ru(iii) intermediate chelating/activating the aldimine, and the occurrence of single-electron transfer (SET) to generate a vinyl radical, followed by vinylation and then an intramolecular 6π-electrocyclization of 1,3-hexatrene to form the product.

Spokewise Total Syntheses of Four Alkaloids and Telescoped Syntheses of Six Additional Alkaloids.

Based on rich sulfur-involving chemical transformations, a novel spokewise synthetic strategy, a subclass of the collective strategies, has been developed to concisely synthesize four erythrina alkaloids through a single-step transformation from a common synthetic precursor. Moreover, six additional erythrina alkaloids have also been synthesized by subsequent 1-2 steps chemical transformations. The current synthetic approaches provide a valuable platform for collective total syntheses of erythrina alkaloids and -natural erythrina alkaloids.

Anchoring Pt Single-Atom Sites on Vacancies of MgO(Al) Nanosheets as Bifunctional Catalysts to Accelerate Hydrogenation-Cyclization Cascade Reactions.

The direct hydrogenation of 2-nitroacylbenzene to 2,1-benzisoxazole presents a significant challenge in the pharmaceutical and fine chemicals industries. In this study, a defect engineering strategy is employed to create bifunctional single-atom catalysts (SACs) by anchoring Pt single atoms onto metal vacancies within MgO(Al) nanosheets. The resultant Pt/MgO(Al) SAC displays an exceptional catalytic activity and selectivity in the hydrogenation-cyclization of 2-nitroacylbenzene, achieving a 97.

Total Synthesis of the Hexacyclic Sesterterpenoid Niduterpenoid B via Structural Reorganization Strategy.

To date, it remains challenging to precisely and efficiently construct structurally intriguing polycarbocycles with densely packed stereocenters in organic synthesis. Niduterpenoid B, a naturally occurring ERα inhibitor, exemplifies this complexity with its intricate polycyclic network comprising 5 cyclopentane and 1 cyclopropane rings, featuring 13 contiguous stereocenters, including 4 all-carbon quaternary centers. In this work, we describe the first total synthesis of niduterpenoid B using a structural reorganization strategy.

Ce-doped TiO supported RuO as efficient catalysts for the oxidation of HCl to Cl.

Reducing the cost of RuO/TiO catalysts is still one of the urgent challenges in catalytic HCl oxidation. In the present work, a Ce-doped TiO supported RuO catalyst with a low Ru loading was developed, showing a high activity in the catalytic oxidation of HCl to Cl. The results on some extensive characterizations of both Ce-doped TiO carriers and their supported RuO catalysts show that the doping of Ce into TiO can effectively change the lattice parameters of TiO to improve the dispersion of the active RuO species on the carrier, which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions.

Organo-cation catalyzed enantioselective α-hydroxylation of pyridinone-fused lactones: asymmetric synthesis of SN-38 and irinotecan.

A catalytic asymmetric α-hydroxylation of pyridinone-fused lactones, containing the core structure of camptothecin, is described. Development of a novel spiropyrrolidine amide (SPA) derived triazolium bromide organo-cation catalyst is crucial for a highly enantioselective oxidation, which also accommodates a wide array of lactones with various substituents. The resulting tricyclic tertiary alcohol with an -quaternary carbon center can be further applied in the synthesis of SN-38 and irinotecan, two anti-cancer drugs derived from camptothecin.

Expansion of Structure Property in Cascade Nazarov Cyclization and Cycloexpansion Reaction to Diverse Angular Tricycles and Total Synthesis of Nominal Madreporanone.

A cascade Nazarov cyclization/dicycloexpansions reaction was developed for the precise synthesis of the angularly fused M/5/N (M=5, 6; N=4-9, 13) tricyclic skeletons. The prioritized expansion of the first ring played a critical role in the transformations, due to the release of ring strain, and the nature of the substituents present on the substrate is another influencing factor. This pioneering cascade reaction features broad substrates scope (33 examples), short reaction time, exceptional yields (up to 95 %), and remarkable regioselectivities (>20 : 1).

Comparison of Endoscopic Ultrasound-guided Cyanoacrylate Injection and Transjugular Intrahepatic Portosystemic Shunt in the Prevention of Gastric Varices Rebleeding.

Objective: The purpose of this study was to investigate the efficacy and safety of endoscopic ultrasound (EUS)-guided injection of cyanoacrylate (CYA) and transjugular intrahepatic portal shunts (TIPSs) in the treatment of patients with cirrhosis with ruptured gastric varices.

Methods: In this retrospective study, 105 patients with liver cirrhosis and gastric varicose veins who were admitted to the First Affiliated Hospital of Anhui Medical University between April 2018 and April 2023 without nonselective β-blockers treatment and no portal vein thrombosis were evaluated. The patients were divided into the transjugular intrahepatic portal shunt (TIPS) group (n = 60) and the EUS-CYA group (n = 45) for the purpose of evaluating postoperative rebleeding rates, complications, survival rates, and other factors.

Fabrication of - Heterostructured Photocatalysts with Triazine-Based Covalent Organic Framework and CuInS for High-Efficiency CO Reduction.

The application of covalent organic frameworks (COFs) for the photocatalytic reduction of CO is mostly limited by severe charge recombination and low sunlight utilization. Herein, a triazine-based COF with an electron-rich and large π-conjugated system (TCOF) was employed as a building block and integrated with CuInS (CIS) to construct a noble-metal-free and high-efficiency photocatalyst for CO reduction. The in situ growth of CIS nanosheets on TCOF creates a - heterojunction, named CIS@TCOF.

Single Bolus r-SAK Before Primary PCI for ST-Segment-Elevation Myocardial Infarction.

Background: It is uncertain whether adjunctive thrombolysis is beneficial for patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention (PCI) within 120 minutes of presentation. This study was to determine whether in patients presenting with ST-segment-elevation myocardial infarction a single bolus recombinant staphylokinase (r-SAK) before timely PCI leads to improved patency of the infarct-related artery and reduces the infarct size.

Methods: This is an open-label, prospective, multicenter, randomized study.