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Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science china chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-c.eng Tang Ding-Kang chen Ming-Ming cao Yao-Wen chang Hong-Yu Tang chun-Mao Yuan Jun-Bo yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of chinese Academy of Sciences Lab of computational chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at c-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

Propagating subduction initiation of the caroline Plate at the Mussau Trench

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Science china Earth Sciences 2025年第1期68卷 253-269页

作者： chun-Feng LI Yongkang Deng Tao WU Dongdong DONG Guoliang ZHANG Jiazheng ZHANG Yutao LIU Yaqing LI Fugui TANG Lulu ZHANG Department of Marine Sciences Zhejiang University Laboratory of Marine Mineral Resources Laoshan Laboratory Key Lab of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Key Lab of Ocean and Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Science & Technology on Integrated Information System Lab Institute of Software Chinese Academy of Sciences

New seismic imaging from the Mussau Trench confirms that, under horizontal compression on an oceanic plate boundary, it is within the young and weak oceanic plate that a trench will develop, and it is the young plate, not so long after its birth, that starts to subduct toward the old plate. The Mesozoic Pacific Plate cannot easily bend, under the joint horizontal compression and vertical gravity pull, even with a pre-existing weak zone in place and with a large age offset across the plate boundary. The bending of the caroline Plate near the northern end of the Mussau Trench started only after a long-time span of trench migration, and/or after a prolonged transition from initial compression to trench development. Highly contrasting trench deformation and sedimentary accretion between two parallel seismic sections support an evident migration of underthrusting or significant longitudinal heterogeneity along the trench. The swift transition from underthrusting to non-thrusting can be explained by a counter-clockwise rotation of the caroline Plate. That miniature accretionary wedges develop even before the subduction initiates imply strong compression and uplifting before the underthrusting can kick-start. Rotation of the caroline Plate have been halted as the Mussau Trench is seismically rather quiet and the Lyra Trough to the east shows relaxational extension.

关键词： Mussau Trench Subduction initiation Seismic reflection caroline Plate

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Deciphering Water Oxidation catalysts:The Dominant Role of Surface chemistry over Reconstruction Degree in Activity Promotion

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Nano-Micro Letters 2025年第3期17卷 340-354页

作者： Li An Jianyi Li Yuanmiao Sun Jiamin Zhu Justin Zhu Yeow Seow Hong Zhang Nan Zhang Pinxian Xi * Zhichuan JXu chun‑Hua Yan State Key Laboratory of Applied Organic chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceFrontiers Science Center for Rare IsotopesCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000People’s Republic of China School of Materials Science and engineering Nanyang Technological UniversitySingapore 639798Singapore Faculty of Materials Science and Energy engineering Institute of Technology for Carbon NeutralityShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Key Laboratory of Electromagnetic Materials and Devices National Center for International Research On Photoelectric and Energy MaterialsSchool of Materials and EnergyElectron Microscopy CenterYunnan UniversityKunming 650091People’s Republic of China State Key Laboratory of Baiyunobo Rare Earth Resource Researches and comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030People’s Republic of China Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU‑HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryPeking UniversityBeijing 100871People’s Republic of China

Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution *** surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity ***,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is *** substituting Fe content influences both current change tendency and surface reconstruction ***_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)*** reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based ***,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term ***,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction *** effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface *** finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.

关键词： Oxygen evolution reaction Perovskite oxides Doping Activation and reconstruction

APPLYING PROcESS MINING APPROAcH TO SUPPORT THE VERIFIcATION OF A MULTI-AGENT SYSTEM

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Journal of Systems Science and Systems engineering 2010年第2期19卷 131-149页

作者： c.OU-yang Yeh-chun JUAN Depart.of Industrial Management National Taiwan University of Science and Technology Depart.of Industrial engineering and Management Ming Chi University of Technology

Using agent development tools to construct an agent-based system is a well applied approach. However, the development tools usually do not have the function to check the feasibility about the workflow of the agent system during it implementation stage. Therefore, to develop an evaluation approach to analyze the feasibility of a developing agent system such that the improper workflow of an agent system can be found in the early design stage is a necessary task to reduce the risk of implementation. In this research, a Petri Net （PN） based three-stage evaluation approach was developed. In the conceptual stage, the pitfall of the current agent system developing process was examined and an improvement analysis process was specified. Then, in the system design stage, an evaluation approach which extracted the process log file from a developing agent system into a PN model in terms of a process mining approach-or algorithm was proposed. This model was simulated in a PN simulation package. The agent system performance was evaluated in terms of analyzing the deadlock phenomena of the PN model. Finally, in the implementation stage, the proposed concept was implemented by using an agent developing tool JADE and a PN simulation tool cPN. An agent-based robotic assembly system was used to examine the possible deadlock of the agent system.

关键词： Agent-based systems workflow feasibility process mining Petri Nets

chiral phosphoramidite ligand-modulated palladium auto-tandem catalysis for asymmetric dehydrogenative dienylation of imines with α-alkenes

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Science china chemistry 2025年

作者： Zhong-Sheng Nong Hao-Fan Qian Ying-chun chen Pu-Sheng Wang Liu-Zhu Gong Hefei National Research center for Physical Sciences at the Microscale and Department of chemistry University of Science and Technology of China Key Laboratory of Drug Targeting and Drug Delivery System (Sichuan University) Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University School of Materials and chemistry Southwest University of Science and Technology

The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community. Transition metal-catalyzed asymmetric functionalization of allylic c–H bond represents a unique alternative toward this goal. However, enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered. Here, we report a highly enantioselective dehydrogenative dienylation of imines with unactivated α-alkenes driven by the synergistic action of palladium complex and carboxylic acid. chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range of α-alkenes and imines to be transformed into chiral dienylamines. Mechanistic studies suggest that the dienes could be in situ generated from α-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants, and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst. Notably, the second β-H elimination occurring in the dienylation event might be the turnover-limiting step.

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catalytic atroposelective synthesis of indolyl quinazolinones bearing N-N/c-c diaxes

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Science china chemistry 2025年

作者： Ning-Yi Wang Shuo Gao Zhu-Di Shu Bei-Bei c.eng chun Ma Yu-chen Zhang Feng Shi Research center of chiral Functional Heterocycles School of Chemistry and Materials Science Jiangsu Normal University School of Petrochemical engineering Changzhou University School of chemistry and chemical engineering Henan Normal University

The first catalytic atroposelective synthesis of indole derivatives bearing N-N/c-c diaxes has been established by the strategy of de novo ring formation. By this strategy, various indolyl quinazolinones bearing vicinal N-N/c-c diaxes were synthesized in high yields with overall good diastereoselectivities and excellent enantioselectivities via chiral phosphoric acid-catalyzed onepot asymmetric formal (5+1) cycloaddition/oxidation reaction. Moreover, such indolyl quinazolinones bearing vicinal N-N/cc diaxes have good configurational stability and could be converted into new chiral ligands with applications in asymmetric catalysis. Therefore, this work not only offered a new member for the family of diaxial atropisomers, but also provided a powerful strategy for catalytic asymmetric synthesis of atropisomers bearing N-N/c-c diaxes.

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Post-metallic stent placement bleeding caused by stent-induced ulcers

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World Journal of Gastroenterology 2005年第36期11卷 5739-5741页

作者： chun-Tao Wai christopher Khor Siew-eng Lim Khek-Yu Ho Department ofMedicine National University Hospital 5 Lower Kent Ridge RoadSingapore 119074 Singapore Department of Hematology and Oncology NationalUniversity Hospital 5 Lower Kent Ridge Road Singapore 119074Singapore

Placement of self-expandable metal stents （SEIVIS） is an effective mode of palliative treatment for patients with malignant gastrointestinal obstruction. Gastrointestinal mucosal bleeding complicates about 5% of placement of SEIVIS but is not well described. We report three cases of gastrointestinal bleeding post-SEIVIS placement and suggest that bleeding is caused by direct mucosal infringement by the sharp edges of the ends of the stents. 2005 The WJG Press and Elsevier Inc. All rights reserved

关键词： colorectal cancer Gastric cancer Stricture

Synthesis and characterization of Hydroxypropyl cellulose from Bacterial cellulose

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chinese Journal of Polymer Science 2014年第4期32卷 439-448页

作者： chun-tao chen yang Huang chun-lin Zhu Ying Nie Jia-zhi yang 孙东平 chemicobiology and Functional Material Institute School of Chemical EngineeringNanjing University of Science and Technology

Bacterial cellulose produced by Acetobacter xylinum has been reacted with propyleneoxide to synthesize hydroxypropyl cellulose （HPc） under different reaction conditions while diluted by toluene. The effects of mass ratio of bacterial cellulose to propyleneoxide, dilutability of toluene, reaction temperature （T） and time （t） were investigated by series of experiments. The degree of substitution （DS）, hydroxypropyl content （A） and yield （η） were compared. The optimized product exhibited cold-water solubility and hot-water gelatinization in aqueous medium. Further study was carried out with FTIR, TGA, XRD, SEM and 13c-NMR for characterization. The water/air contact angle measurement reveals that it is a good hydrophobic material with good mechanical properties.

关键词： Bacterial cellulose Hydroxypropylation HPc Hydrophobic Biocompatibility.

A New Furost-20(22)-ene Oligoglycoside from Asparagus cochinchinensis

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chinese chemical Letters 2003年第7期14卷 717-719页

作者： Yong chun yang Sheng yang HUANG Shun Yan MO chun yang Jian Gong SHI Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050

A new furost-20(22)-ene oligoglycoside named as aspacochioside c was isolated from the roots of Asparagus cochinchinensis (Lour.) Merr.. Its structure was elucidated to be 26-O-b- D-glucopyranosyl-(25S)-5b-furost-20(22)-en-3b,26-diol-3-O-a-L-rhamnopyranosyl-(14)-b-D- glucopyranoside on the basis of spectroscopic techniques including 1D and 2D NMR experiments.

关键词： Asparagus cochinchinensis (Lour.) Merr Liliaceae, furost-20(22)-ene oligoglycoside aspacochioside c.