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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-Cheng 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

面向BORO和BOPS的零售商退货策略与渠道决策

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管理工程学报 2025年第1期39卷 271-284页

作者：毛照昉苗琪琪杨哲杜泽霖天津大学管理与经济学部天津300072

消费者体验需求的提升促使零售商不断探索新渠道模式,以提高原有实体店效益的同时优化线上经营策略。本文分别考虑传统BORO(buy online and return online)和开通BOPS(buy online and pickup in store)两种渠道情形,构建零售商针对消费... 详细信息

消费者体验需求的提升促使零售商不断探索新渠道模式,以提高原有实体店效益的同时优化线上经营策略。本文分别考虑传统BORO(buy online and return online)和开通BOPS(buy online and pickup in store)两种渠道情形,构建零售商针对消费者线上购买并在线上或线下退款的差异化退货策略利润模型,分析两种渠道情形下的最优定价和最优退货策略,进而考虑BOPS渠道的溢出效应,分析零售商在相同退货策略下是否应该开通BOPS渠道。结果表明:(1)在两种情形下,随着线下商店数量的增多,零售商均会倾向于在低开店成本下选择全额退款策略,倾向于在高开店成本下选择部分退款策略;(2)在同渠道情形下,全额退款策略的定价始终低于部分退款策略。在同退货策略下,BOPS情形下的定价始终低于BORO情形;(3)高溢出效应和多商店数量都促使零售商选择开通BOPS渠道,但商店数量决定了BOPS线下麻烦成本规模因子对零售商开通BOPS渠道起推动还是抑制作用。本文为既定商店数量下多渠道零售商退货策略与渠道选择提供了决策支持。

关键词：商店数量 BORO BOPS 退货策略渠道选择

Extraction and Crystal Structure of Karounidiol

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Chinese Journal of Structural Chemistry 2003年第4期22卷 431-434页

作者： CHAOZhi-mao wANGCheng InstituteofChineseMateriaMedica ChinaAcademyofTraditionalChineseMedicineBeijing100700China InstituteofMateriaMedica PekingUnionMedicalCollegeandChineseAcademyofMedicalSciencesBeijing100050China

The title compound of karounidiol (C30H48O2), a main active triterpene component of snakegourd seed, was isolated from unsaponifiable matter of the seed oil of Trichosanthes kirilowii Maxim., and characterized by X-ray diffraction analysis. It crystallizes in orthorhombic system, space group P212121 with C30H48O2CH3OHH2O (C31H54O4), a = 7.515(1), b = 14.407(1), c = 27.799(2) , V = 3009.8(5) 3, Z = 4, Dx = 1.087 g/cm3, Mr = 490.77, f(000) = 1088 and = 0.086 mm-1. The final R = 0.0840 and wR = 0.2289 for 2752 observed reflections (|f|2 ≥ 2|f|2). The molecular crystal structure of karounidiol shows relative stereochemistry of (3,13,14, 20)-3,29-dihydroxy-13-methyl-26-norolean-7,9(11)-diene. The molecule is composed of five six- membered rings with ring junctures of A/B trans, C/D trans and D/E cis.

关键词： karounidiol crystal structure Trichosanthes kirilowii triterpene

Proof of Two Supercongruences of Truncated Hypergeometric Series_(4)f_(3)

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1015-1028页

作者： Guo Shuai mao Department of Mathematics Nanjing University of Information Science and TechnologyNanjing 210044P.R.China

In this paper,we prove two supercongruences conjectured by Z.-*** via the wilf-Zeilberger *** of them is,for any prime p>3,4f3[7/6 1/2 1/2 1/2 1/6 1 1]-1/8]-1/2≡p(-2/p)+p^(3)/4(2/p)Ep-3 (mod p^(4))where(·/p)stands f... 详细信息

关键词： Supercongruence truncated hypergeometric series wilf–Zeilberger method Euler numbers Legendre symbol

The Effect of the Chain Length on MMA free Radicl Polymerization

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Chinese Chemical Letters 2001年第11期12卷 1041-1042页

作者： wang, M mao, YG Lu, YY Yang, Rf Li, f Shen, JC Jilin Univ Minist Educ Key Lab Supramol Struct & Spect Changchun 130023 Peoples R China

In the polymerization process of methyl methacrylate (MMA), the Arrhenius parameters (activation energy and frequency factor) of propagating reaction monotonically decrease with increasing monomer conversion. At the beginning and middle stage of the propagating reaction, the increase of radical chain length is the main reason of above mentioned change. And at the end stage, the sharp decrease of k(p) indicates that the activation energy is approximately incline to zero and the propagating reaction is controlled by molecular diffusion motion.

关键词： MMA Arrhenius parameters propagating reaction radical chain length

The Battle to Sequence the Bread wheat Genome:A Tale of the Three Kingdoms

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Genomics, Proteomics & Bioinformatics 2020年第3期18卷 221-229页

作者： Jiantao Guan Diego f.Garcia Yun Zhou Rudi Appels Aili Li Long mao National Key facility for Crop Gene Resources and Genetic Improvement Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijing 100081China Collaborative Innovation Center of Crop Stress Biology&Institute of Plant Stress Biology School of Life ScienceHenan UniversityKaifeng 475004China AgriBio Centre for AgriBioscienceDepartment of Economic DevelopmentJobsTransportand ResourcesLa Trobe UniversityMelbourneVIC 3083Australia

In the year 2018,the world witnessed the finale of the race to sequence the genome of the world’s most widely grown crop,the common *** has been known to bear a notoriously large and complicated genome of a polyploidy nature.A decade competition to sequence the wheat genome initiated with a single consortium of multiple countries,taking a conventional strategy similar to that for sequencing Arabidopsis and rice,became ferocious over time as both sequencing technologies and genome assembling methodologies *** different stages,multiple versions of genome sequences of the same variety(e.g.,Chinese Spring)were produced by several groups with their special ***,16 years after the rice genome was finished and 9 years after that of maize,the wheat research community now possesses its own reference *** with these genomics tools,wheat will reestablish itself as a model for polyploid plants in studying the mechanisms of polyploidy evolution,domestication,genetic and epigenetic regulation of homoeolog expression,as well as defining its genetic diversity and breeding on the genome *** enhanced resolution of the wheat genome should also help accelerate development of wheat cultivars that are more tolerant to biotic and/or abiotic stresses with better quality and higher yield.

关键词： Common wheat Homoeologous genomes Polyploid Sequencing Triticum aestivum

日粮中添加枯草芽孢杆菌对高氧气调包装猪肉蛋白质和脂质氧化的影响

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食品科学 2025年第1期46卷 142-148页

作者：张悦于江刘飞张玉玉张一敏毛衍伟山东农业大学食品科学与工程学院山东泰安271018 山东省农业科学院畜牧兽医研究所农业农村部畜禽生物组学重点实验室山东济南250100

为探究日粮添加枯草芽孢杆菌对猪肉抗氧化能力以及高氧气调包装贮藏期间猪肉肉色、蛋白质氧化、脂质氧化和感官品质的影响,选取对照组(只饲喂基础日粮)和处理组(基础日粮添加枯草芽孢杆菌)的三元杂交(杜洛克×长白×大约克)猪各6只,屠... 详细信息

为探究日粮添加枯草芽孢杆菌对猪肉抗氧化能力以及高氧气调包装贮藏期间猪肉肉色、蛋白质氧化、脂质氧化和感官品质的影响,选取对照组(只饲喂基础日粮)和处理组(基础日粮添加枯草芽孢杆菌)的三元杂交(杜洛克×长白×大约克)猪各6只,屠宰后取背最长肌测定抗氧化酶活性,其余背最长肌样品进行高氧气调包装,4℃冷库贮藏,分别在0、5、10、15、20?d测定肉色、丙二醛(malondialdehyde,MDA)、羰基和巯基含量,并进行感官评价。结果表明:与对照组相比,处理组能够显著提高超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性(P<0.05),增强猪肉的抗氧化能力;日粮中添加枯草芽孢杆菌可以显著改善高氧气调包装猪肉的肉色(P<0.05);在低温贮藏期间,处理组能够显著降低MDA含量(P<0.05),抑制高氧气调包装猪肉的脂肪氧化;日粮中添加枯草芽孢杆菌能够显著抑制高氧气调包装猪肉的蛋白质氧化、羰基的生成和巯基损失(P<0.05),同时显著提高猪肉打开包装前的颜色和打开包装后的总体喜爱度评分(P<0.05)。综上,在日粮中添加枯草芽孢杆菌可提高猪肉的抗氧化能力、改善猪肉在高氧气调包装中的肉色、抑制蛋白质和脂质氧化,提高猪肉的食用品质。

关键词：枯草芽孢杆菌猪肉抗氧化能力脂质氧化蛋白质氧化

Effects of Sm Doping to Improve the Thermoelectric Properties of ZnO Ceramics

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Journal of wuhan University of Technology(Materials Science) 2022年第6期37卷 1166-1171页

作者： fENG Bo mao wentao School of Mechanical and Electrical Engineering Wuhan Donghu UniversityWuhan 430070China Institute of Engineering and Technology Hubei University of Science and TechnologyXianning 437100China

A series of Sm doped ZnO based thermoelectric materials were prepared by mechanical alloying and spark plasma *** effects of Sm doping on ZnO based thermoelectric materials were systematically studied by means of electrical and thermal properties tests combined with first principles calculations of energy band,density of states and elastic *** experimental results show that the substitution of Sm at Zn site could cause the valence band and conduction band moving down,and the 4f orbitals of Sm could contribute to the increase of the density of states near the fermi level,corresponding to the increase of carrier concentration and electrical *** substitution of Sm at Zn site could cause the decrease of effective mass and Seebeck *** substitution of Sm at Zn site could lead to the decrease of Young's modulus and lattice thermal conductivity,which contribute to the decrease of thermal ***,the highest dimensionless thermoelectric figure of merit(ZT)value has been increased to 0.346,which is 3.48 times as pristine ZnO.

关键词： Sm doping energy band engineering phonons ceramics

Photoelectron Spectroscopy, Photoionization Mass Spectroscopy, and Theoretical Study on CCl3SSCN

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Chinese Journal of Chemical Physics 2008年第2期21卷 93-98页

作者： Lin Du Li Yao mao-fa Ge Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Trichloromethanesulfenyl thiocyanate, CCl3SSCN, was generated and studied by photoelectron spectroscopy （PES）, photoionization mass spectroscopy （PIMS）, and theoretical calculations. This molecule exhibits a gauche conformation, and the torsional angle around S-S bond is 91.4° due to the sulfur-sulfur lone pair interactions. After ionization, the ground-state cationic-radical form of CCl3SSCN＋ adopts a trans planar main-atom structure with Cs symmetry. The highest occupied molecular orbital （HOMO） of CC13SSCN corresponds to the electrons mainly localized on the sulfur 3p lone pair MO. The first ionization energy is determined to be 10.40 cV.

关键词： Photoelectron spectroscopy Photoionization mass spectroscopy Electronic structure