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Steroidal scaffold decorations in Solanum alkaloid biosynthesis

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Molecular Plant 2024年第8期17卷 1236-1254页

作者： Rosalind Lucier Mohamed O.Kamileen Yoko Nakamura Sofiia Serediuk Ranjit Barbole Jens Wurlitzer Maritta Kunert Sarah Heinicke Sarah E.O'Connor Prashant D.Sonawane Department of Natural Product Biosynthesis Max Planck Institute for Chemical Ecology07745 JenaGermany Research Group Biosynthesis and NMR Max Planck Institute for Chemical Ecology07745 JenaGermany Biochemical Sciences Division CSIR-National Chemical LaboratoryPune 411008MaharashtraIndia

Steroidal glycoalkaloids(SGAs)are specialized metabolites produced by hundreds of Solanum species,including important vegetable crops such as tomato,potato,and *** it has been known that SGAs play important roles in defense in plants and“anti-nutritional"effects(e.g.,toxicity and bitterness)to humans,many of these molecules have documented anti-cancer,anti-microbial,antiinflammatory,anti-viral,and anti-pyretic *** these,α-solasonine andα-solamargine isolated from black nightshade(Solanum nigrum)are reported to have potent anti-tumor,anti-proliferative,and anti-inflammatory ***,α-solasonine andα-solamargine,along with the core steroidal aglycone solasodine,are the most widespread SGAs produced among the Solanum ***,it is still unknown how plants synthesize these bioactive steroidal *** comparative metabolomictranscriptome-guided approach,biosynthetic logic,combinatorial expression in Nicotiana benthamiana,and functional recombinant enzyme assays,here we report the discovery of 12 enzymes from *** that converts the starting cholesterol precursorto solasodine aglycone,and the downstreamα-solasonine,α-solamargine,and malonyl-solamargine SGA *** further identified six enzymes from cultivated eggplant that catalyze the production ofα-solasonine,α-solamargine,and malonyl-solamargine SGAs from solasodine aglycone via glycosylation and atypical malonylation *** work provides the gene tool box and platform for engineering the production of high-value,steroidal bioactive molecules inheterologoushosts usingsyntheticbiology.

关键词： steroidal glycoalkaloids Solanum biosynthetic pathway α-solamargine malonyl-solamargine specialized metabolites

Morphological Heredity of Intermetallic Nb_(5)Si_(3)Dendrites in Hypereutectic Nb-Si Based Alloys via Non-Equilibrium Solidification

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 393-400页

作者： Yueling Guo Lina Jia Wenjun Lu Hu Zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Research Center of Light‑alloy Materials Frontier Institute of Science and Technology InnovationBeihang UniversityBeijing 100191China max-planck-Institut für Eisenforschung Max‑Planck‑Straße 140237 DüsseldorfGermany

For hypereutectic Nb-Si based alloys,primary Nb_(5)Si_(3)phases typically grow in a faceted mode during equilibrium or near-equilibrium solidification,which damages the ductility and *** address this issue,here we artificially manipulate the growth morphology of Nb_(5)Si_(3)using electron beam surface melting(EBSM)and subsequent annealing *** show that such a non-equilibrium solidification pathway enables the transition from faceted growth to non-faceted dendritic growth of Nb_(5)Si_(3),along with evident microstructure refinement,generation of metastableβ-Nb_(5)Si_(3)phases and elimination of chemical *** transformation fromβ-Nb_(5)Si_(3)toα-Nb_(5)Si_(3)and Nb solid solution(Nbss)particles is triggered by the annealing treatment at 1450°C for 5 ***,we find the annealing-mediated formation of inherited Nb_(5)Si_(3)dendrites that maintain the dendritic morphology of the original as-solidifiedβ-Nb_(5)Si_(3)*** work thus provides a feasible routine to obtain thermally stable and refinedα-Nb_(5)Si_(3)dendrites in hypereutectic Nb-Si based alloys.

关键词： Nb-Si alloy Intermetallics Nb_(5)Si_(3) Rapid solidification Dendritic growth

CREEP DEFORMATION OF INTERMETALLIC ALLOYS

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Acta Metallurgica Sinica(English Letters) 1995年第Z1期8卷 431-440页

作者： Gerhard Sauthoff(max-planck-Institut fur Eisenforschung GmbH., D-40074 Dusseldorf,Germany) max-planck-Institut fur Eisenforschung GmbH Dusseldorf Germany

Intermetallics for structural applications at high temperatures must show a sufficient high temperature strength which is controlled by creep processes. In the first section the creep behaviour of single-phase intermetallic alloys is overviewed with respect to stress and temperature dependence and effects of composition and microstructure. It is shown in particular that creep deformation is controlled by diffusion. The second section refers to multiphase intermetallic alloys, and both particulate and non-particulate alloys are regarded. Data are presented for single-phase and multiphase alloys based on B2 phases and lesscommon phases and the consequences of diffusion control for alloy design are discussed.

关键词： creep B2 phases NiAl particulate alloys,multiphase alloys

Reduced formation of peroxide and radical species stabilises iron-based hybrid catalysts in polymer electrolyte membrane fuel cells

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Journal of Energy Chemistry 2022年第2期31卷 433-438页

作者： Dongyoon Shin Sabita Bhandari Marc FTesch Shannon ABonke Frédéric Jaouen Sonia Chabbra Christoph Pratsch Alexander Schnegg Anna K.Mechler max planck institute for Chemical Energy Conversion Stiftstr.34–3645470 Mülheim an der RuhrGermany ICGM Univ.MontpellierCNRSENSCMMontpellierFrance Fritz Haber institute of the max planck Society Department of Inorganic ChemistryFaradayweg 4-614195 BerlinGermany

The incorporation of Pt into an iron-nitrogen-carbon(Fe NC)catalyst for the oxygen reduction reaction(ORR)was recently shown to enhance catalyst stability without Pt directly contributing to the ORR ***,the mechanistic origin of this stabilisation remained *** is established herein with rotating ring disc experiments that the side product,H_(2)O_(2),which is known to damage FeNC catalysts,is suppressed by the presence of *** formation of reactive oxygen species is additionally inhibited,independent of intrinsic H_(2)O_(2) formation,as determined by electron paramagnetic *** electron microscopy identifies an oxidised Fe-rich layer covering the Pt particles,thus explaining the inactivity of the latter towards the *** insights develop understanding of Fe NC degradation mechanisms during ORR catalysis,and crucially establish the required properties of a precious metal free protective catalyst to improve Fe NC stability in acidic media.

关键词： Electrochemistry Fuel cells Oxygen reduction reaction Non-precious metal catalyst Hybrid catalyst Stability

Thermal Expansion Behavior of Precursor-Derived Amorphous Si-C-N and Si-B-C-N Ceramics

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Journal of Materials Science & Technology 2002年第2期18卷 139-142页

作者： Jianqiang HansJuergenSeifert 等 max-planck-InstitutfureMetallforschungandInstitutfuerNichtmetallischeAnorganischeMaterialien UnversityStuttgartPulvermetallurgischesLaboratoriumHeisenbergstraβe570569StuttgartGermany max-planck-I

Thermal expansion behaviors of some precursor-derived amorphous Si-C-N and Si-B-C-N ceramics, which were shaped by plastic forming after crosslink, were studied. To complete the shrinkage and densification, after thermolysis specimens were heat treated at a temperature of 1400℃ for 10 h in nitrogen atmosphere. The thermal expansion coefficient of VT50-derived amorphous Si-C-N ceramic increases from 1.98×10-6/K at 400℃ to 3.09×10-6/K at 1000℃, of NCP200-derived amorphous Si-C-N ceramic increases from 2.35×10-6/K at 400℃ to 3.45×10-6/K at 1000℃, and of T2-l-derived amorphous Si-B-C-N ceramic increases from 2.08×10-6/K at 400℃ to 3.18×10-6/K at 1000℃. No glass transition for these amorphous ceramic materials was detected, indicating that as-thermolyzed precursor-derived Si-(B-)C-N ceramic materials are amorphous solids, but not glasses.

关键词： Thermal expansion Amorphous ceramics Precursor S-C-N Si-B-C-N

The role of Ca,Al and Zn on room temperature ductility and grain boundary cohesion of magnesium

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Journal of Magnesium and Alloys 2021年第5期9卷 1536-1551页

作者： Supriya Nandy Shao-Pu Tsai Leigh Stephenson Dierk Raabe Stefan Zaefferer max-planck Institut für Eisenforschung Düsseldorf 40237Germany

It is know from literature that small additions(<1 wt%)of Ca,Al and Zn significantly improve the intrinsic ductility of *** exact role of each element,both qualitatively and quantitatively,and their combined effects,however,are poorly *** we achieved a much clearer view on the quantitative role of each element with respect to ductility improvement and on the collaborative effect,particularly of Ca and Zn in *** of our findings and conclusions are in disagreement with data and interpretation found in *** different alloys,namely,Mg-0.1 Ca,Mg-0.1 Ca-1 Al,Mg-0.05 Ca-1 Al,Mg-0.1 Ca-2 Al-1 Zn(all are in wt%)were selected for this *** alloys were treated such that *** grain sizes and textures were *** largely excludes the effect of extrinsic factors on ***-guided slip trace analyses reveal that the addition of Ca eases activation of prismatic and pyramidal II slip *** in-situ deformation experiments in SEM and atom probe tomography observations of grain boundaries direct evidence is given for the individual and synergetic effects of Ca and Zn on grain boundary cohesion as an important contribution to improve the ductility of these *** conclude that Ca reduces the slip anisotropy and ameliorates ductility,however,the weak grain boundary cohesion in the Mg-0.1 wt%Ca alloy limits the material’s tensile *** addition of Zn alters the Ca segregation at the grain boundaries and helps to retain their cohesive strength,an effect which thus enables higher ductility and *** further addition of Al primarily improves the *** results show that the balanced influence of reduced slip anisotropy on the one hand and increased grain boundary cohesion on the other hand allow to design a high strength high ductility rare-earth free Mg alloy.

关键词： Magnesium–Calcium–Zinc alloys Ductility Slip system determination grain boundary cohesion

A Simple Scheme for Directly Measuring the Wigner Functions of Cavity Fields

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Chinese Physics Letters 2003年第2期20卷 227-229页

作者：张智明 DepartmentofPhysics ShanghaiJiaotongUniversityShanghai200240 max-planck-instituteforQuantumOptics H

We propose a scheme for directly measuring the Wigner functions of cavity fields. The scheme is based on the Raman interaction between atoms and cavity fields. We find a simple and direct relation between the Wigner function and the atomic population difference. By suitably choosing the interaction time, we find that the Wigner function is just two times of the atomic population difference. Thus, one can obtain the Wigner function by measuring the atomic populations and calculating the population difference.

关键词： Atoms

Mechano-Stimulation Triggers Turgor Changes Associated with Trap Closure in the Darwin Plant Dionaea muscipula

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Molecular Plant 2014年第4期7卷 744-746页

作者： María Escalante-Pérez Sonke Scherzer Khaled A.S. Al-Rasheid Christoph Dottinger Erwin Neher Rainer Hedrich Department for Membrane Biophysics Max-Planck-Institute for Biophysical ChemistryD-37077 GottingenGermany

The Darwin plant, also known as the Venus flytrap, Dionaea muscipula, has fascinated people since Darwin＇s time. The plant lives in nutrient-poor habitats but has been able to overcome the limitations of its surroundings by evolving a carnivorous lifestyle, particularly by modifying its leaves into active traps to catch animals. When flies, ants, or other small animals touch mechano-sensitive hairs protruding from the inner surface of the bi-lobed trap, it shuts within a fraction of a second.

关键词： VENUS'S flytrap TURGOR

A good example of high-energy radiation delay event

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Chinese Science Bulletin 1997年第4期42卷 313-315页

作者： GAN Weiqun and Rieger Erich1 Purple Mountain Observatory, Nanjing 210008, China 2. max-planck institute of Extraterrestrial Physics, Garching 85740,Germany Purple Mountain Observatory Nanjing China max-planck institute of Extraterrestrial Physics Garching Germany

THE delay of high-energy radiation of solar flares can be divided into two types: one is the energy-dependent delay in the hard X-ray regime, the other is the delay between the hard X-rays and instantaneous γ-ray line (GRL) emissions. Both types have different physical meanings. The former reflects the difference in acceleration or transportation of energetic electrons with various energies, while the latter reflects such a difference between the energetic electrons

关键词： sun. flare X-ray γ-ray.