Helvetica Chimica Acta最新文献_第4页

Ambrox through the Looking Glass: Chemoenzymatic Synthesis and GC-Olfactometric Analysis of 15 Ambrox Stereoisomers 透过玻璃看氨溴索15 种氨溴索立体异构体的化学酶法合成和气相色谱-反应监测分析

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-05-08 DOI: 10.1002/hlca.202400016

Felix Flachsmann, Natalie Aeberli, Sandro Dossenbach, Lucas Hortencio, Heinz Koch, Gerhard Brunner, Benjamin Spenger, Eric Eichhorn, Alessio Fonzo, Raphael Berweger, Dominique Lelièvre

{"title":"Ambrox through the Looking Glass: Chemoenzymatic Synthesis and GC-Olfactometric Analysis of 15 Ambrox Stereoisomers","authors":"Felix Flachsmann, Natalie Aeberli, Sandro Dossenbach, Lucas Hortencio, Heinz Koch, Gerhard Brunner, Benjamin Spenger, Eric Eichhorn, Alessio Fonzo, Raphael Berweger, Dominique Lelièvre","doi":"10.1002/hlca.202400016","DOIUrl":"10.1002/hlca.202400016","url":null,"abstract":"All eight theoretical stereoisomers of (10S)-Ambrox have been synthesized by enzymatic polycyclization of the four geometric isomers of homofarnesol with selected squalene hopene cyclases. This includes the highly strained (+)-(8S,9S)-Ambrox, an isomer historically considered unlikely to exist. The enantiomeric (10R)-series has been prepared by a combination of diastereoselective synthesis and preparative chiral HPLC. Thus, for the first time, the synthesis and sensory properties of all but one stereoisomers of Ambrox are presented. The results solve a long standing peradventure: the commercial product (−)-Ambrox exhibits by far the strongest odour, the previously described 9-epi-Ambrox is 26 times weaker. The enantiomer difference between (−)-and (+)-Ambrox was also found much higher than in previous reports (1000 vs. 8 times). The (8R)-configuration was identified as the single most important structural feature for high odour strength.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sustainable Twist – Towards Highly Atom Efficient Grignard Processes 可持续的扭转 - 实现高原子效率的格氏过程

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-05-07 DOI: 10.1002/hlca.202400048

Philipp Kohler, Eva Kirchner, Emilia Păunescu, Ulrich Mayerhöffer

引用次数: 0

New Phases in the Sc−Mn−Si and Sc−Mn−Al−Si Systems Through Molten Indium Flux Synthesis 通过熔融铟助熔剂合成钪-锰-硅和钪-锰-铝-硅体系中的新物相

IF 1.8 4区化学

Helvetica Chimica Acta Pub Date : 2024-05-06 DOI: 10.1002/hlca.202400018

Robin Lefèvre, Felix Eder, Fabian O. von Rohr

{"title":"New Phases in the Sc−Mn−Si and Sc−Mn−Al−Si Systems Through Molten Indium Flux Synthesis","authors":"Robin Lefèvre, Felix Eder, Fabian O. von Rohr","doi":"10.1002/hlca.202400018","DOIUrl":"10.1002/hlca.202400018","url":null,"abstract":"Through the application of synthesis via molten indium flux, we have been able to expand the ternary Sc−Mn−Si system and the quaternary Sc−Mn−Al−Si system. Specifically, we report on five previously unknown chemical compounds, namely β-ScMnSi2, Sc4+xMn4Si7–2x, Sc2Mn4Si5, Sc2Mn3Si4, and Sc4Mn2AlSi4. The compounds with the stoichiometries Sc2Mn4Si5, Sc2Mn3Si4, and Sc4Mn2AlSi4 have previously not been reported. We find that these crystallize in the V6Si5, Hf2Ru3Si4, and Ho4Ni2InGe4 structure types, respectively. For the ternary compounds with the stoichiometries of ScMnSi2 and Sc4+xMn4Si7–2x, we find clearly deviating structural solutions compared to earlier reports. β-ScMnSi2 is found to crystallize in the monoclinic crystal system isostructural to a supercell of the MnTiSi2 structure and clearly deviating from the known orthorhombic α-polymorph. The compound Sc4+xMn4Si7–2x is structurally very similar to Sc4Mn4Si7, but exhibits the P4/nmm space group instead of I4/mmm, and is related to the Zr4Co4Ge7 structure. Disorder between Si and Sc sites leads to the off-stoichiometric composition, for which we found x=0.287(5).","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advances in the Synthesis of Heterocycles with Two and Three Heteroatoms using Hydrazonoyl Halides 利用肼酰卤合成具有两个和三个杂原子的杂环的进展。

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-30 DOI: 10.1002/hlca.202400058

Nargiza R. Yamaletdinova, Rail R. Gataullin

{"title":"Advances in the Synthesis of Heterocycles with Two and Three Heteroatoms using Hydrazonoyl Halides","authors":"Nargiza R. Yamaletdinova, Rail R. Gataullin","doi":"10.1002/hlca.202400058","DOIUrl":"10.1002/hlca.202400058","url":null,"abstract":"The review covers the results of studies published in the literature on the use of hydrazonoyl halides in the synthesis of five- (pyrazoles, thiazoles, triazoles, oxa- and thiadiazoles), six- (oxa- and thiadiazines, indazoles, pyridazines, pyrazines, tetrazines) or seven-membered (benzotriazepine) heterocycles. In the formation of these heterocycles, the main intermediate stage of the reaction is the in situ generation of nitrilimine, which enters into a cycloaddition reaction with substituted acetylenes (including in situ generated benzynes, naphthynes), allenes, activated olefins, anthranilic acid derivatives, organosulfur compounds (mercaptoaldehydes, mercaptocarboxylic acids) or with fused heterocycles. Examples are given of the formation of heterocycles by replacing the halogen atom from a hydrazonoyl halide molecule with a nucleophilic group, followed by exhaustive intramolecular cyclization into the target compound. There are discussions of reactions in which the cycloaddition of the nitrilimine to the in situ synthesized Knoevenagel condensation product (from CH-acid compounds, such as di- and monocarbonyl compounds, dinitrile malonic acid) occurs, leading to spiro-linked or conventional pyrazoles. Some syntheses of biologically active representatives are shown.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Atomic Tailoring of Ubiquitin Side Chains Influences E2-Mediated Ubiquitin Chain Formation 超泛素侧链的原子修饰影响 E2 介导的超泛素链形成

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-24 DOI: 10.1002/hlca.202400003

Haewon Song, Toshiki Mikami, Sohei Majima, Jeffrey W. Bode

{"title":"Atomic Tailoring of Ubiquitin Side Chains Influences E2-Mediated Ubiquitin Chain Formation","authors":"Haewon Song, Toshiki Mikami, Sohei Majima, Jeffrey W. Bode","doi":"10.1002/hlca.202400003","DOIUrl":"10.1002/hlca.202400003","url":null,"abstract":"Ubiquitin (Ub) is a small, highly conserved protein essential for eukaryotic biology, and is unique in its formation of polyubiquitin chains by conjugation to one of its seven lysine side chains. Here we report that atomic tailoring of Ub side chains – i. e. the insertion, deletion, or replacement of specific atoms – has significant and unexpected consequences on the enzymatic conjugation of Ub oligomers by isopeptide bond formation mediated by E2 conjugating enzymes. These studies employed chemical synthesis and ligation methods to prepare numerous specifically tailored Ub monomers on multi-milligram scales. While some modifications including N-terminal acylation and methionine replacement did not affect protein folding or Ub chain formation with Ube2 K, other modifications had a pronounced effect of oligomerization with Ubc13/Mms2. We observed that Ala46Hse mutation obliterates the ability of this Ub monomer to accept another Ub at Lys63 in Ubc13-mediated conjugations. Exhaustive replacement of all seven lysines with shorter surrogates Orn, Dab, or Dap essentially blocks Ub chain formation, and in the case of Dap, precludes proper folding of the Ub protein.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140661424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cover Picture: (Helv. Chim. Acta 4/2024) 封面图片： (Helv. Chim. Acta 4/2024)

IF 1.8 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-15 DOI: 10.1002/hlca.202470401

引用次数: 0

The Two Janus Faces of CpRu-Based Deallylation Catalysts and Their Application for in Cellulo Prodrug Uncaging 基于 CpRu 的脱烯丙基催化剂的两面性及其在细胞内原药释放中的应用

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-15 DOI: 10.1002/hlca.202400053

Alain Baiyoumy, Robin Vinck, Thomas R. Ward

引用次数: 0

Controlled Release of Volatile Enones from Monomeric and Dimeric Thioether, Sulfoxide and Sulfone Profragrances 单体和二聚体硫醚、亚砜和砜类增殖体中挥发性烯酮的可控释放

IF 1.8 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-10 DOI: 10.1002/hlca.202400046

Alain Trachsel, Sabine Leocata, Jean-Yves de Saint Laumer, Andreas Herrmann

{"title":"Controlled Release of Volatile Enones from Monomeric and Dimeric Thioether, Sulfoxide and Sulfone Profragrances","authors":"Alain Trachsel, Sabine Leocata, Jean-Yves de Saint Laumer, Andreas Herrmann","doi":"10.1002/hlca.202400046","DOIUrl":"10.1002/hlca.202400046","url":null,"abstract":"Thioether (sulfide) profragrances are readily prepared by 1,4-addition of alkanethiols to enones (thia-Michael reaction). Under ambient conditions, they slowly release the parent enones, thus generating a long-lasting perfumery effect. The fragrance release of profragrances obtained by 1,4-addition of S, O and N nucleophiles to enones was compared on cotton and on a hard surface for monomeric and dimeric structures. To avoid the uncontrolled generation of volatile sulfur compounds from thioethers, we investigated the extent to which different side reactions occurred next to the expected formation of enones and alkanethiols. Headspace analyses on cotton showed that enones and aldehydes were the major reaction products, whereas none or only traces of β-mercaptoketones, diketones or alkanethiols were detected. The absence of alkanethiols indicated that 1,4-elimination of thioethers was not a major pathway for fragrance release. Extraction of the cotton sheets after analysis showed that thioethers were oxidised to sulfoxides, which then can generate enones by 1,4-elimination. Thioethers, sulfoxides and sulfones were shown to efficiently release enones in practical applications.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140571705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Total Synthesis of Core 3 & Core 4-Type Mucin Glycan Derivatives 核心 3 型和核心 4 型粘蛋白聚糖衍生物的全合成

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-03 DOI: 10.1002/hlca.202400026

Carmen R. Cori, Rachel Hevey

{"title":"Total Synthesis of Core 3 & Core 4-Type Mucin Glycan Derivatives","authors":"Carmen R. Cori, Rachel Hevey","doi":"10.1002/hlca.202400026","DOIUrl":"10.1002/hlca.202400026","url":null,"abstract":"Recent studies have demonstrated the ability of mucin O-glycans to attenuate virulence in diverse, cross-kingdom pathogens, sparking interest in their development as a novel therapeutic approach against infection. Although their virulence attenuating activity is evident, mucin glycans obtained from native sources comprise mixtures of several hundred distinct structures, and therefore the specific active glycan epitopes and molecular mechanisms of virulence attenuation remain unclear. Individual mucin glycan structures cannot be purified from native sources and are not amenable to automated synthesis; therefore, to further investigate the phenomena of virulence attenuation we have been developing convergent and scalable methods (>30 mg per target glycan) to assemble a mucin O-glycan library in sufficient scale and purity to facilitate biological studies. Previously we described a method to obtain core 1 & core 2-type mucin glycan derivatives that have since been used to identify active epitopes in Candida albicans and Vibrio cholerae. In the current study, we describe the expansion of our glycan library to include core 3 & core 4-type derivatives, increasing the structural diversity of our platform for biological evaluation.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140571667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of N-Substituted Pyrrole-2,5-dicarboxylic Acids from Pyrroles 从吡咯合成 N-取代的吡咯-2,5-二羧酸

IF 1.8 4区化学

Helvetica Chimica Acta Pub Date : 2024-04-03 DOI: 10.1002/hlca.202400036

Jan-Simon Jeshua Friedrichs, Dr. Luca Schmermund, Dr. Corinna Urmann, Prof. Dr. Volker Sieber

引用次数: 0