Efficient synthesis of piperazinyl amides of 18β-glycyrrhetinic acid

• Dong Cai,
• ZhiHua Zhang,
• Yufan Meng,
• KaiLi Zhu,
• LiYi Chen,
• ChangXiang Yu,
• ChangWei Yu,
• ZiYi Fu,
• DianShen Yang and
• YiXia Gong

Beilstein J. Org. Chem. 2020, 16, 798–808, doi:10.3762/bjoc.16.73

• [3], antitumor [4], and antibacterial [5] activity and their proberties as hepatic protective agents [6]. Over the past few decades, the emphasis was placed primarily on explaining structure–activity relationships of 18β-glycyrrhetinic acid derivatives to enhance their biological activity. The

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• amphidinolide V, whose biological activities were thoroughly evaluated. It is important to note, that the analogs of amphidinolide V designed by Fürstner gave the first insights into the structure–activity relationships for this family of compounds and revealed that the steric structure of the macrolactone is a

Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes

• Zeguo Fang,
• Nawaf Al-Maharik,
• Peer Kirsch,
• Matthias Bremer,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2020, 16, 674–680, doi:10.3762/bjoc.16.65

• (Figure 2). Therefore, the aim of the study was to prepare these target liquid crystals and evaluate their properties relative to each other, to establish if there were any obvious structure–activity relationships to emerge for the design of positive or negative dielectric materials. Also the fixed spiro

Chemical tuning of photoswitchable azobenzenes: a photopharmacological case study using nicotinic transmission

• Lorenzo Sansalone,
• Jun Zhao,
• Matthew T. Richers and
• Graham C. R. Ellis-Davies

Beilstein J. Org. Chem. 2019, 15, 2812–2821, doi:10.3762/bjoc.15.274

• )AChR. The structural difference between the native acetylcholine and nicotine are striking, and their diversity reflects the complexity of structure–activity relationships of ligands for nicotinic acetylcholine receptors. For example, the drug homocholine phenyl ether (HoChPE) is an agonist of the

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• executed in the past two decades [38][39][40][41][42][43][44][45][46][47][48][49][50][51]. With the increasingly clear structure–activity relationships (SARs) [52][53][54][55][56][57][58][59][60][61], some derivatives of triptolide, such as minnelide 6 and (5R)-5-hydroxytriptolide (LLDT-8, 7) have

Water inside β-cyclodextrin cavity: amount, stability and mechanism of binding

• Stiliyana Pereva,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2019, 15, 1592–1600, doi:10.3762/bjoc.15.163

• details Different molecular modeling methods (quantum mechanics (QM), molecular dynamics (MD), docking and quantitative structure activity relationships (QSARs)) can be applied in studying the structure, dynamics, and energetics of the host CD systems. However, the results from different modeling (or

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

• Hidekazu Komatsu,
• Takashi Shirakawa,
• Takeo Uchiyama and
• Tsutomu Hoshino

Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27

• alkaline hydrolysates, compounds A and B, were prepared. We discuss here the structure–activity relationships between the derivatives and their necrotic activities toward lettuce. Keywords: cichorinotoxin; lipodepsipeptide; necrotic lesion of lettuce; phytotoxin; Pseudomonas cichorii; Introduction

Unexpected loss of stereoselectivity in glycosylation reactions during the synthesis of chondroitin sulfate oligosaccharides

• Teresa Mena-Barragán,
• José L. de Paz and
• Pedro M. Nieto

Beilstein J. Org. Chem. 2019, 15, 137–144, doi:10.3762/bjoc.15.14

• crucial to determine structure–activity relationships and elucidate the particular sugar sequences involved in the interactions between CS and target proteins that regulate these biological functions. For this reason, several approaches have been reported for the synthesis of these molecules [2][3][4][5

Synthesis and biological evaluation of 1,2-disubstituted 4-quinolone analogues of Pseudonocardia sp. natural products

• Stephen M. Geddis,
• Teodora Coroama,
• Suzanne Forrest,
• James T. Hodgkinson,
• Martin Welch and
• David R. Spring

Beilstein J. Org. Chem. 2018, 14, 2680–2688, doi:10.3762/bjoc.14.245

• PQS analogues, which has been hitherto underexplored. Keywords: antibiotics; cross-coupling; heterocycles; quorum-sensing; structure–activity relationships; Introduction The quinolone core has long been implemented in structures possessing formidable activity in a broad range of fields, including

• transposition, whilst 4, 7 and 8 were derivatised from 1. In this current work, we turn to the further elucidation of the biological activity of this class of compounds. In order to gain additional insight into the associated structure–activity relationships (SAR), it was desired to generate analogues of the

Non-native autoinducer analogs capable of modulating the SdiA quorum sensing receptor in Salmonella enterica serovar Typhimurium

• Matthew J. Styles and
• Helen E. Blackwell

Beilstein J. Org. Chem. 2018, 14, 2651–2664, doi:10.3762/bjoc.14.243

• start to delineate structure–activity relationships (SARs) for SdiA:AHL interactions. Using a cell-based reporter of SdiA in Salmonella enterica serovar Typhimurium, several non-natural SdiA agonists and the first set of SdiA antagonists were identified and characterized. These compounds represent new

• , and follow-up studies were performed in an E. coli SdiA reporter. The results provide a broad picture of the types of AHL scaffolds that can agonize and antagonize S. Typhimurium SdiA, allowing for the definition of key structure–activity relationships (SARs) for the modulation of SdiA activity. These

Synthesis of 1,4-imino-L-lyxitols modified at C-5 and their evaluation as inhibitors of GH38 α-mannosidases

• Maroš Bella,
• Sergej Šesták,
• Ján Moncoľ,
• Miroslav Koóš and
• Monika Poláková

Beilstein J. Org. Chem. 2018, 14, 2156–2162, doi:10.3762/bjoc.14.189

• be more potent and selective inhibitors of the target enzyme. Moreover, proposed N-benzyl substituent at the pyrrolidine core was also confirmed to be essential for selectivity [30]. In this study, we explored structure–activity relationships (SAR) of pyrrolidine derivatives 1 with different

Defining the hydrophobic interactions that drive competence stimulating peptide (CSP)-ComD binding in Streptococcus pneumoniae

• Bimal Koirala,
• Robert A. Hillman,
• Erin K. Tiwold,
• Michael A. Bertucci and
• Yftah Tal-Gan

Beilstein J. Org. Chem. 2018, 14, 1769–1777, doi:10.3762/bjoc.14.151

• stimulating peptide (CSP); protein–peptide interactions; quorum sensing; Streptococcus pneumoniae; structure–activity relationships (SAR); Introduction Quorum sensing (QS), a cell-density mechanism utilized by bacteria to assess their population density through the detection of diffusible signal molecules

• characterization details). Structure–activity relationships of CSP1 analogs To assess QS modulation, we utilized the β-gal reporter strains, constructed by Lau and co-worker [31]. In these strains the lacZ gene is under the control of QS (pcomX). Thus, upon QS activation, ComE will bind pcomX and transcribe lacZ

Natural and redesigned wasp venom peptides with selective antitumoral activity

• Marcelo D. T. Torres,
• Gislaine P. Andrade,
• Roseli H. Sato,
• Cibele N. Pedron,
• Tania M. Manieri,
• Giselle Cerchiaro,
• Anderson O. Ribeiro,
• Cesar de la Fuente-Nunez and
• Vani X. Oliveira Jr.

Beilstein J. Org. Chem. 2018, 14, 1693–1703, doi:10.3762/bjoc.14.144

• of selective anticancer peptide therapeutics. Keywords: breast cancer; decoralin; MCF-7 cells; peptide design; selective anticancer peptides; structure–activity relationships; Introduction Approximately 12% of U.S. women develop breast cancer according to the U.S. Breast Cancer website (http

• specific case of Dec-NH2 and its analogs, helical propensity, having higher hydrophobicity, hydrophobic momentum, and displaying a net positive charge appeared to correlate with improved antitumoral activity. These results add to our current understanding of the structure–activity relationships of ACPs and

Enantioselective phase-transfer catalyzed alkylation of 1-methyl-7-methoxy-2-tetralone: an effective route to dezocine

• Ruipeng Li,
• Zhenren Liu,
• Liang Chen,
• Jing Pan and
• Weicheng Zhou

Beilstein J. Org. Chem. 2018, 14, 1421–1427, doi:10.3762/bjoc.14.119

• enantiomeric ratio of 79:21. This method can be easily performed in large scale. In addition, the structure–activity relationships for the cinchona alkaloids catalysts were elucidated. Experimental All solvents and reagents were of commercial sources and used without further purification. Melting points were

Novel unit B cryptophycin analogues as payloads for targeted therapy

• Eduard Figueras,
• Adina Borbély,
• Mohamed Ismail,
• Marcel Frese and
• Norbert Sewald

Beilstein J. Org. Chem. 2018, 14, 1281–1286, doi:10.3762/bjoc.14.109

• [2][3]. Their high cytotoxicity prompted manifold studies that were initially focussed on the total synthesis and structure–activity relationships [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. This work resulted in the identification of cryptophycin-52, a highly biologically active

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• of cytotoxicity, structure–activity relationships and electrochemical behaviour [95]. Derivatives that contain an aromatic amine and salicylaldehyde or 2-pyridinecarboxaldehyde moieties were found to be the most active against the HL-60 (promyelocytic leukaemia) cell line. Zhou et al. obtained

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• purity. To obtain clear structure–activity relationships data on lipid A–TLR4 interaction as well as unambiguous correlation of the lipid A acylation and phosphorylation pattern to its capacity in induction of different (i.e., MyD88-dependent and TRIF-dependent) signaling pathways, numerous well-defined

• chain β-hydroxy fatty acids, anomeric phosphorylation and the synthesis of binary glycosyl phosphodiesters involving two amino sugars. Explicit structure–activity relationships data obtained with synthetic lipid A derivatives would also help to design novel therapeutic approaches for sepsis and

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• discussion of more recent contributions. Furthermore, a detailed discussion of molecular targets and structure–activity relationships is provided. Keywords: Buruli ulcer; mode of action; mycolactones; structure–activity relationships; target elucidation; total synthesis; Review I. Mycolactones and Buruli

Synthesis of novel 13α-estrone derivatives by Sonogashira coupling as potential 17β-HSD1 inhibitors

• Ildikó Bacsa,
• Rebeka Jójárt,
• János Wölfling,
• Gyula Schneider,
• Bianka Edina Herman,
• Mihály Szécsi and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2017, 13, 1303–1309, doi:10.3762/bjoc.13.126

• compounds and their precursors from Table 1 are taken into consideration, some valuable structure–activity relationships appear. 13α-Estrone (1) displays 17β-HSD1 inhibitory potential similar to that of the natural substrate estrone. Iodination at C-2 of 1 improves the inhibitory potential, resulting in a

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• analogous way. This facilitates the development of models with higher predictive performance and the identification of the factors that have the most influence over the property being modelled, leading to clearer interpretation of the structure–activity relationships represented by the model. This

G-Protein coupled receptors: answers from simulations

• Timothy Clark

Beilstein J. Org. Chem. 2017, 13, 1071–1078, doi:10.3762/bjoc.13.106

• have often observed that in quantitative structure–activity relationships (QSAR) for GPCRs, agonists give far better results than antagonists [40]. Metadynamics simulations on the vasopressin receptor [41] revealed the reason for this behavior. As also found previously in unbiased simulations of the β2

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• [34][35], thermodynamics [36][37], structure–activity relationships [38][39] have been extensively described elsewhere, therefore they are out of the scope of this review. Herein the focus is on the various catalytic reactor systems and technological solutions reported in the literature for this

Computational methods in drug discovery

• Sumudu P. Leelananda and
• Steffen Lindert

Beilstein J. Org. Chem. 2016, 12, 2694–2718, doi:10.3762/bjoc.12.267

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

• Tai Nguyen Van,
• Audrey Hospital,
• Corinne Lionne,
• Lars P. Jordheim,
• Charles Dumontet,
• Christian Périgaud,
• Laurent Chaloin and
• Suzanne Peyrottes

Beilstein J. Org. Chem. 2016, 12, 1476–1486, doi:10.3762/bjoc.12.144

• effectiveness of cN-II inhibitors in the treatment of these diseases [4][5]. As a result of our interest in this area, we and others [6] have investigated a number of structure–activity relationships (SAR) [7][8] and various medicinal chemistry approaches [9][10] to identify potential cN-II inhibitors. As part

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• -aryl-3-(4-methanesulfonylphenyl)pyrones 49 had been synthesized to get insights into structure activity relationships, whereby 6-methyl-3-(4-methanesulfonylphenyl)-4-phenylpyran-2-one (50) showed the best combination of inhibitory concentration and selectivity (IC50 = 0.68 µM, SI = 904; Figure 11) [56