NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• interaction between the 14-3-3 protein and its phosphorylated cargo proteins [42][44][45]. Another ligand with just one GCP unit targets the central pore of the 14-3-3 dimer [43]. Unfortunately, these systems have not yet been studied by NMR. However, several other 14-3-3 inhibitors and stabilizers serve as

• signal intensities (tau bound by 14-3-3 compared to free tau) show a decrease for tau residues that are part of the 14-3-3 binding epitopes due to line broadening. In the presence of chimeric inhibitors, in which a small molecule was fused to a 14-3-3 binding peptide, the inhibitors target the unlabeled

• protein in unlabeled minimal media by simply adding the isotope-labeled amino acid, without the need for auxotrophic strains or metabolic enzyme inhibitors [108]. The assignment of all Lys residues, beyond the assignments available from classic uniform 15N- and 13C-labeling, was achieved by specific 15N

Synthesis of 1,4-benzothiazinones from acylpyruvic acids or furan-2,3-diones and o-aminothiophenol

• Ekaterina E. Stepanova,
• Maksim V. Dmitriev and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2020, 16, 2322–2331, doi:10.3762/bjoc.16.193

• use. Particularly, some enaminones I and II were found to show antioxidant [3], antimycotic [7][8], antimycobacterial [9][10], anti-Alzheimer’s disease (JNK3 inhibitors) [11], platelet aggregation inhibitory [12], antimicrobial [7] and analgesic [13] activities. Enaminones II were reported as

Lipophilicity trends upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl groups

• Benjamin Jeffries,
• Zhong Wang,
• Robert I. Troup,
• Anaïs Goupille,
• Jean-Yves Le Questel,
• Charlene Fallan,
• James S. Scott,
• Elisabetta Chiarparin,
• Jérôme Graton and
• Bruno Linclau

Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182

• give analogue 7b reduced the lipophilicity. Interestingly, while the nonfluorinated 7a and 7c diastereomers have different logD7.4 values, this is not the case for their fluorinated analogues 7b and 7d. Oxazine derivative 8 featured in the development of centrally active β-secretase (BACE1) inhibitors

Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst

• Jannis Ludwig,
• Julian Helberg,
• Hendrik Zipse and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2119–2126, doi:10.3762/bjoc.16.179

• , spiropyranes, and stilbenes [2]. Diarylethenes were reported in the context of photoswitchable catalysis as inhibitors of the Karstedt´s catalyst [3] and for pKa modulation in acid–base-controlled processes [4]. Molecular motors for stereodivergent anion binding catalysis [5], azopeptides for the acetylation

Muyocopronones A and B: azaphilones from the endophytic fungus Muyocopron laterale

• Ken-ichi Nakashima,
• Junko Tomida,
• Tomoe Tsuboi,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 2100–2107, doi:10.3762/bjoc.16.177

• (Dothideomycetes) were reported as intercellular adhesion molecule-1 (ICAM1) expression inhibitors in a patent literature [28]. Therefore, the presence of the 2,4-dimethyl-3-hydroxyhexanoate moiety may be a potential chemical marker for Dothideomycetes, although this is difficult to conclude due to the fact that

Convenient access to pyrrolidin-3-ylphosphonic acids and tetrahydro-2H-pyran-3-ylphosphonates with multiple contiguous stereocenters from nonracemic adducts of a Ni(II)-catalyzed Michael reaction

• Alexander N. Reznikov,
• Dmitry S. Nikerov,
• Anastasiya E. Sibiryakova,
• Victor B. Rybakov,
• Evgeniy V. Golovin and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2020, 16, 2073–2079, doi:10.3762/bjoc.16.174

• Micromonospora [5]. Dipeptide analogs with phosphonoproline 2 and piperidine-2-phosphonic acid 3 are potent inhibitors of dipeptidyl peptidase IV [6][7]. Oxygen-containing heterocycles containing a phosphoryl group are also of interest in the development of new drugs. It is known that phosphorylated carbohydrate

• analogues 4 and 5 are neuraminidase inhibitors (Figure 1) [8][9]. These circumstances create an interest in discovering synthetic routes for obtaining nonracemic phosphoryl-substituted heterocycles. Thus, in recent years, effective methods for the asymmetric synthesis of chiral phosphonates containing

Automated high-content imaging for cellular uptake, from the Schmuck cation to the latest cyclic oligochalcogenides

• Rémi Martinent,
• Javier López-Andarias,
• Dimitri Moreau,
• Yangyang Cheng,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2020, 16, 2007–2016, doi:10.3762/bjoc.16.167

• recorded for microtiter plates with hundreds to thousands of wells. This standard HT screening provides access to quantitatively reliable curves for the dependence on the concentration, incubation time, activators, inhibitors, and so on within a reasonable time. High-content screening (HCS) combines this

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• site of GlfT2, none of these compounds serve as efficient inhibitors of the enzymes involved in the mycobacterial galactan biosynthesis. Keywords: GlfT2; molecular modeling; mycobacterium tuberculosis; synthesis; transition state inhibitors; Introduction Tuberculosis (TB) is one of the most prevalent

• silico based design of possible GlfT2 inhibitors that mimic the TS structure. The galactofuranosyltransferase GlfT2 is a bisubstrate enzyme with a single catalytic domain and its catalytic reaction transition state shares some structural similarities with the previously modeled N

• -acetylglucosaminyltransferase I (GnT-I) reaction transition state [11]. Previously, we have designed 2-thiohexofuranoside skeletons bearing a phosphate group in position 1 by molecular modeling as potential transition state inhibitors of human glycosyltransferase I (GnT-I) [12], the bisubstrate enzyme requiring a metal co

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• (trade name Sivextro), which exhibits antibiotic activity is another oxazolidinone drug approved by the FDA in 2014 [11]. Befloxatone and toloxatone, N-substituted phenyloxazolidinone derivatives, are reversible inhibitors of monoamine oxidase (MAO) [12][13]. N-Aryloxazolidinedione compounds, which are

Facile synthesis of 7-alkyl-1,2,3,4-tetrahydro-1,8-naphthyridines as arginine mimetics using a Horner–Wadsworth–Emmons-based approach

• Rhys A. Lippa,
• John A. Murphy and
• Tim N. Barrett

Beilstein J. Org. Chem. 2020, 16, 1617–1626, doi:10.3762/bjoc.16.134

• inhibitors based on the tripeptide sequence Arg–Gly–Asp (RGD) are potential therapeutics for the treatment of idiopathic pulmonary fibrosis (IPF). Herein, we describe an expeditious three-step synthetic sequence of Horner–Wadsworth–Emmons olefination, diimide reduction, and global deprotection to synthesise

• ; Introduction Tetrahydronaphthyridines are prominent in peptidomimetic pharmaceuticals as arginine mimetics and they are widely used in Arg–Gly–Asp (RGD) peptide mimetics such as αv integrin inhibitors [1]. Tetrahydronaphthyridines represent less basic but more permeable alternatives to arginine (pKa ≈ 7 versus

• 13.8) [1] replicating the side-on salt-bridge binding interaction made between the guanidinium functionality of arginine and an aspartic acid residue in the protein. Consequently, this moiety has been used in various integrin inhibitors (Figure 1) [2][3][4][5][6][7][8]. Current routes to install

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• rutaceous plants [9]. Examples from microbes include chymase inhibitors SF2809-I to VI from an actinomycete of the genus Dactylosporangium [10], a quorum sensing signaling molecule 2,4-dihydroxyquinoline (DHQ, 4) from Gram-negative bacteria Pseudomonas aeruginosa and Burkholderia thailandensis, [7], and 4-O

One-pot synthesis of 1,3,5-triazine-2,4-dithione derivatives via three-component reactions

• Gui-Feng Kang and
• Gang Zhang

Beilstein J. Org. Chem. 2020, 16, 1447–1455, doi:10.3762/bjoc.16.120

• anticancer [10][11], antimicrobial [12], antiviral agents [13][14], and eosinophilia inhibitors [15]. Therefore, it is highly desirable to develop efficient and practical synthetic methods for triazinethione architectures and to expand the structure diversity of this class of compounds for medicinal

The McKenna reaction – avoiding side reactions in phosphonate deprotection

• Katarzyna Justyna,
• Joanna Małolepsza,
• Damian Kusy,
• Waldemar Maniukiewicz and
• Katarzyna M. Błażewska

Beilstein J. Org. Chem. 2020, 16, 1436–1446, doi:10.3762/bjoc.16.119

• Michael acceptor, as such is currently popular in the development of covalent inhibitors [43]. The reaction was carried out in the presence of 12 equiv BTMS at 35 °C. The disappearance of the signals originating from the vinyl protons (multiplets at δ 5.56–5.66 and 5.95–6.10 ppm) and the appearance of the

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• discovery of pan-CDK inhibitors. For this, 3-bromo-2,2-bis(bromomethyl)propan-1-ol (20) was transformed into 3-bromomethyl-3-hydroxymethyl-1-tosylazetidine (21), which was treated with Ph3P/CBr4 to yield 3,3-bis(bromomethyl)-1-tosylazetidine (22) in 52% yield. The double displacement of 3,3-bis(bromomethyl

• -2,4-diol and treated it with sodium sulfide to afford 2,4-di(benzyloxymethyl)thietane (49). Compound 49 was then further transformed into two different anomeric thietanose nucleosides 1 and 50 [4] (Scheme 11). In the development of novel class I phosphoinositide 3-kinase (PI3k) inhibitors, 6-bromo-3,3

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• ]. Specifically, bisphosphonates act as osteoclast resorption inhibitors, augmenting the bone density and preventing osteoporosis [4]. Moreover, some bisphosphonates have gained attention as potential antiinflammatory agents by in vitro and in vivo assays [5][6][7][8]. Additionally, bisphosphonates have been

• molecular docking studies were performed to account for a possible action mechanism as MMP-8 and MMP-9 inhibitors. Results and Discussion Chemistry As part of our ongoing interest in the discovery of new antiinflammatory agents, our research group have previously addressed the synthesis and in vivo

• mechanism of action of the bisphosphonates 3–6, we propose that the tested derivatives are acting as MMP inhibitors. In this respect, MMP-8 and MMP-9 isoenzymes are related to inflammatory processes in different tissues [32][33][34][35]. Furthermore, for MMP-8 and MMP-9, enzyme–inhibitor interaction modes

Synthesis of pyrrolidinedione-fused hexahydropyrrolo[2,1-a]isoquinolines via three-component [3 + 2] cycloaddition followed by one-pot N-allylation and intramolecular Heck reactions

• Xiaoming Ma,
• Suzhi Meng,
• Xiaofeng Zhang,
• Qiang Zhang,
• Shenghu Yan,
• Yue Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2020, 16, 1225–1233, doi:10.3762/bjoc.16.106

• crispine A isolated from Carduus crispus L has antitumor activity [3]. Erythrina alkaloids have curare-like neuromuscular blocking activities [4], and also antioxidant activity against DPPH free radicals [5]. Lamellarins isolated from marine invertebrates [6] are inhibitors for HIV-1 integrase and also

Anthelmintic drug discovery: target identification, screening methods and the role of open science

• Frederick A. Partridge,
• Ruth Forman,
• Carole J. R. Bataille,
• Graham M. Wynne,
• Marina Nick,
• Angela J. Russell,
• Kathryn J. Else and
• David B. Sattelle

Beilstein J. Org. Chem. 2020, 16, 1203–1224, doi:10.3762/bjoc.16.105

• developed helminth analysis methods using CellProfiler. A virtual screening approach was used to identify inhibitors of S. mansoni thioredoxin glutathione reductase [140]. These virtual hits were then tested in a CellProfiler-based high content screen using S. mansoni schistosomula, which determines both

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• in the last few years due to the discovery that truxillic acid derivatives are inhibitors of FABP (fatty acid binding proteins), which are responsible for the cellular reuptake of anandamide, an endocannabinoid neurotransmitter, and that they can be involved in a very efficient treatment for chronic

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• the HRMS measurements is appreciated. Funding The University of Zagreb short term scientific support under the title “Synthesis and functionalization of novel (hetero)polycyclic photoproducts as cholinesterase inhibitors” is gratefully acknowledged.

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• active small molecules that exhibit antihypertensive activity [7][8]. Moreover, these heterocycles can be used as 5-HT3 antagonists [9], rho kinase inhibitors [10], thymidylate synthetase inhibitors [11], PARP-1 inhibitors [12], melatonin MT1 and MT2 receptor agonist [13], and fascin-targeted

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• over the last few decades. ᴅ- or ʟ-fluorinated phenylalanines have had considerable industrial and pharmaceutical applications and they have been expanded also to play an important role as potential enzyme inhibitors as well as therapeutic agents and topography imaging of tumor ecosystems using PET

• , geometry, conformation, reactivity, and moreover the bioavailability of the analogue [1]. Fluorinated amino acids (FAAs) have considerable industrial and pharmaceutical potential [2]. Also, they have played an important role as enzyme inhibitors as well as therapeutic agents [3][4]. Moreover, they modulate

• ees < 98%. The products were hydrolyzed and deprotected in a two-step protocol to afford the desired products 77a,b [55] (Scheme 18). Interestingly substitution of Phe by either 77b or 77a in the proteasome inhibitors bortezomib or epoxymicin, led to an increase in the efficiency as anticancer

Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition

• Sivaraman Balasubramaniam,
• Sajith Vijayan,
• Liam V. Goldman,
• Xavier A. May,
• Kyra Dodson,
• Sweta Adhikari,
• Fatima Rivas,
• Davita L. Watkins and
• Shana V. Stoddard

Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59

• inhibitors (HDACis). The targets of interest (TOI) are analogues of panobinostat, one of the most potent and versatile HDACi reported. By simply replacing the phenyl core of panobinostat with that of a diazine derivative, docking studies against HDAC2 and HDAC8 revealed that the four analogues exhibit

• lay the foundation for future design strategies toward more potent HDACis for HDAC8 isozymes and further therapeutic applications for neuroblastoma. Keywords: diazine; histone deacetylase; inhibitors; isozymes; panobinostat; Introduction One of the most important posttranslational modifications

• development of novel HDAC inhibitors (HDACis) has become a rapidly evolving area where targeted inhibition has emerged in clinical research as a potential therapeutic approach for the treatment of various cancers as well as neurodegenerative disorders and immune related diseases [3][4][5]. Of specific

Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin

• Anna R. Bockman and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2020, 16, 509–514, doi:10.3762/bjoc.16.46

• molybdopterin [1]. Owing to this biological relevance, pterins are an attractive building block in the development of various pharmaceuticals, with methotrexate being the most well-known [2]. In addition to pteridine derivatives being used as inhibitors of dihydrofolate reductase and dihydropteroate synthase

• , pterins have been a useful scaffold in the development of inhibitors of ricin [3][4], methionine synthase [5], nitric oxide synthase [6], shigella [7], and aldose reductase [8], as well as for treatment of leishmaniosis [9]. In addition to their therapeutic potential, pterin derivatives have been an

• for ricin toxin A (RTA) inhibitors [14]. By deprotonation of the lactam NH, and conversion to the DBU salt, the pterin easily dissolves in methanol at high concentrations, unprecedented for unfunctionalized pterins. This greatly accelerated the development of a library of bioactive pterins, as it

Synthesis of 4-amino-5-fluoropyrimidines and 5-amino-4-fluoropyrazoles from a β-fluoroenolate salt

• Tobias Lucas,
• Jule-Philipp Dietz and
• Till Opatz

Beilstein J. Org. Chem. 2020, 16, 445–450, doi:10.3762/bjoc.16.41

• nucleoside analogues which can either act as antimetabolites or as nucleoside reverse transcriptase inhibitors (NRTIs). Two of the most common 5-fluoropyrimidines are the cytostatic 5-fluorouracil (1) [27] and the antimycotic prodrug 5-fluorocytosine (2) [28][29], which is also part of the anti-HIV agents

Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors

• Man-Man Wang,
• Hao Huang,
• Lei Shu,
• Jian-Min Liu,
• Jian-Qiu Zhang,
• Yi-Le Yan and
• Da-Yong Zhang

Beilstein J. Org. Chem. 2020, 16, 233–247, doi:10.3762/bjoc.16.25

• dioxygenase (HPPD) inhibitors. Preliminary bioassay results reveal that these derivatives are promising Arabidopsis thaliana HPPD (AtHPPD) inhibitors, in particular compounds I12 (Ki = 0.011 µM) and I23 (Ki = 0.012 µM), which exhibit similar activities to that of mesotrione, a commercial HPPD herbicide (Ki

• various species and genera and providing a theoretical basis for the design of inhibitors that are highly selective and safe [2]. In plants, HPPD inhibitors competitively restrain HPPA from chelating to FeII. The production of plastoquinone is inhibited and phytoene is accumulated when the transformation

• of HPPA to HGA is interfered with an HPPD inhibitor [9][10]; consequently, plants become severely damage when exposed to sunlight, ultimately resulting in bleaching symptoms followed by necrosis and death [11][12]. Therefore, HPPD inhibitors play important roles in the herbicide industry. In addition