Design and synthesis of a bis-macrocyclic host and guests as building blocks for small molecular knots

• Elizabeth A. Margolis,
• Rebecca J. Keyes,
• Stephen D. Lockey IV and
• Edward E. Fenlon

Beilstein J. Org. Chem. 2020, 16, 2314–2321, doi:10.3762/bjoc.16.192

• molecular knots. The modular second-generation approach to small trefoil knots described herein involves electrostatic interactions between an electron-rich bis-macrocyclic host compound and electron-deficient guests in the threading step. The bis-macrocyclic host was synthesized in eight steps and 6.6

• . Keywords: alkynes; azides; host–guest; macrocycles; molecular knots; Introduction Macrocycles have played a central role in the development of molecular recognition, self-assembled molecular devices, and molecular topology [1][2][3][4][5][6]. For example, early work by Pedersen on crown ethers [1], Lehn

• ]. Herein the synthesis of a unique bis-macrocyclic host 1 is described (Figure 1). Host 1 was designed to be a second-generation building block in the thread–link–cut (TLC) approach to molecular knots [13]. The two 25-atom macrocycles are electron-rich and complementary to the electron-deficient guests bis

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• amines led to the increase in the Stokes shift and a significant red shift between the absorption and the emission maxima. This was due to the varying electronic contributions to the host structure induced by the heterocyclic amino constituents [50][51][52] (Figure 4). Hydroxide anion sensing properties

The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

• Patrizia Andreozzi,
• Lorenza Tamberi,
• Elisamaria Tasca,
• Gina Elena Giacomazzo,
• Marta Martinez,
• Mirko Severi,
• Marco Marradi,
• Stefano Cicchi,
• Sergio Moya,
• Giacomo Biagiotti and
• Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

• nanoparticles, depending on the degree of substitution. For example, reaction of vicinal diols of dextran with hydrophobic PBA generates boronate esters, which form nanoparticles in water and are capable to host the anticancer drug doxorubicin [27]. In this report, the advantages of the milling process, such as

Tools for generating and analyzing glycan microarray data

• Akul Y. Mehta,
• Jamie Heimburg-Molinaro and
• Richard D. Cummings

Beilstein J. Org. Chem. 2020, 16, 2260–2271, doi:10.3762/bjoc.16.187

• methods of analysis which may be supported by some of these automated tools. 1. GlycoPattern: Status: Currently Unavailable – Transitioning to new host. Address: N/A. Description: GlycoPattern is a web based resource to support the analysis of glycan array data [42]. Under the hood, it utilizes the

Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations

• Ian Walsh,
• Matthew S. F. Choo,
• Sim Lyn Chiin,
• Amelia Mak,
• Shi Jie Tay,
• Pauline M. Rudd,
• Yang Yuansheng,
• Andre Choo,
• Ho Ying Swan and
• Terry Nguyen-Khuong

Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176

• of heterogeneity and is influenced by several factors including the host expression system and process parameters such as temperature shifts, pH, and the type of basal/feed media [7]. To understand how these environmental factors impact the glycosylation of a biologic, analytical methods are needed

Synthesis of monophosphorylated lipid A precursors using 2-naphthylmethyl ether as a protecting group

• Jundi Xue,
• Ziyi Han,
• Gen Li,
• Khalisha A. Emmanuel,
• Cynthia L. McManus,
• Qiang Sui,
• Dongmian Ge,
• Qi Gao and
• Li Cai

Beilstein J. Org. Chem. 2020, 16, 1955–1962, doi:10.3762/bjoc.16.162

• continued rise of problematic bacterial infections. Notably, the LPS pathogenicity is almost entirely due to lipid A because it leads to immunostimulatory effects when LPS dissociates from bacterial membranes within a host [5]. While these immunostimulatory effects can be beneficial in the setting of

Design, synthesis and application of carbazole macrocycles in anion sensors

• Alo Rüütel,
• Ville Yrjänä,
• Sandip A. Kadam,
• Indrek Saar,
• Mihkel Ilisson,
• Astrid Darnell,
• Kristjan Haav,
• Tõiv Haljasorg,
• Lauri Toom,
• Johan Bobacka and
• Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

• synthesis to access up to –[CH2]10– macrocycles or acyl halides to access up to –[CH2]14– macrocycles. Seventy-five receptor–anion complexes were modelled and studied with COSMO-RS, in addition to all free host molecules. In order to predict initial selectivity towards carboxylates, 1H NMR relative

• carboxylate anion will prove challenging. Secondly, the X-COO− group itself may become protonated under specific conditions. In this scenario, selectivity would be lost immediately. This puts restraints on the molecular design of the receptor molecule. The host molecule cannot include any functional groups

• attractive neutral host for anions [13]. It is formally a 16-membered ring, but for the above reasons no anion, not even F− fitted inside the ring – all bound anions reside on the surface of the ring [14]. Often in such cases, two receptors stack the guest molecule in a “sandwich” like manner, e.g., the

Synthesis of the tetrasaccharide repeating unit of the O-specific polysaccharide of Azospirillum doebereinerae type strain GSF71^T using linear and one-pot iterative glycosylations

• Arin Gucchait,
• Pradip Shit and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2020, 16, 1700–1705, doi:10.3762/bjoc.16.141

• Azospirillum rely on capsular and O-specific polysaccharides present in the bacteria cell wall [12]. Due to their structural orientation, cell-wall polysaccharides play a pivotal role in the initial stage of the host–microbes interactions and colonization of rhizobacteria in the plant roots [13]. Therefore, it

Synthesis of Streptococcus pneumoniae serotype 9V oligosaccharide antigens

• Sharavathi G. Parameswarappa,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2020, 16, 1693–1699, doi:10.3762/bjoc.16.140

• are still of growing concern due to an increase in non-vaccine serotypes and the cost of implementing these expensive vaccines in national immunization programs [4][5][6]. CPS is an important bacterial virulence factor and is critical for the interaction with the host as it helps the bacteria to

• escape the host immune response [1][7]. These polysaccharides of SP consist of repeating units (RU) that range from di- to heptasaccharides that may be branched and/or charged [8]. Modifications such as O-acetylation, phosphorylation, and sulfation further increase CPS complexity. Many bacterial

Clickable azide-functionalized bromoarylaldehydes – synthesis and photophysical characterization

• Dominik Göbel,
• Marius Friedrich,
• Enno Lork and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2020, 16, 1683–1692, doi:10.3762/bjoc.16.139

• non-radiative transitions can be achieved by the host–guest method [50][51][52] or by crystallization [53][54][55][56][57]. In difference to the liquid phase, the highly ordered packing and the restriction of molecular motions in the crystalline state favor a persistent luminescence. The promotion of

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida)

• Cora Hertzer,
• Stefan Kehraus,
• Nils Böhringer,
• Fontje Kaligis,
• Robert Bara,
• Dirk Erpenbeck,
• Gert Wörheide,
• Till F. Schäberle,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2020, 16, 1596–1605, doi:10.3762/bjoc.16.132

• [25]. Yet determining the origin and in vitro production of these metabolites is anything but trivial. Sponges are known to host complex symbiont communities, with up to 30–60% as microbial biomass [13][77]. These highly species-specific communities are most probably vertically transmitted [78] and

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• moulds, which could not be achieved with the blue laser [50]. Heterogeneous upconversion systems are generally crystalline nanomaterials comprising a host matrix of typically NaYF4, doped with a mixture of lanthanide ions, which act as light-absorbing sensitisers (e.g., Yb3+) and energy-combining

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

• in the host organisms. Keywords: antioxidant; Burkholderia sp; quinolone; soil bacterium; Zn2+ enrichment culture; Findings 4-Hydroxy-2(1H)-quinolone (3) is a unique structural motif mostly found in alkaloids from rutaceous plants (family Rutaceae) [1][2]. This motif has several tautomeric forms

• reactive oxygen species (ROS), is implemented in eukaryotic cells, including protists [32], as an innate immune response to deactivate foreign substances or as part of phagocytic digestion of internalized nutrients [33]. Pathogenic microbes are equipped with a multitude of strategies to circumvent host

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• stereoselective approaches of substrates and reagents or catalysts in a variety of processes. Examples include the substrate–enzyme recognition (the host–guest interaction) responsible for inducing pharmacological activity, the DNA-intercalation capable of generating biomolecular activity, molecular dynamics [63

[3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin

• Margareta Sohora,
• Leo Mandić and
• Nikola Basarić

Beilstein J. Org. Chem. 2020, 16, 1296–1304, doi:10.3762/bjoc.16.110

• the macrocyclic host affected the stereochemistry of the reaction. Moreover, we studied photodecarboxylation reactions initiated by the phthalimide chromophore [17][18][19] and applied them in cyclizations with memory of chirality [20] and diastereoselective peptide cyclizations [21

• . Irradiation of such a complex leads to decarboxylation and formation of the reactive intermediate, azomethine ylide, within the supramolecular host. The subsequent [3 + 2] cycloaddition within the inclusion complex gives heterocyclic cycloadducts, even though it is conducted in aqueous solvent in which ylides

• have short lifetimes. The reaction needs to be optimized for different substrates with the right choice of host size. However, the proof of principle provides a new idea for the development of supramolecular systems for the tuning of photochemical reactivity. Experimental General 1H and 13C NMR

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

• schistosomiasis treatment is the effect which climate change may have on aquatic environments (and the intermediate freshwater snail host Biomphalaria glabrata) and therefore on the distribution of water-borne diseases like schistosomiasis [47]. Similarly to the STHs, the WHO 2020 target for schistosomiasis is

• and at low cost which enables high-throughput chemical and genetic screening studies. It is often difficult or impossible to undertake comparable studies on parasitic worms due to the challenges of maintaining parasitic worms outside their host, although rodent models are available for many classes of

• Genomic resources are important for target identification, particularly in the case of parasites, as the life stages found in the host are often difficult to obtain or culture, and few molecular tools are available. WormBase ParaSite [107] is an important central resource for helminth genomic data [108

Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

• Nuray Altinolcek,
• Ahmet Battal,
• Mustafa Tavasli,
• William J. Peveler,
• Holly A. Yu and
• Peter J. Skabara

Beilstein J. Org. Chem. 2020, 16, 1066–1074, doi:10.3762/bjoc.16.93

• synthesised solar cells (DSSCs) and sensors [1][2]. In OLEDs, carbazole derivatives are frequently used as host materials [3][4][5]. In this respect the most frequently used host materials are 1,3-bis(N-carbazolyl)benzene (mCP) [6] and polyvinylcarbazole (PVK) [7]. Carbazole derivatives, either just by

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• demonstrated maximum external quantum efficiencies up to 3.2%. Keywords: acridan; hole mobility; host; OLED; thermally activated delayed fluorescence; Introduction Organic light emitting diodes (OLEDs) are perfect candidates for multicolor displays and for next generation energy saving large area-lighting

• are required [8]. Since the selection of suitable hosts is very important for achieving high OLED efficiencies, there was considerable interest in host compounds for TADF emitters in recent years [9][10]. The host compounds for TADF-based OLEDs must match a number of censorious requests. For example

• , high singlet and triplet energies (higher than those of the guest) are required for host compounds for qualifying host–guest energy transfer, thus implying restrict of the emissive excitons on the TADF emitters [11]. High glass-transition temperatures are also required for increasing the morphological

Reversible photoswitching of the DNA-binding properties of styrylquinolizinium derivatives through photochromic [2 + 2] cycloaddition and cycloreversion

• Sarah Kölsch,
• Heiko Ihmels,
• Jochen Mattay,
• Norbert Sewald and
• Brian O. Patrick

Beilstein J. Org. Chem. 2020, 16, 111–124, doi:10.3762/bjoc.16.13

• an aggregation of the molecules along the DNA backbone at very high ligand concentrations. Nevertheless, the CD and LD spectroscopic data revealed at least some specific binding interactions of 4b with DNA that caused a distinct orientation of the aromatic units relative to the host DNA. In

The interaction between cucurbit[8]uril and baicalein and the effect on baicalein properties

• Xiaodong Zhang,
• Jun Xie,
• Zhiling Xu,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 71–77, doi:10.3762/bjoc.16.9

• Xiaodong Zhang Jun Xie Zhiling Xu Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China 10.3762/bjoc.16.9 Abstract The host–guest interactions between baicalein (BALE) and cucurbit[8]uril (Q[8]) and the

• corresponding properties of the inclusion complex were studied using 1H NMR, IR and UV–vis spectroscopy and DTA. The results showed that BALE forms an inclusion compound (1:1) with Q[8], and the properties of baicalein are changed by cucurbit[8]uril. Keywords: baicalein; cucurbit[8]uril; host–guest interaction

• compounds such as calixarenes, crown ethers and cyclodextrins, which can be used to form a stable inclusion complex with the drug, and improving the bioavailability of the drug [34][35]. Herein, we describe the results of the investigations of host–guest interactions between BALE and Q[8] in an aqueous

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

• Soleiman E. Helaly,
• Wilawan Kuephadungphan,
• Patima Phainuphong,
• Mahmoud A. A. Ibrahim,
• Kanoksri Tasanathai,
• Suchada Mongkolsamrit,
• Janet Jennifer Luangsa-ard,
• Souwalak Phongpaichit,
• Vatcharin Rukachaisirikul and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

• microorganisms held together within a self-produced matrix of extracellular polymeric substances, plays an important role as a main virulence determinant in staph infections [1][2]. Within a biofilm, bacteria become tolerant toward antibiotics and host immune responses greater than their planktonic (free

Two new aromatic polyketides from a sponge-derived Fusarium

• Mada Triandala Sibero,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Ocky K. Karna Radjasa,
• Agus Sabdono,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2941–2947, doi:10.3762/bjoc.15.289

• sponges in massive amounts leads to environmental disturbance since marine sponges play a key role in building coral reefs [3][4]. As a filter feeder, sponges host an enormous amount of microorganisms including algae, bacteria, actinomycetes, and fungi [5][6][7]. Many of these microorganisms produce

Automated glycan assembly of arabinomannan oligosaccharides from Mycobacterium tuberculosis

• Alonso Pardo-Vargas,
• Priya Bharate,
• Martina Delbianco and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2019, 15, 2936–2940, doi:10.3762/bjoc.15.288

• , Germany 10.3762/bjoc.15.288 Abstract Arabinomannan (AM) polysaccharides are clinical biomarkers for Mycobacterium tuberculosis (MTB) infections due to their roles in the interaction with host cells and interference with macrophage activation. Collections of defined AM oligosaccharides can help to improve

• for infection [6][7][8][9][10] due to their roles in the interaction with host cells, interference with macrophage activation, and immunosuppression of T cell responses [11][12]. Diagnosis of tuberculosis in patients with HIV coinfections is possible by immunodetection of AMs and their lipidated

Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis

• David C. B. Siebert,
• Roman Sommer,
• Domen Pogorevc,
• Michael Hoffmann,
• Silke C. Wenzel,
• Rolf Müller and
• Alexander Titz

Beilstein J. Org. Chem. 2019, 15, 2922–2929, doi:10.3762/bjoc.15.286

• (arg3-arg4-arg5) gene arg2 was integrated into the host chromosome at a different locus. The obtained mutant strain M. xanthus DK1622 ∆mchA-tet::pArg345-V1-nptII-arg2 was shown to produce argyrins indicating that the engineered operon is functionally expressed via the integrated pArg345-V1 construct

Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds

• Daniel R. Sutherland,
• Nidhi Sharma,
• Georgina M. Rosair,
• Ifor D. W. Samuel,
• Ai-Lan Lee and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285

• photoluminescence quantum yield (ΦPL) of 3 is poor at 4%. We next investigated the solid-state PL behavior of 3 in a 10 wt %-doped thin film using PMMA as host matrix. The PL spectrum of 3 exhibited two bands, one at 550 nm, corresponding to the emission of 3 and a second high-energy band at 450 nm that was

• attributed to the PMMA host matrix [39]. The narrower emission profile of 3 in the solid state than in DCM solution could be due to the suppression of various nonradiative vibrational modes in the inert host matrix PMMA. Compound 3 showed a low ΦPL of 6% under nitrogen atmosphere. Time-resolved PL