Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• 0.1% w/v poly-ʟ-lysin solution in water (Sigma-Aldrich) and immediately deposited onto freshly cleaved mica to be incubated for 10 min at room temperature to allow adsorption. The surface was then rinsed using 600 µL of ultrapure 0.2 µm filtered water and slowly dried using compressed air. Imaging was

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• rate of decomposition was reduced significantly (green line in Figure 3). The hydrolysis of the four hypervalent iodine(V) fluorides was also investigated in acetonitrile-d3 by adding 5 equivalents of water. All four compounds decomposed to their corresponding iodosyl compounds and the order of

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• chlorine atom in the chlorovinyl fragment to the hydroxy group, probably under the influence of water (Figure 4). It is worth noting that the synthesis of Ugi bisamides 5–8 (Table 1) yielded compounds 10 and ketobisamide 12 in some cases. For example, in the Ugi reaction involving benzyl isocyanide (4b

• moiety under the influence of water. The appearance of HCl in these cases was identified by the specific odor and detected by pH measurements. It is likely that this catalytic amount of HCl is enough for the conversion and formation of the amides 10. To confirm the influence of HCl and its necessity to

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• control of the current [32][33][34]. Early studies on the electrochemical oxidation of phenols revealed that the oxidation passes through a phenoxonium ion and forms acetals in methanol but quinones in the presence of water [35][36][37]. However, the reaction is sometimes accompanied by the formation of

• shown), where methanol further served as nucleophile. Some THF was needed to improve the solubility of some of the substrates. Acidic conditions (Table 1, entry 5) or methanol/water (Table 1, entry 6) gave a complex mixture with overoxidized products. Although the desired oxidation is a 4-electon

• flowrate of 100 µL/min. The current was increased from 1 mA to 13 mA to increase the electron equivalents from 1 F/mol to 8 F/mol at a potential of 1.7–3.0 V. The crudes, after evaporation of the solvents, were further hydrolysed with a mixture of HCl, acetic acid, and water to release the quinones before

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• spirosteroids was underscored by the synthesis of spironolactone [3] (Figure 1), which plays a pivotal role in edema treatment. Aldosterone, implicated in water and salt retention in conditions such as congestive heart failure, hypertension, nephrosis, liver cirrhosis, and toxemia of pregnancy, prompted the

• –water–NaOAc mixture. Spiro heterocycle 99 was obtained in 52% overall yield as a single product (Scheme 29). The reaction mechanism was elucidated based on the hard and soft acid and base theory. Spiro-1,3,4-thiadiazoline steroids In 2006, Mazoir et al. [56] reported the synthesis of 4α,14α-dimethyl-5α

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• approach, they used a chiral boron catalyst as a Lewis acid and achieved at best an endo/exo selectivity of 1.9:1 in a similar DA reaction. The use of Diels–Alderase in their recent work significantly improved the endo/exo selectivity under mild conditions in water, thereby highlighting the strengths of

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• diverse marine holobionts such as sponges [3][4], sediments [5], algae [6], and corals [7] using media that mimic the native salt water habitat. Strains of this genus are detected together with Pseudovibrio and Ruegeria strains that grow in identical culture conditions, and hence obtaining axenic

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• . Romão Ramalho, 59, 7000-671 Évora, Portugal 10.3762/bjoc.20.145 Abstract A new paradigm for energy is underway demanding decarbonized energy systems. Some of them rely on emerging electrochemical devices, crucial in hydrogen technologies, including fuel cells, CO2 and water electrolysers, whose

• applications and performances depend on key components such as their separators/ion-exchange membranes. The most studied and already commercialized Nafion membrane shows great chemical stability, but its water content limits its high proton conduction to a limited range of operating temperatures. Here, we

• exchange membrane devices [5][6], such as proton exchange membrane fuel cells (PEMFCs) [3][7][8][9], due to their high-power density and high power-to-weight ratio, and CO2 electrolysers, which can reduce the polluting gas CO2 and produce syngas from the co-electrolysis of CO2 and water [10][11], or water

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• than two chiral centers were not included. This resulted in 271,026,660 library members with nearly 85% expected synthetic accessibility according to the model experiments described in the previous section. Distributions of the resulting chemical space over molecular weight (MW), 1-octanol–water

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds

• Ka-Lung Hung,
• Leong-Hung Cheung,
• Yikun Ren,
• Ming-Hin Chau,
• Yan-Yi Lam,
• Takashi Kajitani and
• Franco King-Chi Leung

Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142

• ][40]. Photoresponsive supramolecular amphiphiles are responsive, complex, and adaptable in aqueous medium [41][42][43]. Supramolecular assemblies of photoresponsive molecular amphiphiles in aqueous medium can undergo transformation in solution or at the air–water interface and even sustained

• were investigated in aqueous medium. An aqueous solution of 5.0 wt % DA11 in Milli-Q water was prepared, followed by deprotonation with 1.0 equivalent of NaOH, showing excellent solubility up to 93 mM, giving a deep purple solution. An aqueous 43 µM solution DA11, diluted from the 5.0 wt % stock

• source (380–800 nm, 300 W) positioned at a distance of 1 cm from the sample. Preparation of aqueous samples All aqueous solutions of DAn were prepared according to the following general procedure: DAn (5.0 wt %) was mixed with 1.0 equivalent NaOH in Milli-Q water. The obtained aqueous solution was

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• only slightly more stable than the other three conformers in both the gas phase and implicit water [4]. Hence, it appears that strong intramolecular interactions, and not only hydrogen bonding, govern the orientation of the fluorine atom in the F‒C‒C‒N fragment, favoring the cis-isomer of 3

Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor

• Koichi Mitsudo,
• Atsushi Osaki,
• Haruka Inoue,
• Eisuke Sato,
• Naoki Shida,
• Mahito Atobe and
• Seiji Suga

Beilstein J. Org. Chem. 2024, 20, 1560–1571, doi:10.3762/bjoc.20.139

• ). To ensure the capture of 2a, we performed reduction with phosphoric acid (pKa = 2.12). Although the generation of 3a was suppressed, only a trace amount of 2a was obtained, and almost 1a was recovered (Table 2, entry 4). This was probably because the presence of water inhibited the reaction

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• . After the extractions were finished and dried by rotary evaporation, the extract was resuspended in basic water (pH 10 using NaOH) and vacuum filtered to remove insoluble particulates. Liquid–liquid extraction was performed three times with basic water and DCM. The DCM layer was collected and dried

• . Afterward, the extract was resuspended in 0.1% formic acid in water. A Combiflash EZ prep system was used to purify the burpitides from C. americanus. Water with 0.1% formic acid (A) and methanol (B) were used as solvents for a reversed phase column (C18 21 × 250 mm Kinetix 5 µm C18 100 Å (00G-4601-P0-AX5

• min, 5% B; 13 min, 5% B where solvent A was water with 0.1% of formic acid and solvent B was acetonitrile with 0.1% of formic acid. A top 5 HCD method at 25 NCE (200–2000 m/z) was used on each plant tissue extract. See Supporting Information File 1, Table S2 for complete acquisition parameters. The

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• nucleophiles, including water to give benzylic alcohols, or methanol to give methoxy products. Musacchio and co-workers reported a similar approach for benzylic fluorination (Figure 33) [84], which followed a similar mechanistic blueprint to that reported by the Doyle group. Using tert-butoxide radicals

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• residual water during column chromatography. Unfortunately, attempts to assign the absolute configuration of products 5 failed, as we have not been able to obtain any crystals suited for single crystal X-ray diffraction analysis. Finally, we also tested the suitability of products 5 to access acyclic α-AA

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• is introduced on the azobenzene to increase the water solubility. The influence of ortho, meta, and para-substitution patterns of the azobenzene on the lectin binding has also been studied. Synthesis The β-O-galactosyl p,p'-bis-substituted azobenzene derivative 1 was prepared from galactose and

• commercially available p,p’-dihydroxyazobenzene (6), by using our recently developed DMC (2-chloro-1,3-dimethylimidazolinium chloride)-mediated one-pot glycosylation method in water [28], followed by O-alkylation of the remaining hydroxy group with BrCH2CH2NHBoc and acidic deprotection (Scheme 1). Three

• respectively 71%, 41%, and 37% total yields (Scheme 1). Photophysical characterization The photoswitching properties of galactosyl azobenzenes 1–5 were realized in water or in Tris buffer containing 5 to 10% DMSO, in accordance with the biophysical evaluation conditions by using ITC. All these compounds

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• molecular sieves as water scavengers, but it showed no positive influence on the reaction efficiency (Table 1, entry 20). It should be noted that no competing aza-Michael adduct was monitored in all of the evaluated reaction conditions. According to the above screening results, the generality of the

Selectfluor and alcohol-mediated synthesis of bicyclic oxyfluorination compounds by Wagner–Meerwein rearrangement

• Ziya Dağalan,
• Muhammed Hanifi Çelikoğlu,
• Saffet Çelik,
• Ramazan Koçak and
• Bilal Nişancı

Beilstein J. Org. Chem. 2024, 20, 1462–1467, doi:10.3762/bjoc.20.129

• rearrangement using benzonorbornadiene and the chiral natural compound (+)-camphene as bicyclic alkenes, selectfluor as an electrophilic fluorine source, and water and various alcohols as nucleophile sources. The structure of bicyclic oxy- and alkoxyfluorine compounds was determined by NMR and QTOF-MS analyses

• materials, supramolecular and bioactive compounds [13][14][15][16][17]. To the best of our knowledge, although the oxyfluorination of various olefins with water and alcohols is known in the literature [18][19][20][21][22][23][24][25][26], there is no systematic study on the oxyfluorination of bicyclic

• alkenes. We previously developed a dihomohalogenation method using selectfluor as an oxidant [27]. Herein, we synthesized bicyclic oxy- and alkoxyfluorine compounds using selectflour as an electrophilic fluorination reagent, water and various alcohols as an nucleophile. Results and Discussion In this

Synthesis of cyclic β-1,6-oligosaccharides from glucosamine monomers by electrochemical polyglycosylation

• Md Azadur Rahman,
• Hirofumi Endo,
• Takashi Yamamoto,
• Shoma Okushiba,
• Norihiko Sasaki and
• Toshiki Nokami

Beilstein J. Org. Chem. 2024, 20, 1421–1427, doi:10.3762/bjoc.20.124

• current conditions until 1.2 F/mol of total charge had been consumed. Then, the reaction temperature was elevated to 0 °C, and this temperature was kept for 1 h. The reaction was quenched with Et3N (0.5 mL), and the reaction mixture was dissolved in EtOAc and washed with water to remove electrolyte. It

Challenge N- versus O-six-membered annulation: FeCl₃-catalyzed synthesis of heterocyclic N,O-aminals

• Giacomo Mari,
• Lucia De Crescentini,
• Gianfranco Favi,
• Fabio Mantellini,
• Diego Olivieri and
• Stefania Santeusanio

Beilstein J. Org. Chem. 2024, 20, 1412–1420, doi:10.3762/bjoc.20.123

• yield of 6 was observed alongside a decreased yield of 5, in all those cases that required prolonged reaction times (24–30 h). This event led us to suppose the formation of carbinolamine 6 from N,O-aminal 5 owing to the nucleophilic attack of a water molecule, probably caused by the enriched moisture

• catalytic cycle. Similar to what was previously observed, the elimination of the trichloro(alkoxy)ferrate(III) anion from intermediate C provides the iminium ion D, susceptible to nucleophilic attack by a water molecule present in the reaction medium, leading to the carbinolamines 6. This latter synthesis

• line with the values found for the slower reactions previously described (compounds 6b,d,g,i,n–p). By adding 500 μL of water to the medium the cyclization did not proceed, and the starting material 4j was recovered unchanged (experiment B, Scheme 5). This observation seems to suggest that the presence

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

• Simone Gräßle,
• Laura Holzhauer,
• Nicolai Wippert,
• Olaf Fuhr,
• Martin Nieger,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

• aromatic and aliphatic alkynes 20a–h in a copper-catalyzed azide–alkyne cycloaddition (CuAAC). All attempted reactions could be conducted under standard conditions using copper sulfate and sodium ascorbate in THF/water (depicted in Scheme 3 and Figure 2). For selected derivatives, 21sd and 21vg, crystals

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• reaction [30][31]. Daemi et al. employed polyurethane nanomicelles as an eco-friendly and efficient polymeric ionic solvent [32]. Morooka et al. used supercritical water for the catalys-free Cannizzaro-type reaction of acetaldehyde [33]. Thus, the originally developed Cannizzaro reaction was subjected to

Synthesis of 1,2,3-triazoles containing an allomaltol moiety from substituted pyrano[2,3-d]isoxazolones via base-promoted Boulton–Katritzky rearrangement

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117

• of water on the considered recyclization. So, carrying out the process in 80% aqueous EtOH resulted in a diminished yield (Table 1, entry 16). Thus, optimal conditions for the investigated recyclization are the application of K2CO3 in EtOH at reflux for 2 h. The elaborated conditions allowed us to

Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

• Ayhan Yıldırım

Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114

• reactions in water due to the remarkable lack of water solubility of the highly hydrophobic aminofurans selected in this study. Therefore, the decision was made to perform these reactions using vegetable oil as an alternative green solvent system. For this purpose, SSO, OO, OA and LM, which can act as

Oxidative hydrolysis of aliphatic bromoalkenes: scope study and reactivity insights

• Amol P. Jadhav and
• Claude Y. Legault

Beilstein J. Org. Chem. 2024, 20, 1286–1291, doi:10.3762/bjoc.20.111

• the formation of the phenyl tosyloxy iodonium intermediate A from catalytic HTIB. Dialkyl bromoalkene 1 then associates with A followed by attack of tosyloxy or water, delivering iodonium intermediate B. Being a better leaving group, the bromide anion is then expelled, which becomes a counterion for