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Search for "function" in Full Text gives 1112 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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

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  • ), whose sequential acylation process by iso(thio)cyanates 3a–h gives rise to the asymmetric (thio)urea derivatives (intermediate II). The spontaneous nucleophilic attack of the (thio)amide nitrogen on the terminal methyl ester function at C-4 of the starting azo-ene system provides a regioselective
  • keto function of the hydrazone moiety and the open-chain hemiacetal or aldehyde hydrate in Brønsted acid medium to access 1H-imidazo[5,1-c][1,4]oxazine derivatives (Scheme 1) [21]. Considering that the hydrazone function at C-4 of 4a–r may exist in a tautomeric equilibrium with the corresponding ene
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Published 26 Jun 2024

Rhodium-catalyzed homo-coupling reaction of aryl Grignard reagents and its application for the synthesis of an integrin inhibitor

  • Kazuyuki Sato,
  • Satoki Teranishi,
  • Atsushi Sakaue,
  • Yukiko Karuo,
  • Atsushi Tarui,
  • Kentaro Kawai,
  • Hiroyuki Takeda,
  • Tatsuo Kinashi and
  • Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 1341–1347, doi:10.3762/bjoc.20.118

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  • developing novel inhibitors of integrin function, we identified a drug candidate (10n) through high throughput screening (HTS) that inhibits the integrin complex formation, which is an important step for integrin activation. The binding inhibitor 10n was effective as IC50 of 190 μM in AlphaScreen system, and
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Published 12 Jun 2024

Mechanistic investigations of polyaza[7]helicene in photoredox and energy transfer catalysis

  • Johannes Rocker,
  • Till J. B. Zähringer,
  • Matthias Schmitz,
  • Till Opatz and
  • Christoph Kerzig

Beilstein J. Org. Chem. 2024, 20, 1236–1245, doi:10.3762/bjoc.20.106

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  • thorough photochemical characterization is essential for efficient light-driven applications. In this article, the mode of action of a polyazahelicene catalyst (Aza-H) was investigated using laser flash photolysis (LFP). The study revealed that the chromophore can function as a singlet-state photoredox
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Published 28 May 2024

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

  • Vishnu Selladurai and
  • Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

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  • electrons over the adjacent carboxylate function, which prompted the selenation pathway, leading to the formation of two of the isomeric diorganyl selenides of methyl anthranilate. The diaryl selenides were structurally characterized using single-crystal X-ray diffraction. Density functional theory
  • aniline with an electron-donating function (i.e., o-anisidine) undergo significant polymerization in the presence of SeO2, we were interested in studying this reaction using methyl anthranilate, having an electron-withdrawing group (Scheme 4). To our surprise, the quantity of polymer 3 formed was low
  • . Conclusion Aniline and o-anisidine underwent a predominant oxidative polymerization reaction with SeO2. Therein, electrophilic selenation was poor. The reactivity of the NH2 unit towards oxidation could be partially suppressed by the presence of an electron-withdrawing function. Consequently, for methyl
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Published 27 May 2024

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

  • Jinmin Gao,
  • Liyuan Li,
  • Shijie Shen,
  • Guomin Ai,
  • Bin Wang,
  • Fang Guo,
  • Tongjian Yang,
  • Hui Han,
  • Zhengren Xu,
  • Guohui Pan and
  • Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

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  • , Supporting Information File 1) [21][22]. In this study, we reveal the previously undisclosed facet that AlpJ-family oxygenases can function as cofactor-independent oxygenases when the hydroquinone intermediate CR1 (8) serves as the substrate. In this context, the enzymes autonomously catalyze oxidative C–C
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Published 23 May 2024

Two-fold addition reaction of silylene to C60: structural and electronic properties of a bis-adduct

  • Masahiro Kako,
  • Masato Kai,
  • Masanori Yasui,
  • Michio Yamada,
  • Yutaka Maeda and
  • Takeshi Akasaka

Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100

Graphical Abstract
  • with excellent properties as organic photovoltaic materials [9][10][11][12][13][14]. Furthermore, regioisomerically pure bis-functionalized fullerenes function better as electron acceptors in organic thin-film solar cells than mixtures of the corresponding regioisomers do [12][13][14]. Therefore
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Published 22 May 2024

Synthesis of 1,4-azaphosphinine nucleosides and evaluation as inhibitors of human cytidine deaminase and APOBEC3A

  • Maksim V. Kvach,
  • Stefan Harjes,
  • Harikrishnan M. Kurup,
  • Geoffrey B. Jameson,
  • Elena Harjes and
  • Vyacheslav V. Filichev

Beilstein J. Org. Chem. 2024, 20, 1088–1098, doi:10.3762/bjoc.20.96

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  • function in an organism, but the activities can also be detrimental. CDA is highly active in the liver and spleen, which results in deamination and consequent deactivation of several chemotherapeutic agents, including the anticancer agents cytarabine, gemcitabine and 5-aza-2'-deoxycytidine (decitabine) [2
  • kinetic data using Lambert’s W function [71]. This method provides better estimates for the Michaelis–Menten constant (KM) and maximum velocity (Vmax) than nonlinear regression analysis of the initial rate (V0). It is also superior to any of the known linearised transformations of the Michaelis–Menten
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Published 15 May 2024

Mild and efficient synthesis and base-promoted rearrangement of novel isoxazolo[4,5-b]pyridines

  • Vladislav V. Nikol’skiy,
  • Mikhail E. Minyaev,
  • Maxim A. Bastrakov and
  • Alexey M. Starosotnikov

Beilstein J. Org. Chem. 2024, 20, 1069–1075, doi:10.3762/bjoc.20.94

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  • us to try another protecting group for the formyl function, namely arylhydrazone. Thus, reactions of compounds 7a–c with a number of arylhydrazines afforded the corresponding hydrazones 11 which were not isolated and subjected to cyclization under the action of K2CO3 (Scheme 5). In most cases the
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Published 14 May 2024

Novel analogues of a nonnucleoside SARS-CoV-2 RdRp inhibitor as potential antivirotics

  • Luca Julianna Tóth,
  • Kateřina Krejčová,
  • Milan Dejmek,
  • Eva Žilecká,
  • Blanka Klepetářová,
  • Lenka Poštová Slavětínská,
  • Evžen Bouřa and
  • Radim Nencka

Beilstein J. Org. Chem. 2024, 20, 1029–1036, doi:10.3762/bjoc.20.91

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  • suitably decorated benzoxazole derivative 12a. The benzoxazole core showed increased sensitivity towards a basic environment, resulting in the ring-opened side product 13 through saponification of the ester function of compound 12a. The identification of this side product proved to be challenging due to
  • insufficient evidence provided even by meticulous NMR analysis and eventually had to be confirmed by X-ray crystallography (Figure S1, Supporting Information File 1). Changing the ester function from an ethyl to an allyl group enabled a very mild cleavage using a Pd-mediated reaction with triethylsilane [28
  • curves. C) The IC50 values were determined using the GraphPad algorithm (IC50 value of compound 1 was published by Dejmek et al. [24]), the BEI was calculated using the function pIC50 [mol/L]/MW [kDa]. Synthetic pathway to benzoxazole analogue 2 of HeE1-2Tyr (1). Reagents and conditions: a) TMSN3, TfOH
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Published 06 May 2024

Carbonylative synthesis and functionalization of indoles

  • Alex De Salvo,
  • Raffaella Mancuso and
  • Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

Graphical Abstract
  • , the metal-catalyzed direct C–H carbonylation of indoles is an effective and straightforward approach to synthesize indole derivatives containing a carbonyl function in position 3. On the other hand, only a few examples to synthesize indole-2-carbonyl derivatives have been realized. One example is the
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Published 30 Apr 2024

Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

  • Min Li and
  • Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

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  • potential of TSs to generate terpenoids has been underestimated. With the development of synthetic biology technologies, an efficient precursor-providing chassis was constructed. Together with the accumulation of genome sequencing data, we systematically evaluated the function of TSs and discovered new
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Published 30 Apr 2024

Monitoring carbohydrate 3D structure quality with the Privateer database

  • Jordan S. Dialpuri,
  • Haroldas Bagdonas,
  • Lucy C. Schofield,
  • Phuong Thao Pham,
  • Lou Holland and
  • Jon Agirre

Beilstein J. Org. Chem. 2024, 20, 931–939, doi:10.3762/bjoc.20.83

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  • modelling of glycoproteins and protein–carbohydrate complexes is pivotal in understanding the complex biochemical interactions that affect the physiological function of cells [1]. Any mechanistic analysis done with finely grained approaches such as QM/MM [2] relies heavily on the correctness of the starting
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Published 24 Apr 2024

(Bio)isosteres of ortho- and meta-substituted benzenes

  • H. Erik Diepers and
  • Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

Graphical Abstract
  • racemic mixtures of bioisosteres 1,5-BCHs (±)-64 and (±)-71. Their analysis showed that all compounds display similar antifungal activity over a wide range of concentrations, validating the proposition that 1,5-BCHs can function as bioisosteres of ortho-benzenes (Figure 9) [45]. 1,5-Disubstituted 3
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Published 19 Apr 2024

Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

  • Kara A. Strickland,
  • Brenda Martinez Rodriguez,
  • Ashley A. Holland,
  • Shelby Wagner,
  • Michelle Luna-Alva,
  • David E. Graham and
  • Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

Graphical Abstract
  • (Scheme 1) [20][21]. Vs NnlA contains a Per-Arnt-Sim (PAS) domain – protein domains that often bind heme and function as gas or redox sensors [20]. Indeed, Vs NnlA was shown to contain a heme cofactor [21]. Mutagenesis of a predicted histidine ligand to this heme resulted in loss of the heme and the
  • variant could not degrade NNG. Additionally, this heme must be reduced to the ferrous (FeII) state to initiate NNG degradation. Therefore, the heme is critical for NnlA’s NNG degradation activity. While the activity of NnlA is established less is known about its physiological function and, for that matter
  • , the physiological function of its substrate NNG. This compound is one of the few known nitramine natural products and the only one produced by bacteria instead of fungi [22]. Its only known natural sources are strains of Streptomyces bacteria [23][24]. The abundance and distribution of these NNG
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Published 17 Apr 2024

Discovery and biosynthesis of bacterial drimane-type sesquiterpenoids from Streptomyces clavuligerus

  • Dongxu Zhang,
  • Wenyu Du,
  • Xingming Pan,
  • Xiaoxu Lin,
  • Fang-Ru Li,
  • Qingling Wang,
  • Qian Yang,
  • Hui-Min Xu and
  • Liao-Bin Dong

Beilstein J. Org. Chem. 2024, 20, 815–822, doi:10.3762/bjoc.20.73

Graphical Abstract
  • File 1). To validate the function of the presumed DMS, we cloned its gene into the pETDuet-1 vector to form plasmid pLD10050, which was transformed into our truncated artificial FPP-overproduction system in E. coli to yield strain DL10092 [34]. Analysis of the fermentation extracts revealed that
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Published 16 Apr 2024

Advancements in hydrochlorination of alkenes

  • Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

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  • (anti-Markovnikov product). One plausible explanation for this intriguing observation is that K10 and other zeolites may function both as Brønsted acids and radical initiators [63]. Consequently, it is likely that both ionic and radical pathways are concurrently in operation. The in situ generation of
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Published 15 Apr 2024

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

  • Zhongwei Hua,
  • Nan Liu and
  • Xiaohui Yan

Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68

Graphical Abstract
  • , and epileptic disorders [26][27]. Four mechanisms have been reported for the treatment of Alzheimer's disease with crocins. Crocins function as antioxidants that slow down the progression of the disease by increasing the ʟ-glutathione (GSH) level and reducing the presence of reactive oxygen species
  • healthy and hypertensive rats depending on the dose [43]. In an angiotensin II-induced acute hypertension model, crocins could probably improve cardiovascular function by reducing the ROS level [44]. Chen et al. found that crocins could reduce inflammation and oxidative stress in the rat placenta and
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Published 09 Apr 2024

Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis

  • Zhiyong Yin and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67

Graphical Abstract
  • by the preceding modules (highlighted in purple) [14][16]. Furthermore, the structures of 1 and 2 show a shifted triene portion that is not in conjugation with the carboxylic acid function. NMR studies of off-loaded intermediates with the TE deletion mutant revealed that these double bond shifts are
  • , to investigate the function of the KS domain BaeJ-KS2 the synthesis of 13C-labelled (S)-11 as a mimic of the intermediate bound to the ACP of module 3 was performed. It was planned to introduce the 13C-labelling from (5-13C)glutamate into the γ-aminobutyrate portion of (S)-11. For this purpose, the
  • significant importance. Many KSs within trans-AT PKSs function as gatekeepers, facilitating the transfer of intermediates along the assembly line without participating in chain elongation. For instance, the final KS of the bacillaene PKS lacks condensation capability, but may serve to ensure proper double
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Published 05 Apr 2024

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

  • Senze Qiao,
  • Zhongyu Cheng and
  • Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

Graphical Abstract
  • and multifunctional enzymatic assembly, nonribosomal peptide synthases (NRPS), polyketide synthases (PKS), and hybrid NRPS/PKS systems, which are organized into sets of functional domains known as modules and function through a similar mechanism [9][10][11][12]. Each NRPS module is composed of three
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Published 04 Apr 2024

Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari

  • Fumito Sato,
  • Terutaka Sonohara,
  • Shunta Fujiki,
  • Akihiro Sugawara,
  • Yohei Morishita,
  • Taro Ozaki and
  • Teigo Asai

Beilstein J. Org. Chem. 2024, 20, 714–720, doi:10.3762/bjoc.20.65

Graphical Abstract
  • determined to be (−)-sandaracopimaradiene (Figure 3B). We then turned our attention to the individual function of these enzymes. With this aim, AsPS and AsCPS were expressed in Escherichia coli as N-terminal hexa-histidine-tagged proteins and purified by Ni-affinity chromatography (see Supporting Information
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Published 03 Apr 2024

A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1-b]oxazol-6-ium salts

  • Andrew D. Gillie,
  • Matthew G. Wakeling,
  • Bethan L. Greene,
  • Louise Male and
  • Paul W. Davies

Beilstein J. Org. Chem. 2024, 20, 621–627, doi:10.3762/bjoc.20.54

Graphical Abstract
  • secondary gold-ligand interactions [8][9][10], chiral environments [11][12][13] including those enabling secondary interactions with substrates for asymmetric catalysis [14], cooperative and bimetallic catalysis [7][15], and redox-enabling function for Au(I)/(III) cycles [16][17]. Such L-shaped ligands
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Published 18 Mar 2024

A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A

  • Michael O. Akintubosun and
  • Melanie A. Higgins

Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51

Graphical Abstract
  • essential for in vivo antimicrobial activity suggesting a distinct biological function independent of ribosome binding. The hygromycin A biosynthetic gene cluster has been identified and the biosynthesis of the aminocyclitol has been proposed (Figure 1) [8][9]. Starting from glucose-6-phosphate, the pathway
  • is a myo-inositol dehydrogenase. These types of enzymes typically use NAD+ as a cofactor [12][13]. So, we first tested Hyg17 with myo-inositol and NAD+ and found that it was able to produce NADH, suggesting it can function as a myo-inositol dehydrogenase (Figure 2a). Since this assay tests for the
  • the enzyme function initiative (EFI-EST) [30] web tool. An SSN was created by inputting the Hyg17 sequence into the Sequence BLAST function and retrieving the top 500 sequence hits along with sequences from the protein family PF01408 in which Hyg17 is found. The sequences were filtered for bacterial
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Published 14 Mar 2024

Switchable molecular tweezers: design and applications

  • Pablo Msellem,
  • Maksym Dekthiarenko,
  • Nihal Hadj Seyd and
  • Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Graphical Abstract
  • luminescence properties of the system could then be regulated by closing/opening but also by the addition of Cl− that could form hydrogen bonding with the amide function of the spacer between the switching and the functional units. The WLA has also been applied to obtain switchable molecular tweezers for
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Published 01 Mar 2024

Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells

  • Fumihiro Ishikawa,
  • Sho Konno,
  • Hideaki Kakeya and
  • Genzoh Tanabe

Beilstein J. Org. Chem. 2024, 20, 445–451, doi:10.3762/bjoc.20.39

Graphical Abstract
  • ; Introduction Nonribosomal peptides (NRPs) exhibit various biological activities and have been used as therapeutic agents, such as antibiotics, anticancer agents, and immunosuppressants [1]. Additionally, NRPs function as virulence factors, such as siderophores and genotoxins [2]. Therefore, inhibiting their
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Published 26 Feb 2024

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

  • Eiichi Kayahara,
  • Yoshiyuki Mizuhata and
  • Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

Graphical Abstract
  • function. After our first report on the selective encapsulation of C60 by [10]CPP (the number in the brackets is the number of paraphenylene units in the CPP) (Figure 1a) [22], the concave inner surface of CPPs was found to interact with a variety of molecules with convex surfaces through π–π interactions
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Published 23 Feb 2024
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