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Search for "function" in Full Text gives 1031 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Synthesis of 1,4-azaphosphinine nucleosides and evaluation as inhibitors of human cytidine deaminase and APOBEC3A
Beilstein J. Org. Chem. 2024, 20, 1088–1098, doi:10.3762/bjoc.20.96
- 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
Mild and efficient synthesis and base-promoted rearrangement of novel isoxazolo[4,5-b]pyridines
Beilstein J. Org. Chem. 2024, 20, 1069–1075, doi:10.3762/bjoc.20.94
- 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
Novel analogues of a nonnucleoside SARS-CoV-2 RdRp inhibitor as potential antivirotics
Beilstein J. Org. Chem. 2024, 20, 1029–1036, doi:10.3762/bjoc.20.91
- 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
Carbonylative synthesis and functionalization of indoles
Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87
- , 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
Enhancing structural diversity of terpenoids by multisubstrate terpene synthases
Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86
- 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
Monitoring carbohydrate 3D structure quality with the Privateer database
Beilstein J. Org. Chem. 2024, 20, 931–939, doi:10.3762/bjoc.20.83
- 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
(Bio)isosteres of ortho- and meta-substituted benzenes
Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78
- 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
Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria
Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75
- (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
Discovery and biosynthesis of bacterial drimane-type sesquiterpenoids from Streptomyces clavuligerus
Beilstein J. Org. Chem. 2024, 20, 815–822, doi:10.3762/bjoc.20.73
- 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
Advancements in hydrochlorination of alkenes
Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72
- (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
Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins
Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68
- , 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
Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis
Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67
- 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
Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization
Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66
- 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
Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari
Beilstein J. Org. Chem. 2024, 20, 714–720, doi:10.3762/bjoc.20.65
- 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
A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1-b]oxazol-6-ium salts
Beilstein J. Org. Chem. 2024, 20, 621–627, doi:10.3762/bjoc.20.54
- 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
A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A
Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51
- 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
Switchable molecular tweezers: design and applications
Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45
- 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
Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells
Beilstein J. Org. Chem. 2024, 20, 445–451, doi:10.3762/bjoc.20.39
- ; 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
Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges
Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38
- 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
Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles
Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36
- prostate cancer. The same apoptotic function can be observed in colon and pancreatic cancer, since BIMs (specifically DIM-C-pPhOCH3 (5)) can act as a Nur77 (Nuclear Receptor 4A1) antagonist, which modulates the life cycle of cells [6]. The correlation between lower lung cancer risk and the consumption of
- cruciferous vegetables has also been showcased, due to the function of BIMs as oxidative stress inhibitors; however, the specific mechanism of action has yet to be determined [1][6]. This capability of BIMs to act as Nur77 antagonists, has resulted in their examination as potential anti-Parkinson’s disease
- antiviral properties. BIMs function as selective antibacterial agents against several virulent Escherichia coli (E. coli) strains, which can cause many gut and urinary tract infections. They act by damaging DNA molecules and inhibiting their replication in bacteria, while also targeting the proteins that
Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines
Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34
- 1), the energetically preferred tautomer is the 14H-form 7a. The least stable 7H-isomer 7b conforms to a minimum on the corresponding potential energy surface. However, the stable wave function of 7b corresponds to an electronic state with a broken symmetry [20], indicating the presence of two
- the geometry without imposing symmetry restrictions, followed by analyzing the stability of the DFT wave function. The images of the molecular structures in Figure 1 and Figure S6, Supporting Information File 1, were obtained using the Chemcraft program [35]. DFT-calculated molecular geometry (B3LYP/6
Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin
Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31
- and tissues, thereby offering insights into cellular heterogeneity and function. For instance, the use of wheat germ agglutinin (WGA) and concanavalin A (ConA) has been instrumental in selectively staining cells based on their glycan expression [4], including single-cell approaches [5][6]. In the
- in which its preferred binding motifs occur (O-glycans, milk glycans, GAGs) are absent from most plants, including melons. We thus hypothesize that the role of this lectin might be to recognize non-self epitopes, such as for protection against pathogens, which is a common function in plant lectins [3
- and the range of their binding specificities, but also our knowledge of melon lectins in particular, which has remained limited so far. Further experiments are still required to determine the role of the C-terminal domain, as well as the physiological function of the full-length CMA1 protein
Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold
Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15
- are excellent substrates for such reactions, affording electrophilic carbonyl derivatives susceptible to react with nucleophiles in the acidic reaction mixture [4][5][6][7][8]. Consequently, the Hock rearrangement is likely to be part of tandem processes involving this carbonyl function [9][10][11
- surrogate of the aldehyde function when it is engaged in a tandem photooxygenation and Hock rearrangement, involving allylic hydroperoxide intermediates in an acidic medium. In the presence of aromatic nucleophiles, the aldehyde intermediate of the Hock rearrangement can be involved in tandem Friedel–Crafts
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- cyclopentadiene moieties. TCBD 4, obtained through the [2 + 2] CA–RE reaction, continues to function as an electron-accepting alkene, as shown in Scheme 4. Subsequent [2 + 2] CA–RE reactions involving electron-rich alkynes yield tetracyano-1,3,5-hexatrienes (TCHTs). These reactions occur seamlessly in a one-pot
Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations
Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10
- gas phase; the C60 + C60 dimerization is slightly endothermic with a barrier around 30 kcal mol−1, whereas dimerization for the radical cation is exothermic with a tiny (or almost nil) barrier, which makes this initial step of the reaction drastically faster. Therefore, the main function of the CNT is
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