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Search for "distribution" in Full Text gives 555 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities
Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248
- prolonged incubation. The B. subtilis strains were added at a community assembly phase when Bacillus was the dominating genus, so that the general genera distribution was not expected to be influenced extensively. Nevertheless, after 48 h cocultivation, the final relative abundance of the Bacillus genus was
A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles
Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238
- the results are presented in Figure 4. The LS-FAS-Cu catalyst featured irregular and blocky morphology with uneven size from 100 nm to 400 nm (Figure 4a–d). In addition, the elemental mapping images clearly revealed the presence and uniform distribution of C, Cu, O, and S in LAS-FAS-Cu. XPS was
Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system
Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232
- rare case where no primer is needed for the formation of RWLM. To our knowledge, there is only one other example of a binary system with such a behavior [59]. Moreover, the surfactant, that was used as a precursor exhibits a certain distribution of the molecular weight but still was able to form
3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia
Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228
- color patterns (see Supporting Information File 1, Figure S1) [4], are widely distributed, and parapatric in north-eastern Peru [5]. Despite the geographic overlap in distribution, a recent genetic study showed limited gene flow [4]. Reproductive isolation in mimetic butterflies can be driven by
- . The position of the double bonds in the acyl chain of the esters can be explained by a biosynthetic pathway described in detail in Scheme 5. The double bond distribution is consistent with both desaturases acting on palmitic acid, leading to the respective hexadecenoic acids. These acids are the
Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of 1JC,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites
Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222
- members, nocarimidazoles C (1) and D (2), were obtained from a marine-derived actinomycete of the genus Kocuria. The exclusive origin of these metabolites from marine bacteria, as well as the distribution among phylogenetically distinct taxa imply their potential function in the adaptation of the
Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes
Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219
- nanoparticles with the desired diameter of 8–10 nm and a relatively narrow size distribution [40]. This method entailed the rapid addition of a hot aqueous solution of tetrachloroauric(III) acid to aqueous sodium citrate at 100 °C. After dialysis to remove excess citrate, the resulting solution was treated with
Vicinal difluorination as a C=C surrogate: an analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity
Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216
- seem to dominate the conformer population distribution of 2 in chloroform solution, because the weight-averaged calculated J-values of 2a–c match the experimentally-measured J-values quite well (Figure 2). But none of the structures 2a–c are a close conformational match with piperine (1). A noteworthy
A consensus-based and readable extension of Linear Code for Reaction Rules (LiCoRR)
Beilstein J. Org. Chem. 2020, 16, 2645–2662, doi:10.3762/bjoc.16.215
- discussed or described. We hope to encourage that adoption through our LiCoRRICE examples. Increased FAIRness will facilitate the validation and distribution of developing glycoinformatics toolkits. Easy-to-use glycoinformatics toolkits, made possible by the fluency of interoperability across tools, are one
Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate
Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211
- size distribution was measured from the desorption branch using the nonlocal density functional theory (NLDFT) model assuming a cylindrical pore structure. The average pore size was determined by the Dubinin–Radushkevich (DR) plot of the N2 desorption isotherm. The relative microporosity percentage is
Comparative ligand structural analytics illustrated on variably glycosylated MUC1 antigen–antibody binding
Beilstein J. Org. Chem. 2020, 16, 2540–2550, doi:10.3762/bjoc.16.206
- -antigen’. Root-mean-square-analysis In solution (unbound), the RMSD (Figure 2) has a broad spread and a similar center for both the antigen and Tn-antigen. It is readily apparent that the glycosylated antigen has a bimodal distribution (secondary peak at 5.7 Å), indicating at least one other interesting
- conformation. On consideration of the RMSD for the bound antigens, a narrowing in the distributions is noted. Bound Tn-antigen (Figure 2F) has the narrowest distribution, with a spread from 0.8 Å to 1.6 Å; this unimodal distribution is centered at 1.25 Å. There is no longer a secondary peak, indicating that
- there is restricted movement on binding. The bound antigen (Figure 2E), instead has a bimodal distribution with a significant population centered at 1.25 Å, a minor population centered at 2.25 Å, and a broad tail that extends to 3.5 Å. While there is restricted movement on binding, the antigen shows
Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors
Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202
- sequestration [7]. Still, photochemistry has not been exploited much in industry since the distribution of light inside a photoreactor brings a lot of complexity to the reactor design. Unlike thermochemical reactions, it is not feasible to scale up photoreactions by increasing the dimensions of the reactor due
- to the exponential attenuation of light. Nonuniform light distribution often leads to a lower selectivity and longer reaction times, which in turn lowers the productivity [8][9]. Since photoreactions are intrinsically quite fast, mass transfer limitations should also be taken into account while
- emerged as alternatives to batch operation. Due to the small characteristic length of microreactors, more uniform light distribution could be obtained. The elimination of overirradiation or dark zones results in less side product formation. Mass transfer limitations can be alleviated in these
Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction
Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201
- Figure 1, a relatively uniform distribution for both ChNCs and ChsNCs with individual rod-like nanocrystals was observed, with an average length of 231 ± 38 nm for the ChNC and 159 ± 34 nm for the ChsNC (Supporting Information File 1, Figure S1). These measures were made from parts in the grid where the
- survey XPS scan showed no Cl contribution to the overall atom distribution suggesting that no PdCl2 species were present in the nanocomposites. For the second point, high-resolution XPS spectra on the O 1s scan of both the PdNP@ChNC and PdNP@ChsNC samples show the exact same symmetric peak, similar to
Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction
Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200
- . Penoxsulam (I) has a rotatable C–C(F) bond (as analyzed in the previous section) and, consequently, has the dependence of the molecular dipole moment μ with the rotation around this bond. It is well-known that μ is influenced by two main factors: the molecular dimensions and the electron distribution [26
Hierarchically assembled helicates as reaction platform – from stoichiometric Diels–Alder reactions to enamine catalysis
Beilstein J. Org. Chem. 2020, 16, 2338–2345, doi:10.3762/bjoc.16.195
- statistical ligand distribution Li[Li3(1)3(L*)3Ti2] (L* = 3–7-H2). The given formula only describes the ratio of the ligands but in fact a statistical mixture of complexes Li[Li3(L*)6Ti2], Li[Li3(1)(L*)5Ti2], Li[Li3(1)2(L*)4Ti2], Li[Li3(1)3(L*)3Ti2], Li[Li3(1)4(L*)2Ti2], Li[Li3(1)5(L*)1Ti2], and Li[Li3(1)6Ti2
- residues were introduced instead of the diene ligands. Again helicates with a statistical distribution of chiral ligands and of the new amine ligands in the complex were investigated as catalysts. The ligands with potential catalytic activity were synthesized in a three-step approach (Scheme 4). Initially
- ][31] stereoselectivity of a Diels–Alder reaction by use of different solvents. The heteroleptic complexes are mixtures with an average ligand distribution as shown [13]. Elucidating the pathway of the stereoinduction of the Diels–Alder reaction. Ten equivalents of chiral ammonium salt are added to the
Formation of an exceptionally stable ketene during phototransformations of bicyclo[2.2.2]oct-5-en-2-ones having mixed chromophores
Beilstein J. Org. Chem. 2020, 16, 2297–2303, doi:10.3762/bjoc.16.190
- distribution of these photoproducts may be wavelength dependent [7]. In order to investigate the photoreaction of such enones, we observed a complete 1,2-acyl shift (1,2-AS) photoproduct formation when 1a–h have been irradiated (Scheme 1) [14][16]. We also observed that such a rearrangement took place very
Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator
Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185
- distribution (NNLS analysis). UV–vis titrations of compound 4 (c = 1.0 × 10−6 M), with ct-DNA at pH 7.0 (a) and at pH 5 (b). Insets: dependence of Abs (384 nm) on c(ct-DNA), line – non-linear fit to Scatchard equation [28]. Measurement done in Na cacodylate buffer, I = 0.05 M. a) CD titration of ct-DNA (c
Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis
Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183
- a positive impact on the biological absorption and distribution. Moreover, C–H/C–F substitution strongly decreases the basicity of neighboring amines (and lowers the pKa by a similar increment) due to the σ-inductive effect of F. This results in i) a higher oral bioavailability [19], ii) a potential
- most abundant in the solar distribution [78][79], instead absorbing only short wavelengths of UV light, ii) the photoexcitation of simple organic molecules by requisite high-energy UV photons populates higher-order excited states that undergo uncontrolled photodecomposition, such as Norrish-type
- distribution of fluorinated products, with a large preference for fluorination at the penultimate carbon (that would form a secondary radical), consistent with the polarity matching selectivity shown previously (Figure 10) [198][201]. Lectka and co-workers pointed out that the triplet energy of aliphatic
Lipophilicity trends upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl groups
Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182
- ]. In this case, the expected lipophilicity reducing effect is offset by the electron-withdrawing effect on the nitrogen (ΔlogP +0.34). The reduction in amine basicity also shifts the distribution of free base and protonated species, resulting in a higher proportion of free base in solution at pH 7.4
- by reversed-phase HPLC). Lipophilicity modulations discussed in this contribution. Distribution of the experimental lipophilicity values of series D, E and F (* denotes an estimated value, see Supporting Information File 1). Comparison of lipophilicities between the linear alkyl, isopropyl
GlypNirO: An automated workflow for quantitative N- and O-linked glycoproteomic data analysis
Beilstein J. Org. Chem. 2020, 16, 2127–2135, doi:10.3762/bjoc.16.180
- -specific or peptide-specific. If the user trusts Byonic’s site-specific assignment, then all peptide variants that contain that site are included in calculations of its occupancy and glycoform distribution. If the user prefers to perform a peptide-specific analysis, then each proteolytically unique peptide
- grouping: site-specific analysis, or peptide-specific analysis. For site-specific analysis, the site-specificity of glycosylation assigned by Byonic was trusted, and all peptide variants that contained that site were included in calculations of its occupancy and glycoform distribution. PSMs with identical
Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations
Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176
- glycans are drawn in SNFG notation [20]. Boxplots showing the quantitation of the 11 different bioreactor conditions. The boxplots show the peak area distribution (expressed as % relative abundance) for each of the 11 bioreactor conditions. Points are averaged relative abundances for three replicates
A complementary approach to conjugated N-acyliminium formation through photoredox-catalyzed intermolecular radical addition to allenamides and allencarbamates
Beilstein J. Org. Chem. 2020, 16, 1983–1990, doi:10.3762/bjoc.16.165
- -acyliminium intermediate is provided to explain the addition product distribution. Results and Discussion We began our study by using the iridium catalyst Ir[(ppy)2(dtbbpy)]PF6 (17) and the reaction conditions used in the addition of amine nucleophiles to enamides [48][50]. By exploiting these reaction
Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions
Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159
- achieve a better performance a homogeneous distribution of the catalyst and the scavenger within the fixed bed reactor seems to be preferable as it has been observed in multicatalytic systems [42]. In this case, two different fixed bed reactors were prepared with a well-disperse mixture formed by 50 mg of
- PdNPs (Figure 9). However, the images show that for the system 8a + 9c the number of particles and their size distribution are larger than for 8a + 9a. This trend is different to the one observed in batch experiments. Conclusion The results here presented confirm the viability of using polymeric
- images of the polymers after the Negishi reaction between 5 and 6. a) 8a, bar scale 20 nm, PdNP size distribution 4.91 ± 1.26 nm. b) 8a + 9a, bar scale 50 nm, PdNP size distribution 4.23 ± 1.65 nm. c) 8a + 9b, bar scale 50 nm, PdNP size distribution 3.61 ± 1.36 nm. d) 8a + 9c, bar scale 50 nm, PdNP size
Regiodivergent synthesis of functionalized pyrimidines and imidazoles through phenacyl azides in deep eutectic solvents
Beilstein J. Org. Chem. 2020, 16, 1915–1923, doi:10.3762/bjoc.16.158
- heating to 473 K until blue spots appeared. Column chromatography was conducted by using silica gel 60 with a particle size distribution of 40–63 μm and 230–400 ASTM, using hexane/EtOAc mixtures as the eluent. High-resolution mass spectrometry (HRMS) analyses were performed using a Bruker microTOF QII
Design, synthesis and application of carbazole macrocycles in anion sensors
Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157
- hydrogen bonding. The primary site of interaction is the X-COO− group. The geometry of the carboxylate group (and to a large extent also its charge distribution) is the same for all carboxylate anions. Therefore, high affinity towards carboxylates is easily achievable, but selectivity towards a specific
Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio
Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154
- (Figure 3a). Note that the sign distribution of the Δδ(S − R) values in β,β-substituted carboxylic acids is inverted from that observed in the α,α-substituted counterparts (Figure 3b) because the PGME anisotropy group is flipped upside down due to the insertion of an extra methylene group between the
- test compounds. Structures of the compounds 1–5. COSY (bold lines) and selected HMBC correlations (arrows) for 1–4. a) Distribution of positive (red) and negative (blue) Δδ(S − R) values (in ppm) calculated from the 1H NMR chemical shifts of the (S)- and (R)-PGME amides of 1–4. b) Comparison of the
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