Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation

• Sebastian Haferkamp,
• Andrea Paul,
• Adam A. L. Michalchuk and
• Franziska Emmerling

Beilstein J. Org. Chem. 2019, 15, 1141–1148, doi:10.3762/bjoc.15.110

• data using cross validation with 20 randomly selected segments. MCR iterations were initialized with the constraints of "non-negative spectra" and "non-negative concentrations", and sensitivity to pure compounds was set to 100. The maximum number of iterations was set at 250. Mass spectrometry: Mass

New terpenoids from the fermentation broth of the edible mushroom Cyclocybe aegerita

• Frank Surup,
• Florian Hennicke,
• Nadine Sella,
• Maria Stroot,
• Steffen Bernecker,
• Sebastian Pfütze,
• Marc Stadler and
• Martin Rühl

Beilstein J. Org. Chem. 2019, 15, 1000–1007, doi:10.3762/bjoc.15.98

• spectrometry and NMR spectroscopy. The relative configurations of 2–4 were assigned by ROESY correlations, and 3JH,H coupling constants in the case of 4. Applying quantitative PCR for gene expression validation, we linked the production of bovistol and its derivatives to the respective biosynthesis gene

Design and synthesis of multivalent α-1,2-trimannose-linked bioerodible microparticles for applications in immune response studies of Leishmania major infection

• Chelsea L. Rintelmann,
• Tara Grinnage-Pulley,
• Kathleen Ross,
• Daniel E. K. Kabotso,
• Angela Toepp,
• Anne Cowell,
• Christine Petersen,
• Balaji Narasimhan and
• Nicola Pohl

Beilstein J. Org. Chem. 2019, 15, 623–632, doi:10.3762/bjoc.15.58

• intracellular monitoring and validation of T cell antigen presentation. This new probe would also be linked to the surface of a polyanhydride copolymer microparticle based on 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic anhydride (SA) to allow for enhanced internalization and uptake of the immunogenic

• pathogen (1 μm in diameter) and provide a multivalent display of the synthetic α-1,2-trimannose similar to the Leishmania promastigote cell-wall glycans. Furthermore, a tethered fluorophore would allow for immunofluorescence assays, intracellular trafficking, and validation of T cell-mediated antigen

Synthesis of the polyketide section of seragamide A and related cyclodepsipeptides via Negishi cross coupling

• Jan Hendrik Lang and
• Thomas Lindel

Beilstein J. Org. Chem. 2019, 15, 577–583, doi:10.3762/bjoc.15.53

• A (1, Scheme 1) [1][2], is an ideal situation for the validation of the chemoselectivity and efficiency of photoaffinity labelling. Recently, it has been determined by cryo-electron microscopy how jasplakinolide A (1) binds to F-actin and alters the actin skeleton in vivo, resulting in pronounced

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• reactions can be integrated in the toolbox of chemical proteomics. Recently, following a similar strategy, Lu et al. reported on-DNA RCM and CM, an application potentially useful to generate DNA-encoded libraries for hit identification and target validation [90]. Substrates appended to oligonucleotides

Synthesis of a tubugi-1-toxin conjugate by a modulizable disulfide linker system with a neuropeptide Y analogue showing selectivity for hY1R-overexpressing tumor cells

• Rainer Kufka,
• Robert Rennert,
• Goran N. Kaluđerović,
• Lutz Weber,
• Wolfgang Richter and
• Ludger A. Wessjohann

Beilstein J. Org. Chem. 2019, 15, 96–105, doi:10.3762/bjoc.15.11

• should be made to improve activity after internalization of the PDC. Overall, the investigations carried out up to this point provide a biological validation of the developed conjugate. The principally modular conjugation protocol for tubugis bears promise for further cancer targeting conjugates

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• recently been approved or reached clinical validation can be found in Figure 2. If we analyze their mechanism of action, nearly all of them are currently being investigated as oncological treatments. For example, navitoclax (1, Figure 2), a Bcl-2/Bcl-XL inhibitor developed by Abbot Laboratories is

Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

• Aleksey A. Vasilev,
• Meglena I. Kandinska,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• David Sucunza,
• Juan J. Vaquero,
• Obis D. Castaño,
• Stanislav Baluschev and
• Silvia E. Angelova

Beilstein J. Org. Chem. 2017, 13, 2902–2914, doi:10.3762/bjoc.13.283

• ) in methanol for compounds 5a–d, TO and TO-7Cl in methanol. Supporting Information Supporting Information File 486: Characterisation data for the compounds: NMR and GS–MS spectra; validation of the theoretical computations; photostabilities at 532 nm. Acknowledgements The theoretical calculations

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• -regulation of Bim. Furthermore, the suggested interaction of mycolactone A/B with FKBP12 is supported by the protective effects of an excess of FK506 against mycolactone-induced apoptosis. However, further experimental validation of the mycolactone-FKBP12 interaction, e.g., by SPR, NMR or X-ray

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

• Alexis Perry and
• Christina J. Kousseff

Beilstein J. Org. Chem. 2017, 13, 1542–1550, doi:10.3762/bjoc.13.154

• constant for all merocyanine complexes of different metals, and indeed for different merocyanine complexes of the same metal. We thus sought initial validation of UV–vis data by direct comparison with data from 1H NMR, derived from merocyanine complexes of two non-paramagnetic metal cations, Mg2+ and Zn2

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• distortion and particular caution should be given to crystallographic reports where there is a wrong linkage distance specification or a mistaken anomer and handedness. Automated detection, building and validation of sugar models starting from X-ray diffraction data are being implemented [34]. Carbohydrate

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

• Katarina Kemper,
• Max Hirte,
• Markus Reinbold,
• Monika Fuchs and
• Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

• of highly functionalized compounds. Novel approaches discussed in this review include metabolic engineering as well as site-directed mutagenesis to expand the natural terpene landscape. Focusing mainly on the validation of successful integration of engineered biosynthetic pathways into optimized

Self-optimisation and model-based design of experiments for developing a C–H activation flow process

• Alexander Echtermeyer,
• Yehia Amar,
• Jacek Zakrzewski and
• Alexei Lapkin

Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18

• 98.72%. The experimentally obtained yields in the validation of the two sets of conditions were determined to be >99%, which is caused by the uncertainty of the applied GC method including sample preparation, which lead to ±1% variance in the yield value. The algorithm is not expected to exhibit fast

• of samples needed in the experiment and the statistical t-test results. Results of the parameter estimation showing the final values, initial guesses, 95% confidence intervals (CI) and t-values for each of the 8 parameters. Experimental conditions and results of the experimental validation of the two

Biochemical and structural characterisation of the second oxidative crosslinking step during the biosynthesis of the glycopeptide antibiotic A47934

• Veronika Ulrich,
• Clara Brieke and
• Max J. Cryle

Beilstein J. Org. Chem. 2016, 12, 2849–2864, doi:10.3762/bjoc.12.284

• the models where appropriate. TLS input files were generated using the TLS-Motion Determination Server [59][60]. Structure validation was performed using MOLPROBITY [61] and PROCHECK [62]. Structure-based sequence alignments were carried out with SSM [63] as implemented in COOT and comparisons to

cis-Diastereoselective synthesis of chroman-fused tetralins as B-ring-modified analogues of brazilin

• Dimpee Gogoi,
• Runjun Devi,
• Pallab Pahari,
• Bipul Sarma and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2016, 12, 2816–2822, doi:10.3762/bjoc.12.280

• might undergo a competitive semipinacol rearrangement to give ring contracted product 11. With all these concerns in our mind, we started this work first with the synthesis of compound (±)-5a from glycidyl ether (±)-6a as a model reaction for validation and optimization studies. (±)-6a was synthesized

Computational methods in drug discovery

• Sumudu P. Leelananda and
• Steffen Lindert

Beilstein J. Org. Chem. 2016, 12, 2694–2718, doi:10.3762/bjoc.12.267

Biomimetic synthesis and HPLC–ECD analysis of the isomers of dracocephins A and B

• Viktor Ilkei,
• András Spaits,
• Anita Prechl,
• Áron Szigetvári,
• Zoltán Béni,
• Miklós Dékány,
• Csaba Szántay Jr,
• Judit Müller,
• Árpád Könczöl,
• Ádám Szappanos,
• Attila Mándi,
• Sándor Antus,
• Ana Martins,
• Attila Hunyadi,
• György Tibor Balogh,
• György Kalaus (†),
• Hedvig Bölcskei,
• László Hazai and
• Tibor Kurtán

Beilstein J. Org. Chem. 2016, 12, 2523–2534, doi:10.3762/bjoc.12.247

• the stereochemical studies of flavanoid alkaloids, the solution TDDFT–ECD calculation method [6] was applied to 2a–d and 3a–d. For the validation of our computational approach on flavonoids, the ECD spectra of (R)-naringenin ((R)-1), the building blocks of dracocephins A and B, were calculated first

Inhibition of peptide aggregation by means of enzymatic phosphorylation

• Kristin Folmert,
• Malgorzata Broncel,
• Hans v. Berlepsch,
• Christopher H. Ullrich,
• Mary-Ann Siegert and
• Beate Koksch

Beilstein J. Org. Chem. 2016, 12, 2462–2470, doi:10.3762/bjoc.12.240

• of phosphorylation, time-dependent CD (circular dichroism) measurements were performed. To ensure comparable and reproducible starting conditions, a disaggregation and concentration validation assay using HFIP (1,1,1,3,3,3-hexafluoropropan-2-ol) was performed. Thus, all aggregates that may have

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• multiple structural isomers of bridged polycycles from a common intermediate offer multiple advantages: saved time and effort by avoiding the validation of new strategies for each target, accumulated understanding of the key reactions in the strategy for higher yields and improved efficiency, and rapid

Is conformation a fundamental descriptor in QSAR? A case for halogenated anesthetics

• Maria C. Guimarães,
• Mariene H. Duarte,
• Josué M. Silla and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2016, 12, 760–768, doi:10.3762/bjoc.12.76

• structures encode biological activities. A previous study using log P (the octanol/water partition coefficient) as descriptor showed a good correlation with pMAC [21], but the resulting model was not validated. Thus, the present study provided an internal (through leave-one-out cross-validation) and external

• validation to attest the reliability of the MIA-QSAR model. This was checked through the respective root mean square errors (RMSE) and the determination coefficients for the plot of actual vs predicted pMAC (q2 and r2test > 0.5 are considered acceptable). Also, since the MIA-QSAR model was obtained from PLS

Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• , and quantitate concentrations, would be a large validation of the method. To accomplish this we used serum albumins as the cross-reactive receptors, paired with a series of hydrophobic indicators [107]. The method worked extremely well (Figure 10C), and we are currently pursuing the analysis of

• -well plates [107]. The array components consisted of BSA and HSA (100 µM), glyceride (90 µM), DNSA (60 µM), ANS (60 µM), NBD-FA (60 µM), metathesized glyceride (90 µM), AF (100 µM), and DNSA (60 µM) in phosphate buffer with <5% (v/v) THF. Cross-validation: 98%. Two seemingly impossible targets to make

Learning from the unexpected in life and DNA self-assembly

• Jennifer M. Heemstra

Beilstein J. Org. Chem. 2015, 11, 2713–2720, doi:10.3762/bjoc.11.292

• validation of our hypothesis regarding the thermodynamics of split aptamer assembly. In the short term, this allowed us to overcome the challenge of background signal by reducing the ionic strength, and we were delighted to observe dose-dependent ligation of the split aptamer fragments with increasing

The Beilstein Journal of Organic Chemistry and the changing face of scientific publishing

• Martin G. Hicks and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2015, 11, 2242–2244, doi:10.3762/bjoc.11.242

• computer-readable formats for validation and searching. Reading patterns have significantly changed. The number of articles published per year has significantly increased over the last decades, thus routinely “keeping up with the literature” is no longer possible as it was in the past. However, since

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• validation of the absolute configurations based on the TD-DFT method. Although the observed Cotton effect associated with TTF moieties is relatively weak, each chiral allene is stable towards the racemization under ambient light. A chiral copolymer based on TTF and a chiral 1,3-diphenylallene as the main

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• differences in rates of diastereomer decomposition. Calculation of acylphosphonite inversion barrier. As described in the Introduction, inversion barriers for phosphines, acylphosphines, and phosphites are known. These were calculated first for validation of the method. The structures of chiral phosphine 18