Herpetopanone, a diterpene from Herpetosiphon aurantiacus discovered by isotope labeling

• Xinli Pan,
• Nicole Domin,
• Sebastian Schieferdecker,
• Hirokazu Kage,
• Martin Roth and
• Markus Nett

Beilstein J. Org. Chem. 2017, 13, 2458–2465, doi:10.3762/bjoc.13.242

• were mainly reported from plants and, to a lesser degree, also from fungi and marine invertebrates. In recent years, however, the discovery of terpenoids from prokaryotes has gained momentum. The ease of DNA sequencing has strongly favored this development, contributing to the identification of

• subject to enzymatic modifications in their native producers. The exclusive testing of a terpene cyclase might hence unveil a biosynthetic intermediate rather than the final product of a secondary metabolite pathway [5][6]. To avoid this problem, we here describe a method for the identification of

• protons of the methylene group in position 11 are magnetically non-equivalent. This feature led to the pairwise occurrence of correlation peaks in the HMBC spectrum and promoted the identification of their 13C coupling partners. In addition to the expected interactions with C-13 and C-14, H-11a and H-11b

Sulfation and amidinohydrolysis in the biosynthesis of giant linear polyenes

• Hui Hong,
• Markiyan Samborskyy,
• Katsiaryna Usachova,
• Katharina Schnatz and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2017, 13, 2408–2415, doi:10.3762/bjoc.13.238

• , the successful identification of a specific mediomycin amidinohydrolase encoded at a location on the genome remote from the med cluster, and genetic and biochemical evidence for the respective roles played by these sulfotransferase and amidinohydrolase enzymes in the production of mediomycins. Results

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• after purification by column chromatography shows no traces of copper in the ESR spectrum (Supporting Information File 1, Figure S21). X-ray crystal structure analysis Single-crystal X-ray structure analysis was performed for all products. It provided clear identification of the novel triazole

Is the tungsten(IV) complex (NEt₄)₂[WO(mnt)₂] a functional analogue of acetylene hydratase?

• Matthias Schreyer and
• Lukas Hintermann

Beilstein J. Org. Chem. 2017, 13, 2332–2339, doi:10.3762/bjoc.13.230

• standard reveals conversion and product selectivity (5 vs 6), or points to important side-reactions through spectroscopic identification and quantification of side-products. Extensive catalyst screening studies that also included established alkyne hydration catalysts have shown that every single of the

• generation of 10, and the source and purification method for substrate 2 were not indicated [13]. Derivatization to 2,4-dinitrophenylhydrazones is a well-established identification method for carbonyl compounds that recommends itself for small amounts of volatile products [38][39]. However, aldehyde

• emphasized by the histogram in Figure 1 which was created from melting point data in the Reaxys database and shows scattering over 30 °C. Consequently, measuring a single or even a mixed melting point with a reference sample is not a reliable identification criterion for 9. An analysis of the compound by

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• understood. Evidently, the identification of as much as possible elements of this network would contribute to its better knowledge. Because of the extremely low BS content in natural sources, studies on their identification almost always included a preliminary chemical synthesis of the compounds in question

• as standards for identification purposes. Typically, such syntheses were carried out by sequential introduction of functional groups into the starting molecule leading to more complex products [3]. This is a suitable approach for the preparation of one or a limited number of BS, but it rapidly

• the contrary, no correlation was observed between the corresponding protons in compound 22, which is consistent with the α-orientation of the epoxide ring. 2β,3β-, 2β,3α- and 2α,3β-diols of type 6–8 Experiments on the identification of steroidal phytohormones in immature seeds of Phaseolus vulgaris

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• chromatography. The extension of π-conjugation by a palladium-catalyzed cross-coupling reaction after a tetramerization reaction proceeds with high yield. Furthermore, since TFEO-Pcs are not only easy to purify but also do not aggregate, their identification by NMR, MS, UV–vis and IR is easy. Consequently

Structural diversity in the host–guest complexes of the antifolate pemetrexed with native cyclodextrins: gas phase, solution and solid state studies

• Magdalena Ceborska,
• Magdalena Zimnicka,
• Aneta Aniela Kowalska,
• Kajetan Dąbrowa and
• Barbara Repeć

Beilstein J. Org. Chem. 2017, 13, 2252–2263, doi:10.3762/bjoc.13.222

• identification of guest–host interactions is possible [17][18]. Any changes in the band position as well as increasing or decreasing of its intensity indicate complex formation. In that sense Raman spectroscopy emerges as an important technique for studying host–guest interactions, in particular for verifying if

Enzymatic synthesis of glycosides: from natural O- and N-glycosides to rare C- and S-glycosides

• Jihen Ati,
• Pierre Lafite and
• Richard Daniellou

Beilstein J. Org. Chem. 2017, 13, 1857–1865, doi:10.3762/bjoc.13.180

• , such enzymatic approaches can nowadays efficiently be utilized in particular for the preparation of pure and well-defined complex glycoproteins [63]. Use of external nucleophiles The identification of the two amino acid side chains in both retaining and inverting GHs is usually performed through site

NHC-catalyzed cleavage of vicinal diketones and triketones followed by insertion of enones and ynones

• Ken Takaki,
• Makoto Hino,
• Akira Ohno,
• Kimihiro Komeyama,
• Hiroto Yoshida and
• Hiroshi Fukuoka

Beilstein J. Org. Chem. 2017, 13, 1816–1822, doi:10.3762/bjoc.13.176

• is, the HClO4 salt of C, could account for all unusual signals. Furthermore, elemental analysis of 12 agreed very closely with its theoretical value and deviated much from that of C. After identification of the product 12, we noticed that Massi and his group obtained the similar adducts during their

18-Hydroxydolabella-3,7-diene synthase – a diterpene synthase from Chitinophaga pinensis

• Jeroen S. Dickschat,
• Jan Rinkel,
• Patrick Rabe,
• Arman Beyraghdar Kashkooli and
• Harro J. Bouwmeester

Beilstein J. Org. Chem. 2017, 13, 1770–1780, doi:10.3762/bjoc.13.171

• based on the identification of this compound and its Cope rearrangement product β-elemene (2) formed by the thermal impact during GC–MS analysis [19] in E. coli headspace extracts under heterologous expression of the terpene synthase gene (Scheme 1). Here we present the diterpene synthase activity of

Theoretical simulation of the infrared signature of mechanically stressed polymer solids

• Matthew S. Sammon,
• Milan Ončák and
• Martin K. Beyer

Beilstein J. Org. Chem. 2017, 13, 1710–1716, doi:10.3762/bjoc.13.165

• infrared bands is not a shift of the peak position, but rather peak broadening and a characteristic change in the relative intensities of the strongest bands, which may serve for the identification and quantification of mechanical stress in polymer solids. Keywords: density functional theory; infrared

A recursive microfluidic platform to explore the emergence of chemical evolution

• David Doran,
• Marc Rodriguez-Garcia,
• Rebecca Turk-MacLeod,
• Geoffrey J. T. Cooper and
• Leroy Cronin

Beilstein J. Org. Chem. 2017, 13, 1702–1709, doi:10.3762/bjoc.13.164

• ]. Therefore, the puzzle most ripe for scientific inquiry is not how did life first arise, but what kind of processes can facilitate the origin of life? Identification of processes that produce complex, autocatalytic chemical networks [8] from simple inputs via gradual, step-wise complexification could go some

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

• a formyl group attached to C8’ and a single bond between C8’ and C9’ (mycolactone G, 10). Due to its unspecific appearance at early stages, the diagnosis of Buruli ulcer is non-trivial and no point-of-care rapid diagnostic test is currently available [64]. Identification of the infection generally

An improved preparation of phorbol from croton oil

• Alberto Pagani,
• Simone Gaeta,
• Andrei I. Savchenko,
• Craig M. Williams and
• Giovanni Appendino

Beilstein J. Org. Chem. 2017, 13, 1361–1367, doi:10.3762/bjoc.13.133

• of the oil, especially in association to phenol [3]. The extraordinarily obnoxious and vesicant properties of croton oil have fostered studies aimed at the identification of its active principles since the very early developments of organic chemistry. Thus, the first chemical study on croton oil was

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• ]. Concurrently, biomimetic computational evolution, feature identification, and learning methods are being developed to solve complex problems in science, medicine and engineering. Many of these new and very useful metaheuristic methods, such as ant colony optimization, agent-based, evolutionary [5][6], and

• analogous way. This facilitates the development of models with higher predictive performance and the identification of the factors that have the most influence over the property being modelled, leading to clearer interpretation of the structure–activity relationships represented by the model. This

Characterization of non-heme iron aliphatic halogenase WelO5* from Hapalosiphon welwitschii IC-52-3: Identification of a minimal protein sequence motif that confers enzymatic chlorination specificity in the biosynthesis of welwitindolelinones

• Qin Zhu and
• Xinyu Liu

Beilstein J. Org. Chem. 2017, 13, 1168–1173, doi:10.3762/bjoc.13.115

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

• based on the fold of the proteins, allowed the identification of 14 main clans (Figure 10). Carbohydrate binding modules: Carbohydrate binding modules (CBM) are defined as a sequence of contiguous amino acids within a carbohydrate-active enzyme with a discrete fold having carbohydrate-binding activity

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• efforts, the GAuNPs showed an incremented lectin identification power, at low protein concentrations, enabling an easy tool for sugar–lectin recognition. The glycan–protein interaction has been studied as well employing surface-enhanced Raman spectroscopy (SERS) exploiting AuNP ability in amplifying Raman

• on the identification of sugar epitopes of the surface envelope glycoprotein of HIV-1, capable of eliciting a protective response. GAuNPs coated with high-mannose type oligosaccharide of HIV-1 gp120, were prepared as glycoconjugate systems able to mimic the natural presentation of gp-120 high-mannose

• indeed promising vector systems to explore vaccination against infectious diseases. Recently, a study on the identification of an optimal vaccine formulation to protect against listeriosis, proposed the use of GAuNPs loaded with glucose and the LLO91-98 Listeria peptide antigen as a system to target DCs

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• understand the flow of processes and associated measurement instruments. The P&ID includes engineering details of equipment, instruments, piping, valves, fittings and their arrangements. It may also include identification numbers for the equipment, pipelines, pumps, and other auxiliary equipment. The most

Use of costic acid, a natural extract from Dittrichia viscosa, for the control of Varroa destructor, a parasite of the European honey bee

• Kalliopi Sofou,
• Demosthenis Isaakidis,
• Apostolos Spyros,
• Anita Büttner,
• Athanassios Giannis and
• Haralambos E. Katerinopoulos

Beilstein J. Org. Chem. 2017, 13, 952–959, doi:10.3762/bjoc.13.96

• ]. However, there are no preceding data on the action of costic acid against varroa. In this publication we report the isolation and structure identification of costic acid as a component of D. viscosa, as well as in vivo and field studies providing strong evidence of the acaricidal action of the acid

• to commercial acaricides. None of the above mentioned trials caused the death of treated bees. Identification of the active component. Spectroscopic data of the active component of D. viscosa indicated that it was a known compound, with the common name costic acid. A literature search indicated that

• there were discrepancies in the reported 13C NMR spectral data of costic acid [36][37][38] and given the importance of the compound in our biological studies, we decided to perform a full spectroscopic identification of the compound which is briefly described as follows: IR spectroscopy clearly

Expression, purification and structural analysis of functional GABA transporter 1 using the baculovirus expression system

• Jing Hu,
• Chris Weise,
• Christoph Böttcher,
• Hua Fan and
• Jian Yin

Beilstein J. Org. Chem. 2017, 13, 874–882, doi:10.3762/bjoc.13.88

• masses were determined by calibration with the PAC peptide calibrant standard. All solutions and buffers used were prepared with sterile pure high-performance LC (HPLC)-grade water (Milli-Q® Water filter apparatus, Millipore) in order to avoid contaminations. Evaluation and identification of the mass

• spectra were performed using the Internet search software Mascot [35]. Purification of GAT1 and protein identification Isolation of GAT1/GFP by the immunoaffinity column The immunoaffinity column was prepared as followed: 200 µL Affi-gel 10 protein-A-sepharose (Amersham Pharmacia, Sweden) were loaded on a

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

• mutations of MvCPS1, W323L:F505Y, and W323F:F505Y completely changed the product specificity towards a novel, so far uncharacterized halimadane type diterpene [58] (Scheme 2). Combinatorial biosynthesis – enzyme design for manufactured terpenes Conventional identification of new enzyme activities involved

• the rapid identification of (di)terpenes. Andersen-Ranberg and co-workers reported recently on the creation of a synthetic collection of monofunctional Class I/Class II diterpene synthase combinations, which lead to high stereoselective syntheses of an impressive number of previously unknown or

• ], sclareol [69] and cis-abienol [64]. A biosynthesis study of salvinorin A (a psychotrophic agent with potential application as neuropsychiatric drug and for addiction treatment) in Salvia divinorum [70] resulted in the identification of five new Class I and Class II diterpene synthases. Moreover, this study

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• -, β- and γ-CD-LA products are shown in Supporting Information File 1, Figure S1. The nature of the separated compounds was partially confirmed by "off line" MALDI–MS measurements of the eluted fractions. Full MALDI–MS identification of all collected LC fractions for α-, β- and γ-CD-LA and LC ELSD

• chromatograms are shown in Supporting Information File 1, Figures S3–S21. Based on the MALDI–MS identification, the main chromatographic peak in Figure 1a has been assigned to free β-CD (fraction f1) while the other eluted species are β-CD-LA having from 1 to 27 monomer units (dilactate), fractions f2–f6

• (elution times: f2 – 3–5 min, f3 – 9–11 min, f4 – 11–13 min, f5 – 13–15 min, f6 – 15–17 min and f7 – 17–19 min). In Figure 1b the MALDI–MS identification of chromatographic peaks for the β-CD-LA sample, chromatographic fraction f5 eluted between 13 and 15 minutes, is exemplified. In the MS spectrum, the

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• ]. In this approach, an optimized catalyst was designed by the integration of the catalyst performances at increasing length scales, from the nanoscale (active metal nanoparticles), to the mesoscale (support) and macroscale (reactor). Thus, after identification of the optimal shape and size of PdNP for

• hours continuous runs (333 K, 1 bar H2). A perusal of Table 1 shows that identification of the most versatile partial hydrogenation flow system for terminal alkynes, either catalyst or reactor, is prevented by significant substrate specificity, lack of experimental data or choice of parameter to be