Remarkable functions of sn-3 hydroxy and phosphocholine groups in 1,2-diacyl-sn-glycerolipids to induce clockwise (+)-helicity around the 1,2-diacyl moiety: Evidence from conformation analysis by ¹H NMR spectroscopy

• Yoshihiro Nishida,
• Mengfei Yuan,
• Kazuo Fukuda,
• Kaito Fujisawa,
• Hirofumi Dohi and
• Hirotaka Uzawa

Beilstein J. Org. Chem. 2017, 13, 1999–2009, doi:10.3762/bjoc.13.196

• of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan 10.3762/bjoc.13.196 Abstract Cell-membrane glycerolipids exhibit a common structural backbone of asymmetric 1,2-diacyl-sn-glycerol bearing polar head groups in the sn-3 position. In this study, the possible

• ; deuterium labeling; sn-glycerol; glycerolipids; glycerophospholipids; helicity; Karplus equation; proton NMR spectroscopy; staggered conformers; Introduction Glycerophospholipids, constituting the basic elements of cytoplasm bilayer membranes, are responsible for several cell functions [1][2][3]. These

• chiral biomolecules have an asymmetric sn-glycerol backbone. Although sn-glycerol is symmetric, an sn-3 phosphate group makes it chiral with an (R)-configuration at the sn-2 position [4]. Such molecular chirality is crucial to not only their biological activities but also for their metaphysical

Sustainable synthesis of 3-substituted phthalides via a catalytic one-pot cascade strategy from 2-formylbenzoic acid with β-keto acids in glycerol

• Lina Jia and
• Fuzhong Han

Beilstein J. Org. Chem. 2017, 13, 1425–1429, doi:10.3762/bjoc.13.139

• phthalides in good to excellent yields. Conclusion: A concise and efficient synthesis strategy of 3-substituted phthalides from 2-formylbenzoic acid and β-keto acids via a catalytic one-pot cascade reaction in glycerol has been accomplished. Keywords: β-keto acid; decarboxylation; glycerol; one-pot cascade

• straightforward method for the preparation of several biologically active compounds of medicinal and agrochemical interest [23][24][25][26][27][28][29][30]. Notably, the decarboxylative reaction of β-keto acids provides a traceless means of activation with CO2 as the only byproduct. On the other hand, glycerol

• transformations have been accomplished using glycerol as a solvent [32][33][34][35][36][37][38][39][40]. Therefore, as part of our ongoing research interest in exploring novel and sustainable transformations of β-keto acids [41][42], we envisioned that the direct utilization of β-keto acids as nucleophilic

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 phorbol from the transesterification reaction mixture, a viscous oil for the presence of glycerol, that requires extended periods (four weeks according to ref. [6]). Furthermore, the unstable ethanol solvate has to be transformed into a more stable hydrate by recrystallization from hot water, a

• glycerol obtained after hydrolysis of the oil and washing with organic solvents must be evaporated with care, maintaining an acidic pH to minimize epimerization to 4α-phorbol [19]. Next, the recovery of phorbol from the resulting ca 10% solution of phorboids in glycerol is difficult under both normal- and

• reverse-phase silica gel chromatography, that fail to separate phorbol from 4α-4-deoxyphorbol (3a) because of their similar chromatographic behavior and of the presence of glycerol. As a result, the week-long crystallization from water was still necessary [19], a process that, tediousness aside, we found

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

• ‘trigger-freeze” approach consists in the use of various soaking times for the crystal with substrate sugars in presence of H2O or glycerol (“trigger step”) followed by the freezing step ranging from a few minutes to several hours. The use of a “freeze-trigger” approach solves the synchronization issue but

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

• atomic composition of matter: N for nitrogen, Fe, for iron, C for carbon). Thus a chemical molecule is information-rich. sn-Glycerol-3-phosphate can be described, including an outline of its three-dimensional configuration, by a limited alphabet of symbols (e.g., the Simplified Molecular Input Line Entry

• Specification (SMILES) code table [8]), C([C@H](COP(=O)(O)O)O)O, while its mirror symmetry sn-glycerol-1-phosphate is summarised as C([C@@H](COP(=O)(O)O)O)O. That this coding is sufficient (if associated to a concrete machine) is visible in Figure 1, where I used these codes with an algorithm to generate the

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• behaviour; nanofibres; self-assembly; Introduction Bolalipids are amphiphilic molecules consisting of two hydrophilic headgroups attached to both ends of a long hydrocarbon spacer [1]. The hydrophobic spacer is composed of either a single alkyl chain or two chains connected via a glycerol moiety. These

• in the chemical structure of those archaeal membrane lipids: the alkyl chains are connected via ether linkages in the inverse sn-2,3 configuration to the glycerol, the alkyl chains sometimes contain a varying number of cyclopentane rings or several methyl branches [2][3], and some of the archaeal

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• ]. It was found that irradiation times of 14 min could be employed to afford CDs from glycerol, glycol, glucose or sucrose. The source of the inorganic ion was important too, as increasing the valency of either the anion or cation would lead to a greater ability to dehydrate the carbon precursor. An

• improved materials with high QYs. Non-glucose monosaccharide-based fluorescent carbon dots In addition to glucose, different monosaccharides and polyols have also been utilised as carbon sources for the synthesis of FCD, although this approach is less common. The ability of glycerol to undergo dehydration

• and polymerisation in the presence of amino groups makes it a cheap and suitable candidate as a molecular precursor for CD synthesis. To that end, Liu et al. demonstrated in 2011 that the microwave-assisted pyrolysis of glycerol in the presence of TTDDA afforded blue-emissive CDs with a QY of 12

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

• Enjuro Harunari,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

• a rotary shaker (200 rpm) at 30 °C for 4 days. Then, the seed culture (3 mL) was transferred into 500 mL K-1 flasks each containing 100 mL of the A-3M production medium consisting of soluble starch 2.0%, glycerol 2.0%, glucose 0.5%, Pharmamedia (Traders Protein) 1.5%, yeast extract 0.3%, and Diaion

Poly(ethylene glycol)s as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins

• Andrea Mascitti,
• Massimiliano Lupacchini,
• Ruben Guerra,
• Ilya Taydakov,
• Lucia Tonucci,
• Nicola d’Alessandro,
• Frederic Lamaty,
• Jean Martinez and
• Evelina Colacino

Beilstein J. Org. Chem. 2017, 13, 19–25, doi:10.3762/bjoc.13.3

• the polymer chain length. After selecting the optimal polymer amount (450 mg mmol−1), the study was carried on by increasing (Table 1, entry 11) or reducing (Table 1, entries 12 and 13) the polymer chain length, changing the end terminal substituents (Table 1, entries 6 vs 3), and adding glycerol

• reactants. Decreased and comparable yields were also observed by reducing the PEG chain length (Table 1, entry 13) and by using glycerol. It is also worth noting here that not only viscosity, but any modification of the physical state of the system impacted the outcome of the reaction. Indeed, HO-PEG-600-OH

• (0.119 cSt) led to comparable yields when replaced by a more viscous liquid like glycerol (1.12 cSt) (Table 1, entry 14), an eco-friendly solvent still not investigated for liquid-assisted grinding procedures. In fact such a compound is becoming a green source of several building blocks since glycerol is

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

• -function relationship of StaF, we attempted to structurally characterise the protein. We were able to determine the crystal structure of StaF to a resolution of 2.1 Å and 2.2 Å using different cryo-protectant solutions (ethylene glycol and glycerol) and by solving the phase problem through molecular

• (≈150 µm length) had formed. The crystals were passed through a cryoprotectant solution (0.1 M phosphate/citrate buffer (pH 4.2), 1.2 M Na2PO4, 0.3 M K2HPO4 and either 25% (v/v) glycerol, or 25% (v/v) ethylene glycol) and then flash cooled in liquid nitrogen for data collection. Two native data sets

• building and refinement were performed using the programs COOT [54] and REFMAC [55] with TLS refinement [56] following a simulated annealing performed in CNS [57][58]. During several rounds of refinement with REFMAC and manual rebuilding, ethylene glycol or glycerol and solvent molecules were included in

Formose reaction controlled by boronic acid compounds

• Toru Imai,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2668–2672, doi:10.3762/bjoc.12.263

• six-carbon sugar alcohols (ethylene glycol, glycerol, erythritol, D-arabinitol, and D-mannitol, respectively) (Figure 2a). In Figure 2b–d, the signals at ca. 5 min may be due to impurities, e.g., inorganic salts. As can be seen in Figure 2b, the HPLC chart for the formose reaction in the absence of

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• , 0.5 M imidazole, 1 mM MgCl2, pH 7.0) and used directly for incubations with 5 mg of (1R)- and (1S)-(1-2H)GPP, solved in incubation buffer (50 mM Tris/HCl, 10 mM MgCl2, 20% v/v glycerol, pH 8.2) to reach a final substrate concentration of 0.2 mg/mL. The enzyme reaction was incubated for 2 h at 28 h

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• compounds substituted the ones that have not received a great research interest. However, among the original selected chemicals, D-sorbitol, together with ethanol and glycerol, still occupy top positions as they encompass all of the desired criteria for bio-based platform compounds. D-Sorbitol, namely 1,4

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• (Scheme 2) [15][16]. The reaction allows obtaining FAMEs and fatty acid glycerol carbonate monoesters (FAGCs), without the concurrent formation of glycerol, a frequently formed highly undesirable byproduct. Enzyme catalysts: A major driving force for the choice of enzymes is their high efficiency, which

• -value chemicals. This holds true also for enzyme-catalyzed transesterification reactions. To cite a few examples, the literature claims the use of lipase as a biocatalyst for i) the reaction of glycerol with DMC for the synthesis of glycerol carbonate (GlyC) under solvent-free conditions. A 60% yield

• ., glycerol) to produce the expected transesterification products with total conversion and selectivity. Ionic liquid-based organocatalysts Conventional acid or base liquid catalysts for transesterification processes often entail several synthetic and environmental concerns including equipment corrosion

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• spin systems for glycerol (Gro) derived from the 2-substituted Xyl and manno (Rha)- and galacto (Fuc)-configurated monosaccharides (Scheme 1). The spectra of compound 2 also showed signals for a methyl group (δH 3.47–3.48, δC 59.9). The values of 13C NMR chemical shifts of the C-5 signals of Rha and

• (S) in 1% AcOH to yield an OS 3 (3 mg). Structures of the OPS from A. halopraeferens Au4 and oligosaccharides obtained from the OPS by Smith degradation (1 and 2) and solvolysis (3). Gro indicates glycerol. 1H and 13C NMR chemical shifts of the oligosaccharides derived from the OPS from A

• . halopraeferens Au4 by Smith degradation (1 and 2) and solvolysis with CF3CO2H (3).a Gro indicates glycerol. 1H and 13C NMR chemical shifts of the OPS from A. halopraeferens Au4.a Supporting Information Supporting Information File 238: 1H and 13C NMR spectroscopy data of the O-specific polysaccharide and of the

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• marinus, which folded with the aid of E. coli protein chaperones (GroEL/GroES) [83]. This resulted in catalysis of CO2 fixation and increase of carbon flux towards the ethanol product and away from glycerol, a major fermentation byproduct (Figure 3). Synthesis of dicarboxylates through pyruvate

Engineering Pichia pastoris for improved NADH regeneration: A novel chassis strain for whole-cell catalysis

• Martina Geier,
• Christoph Brandner,
• Gernot A. Strohmeier,
• Mélanie Hall,
• Franz S. Hartner and
• Anton Glieder

Beilstein J. Org. Chem. 2015, 11, 1741–1748, doi:10.3762/bjoc.11.190

• knock-out strains In a first step, the generated das knock-out strains were characterized by determining their specific growth rate on different carbon sources. As expected, the growth of the single and double knock-out strains on D-glucose and glycerol was not significantly impaired, showing growth

• mg/L biotin supplemented either with 2% (w/v) D-glucose (BMD), 1% (w/v) glycerol (BMG) or 0.5% (v/v) methanol (BMM). Growth rates of the generated das knock-out strains were determined by measuring the optical density (OD600) of cultures in biological triplicate during the exponential growth phase

Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions

• Paul P. Kelly,
• Anja Eichler,
• Susanne Herter,
• David C. Kranz,
• Nicholas J. Turner and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2015, 11, 1713–1720, doi:10.3762/bjoc.11.186

• libraries I–VII and the Tyr96Phe parent with A) ethylbenzene (5), B) the para-methylated derivative 6 and C) the para-brominated derivative 7. Reaction conditions: 180 mg/mL cells, 1 mM substrates, 50 mM sodium phosphate buffer (pH 7.2, 100 mM KCl, 0.4% glycerol (v/v)), 20 °C, 250 rpm, 48 h. Product yields

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• activated 2,2,2-trichloroethyl diester of (±)-3,4-epoxyadipic acid. The stereoselectivity of porcine pancreatic lipase discriminated between the two enantiomers and afforded the chiral (−)-polyester with molecular weight of 7900 Dalton (Figure 9). Yang et al. compared the polymerization of glycerol and a

• . Polyesters containing epoxy moieties. Biocatalyzed synthesis of polyesters containing glycerol. Iataconic (34) and malic (35) acid. Oxidized poly(hexanediol-2-mercaptosuccinate) polymer. C-5-substituted isophthalates. Curcumin-based polyesters. Silylated polyesters. Polyesters containing reactive ether

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• bearing a G1 glycerol dendron tail was also prepared for comparison with the multivalent systems 4a–c and evaluation of the possible presence of cooperative effects (Scheme 1). Polyglycerol 1 (Mn = 9000 g/mol, loading OH = 13.5 mmol/g, PDI = 1.87) was obtained following a previously reported procedure by

Exploring monovalent and multivalent peptides for the inhibition of FBP21-tWW

• Lisa Maria Henning,
• Sumati Bhatia,
• Miriam Bertazzon,
• Michaela Marczynke,
• Oliver Seitz,
• Rudolf Volkmer,
• Rainer Haag and
• Christian Freund

Beilstein J. Org. Chem. 2015, 11, 701–706, doi:10.3762/bjoc.11.80

• literature [19]. The transformation started from the mesylation of the hydroxy groups on the hPG. In the next step, the mesylated polyglycerol was converted to poly(glycerol azide). In the last step, azide functionalities (N3) were reduced to primary amines (-NH2) via Staudinger reduction to obtain the

An integrated photocatalytic/enzymatic system for the reduction of CO₂ to methanol in bioglycerol–water

• Michele Aresta,
• Angela Dibenedetto,
• Tomasz Baran,
• Antonella Angelini,
• Przemysław Łabuz and
• Wojciech Macyk

Beilstein J. Org. Chem. 2014, 10, 2556–2565, doi:10.3762/bjoc.10.267

• regeneration process is enhanced by using a Rh(III)-complex for facilitating the electron and hydride transfer from the H-donor (water or a water–glycerol solution) to NAD+. This resulted in the production of 100 to 1000 mol of CH3OH from one mol of NADH, providing the possibility for practical application

• was evidenced by measuring the amount of photogenerated 1,4-NADH using water or water/glycerol as electron donor. Figure 3b illustrates the results of the photocatalytic regeneration of NADH in presence of various materials after 6 hours of irradiation. Interestingly, for [CrF5(H2O)]2−@TiO2 the yield

• rhodium complex (according to Equation 1), is thus thermodynamically feasible. The photogenerated holes can regain electrons via the oxidation of glycerol. The reduced complex (Rh(I)) reacts with a proton yielding a Rh(III)-hydrido species (Equation 2). The resulting Rh-hydrido-species transfers the

Synthesis of phosphoramidites of isoGNA, an isomer of glycerol nucleic acid

• Keunsoo Kim,
• Venkateshwarlu Punna,
• Phaneendrasai Karri and
• Ramanarayanan Krishnamurthy

Beilstein J. Org. Chem. 2014, 10, 2131–2138, doi:10.3762/bjoc.10.220

• Keunsoo Kim Venkateshwarlu Punna Phaneendrasai Karri Ramanarayanan Krishnamurthy Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037, USA 10.3762/bjoc.10.220 Abstract IsoGNA, an isomer of glycerol nucleic acid GNA, is a flexible (acyclic

• the adenine derivative. The synthetic improvements described here enable an easy access to isoGNA and allows for the further exploration of this structural unit in oligonucleotide chemistry thereby spurring investigations of its usefulness and applicability. Keywords: acyclic nucleic acids; glycerol

• recently reported on the base-pairing properties of isoGNA, an isomer of glycerol derived nucleic acid (Figure 1) [8]. Our motivation was driven by the question “how structurally simple and minimal can an oligonucleotide be and still exhibit base-pairing?” When we studied isoGNA we were surprised to find

Postsynthetic functionalization of glycodendrons at the focal point

• Thisbe K. Lindhorst and
• Katharina Elsner

Beilstein J. Org. Chem. 2014, 10, 1482–1487, doi:10.3762/bjoc.10.152

• for incorporation into lipid bilayers, the di- and tetravalent glycodendrons 6 and 9 were then cross-coupled with the mono-allylated glycerol triether 22 (Scheme 4). The alkene 22 can be derived from commercially available glycerolmonoallyl ether according to the literature [15]. Metathesis with the

• divalent glycodendron 6 led to the desired product 23 as cis/trans mixture in 38% yield, while the glycerol ether dimer was obtained as the main product (not shown). The analogous result was obtained with the tetravalent glycodendron 9 leading to the hetero-cross coupling product 24 as the minor and the

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38