Co-solvation effect on the binding mode of the α-mangostin/β-cyclodextrin inclusion complex

• Chompoonut Rungnim,
• Sarunya Phunpee,
• Manaschai Kunaseth,
• Supawadee Namuangruk,
• Kanin Rungsardthong,
• Thanyada Rungrotmongkol and
• Uracha Ruktanonchai

Beilstein J. Org. Chem. 2015, 11, 2306–2317, doi:10.3762/bjoc.11.251

• shaking incubator (Vision Scientific Co., Ltd., Korean) at 25 °C for 48 h to ensure equilibrium was reached. The samples were then passed through a 0.45 µm Nylon filter, and the concentration of dissolved α-mangostin was determined by high-performance liquid chromatography, HPLC, (Waters, model e2695, USA

Qualitative evaluation of regioselectivity in the formation of di- and tri-6-O-tritylates of α-cyclodextrin

• Keisuke Yoshikiyo,
• Yoshihisa Matsui and
• Tatsuyuki Yamamoto

Beilstein J. Org. Chem. 2015, 11, 1530–1540, doi:10.3762/bjoc.11.168

• ,6C-di-O-trityl-α-CD’s. Keywords: 1H and 13C NMR spectroscopy; quantitative analysis; regioselectivity; tritylation; ultra-fast liquid chromatography (UFLC); Introduction Regioselective modification and deprotection on the primary hydroxy side of cyclodextrins (CDs) are of great importance in

• direction of literature [9], and separated by means of reversed-phase column chromatography. Three regioisomers of di-6-O-trityl-α-CD obtained gave well-separated peaks in UFLC (ultra-fast liquid chromatography) experiment (Figure 1), details of which will be described in the Experimental part. Four

• pyridine was dried over CaH2 and distilled in the presence of CaH2 before use. N,N-Dimethylformamide (DMF) was also dried over CaH2 and distilled before use. Acetonitrile for high performance liquid chromatography was purchased from Wako Pure Chemical Industries Ltd. DMSO-d6 containing 0.05% v/v

Synthesis and evaluation of the biostability and cell compatibility of novel conjugates of nucleobase, peptidic epitope, and saccharide

• Dan Yuan,
• Xuewen Du,
• Junfeng Shi,
• Ning Zhou,
• Abdulgader Ahmed Baoum,
• Khalid Omar Al Footy,
• Khadija Omar Badahdah and
• Bing Xu

Beilstein J. Org. Chem. 2015, 11, 1352–1359, doi:10.3762/bjoc.11.145

• chain from the resin with 95% trifluoroacetic acid (TFA) without N-protecting groups. Later, NAS was obtained by reacting D-glucosamine hydrochloride with the fully protected NA. After cleaving the protecting group on amino acids with 95% TFA, we used reversed-phase high-performance liquid

• chromatography (HPLC) to purify the target conjugates. Gelation properties Supramolecular hydrogels [18][19][20][21][22][23][24] formed by self-assembly of small molecules in water, as demonstrated previously by us and other researchers, have numerous potential applications, such as encapsulation and delivery of

Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines

• Carolin Edinger,
• Jörn Kulisch and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 294–301, doi:10.3762/bjoc.11.34

• applications reported so far, are the uses as building blocks in supramolecular receptors [29][30][31][32][33][34] or the synthesis of high-performance stationary phases for liquid chromatography [35][36][37][38]. (−)-Menthone (2) can be converted to menthylamine by different methods: A general way to convert

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

• liquid chromatography (HPLC) analysis using a Chiralcel OD-H column. The products could be analyzed directly from the crude mixture since the conditions of the HPLC chiral stationary phases were adjusted to the needs of both resolution products (peaks of the alcohol and the acetate enantiomers were well

A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

• Stefanie Wolfram,
• Hendryk Würfel,
• Stefanie H. Habenicht,
• Christine Lembke,
• Phillipp Richter,
• Eckhard Birckner,
• Rainer Beckert and
• Georg Pohnert

Beilstein J. Org. Chem. 2014, 10, 2470–2479, doi:10.3762/bjoc.10.258

• samples. Several probes have been designed for use with liquid chromatography–mass spectrometry (LC–MS). The probes attach covalently to target functional groups like amines, aldehydes/ketones, carboxylic acids and enhance their detection limit in LC–electrospray ionization (ESI) MS. This can be achieved

• ., for biological applications. In contrast, the quantum yield of BNS (6) in 80% water/20% THF (v/v) was below 0.03 and rendering it inappropriate for this purpose. The UV properties allow UV detection after LC separation as could be shown by ultra-performance liquid chromatography (UPLC) coupled to a

New highlights of the syntheses of pyrrolo[1,2-a]quinoxalin-4-ones

• Emilian Georgescu,
• Alina Nicolescu,
• Florentina Georgescu,
• Florina Teodorescu,
• Daniela Marinescu,
• Ana-Maria Macsim and
• Calin Deleanu

Beilstein J. Org. Chem. 2014, 10, 2377–2387, doi:10.3762/bjoc.10.248

• are uncorrected. The IR spectra were recorded on a Nicolet Impact 410 spectrometer, in KBr pellets. The high performance liquid chromatography (HPLC) analyses were performed with an Agilent Chromatograph 1200 Series at room temperature by isocratic elution of acrylonitrile on an Agilent Zorbax SB-C18

Expanding the scope of cyclopropene reporters for the detection of metabolically engineered glycoproteins by Diels–Alder reactions

• Anne-Katrin Späte,
• Verena F. Schart,
• Julia Häfner,
• Andrea Niederwieser,
• Thomas U. Mayer and
• Valentin Wittmann

Beilstein J. Org. Chem. 2014, 10, 2235–2242, doi:10.3762/bjoc.10.232

• and, when feasible, assignments were supported by two-dimensional 1H,1H and 1H,13C correlation spectroscopy (COSY, HMBC and HSQC). HRMS mass spectra were obtained with a micrOTOF II instrument from Bruker Daltonics. Semi-preparative high performance liquid chromatography (HPLC) was conducted on a LC

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• File 1). Characterization of the photoswitchable properties The photochromic behavior of the newly synthesized AZO-glycooligomers was investigated by UV–vis absorption spectroscopy and ultraperformance liquid chromatography (UPLC). Aqueous solutions of Azo-Gal(1,3)-3 and Azo-Gal(1,3,5)-5 (the compounds

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

• Fabrizio Chiodo,
• Marco Marradi,
• Javier Calvo,
• Eloisa Yuste and
• Soledad Penadés

Beilstein J. Org. Chem. 2014, 10, 1339–1346, doi:10.3762/bjoc.10.136

• containing ABC or 3TC (around 10%) in 1 N HCl at different times by liquid chromatography–mass spectrometry (LC–MS, Figure 2). A solution of drugs-GNPs (2 mg/mL) in water was treated with 1 N HCl and 1:1000 dilution aliquots (10 μL) of the GNP solutions were injected into the chromatograph. The free drugs

Chromatographically separable rotamers of an unhindered amide

• Mario Geffe,
• Lars Andernach,
• Oliver Trapp and
• Till Opatz

Beilstein J. Org. Chem. 2014, 10, 701–706, doi:10.3762/bjoc.10.63

• .10.63 Abstract Surprisingly stable formamide rotamers were encountered in the tetrahydroisoquinoline and morphinan series of alkaloids. We investigated the hindered rotation around the amide bond by dynamic high-performance liquid chromatography (DHPLC) and kinetic measurements of the interconversion of

• . Therefore, dynamic high-performance liquid chromatography (DHPLC) [8][9][10] was performed at temperatures between 20 °C and 55 °C. The obtained elution profiles were characterized by distinct plateau formation between the well separated peaks of the Z- and E-rotamers (first and later eluted isomer

New sesquiterpene hydroquinones from the Caribbean sponge Aka coralliphagum

• Qun Göthel and
• Matthias Köck

Beilstein J. Org. Chem. 2014, 10, 613–621, doi:10.3762/bjoc.10.52

• ) and purified by liquid chromatography using RP-18 silica gel with a stepwise gradient from H2O/MeOH (100:0), (85:15), (50:50) to (0:100) yielding fractions A, B, C, and D, respectively. The fraction B was further purified by HPLC using an RP-18 column yielding compounds 1 (2.2 mg, HPLC gradient flow

Organocatalytic asymmetric fluorination of α-chloroaldehydes involving kinetic resolution

• Kazutaka Shibatomi,
• Takuya Okimi,
• Yoshiyuki Abe,
• Akira Narayama,
• Nami Nakamura and
• Seiji Iwasa

Beilstein J. Org. Chem. 2014, 10, 323–331, doi:10.3762/bjoc.10.30

• performed with a Yanaco CHN CORDER MT-6. High-performance liquid chromatography (HPLC) analyses were performed with a JASCO PU-1586 with a UV-1575 UV–vis detector using a chiral column. GC analysis was performed with a Shimadzu model 2014 instrument. Optical rotations were measured on a JASCO P-1030

Decandrinin, an unprecedented C₉-spiro-fused 7,8-seco-ent-abietane from the Godavari mangrove Ceriops decandra

• Hui Wang,
• Min-Yi Li,
• Félix Zongwe Katele,
• Tirumani Satyanandamurty,
• Jun Wu and
• Gerhard Bringmann

Beilstein J. Org. Chem. 2014, 10, 276–281, doi:10.3762/bjoc.10.23

• , Qingdao Mar. Chem. Ind. Co. Ltd.) and RP C18 gel (YMC) were used. High-performance liquid chromatography (HPLC) was performed on a Shimadzu LC-6AD controller with an SPD-20A UV–vis detector equipped with YMC-Pack ODS-A columns (250 × 10 mm i.d., 5 μm and 250 × 4.6 mm i.d., 5 μm). Plant material As

Synthesis and biological activity of N-substituted-tetrahydro-γ-carbolines containing peptide residues

• Nadezhda V. Sokolova,
• Valentine G. Nenajdenko,
• Vladimir B. Sokolov,
• Daria V. Vinogradova,
• Elena F. Shevtsova,
• Ludmila G. Dubova and
• Sergey O. Bachurin

Beilstein J. Org. Chem. 2014, 10, 155–162, doi:10.3762/bjoc.10.13

• . Deuterated solvent peaks were used as internal references: CDCl3 at 7.25 and 77.00 ppm. 19F chemical shifts are reported on δ scale (in ppm) downfield from CF3COOH. Liquid chromatography was performed using Fluka silica gel 60 (0.063–0.200 mm). Melting points were determined with an Electrothermal IA9100

Physalin H from Solanum nigrum as an Hh signaling inhibitor blocks GLI1–DNA-complex formation

• Midori A. Arai,
• Kyoko Uchida,
• Samir K. Sadhu,
• Firoj Ahmed and
• Masami Ishibashi

Beilstein J. Org. Chem. 2014, 10, 134–140, doi:10.3762/bjoc.10.10

• steps of silica gel column chromatography, and reversed-phase high-performance liquid chromatography (HPLC) of the active EtOAc extracts of fraction 1A and 1B yielded physalin H (1) [23], physalin G (2) [24], physalin K (3) [25], isophysalin B (4) [26], physalin F (5) [27] and a mixture of physalin B (6

Synthesis and determination of the absolute configuration of (−)-(5R,6Z)-dendrolasin-5-acetate from the nudibranch Hypselodoris jacksoni

• I. Wayan Mudianta,
• Victoria L. Challinor,
• Anne E. Winters,
• Karen L. Cheney,
• James J. De Voss and
• Mary J. Garson

Beilstein J. Org. Chem. 2013, 9, 2925–2933, doi:10.3762/bjoc.9.329

• ) to give the individual 6E ((7a); 25.2 mg; tR = 50.0 min) and 6Z ((7b); 8.4 mg; tR = 40.0 min) isomers. Analytical enantioselective HPLC separation of the Z-isomer of 5-hydroxydendrolasin (7b) was performed on an Agilent 1200 series liquid chromatography system (isocratic conditions of 2% isopropanol

• the (±)-(6Z)-dendrolasin-5-acetate (1) racemic mixture, the individual 5R- and 5S-enantiomers of (6Z)-dendrolasin-5-acetate, and the natural sample of (−)-(5R,6Z)-dendrolasin-5-acetate, were performed using an Agilent 1200 series liquid chromatography system (isocratic conditions, 5% isopropanol in n

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• liquid chromatography (HPLC). However, the benzenes with three substituents, a 1,2,4- or 1,3,5-trisubstituted pattern, can be characterized by 1H NMR spectroscopy [55][56]. According to this method, we find that the 1H NMR peak of the 1,3,5-trisubstituted benzene isomer 4 appears at 6.83 ppm, for 5a at

New syntheses of 5,6- and 7,8-diaminoquinolines

• Maroš Bella and
• Viktor Milata

Beilstein J. Org. Chem. 2013, 9, 2669–2674, doi:10.3762/bjoc.9.302

• heterocycles. Experimental General. Thin-layer chromatography (TLC) was performed on aluminium plates precoated with 0.2 mm silica gel (25 μm) containing fluorescent indicator 254 nm (Fluka) and stains were visualised by UV light (254 nm or 366 nm). Flash liquid chromatography (FLC) was performed on silica gel

Studies on the photodegradation of red, green and blue phosphorescent OLED emitters

• Susanna Schmidbauer,
• Andreas Hohenleutner and
• Burkhard König

Beilstein J. Org. Chem. 2013, 9, 2088–2096, doi:10.3762/bjoc.9.245

• films. To gain information on the chemical degradation mechanisms, we tried to identify deterioration products by liquid chromatography mass spectrometry (LC–MS) and other analytical methods where applicable. Results and Discussion For our investigations, we chose the four iridium complexes depicted in

New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei

• Annamaria Sinisi,
• Barbara Calcinai,
• Carlo Cerrano,
• Henny A. Dien,
• Angela Zampella,
• Claudio D’Amore,
• Barbara Renga,
• Stefano Fiorucci and
• Orazio Taglialatela-Scafati

Beilstein J. Org. Chem. 2013, 9, 1643–1651, doi:10.3762/bjoc.9.188

• were determined with the HSQC experiment. Two and three bond 1H/13C connectivities were determined by gradient 2D HMBC experiments optimized for a 2,3J = 9 Hz. Medium-pressure liquid chromatography was performed on a Büchi apparatus by using a silica gel (230–400 mesh) column. HPLC was achieved on a

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO₄

• Leandro Lara de Carvalho,
• Robert Alan Burrow and
• Vera Lúcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

• dimensions of 2.0 cm ø × 15.0 cm. The overall cycloadditions were monitored by thin-layer chromatography (silica gel 60 F254 Merck® twice eluted with ethyl acetate/hexane 1:4 v/v) and the visualization was achieved by using iodine impregnated on silica gel or UV light (254 nm). Liquid chromatography was

Synthesis and evaluation of cell-permeable biotinylated PU-H71 derivatives as tumor Hsp90 probes

• Tony Taldone,
• Anna Rodina,
• Erica M. DaGama Gomes,
• Matthew Riolo,
• Hardik J. Patel,
• Raul Alonso-Sabadell,
• Danuta Zatorska,
• Maulik R. Patel,
• Sarah Kishinevsky and
• Gabriela Chiosis

Beilstein J. Org. Chem. 2013, 9, 544–556, doi:10.3762/bjoc.9.60

• = quartet, br = broad, m = multiplet), coupling constant (Hz), integration. High-resolution mass spectra were recorded on a Waters LCT Premier system. Low-resolution mass spectra were obtained on a Waters Acquity Ultra Performance LC with electrospray ionization and SQ detector. High-performance liquid

• chromatography analyses were performed on a Waters Autopurification system with PDA, MicroMass ZQ, and ELSD detector, and a reversed-phase column (Waters X-Bridge C18, 4.6 × 150 mm, 5 µm) using a gradient of (a) H2O + 0.1% TFA and (b) CH3CN + 0.1% TFA, 5 to 95% b over 13 minutes at 1.2 mL/min. All reactions were

Thermotropic and lyotropic behaviour of new liquid-crystalline materials with different hydrophilic groups: synthesis and mesomorphic properties

• Alexej Bubnov,
• Miroslav Kašpar,
• Věra Hamplová,
• Ute Dawin and
• Frank Giesselmann

Beilstein J. Org. Chem. 2013, 9, 425–436, doi:10.3762/bjoc.9.45

• purity of the compounds was checked by high performance liquid chromatography, which was carried out with an Ecom HPLC chromatograph by using a silica-gel column (Separon 7 μm, 3 × 150, Tessek) with a 98/2 mixture of toluene and methanol as eluent (typical flow rate 1 mL/min, retention times for

From bead to flask: Synthesis of a complex β-amido-amide for probe-development studies

• Kevin S. Martin,
• Cristian Soldi,
• Kellan N. Candee,
• Hiromi I. Wettersten,
• Robert H. Weiss and
• Jared T. Shaw

Beilstein J. Org. Chem. 2013, 9, 260–264, doi:10.3762/bjoc.9.31

• acid core was attached to Rink-amide resin and carried through to 1 by a series of elaboration and tagging steps [14][15]. Synthetic intermediates in this route were not characterized, and 1 was ultimately purified by high-performance liquid chromatography and partially characterized by matrix-assisted