Studies toward bivalent κ opioids derived from salvinorin A: heteromethylation of the furan ring reduces affinity

• Thomas A. Munro,
• Wei Xu,
• Douglas M. Ho,
• Lee-Yuan Liu-Chen and
• Bruce M. Cohen

Beilstein J. Org. Chem. 2013, 9, 2916–2924, doi:10.3762/bjoc.9.328

• after heating overnight at reflux. As an alternative linker attachment point, (2-hydroxyethoxy)methyl ether 6 was prepared from the known methylthiomethyl ether 7 using a slight modification of previous conditions (Scheme 2) [24]. Structure elucidation The molecular formula of 2 and 3 was established by

SF002-96-1, a new drimane sesquiterpene lactone from an Aspergillus species, inhibits survivin expression

• Silke Felix,
• Louis P. Sandjo,
• Till Opatz and
• Gerhard Erkel

Beilstein J. Org. Chem. 2013, 9, 2866–2876, doi:10.3762/bjoc.9.323

• µM (1.3 µg/mL). Moreover, it also reduced mRNA levels and protein synthesis of survivin and triggered apoptosis. Keywords: apoptosis; inhibitor; natural products; secondary metabolite; structure elucidation; survivin; Introduction Survivin, a member of the inhibitor of apoptosis (IAP) protein

• transiently transfected Colo 320 cells. In the current study, the fermentation, structure elucidation, and some biological properties of the compound are described. Results and Discussion Identification and structure elucidation SF002-96-1 was obtained by a bio-guided isolation procedure as a colourless oil

[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• to slow down all metabolic processes in living organisms. Potential applications of completely labelled compounds from natural sources in structure elucidation, biosynthetic or pharmacokinetic investigations are discussed. Keywords: biosynthesis; deuterium; labelling; natural products; Streptomyces

Halogenated volatiles from the fungus Geniculosporium and the actinomycete Streptomyces chartreusis

• Tao Wang,
• Patrick Rabe,
• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2767–2777, doi:10.3762/bjoc.9.311

• structure elucidation all possible constitutional isomers for X and Y were obtained by synthesis or from commercial suppliers. Comparison of mass spectra and GC retention times rigorously established the structures of the two chlorinated volatiles. Chlorinated volatiles are not very widespread, but

The myxocoumarins A and B from Stigmatella aurantiaca strain MYX-030

• Tobias A. M. Gulder,
• Snežana Neff,
• Traugott Schüz,
• Tammo Winkler,
• René Gees and
• Bettina Böhlendorf

Beilstein J. Org. Chem. 2013, 9, 2579–2585, doi:10.3762/bjoc.9.293

• The myxobacterial strain Stigmatella aurantiaca MYX-030 was selected as promising source for the discovery of new biologically active natural products by our screening methodology. The isolation, structure elucidation and initial biological evaluation of the myxocoumarins derived from this strain are

• described in this work. These compounds comprise an unusual structural framework and exhibit remarkable antifungal properties. Keywords: antifungal activity; myxobacteria; natural products; Stigmatella aurantiaca; structure elucidation; Introduction Despite declining interest of most big R&D-driven

• ) in relation to the non-treated control. Structures of epothilone A (1), soraphen A1α (2), pyrrolnitrin (3), fenpiclonil (4), myxothiazol A (5), and aurachin A (6). HMBC interactions used for the structure elucidation of myxocoumarin A (7). Chemical structure of myxocoumarin B (9). Postulated

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C₂-symmetric building block: a strategy for the synthesis of decanolide natural products

• Bernd Schmidt and
• Oliver Kunz

Beilstein J. Org. Chem. 2013, 9, 2544–2555, doi:10.3762/bjoc.9.289

• structure elucidation and for correcting erroneous assignments. In particular if ex-chiral pool starting materials with well established absolute configurations are used, such as D-mannitol-derived 1 or L-tartrate-derived ent-1, highly reliable structural assignments become possible. Two decanolides, for

Flexible synthesis of anthracycline aglycone mimics via domino carbopalladation reactions

• Markus Leibeling and
• Daniel B. Werz

Beilstein J. Org. Chem. 2013, 9, 2194–2201, doi:10.3762/bjoc.9.258

• have been isolated from bacteria of the order Streptomycetales. The group of Brockmann, who first found anthracyclines in 1963, described them as red to orange dyes [2]. Their structure elucidation revealed a linear fourfold annulated ring system including two benzene units (A-ring and C-ring). The

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• contains a benzoxepine ring system. The parent alkaloid (+)-cularine (138) was first isolated by Manske in 1938 [117], and its molecular skeleton was assigned on the basis of NMR and X-ray crystallographic studies. The structure elucidation revealed a twist-boat conformation of the dihydrooxepine ring [118

Structure elucidation of β-cyclodextrin–xylazine complex by a combination of quantitative ¹H–¹H ROESY and molecular dynamics studies

• Syed Mashhood Ali,
• Kehkeshan Fatma and
• Snehal Dhokale

Beilstein J. Org. Chem. 2013, 9, 1917–1924, doi:10.3762/bjoc.9.226

Lanostane- and cycloartane-type triterpenoids from Abies balsamea oleoresin

• Serge Lavoie,
• Charles Gauthier,
• Jean Legault,
• Sylvain Mercier,
• Vakhtang Mshvildadze and
• André Pichette

Beilstein J. Org. Chem. 2013, 9, 1333–1339, doi:10.3762/bjoc.9.150

• tetraterpenoids from the cortical oleoresin of the tree bark, featuring an unprecedented C40 scaffold [6]. Herein, we describe the further phytochemical study of A. balsamea oleoresin, which led to the isolation and structure elucidation of three 3,4-seco-lanostane-type triterpenoids 1–3, one cycloartane-type

A new synthetic access to 2-N-(glycosyl)thiosemicarbazides from 3-N-(glycosyl)oxadiazolinethiones and the regioselectivity of the glycosylation of their oxadiazolinethione precursors

• El Sayed H. El Ashry,
• El Sayed H. El Tamany,
• Mohy El Din Abdel Fattah,
• Mohamed R. E. Aly,
• Ahmed T. A. Boraei and
• Axel Duerkop

Beilstein J. Org. Chem. 2013, 9, 135–146, doi:10.3762/bjoc.9.16

• , the indolyloxadiazolone 20 was formed [33] whereas the expected deacetylated glycosides 17–19 were not obtained. Structure elucidation of 20 yielded a melting point of 271–273 °C [33], while literature reports give a value of 102 °C [41] or 285 °C [42]. Therefore, compound 20 was prepared in another

Identification and isolation of insecticidal oxazoles from Pseudomonas spp.

• Florian Grundmann,
• Veronika Dill,
• Andrea Dowling,
• Aunchalee Thanwisai,
• Edna Bode,
• Narisara Chantratita,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 749–752, doi:10.3762/bjoc.8.85

• peaks (Supporting Information File 1, Figure S1) that have not been detected in other entomopathogenic bacteria (data not shown). Subsequent large scale cultivation and purification of the main components led to the isolation of five major compounds, which were subjected to structure elucidation by MS

Synthesis of 2,6-disubstituted tetrahydroazulene derivatives

• Zakir Hussain,
• Henning Hopf,
• Khurshid Ayub and
• S. Holger Eichhorn

Beilstein J. Org. Chem. 2012, 8, 693–698, doi:10.3762/bjoc.8.77

• NMR spectrum (400 MHz, CDCl3) of 9 displays diastereotopic (syn and anti to the ester group) H-atoms at C(4), indicating that the ring-inversion process is still slow at the temperature of the measurement, but the observed dd signals already show some line broadening. Structure elucidation of

Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10

• Teresa Weise,
• Marco Kai,
• Anja Gummesson,
• Armin Troeger,
• Stephan von Reuß,
• Silvia Piepenborn,
• Francine Kosterka,
• Martin Sklorz,
• Ralf Zimmermann,
• Wittko Francke and
• Birgit Piechulla

Beilstein J. Org. Chem. 2012, 8, 579–596, doi:10.3762/bjoc.8.65

• information we carried out GC/MS and proton transfer reaction (PTR)–MS analyses with X. c. pv. vesicatoria 85-10. In addition, we aimed at structure elucidation and on temporal variation of profiles of volatiles produced upon growth on different media. Results and Discussion Effect of Xanthomonas campestris

• online PTR–MS during the incubation experiments cover about four orders of magnitude. The most abundant m/z values (M + H)+ were 59, 30, 33, 41, 43, 57, 71, 73 and higher masses such as 157, 171 and 185 (Figure 4). As PTR–MS only provides molecular mass information, an unambiguous structure elucidation

Synthesis of szentiamide, a depsipeptide from entomopathogenic Xenorhabdus szentirmaii with activity against Plasmodium falciparum

• Friederike I. Nollmann,
• Andrea Dowling,
• Marcel Kaiser,
• Klaus Deckmann,
• Sabine Grösch,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 528–533, doi:10.3762/bjoc.8.60

• ], xenematide [8] and the GameXPeptides [9]. Analysis of the genome sequences of the fully sequenced members of Xenorhabdus and Photorhabdus [10][11] has revealed that several additional compounds and especially even much larger compounds await isolation and structure elucidation. Recently, szentiamide (1) has

Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

• Martin Rempt,
• Florian Weinberger,
• Katharina Grosser and
• Georg Pohnert

Beilstein J. Org. Chem. 2012, 8, 283–289, doi:10.3762/bjoc.8.30

• curve was recorded on the LC–MS system by repeated (3 ×) injection of each standard. Analyte peaks were displayed by their pseudo-molecular-ion trace, and the peak areas were used for quantification. Structure elucidation of known metabolites. The identification of compounds 1–4 was achieved by

Polar tagging in the synthesis of monodisperse oligo(p-phenyleneethynylene)s and an update on the synthesis of oligoPPEs

• Dhananjaya Sahoo,
• Susanne Thiele,
• Miriam Schulte,
• Navid Ramezanian and
• Adelheid Godt

Beilstein J. Org. Chem. 2010, 6, No. 57, doi:10.3762/bjoc.6.57

• oligoPPEs. Supporting Information Supporting information features the syntheses of compounds used for the discussed experiments, the detailed experimental procedures, and the structure elucidation of the products from the iodination of 1,4-dihexylbenzene. Supporting Information File 78: Acknowledgements

• . Nevertheless, the reaction never went to completion: In all cases monoiodination product 11a was found (Scheme 5). Additionally, irrespective of which procedure was followed, the crude product always contained 1,4-dihexyl-2,3-diiodobenzene (12a) (ca. 3%), a constitutional isomer of 10a. The structure

• elucidation of these byproducts based on 1H NMR spectra is outlined in Supporting Information File 1. At least twofold recrystallization is needed to obtain material which contains less than 0.5% of these byproducts (as determined by 1H NMR spectroscopy. The 13C-satellites of the signal of the aromatic

Chemical synthesis using enzymatically generated building units for construction of the human milk pentasaccharides sialyllacto-N-tetraose and sialyllacto-N-neotetraose epimer

• Dirk Schmidt and
• Joachim Thiem

Beilstein J. Org. Chem. 2010, 6, No. 18, doi:10.3762/bjoc.6.18

• accessible selectively unprotected lactose acceptor glycosides the pentasaccharide structures sialyllacto-N-tetraose and the epimer of sialyllacto-N-neotetraose could be obtained in good yields, and subsequently transformed into their peracetylated derivatives for structure elucidation. Thus, a combination

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• work were reported [80]. Total synthesis of asiminocin McLaughlin’s group published a report on the isolation and structure elucidation of asiminocin (198), a C37 ACG with nearly one billion times the cytotoxic potency of a standard reference, adriamycin, as measured against breast carcinoma (MCF-7

Cimicifoetisides A and B, two cytotoxic cycloartane triterpenoid glycosides from the rhizomes of Cimicifuga foetida, inhibit proliferation of cancer cells

• Li-Rong Sun,
• Chen Qing,
• Yan-Li Zhang,
• Shu-Yu Jia,
• Zhong-Rong Li,
• Shen-Ji Pei,
• Ming-Hua Qiu,
• Michael L. Gross and
• Samuel X. Qiu

Beilstein J. Org. Chem. 2007, 3, No. 3, doi:10.1186/1860-5397-3-3

• -monosaccharide, along with seven known compounds, were isolated and were shown to exhibit potent cytotoxicity against two human cancer cell lines. This report describes the isolation, structure elucidation, and cytotoxicity evaluation of these isolates. 2. Results and discussions Cimicifoetiside A (1) (see

8-epi-Salvinorin B: crystal structure and affinity at the κ opioid receptor

• Thomas A. Munro,
• Katharine K. Duncan,
• Richard J. Staples,
• Wei Xu,
• Lee-Yuan Liu-Chen,
• Cécile Béguin,
• William A. Carlezon Jr. and
• Bruce M. Cohen

Beilstein J. Org. Chem. 2007, 3, No. 1, doi:10.1186/1860-5397-3-1

• later identified the byproduct mentioned above as 8-epi-diol 3.[15] Characterization data was given, but the basis of the structure assignment was not stated. The first structure elucidation of one of these compounds was of 8-epi-salvinorin A (1b).[16] The trans-diaxial H-8 coupling constant found in

Diastereoselective synthesis of some novel benzopyranopyridine derivatives

• Pradeep K. Mohakhud,
• Sujeet M. R. Kumar,
• Vasanth M. R. Kumar,
• Ravi M. R. Kumar,
• Moses D. R. Babu,
• Vyas D. R. K and
• Om D. R. Reddy

Beilstein J. Org. Chem. 2006, 2, No. 25, doi:10.1186/1860-5397-2-25

• determined as S,S by X-ray diffraction analysis (Figure 4) (For details see also: Figure 4 and Supporting Information File 1). Structure elucidation of 5b The mass spectrum of 5b displayed a molecular ion at m/z 245 corresponding to the molecular formula C14H15NO3. Interestingly the molecular ion is 18 amu

An efficient synthesis of tetramic acid derivatives with extended conjugation from L-Ascorbic Acid

• Biswajit K. Singh,
• Surendra S. Bisht and
• Rama P. Tripathi

Beilstein J. Org. Chem. 2006, 2, No. 24, doi:10.1186/1860-5397-2-24

• consists of reaction of the above dienyl tetronic acids with different amines separately to form the required intermediate 5-hydroxy tetramic acid derivatives. Thus reaction of 9 first with ethanolic ammonia led to the formation of 5-hydroxy lactam derivative 11 in good yield. The structure elucidation of