A macrolactonization approach to the total synthesis of the antimicrobial cyclic depsipeptide LI-F04a and diastereoisomeric analogues

• James R. Cochrane,
• Dong Hee Yoon,
• Christopher S. P. McErlean and
• Katrina A. Jolliffe

Beilstein J. Org. Chem. 2012, 8, 1344–1351, doi:10.3762/bjoc.8.154

• epimers (Scheme 1). While macrocyclization to give the core 2 could be performed at any of the amide or ester bonds [10], we chose to use a macrolactonization approach to enable ready access to analogues of the LI-F04a core through straightforward Fmoc solid-phase peptide synthesis of the linear

• which the D-allo-Thr protecting group was either tert-butyl or ΨMe,Me'Pro, respectively, to investigate whether a turn-inducer might assist the macrolactonization reaction. Linear peptides 5 and 6 were prepared by standard Fmoc solid-phase peptide synthesis protocols using PyBOP/Hünigs base as the

• of the crude peptide, so obtained, to authentic samples of both 5 and the C-terminal epimer 9 (which was independently prepared by solid-phase peptide synthesis), indicated that the major product obtained upon macrolactonization of 5 under the Corey–Nicolaou conditions was the undesired cyclic

Synthetic glycopeptides and glycoproteins with applications in biological research

• Ulrika Westerlind

Beilstein J. Org. Chem. 2012, 8, 804–818, doi:10.3762/bjoc.8.90

• backbones, or mimics thereof, offer further possibilities to study protein-binding events. Keywords: glycopeptide binding; glycopeptides; glycoprotein synthesis; solid-phase peptide synthesis; synthetic vaccines; Introduction The majority of human proteins are co- or post-translationally modified by mono

Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

• Raheleh Rezaei Araghi,
• Carsten C. Mahrenholz,
• Rudolf Volkmer and
• Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

• three β- and two γ-amino acids, was synthesized by standard solid-phase peptide synthesis and labeled at the N-terminus with the fluorophore 5(6)-tetramethylrhodamine (TAMRA). As described above, the chimera has a modified pentad (β- and γ-amino acids) at the center of its 31-residue sequence (positions

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

• synthesized using solid-phase peptide synthesis, followed by esterification and subsequent cleavage from the resin, deprotection and cyclization to yield 1, assisted by microwave irradiation at every stage with the exception of the esterification (Scheme 1). In detail, a preloaded 2-chlorotrityl chloride

• protists in order to also understand its molecular function. Experimental Synthesis Unless otherwise stated, we used the chemicals in their highest available purity. The progress of the synthesis was monitored with MALDI–MS as well as RP-UPLC coupled with ESI–MS. Solid-phase peptide synthesis. The linear

Synthesis of glycosylated β³-homo-threonine conjugates for mucin-like glycopeptide antigen analogues

• Florian Karch and
• Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2010, 6, No. 47, doi:10.3762/bjoc.6.47

• solid-phase peptide synthesis. By appropriate conjugation, the resulting α/β-hybrid glycopeptide conjugate could be used as an antigen surrogate to elucidate the effects of chemically modified antibody determinants on the immunological properties of glycopeptide antigen analogues. Experimental General

2-Phenyl- tetrahydropyrimidine- 4(1H)-ones – cyclic benzaldehyde aminals as precursors for functionalised β²-amino acids

• Markus Nahrwold,
• Arvydas Stončius,
• Anna Penner,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2009, 5, No. 43, doi:10.3762/bjoc.5.43

• containing e.g. tert-butyl protected side chain functions. Amino acids protected like that are particularly suitable for solid phase peptide synthesis and are thus highly desirable. Our novel ring cleavage concept includes the protection of both ring-nitrogen atoms as carbamates (Scheme 1C). Similar to the

Synthesis of novel photochromic pyrans via palladium- mediated reactions

• Christoph Böttcher,
• Gehad Zeyat,
• Saleh A. Ahmed,
• Elisabeth Irran,
• Thorben Cordes,
• Cord Elsner,
• Wolfgang Zinth and
• Karola Rueck-Braun

Beilstein J. Org. Chem. 2009, 5, No. 25, doi:10.3762/bjoc.5.25

• cyanation, carbonylation and Sonogashira cross-coupling starting from bromo-substituted naphthopyran 1 and benzopyrans 2a/b. A novel photoswitchable benzopyran-based ω-amino acid 6 for Fmoc-based solid-phase peptide synthesis is presented. The photochromic behaviour of the 3-cyano-substituted benzopyran 5a

The first preparative solution phase synthesis of melanotan II

• Vladimir V. Ryakhovsky,
• Georgy A. Khachiyan,
• Nina F. Kosovova,
• Elena F. Isamiddinova and
• Andrey S. Ivanov

Beilstein J. Org. Chem. 2008, 4, No. 39, doi:10.3762/bjoc.4.39

• accomplished in 12 steps with 2.6% overall yield, affording >90% pure peptide without using preparative chromatography. Keywords: melanotan II; solution phase synthesis; peptide synthesis; Introduction Development of solid phase peptide synthesis methodology [1], recombinant techniques for expressing

• 8-fold excess of DCC as the coupling agent and 1-hydroxybenzotriazole (HOBt) as a racemization suppressant. The yield of the cyclized product 12 was 31%, very close to the reported 30% yield for solution-phase cyclization of a related linear heptapeptide obtained by solid phase peptide synthesis [18

A practical synthesis of the ¹³C/¹⁵N- labelled tripeptide N-formyl- Met-Leu-Phe, useful as a reference in solid- state NMR spectroscopy

• Sven T. Breitung,
• Jakob J. Lopez,
• Gerd Dürner,
• Clemens Glaubitz,
• Michael W. Göbel and
• Marcel Suhartono

Beilstein J. Org. Chem. 2008, 4, No. 35, doi:10.3762/bjoc.4.35

• Wolfgang Goethe University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany 10.3762/bjoc.4.35 Abstract A mild synthetic method for N-formyl-Met-Leu-Phe-OH (1) is described. After Fmoc solid phase peptide synthesis, on-bead formylation and HPLC purification, more than 30 mg of the fully

• 13C/15N-labelled tripeptide 1 could be isolated in a typical batch. This peptide can be easily crystallised and is therefore well suited as a standard sample for setting up solid-state NMR experiments. Keywords: Fmoc solid phase peptide synthesis; formylation; f-MLF; magic-angle spinning; Wang resin

• reagent for further formylation reactions, due to the absence of activating agents. To the best of our knowledge, formylation reactions of N-termini with ethyl formate have never been reported before in solid phase peptide synthesis. Other methods of formylation were not tested, since they require