En route to photoaffinity labeling of the bacterial lectin FimH

• Thisbe K. Lindhorst,
• Michaela Märten,
• Andreas Fuchs and
• Stefan D. Knight

Beilstein J. Org. Chem. 2010, 6, 810–822, doi:10.3762/bjoc.6.91

• FimH that can complex α-D-mannosides. However, as the precise nature of the ligand–receptor interactions in mannose-specific adhesion is not yet fully understood, it is of interest to identify carbohydrate recognition domains on the fimbrial lectin also in solution. Photoaffinity labeling serves as an

• appropriate methodology in this endeavour and hence biotin-labeled photoactive mannosides were designed and synthesized for photoaffinity labeling of FimH. So far, the photo-crosslinking properties of the new photoactive mannosides could be detailed with the peptide angiotensin II and labeling of FimH was

• shown both by MS/MS studies and by affino dot–blot analysis. Keywords: diazirines; FimH; lectins; MS/MS analysis; photoactive mannoside ligands; photoaffinity labeling; Introduction Photoaffinity labeling is a technique by which ligand binding sites of a receptor protein can be identified in solution

Novel tetracyclic structures from the synthesis of thiolactone-isatin hybrids

• Renate Hazel Hans,
• Hong Su and
• Kelly Chibale

Beilstein J. Org. Chem. 2010, 6, No. 78, doi:10.3762/bjoc.6.78

• from MeOH at room temperature and subjected to crystallographic analysis (see Supporting Information File 2 for crystallographic data). Figure 3 shows the molecular structure and atom labeling for 4a. The crystals are triclinic with space group P−1 and contains four molecules per unit cell. The crystal

• repulsive steric interaction between the relatively bulky hydroxyl group at C7A and the adjacent methyl group at C5A. Figure 4 shows the molecular structure atom labeling for 4b–c. Both compounds crystallized in the centrosymmetric monoclinic space group P21/n with 4 molecules in the unit cell. Similar to

Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R)- and (S)-aminopropanediol as an acyclic linker

• Daniel Lachmann,
• Sina Berndl,
• Otto S. Wolfbeis and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2010, 6, No. 13, doi:10.3762/bjoc.6.13

• ” ligation strategy has become an important strategy for postsynthetic labeling of DNA [12][13]. Huisgen described first the [2+3]-cycloaddition between alkynes and azides yielding 1,2,3-triazoles [14]. The utility of this reaction as a bioligation method has grown incredibly after Meldal [15] and – almost

Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• signal (for labeling, see Figure 2), downfield shift and strong broadening of the NHD signal as well as changes of the chemical shifts of the CH3F,G, CH2B,C,E, pyridine CH and imidazole or indole CH resonances of 4 or 5 (see Table 2). The signal due to the indole NH of 5 shifted downfield by 0.20–0.40

Synthesis of coumarin or ferrocene labeled nucleosides via Staudinger ligation

• Ivana Kosiova,
• Andrea Janicova and
• Pavol Kois

Beilstein J. Org. Chem. 2006, 2, No. 23, doi:10.1186/1860-5397-2-23

• gives iminophosphoranes which can react with almost any kind of electrophilic reagent, e.g. aldehydes/ketones to form imines or esters to form amides. This so-called Staudinger ligation has been employed in a wide range of applications as a general tool for bioconjugation including specific labeling of

• , [22][23] including specific labeling of nucleic acids, [24] proteomic studies [25][26] and modification of cell surfaces. [17][18] We applied the Staudinger ligation for nucleoside labeling procedures, using coumarin and ferrocene derivatives as labels. According to our knowledge, applications of this

• with maxima of 1a-c. We observed only slight changes of fluorescence intensity in the series of coumarin labeled nucleosides. We also tested the Staudinger ligation as a prospective method for the electrochemical labeling of nucleosides and nucleotides with ferrocene derivatives. 2'-Azido-2

Molecular recognition. 1. Crystal structures of hexaazamacrocyclic amines containing p-xylylene spacers and their adducts with acids

• Teresa Borowiak,
• Grzegorz Dutkiewicz,
• Maciej Kubicki,
• Marek Pietraszkiewicz,
• Agnieszka Gil and
• Rainer Mattes

Beilstein J. Org. Chem. 2005, 1, No. 16, doi:10.1186/1860-5397-1-16

• isolated centrosymmetric molecules. The molecular conformation together with the atom labeling scheme is shown in Figure 4. The overall conformation of the molecule is ellipsoidal with the approximate dimensions of 6.2 and 15.3 Å. All atoms of the molecule (except hydrogens) are within 2.16 Å of the mean

• from one macrocyclic hexa-protonated cation and six fumaric anions, together with the atom labeling scheme. Displacement parameters are drawn at 50% probability level. Symmetry codes: i: 0.5-x, 0.5+y, z; ii: 0.5-x, 0.5+y, 0.5-z; iii 0.5-x, -0.5+y, z; iv: 0.5-x, -0.5+y, 0.5-z The structure of one sheet

• height of one sheet corresponds to the height of the macrocycle, i.e. about 12 Å. The molecular conformation of 1-N-Me, atom labeling scheme indicated. Displacement parameters are drawn at 50% probability level. The unit cell of 1-N-Me, stacks of molecules are indicated. Formulas of macrocyclic amines, 1