Structural Modifications of Deoxycholic Acid to Obtain Three Known Brassinosteroid Analogues and Full NMR Spectroscopic Characterization

Heidy Herrera; Rodrigo Carvajal; Andrés Olea; Luis Espinoza

doi:10.3390/molecules21091139

Structural Modifications of Deoxycholic Acid to Obtain Three Known Brassinosteroid Analogues and Full NMR Spectroscopic Characterization

Molecules ◽

10.3390/molecules21091139 ◽

2016 ◽

Vol 21 (9) ◽

pp. 1139 ◽

Cited By ~ 2

Author(s):

Heidy Herrera ◽

Rodrigo Carvajal ◽

Andrés Olea ◽

Luis Espinoza

Keyword(s):

Deoxycholic Acid ◽

Spectroscopic Characterization ◽

Structural Modifications ◽

Brassinosteroid Analogues

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Spectroscopic characterization and molecular structure of 3,14-dimethyl-2,6,13,17-tetraazapentacyclo[16.4.0.12,17.16,13.07,12]tetracosane

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229616013280 ◽

2016 ◽

Vol 72 (9) ◽

pp. 701-704 ◽

Cited By ~ 1

Author(s):

Dohyun Moon ◽

Yong Pyo Hong ◽

Jong-Ha Choi

Keyword(s):

Molecular Structure ◽

Crystal Packing ◽

Spectroscopic Characterization ◽

Spectroscopic Properties ◽

Structural Modifications ◽

Cxcr4 Receptor ◽

New Synthesis ◽

Hiv Drugs ◽

Ir Spectroscopic ◽

Anti Hiv

Constrained cyclam derivatives have been found to exhibit anti-HIV effects. The strength of binding to the CXCR4 receptor correlates with anti-HIV activity. The conformation of the macrocyclic compound is very important for co-receptor recognition. Therefore, knowledge of the conformation and crystal packing of macrocycles has become important in developing new highly effective anti-HIV drugs. Structural modifications of N-functionalized polyaza macrocyclic compounds have been achieved using various methods. A new synthesis affording single crystals of the title tetraazapentacyclo[16.4.0.12,17.16,13.07,12]tetracosane macrocycle, C22H40N4, is reported. Formaldehyde reacts readily at room temperature with the tetraazatricyclo[16.4.0.02,17]docosane precursor to yield a macropolycycle containing two five-membered rings. Characterization by elemental, spectroscopic and single-crystal X-ray diffraction analyses shows that the asymmetric unit contains half of a centrosymmetric molecule. The molecular structure shows atransconformation for the two methylene bridges owing to molecular symmetry. The crystal structure is stabilized by intramolecular C—H...N hydrogen bonds. NMR and IR spectroscopic properties support the methylene-bridged macrocyclic structure.

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Structural modifications of intercellular junctions.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082510 ◽

1978 ◽

Vol 36 (2) ◽

pp. 330-331

Author(s):

J. Metz ◽

M. Merlo ◽

W. G. Forssmann

Keyword(s):

Gap Junctions ◽

Intercellular Junctions ◽

Cell Isolation ◽

Extrahepatic Cholestasis ◽

Structural Modifications ◽

Pancreatic Duct Ligation ◽

Pancreatic Cells ◽

Duct Ligation ◽

Thin Sectioning ◽

And Function

Structure and function of intercellular junctions were studied under the electronmicroscope using conventional thin sectioning and freeze-etch replicas. Alterations of tight and gap junctions were analyzed 1. of exocrine pancreatic cells under cell isolation conditions and pancreatic duct ligation and 2. of hepatocytes during extrahepatic cholestasis.During the different steps of cell isolation of exocrine pancreatic cells, gradual changes of tight and gap junctions were observed. Tight junctions, which formed belt-like structures around the apex of control acinar cells in situ, subsequently diminished, became interrupted and were concentrated into macular areas (Fig. 1). Aggregations of membrane associated particles, which looked similar to gap junctions, were intermixed within tight junctional areas (Fig. 1). These structures continously disappeared in the last stages of the isolation procedure. The intercellular junctions were finally separated without destroying the integrity of the cell membrane, which was confirmed with porcion yellow, lanthanum chloride and horse radish peroxidase.

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