Chiral Bis(amino alcohol)oxalamide Gelators—Gelation Properties and Supramolecular Organization: Racemate versus Pure Enantiomer Gelation

2003 ◽  
Vol 9 (22) ◽  
pp. 5567-5580 ◽  
Author(s):  
Janja Makarević ◽  
Milan Jokić ◽  
Zlata Raza ◽  
Zoran Štefanić ◽  
Biserka Kojić-Prodić ◽  
...  
Keyword(s):  
Amino Alcohol ◽  
Supramolecular Organization ◽  
Pure Enantiomer

Specific Labeling of Protein Domains with Antibody Fragments

1981 ◽  
Vol 39 ◽  
pp. 416-417
Author(s):  
U. Aebi ◽  
L.E. Buhle ◽  
W.E. Fowler
Keyword(s):  
Image Processing ◽  
Specific Protein ◽  
Antibody Fragments ◽  
Supramolecular Organization ◽  
Two Dimensional ◽  
Ordered Structures ◽  
Virus Capsids ◽  
Processing Techniques

Many important supramolecular structures such as filaments, microtubules, virus capsids and certain membrane proteins and bacterial cell walls exist as ordered polymers or two-dimensional crystalline arrays in vivo. In several instances it has been possible to induce soluble proteins to form ordered polymers or two-dimensional crystalline arrays in vitro. In both cases a combination of electron microscopy of negatively stained specimens with analog or digital image processing techniques has proven extremely useful for elucidating the molecular and supramolecular organization of the constituent proteins. However from the reconstructed stain exclusion patterns it is often difficult to identify distinct stain excluding regions with specific protein subunits. To this end it has been demonstrated that in some cases this ambiguity can be resolved by a combination of stoichiometric labeling of the ordered structures with subunit-specific antibody fragments (e.g. Fab) and image processing of the electron micrographs recorded from labeled and unlabeled structures.

Synthesis and Reactivity of Precolibactin 886

2019 ◽  
Author(s):  
Seth Herzon ◽  
Alan R. Healy ◽  
kevin wernke ◽  
Chung Sub Kim ◽  
Nicholas Lees ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Gene Cluster ◽  
Amino Alcohol ◽  
Biomimetic Synthesis ◽  
Cross Linking ◽  
E Coli ◽  
Hplc Purification ◽  
Structural Assignment ◽  
Biosynthetic Precursor ◽  
Double Oxidation

<div>The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Precolibactin 886 (1) is one of the most complex isolated clb metabolites; it contains a 15-atom macrocycle and an unusual 5-hydroxy-3-oxazoline ring. Here we report confirmation of the structural assignment via a biomimetic synthesis of precolibactin 886 (1) proceeding through the amino alcohol 9. Double oxidation of 9 afforded the unstable α-ketoimine 2 which underwent macrocyclization to precolibactin 886 (1) upon HPLC purification (3% from 9). Studies of the putative precolibactin 886 (1) biosynthetic precursor 2, the model α-ketoimine 25, and the α-dicarbonyl 26 revealed that these compounds are susceptible to nucleophilic rupture of the C36–C37 bond. Moreover, cleavage of 2 produces other known clb metabolites or biosynthetic intermediates. This unexpected reactivity explains the difficulties in isolating full clb metabolites and accounts for the structure of a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 (1) to form a non-genotoxic pyridone, suggesting precolibactin 886 (1) lies off-path of the major biosynthetic route.</div>

A Short, Affordable, One-Pot Synthesis of a Camphor-Derived Amino Alcohol

1995 ◽  
Vol 25 (19) ◽  
pp. 2975-2980 ◽  
Author(s):  
Robert M. Przeslawski ◽  
Suzanne Newman ◽  
Edward R. Thornton ◽  
Madeleine M. Joullié
Keyword(s):  
Amino Alcohol ◽  
One Pot ◽  
One Pot Synthesis

Enantioselective Diels–Alder Reaction of 3-Nitrocoumarins Promoted by Chiral Organoammonium Salt Catalysts

Synlett ◽  
2020 ◽  
Vol 31 (20) ◽  
pp. 2013-2017
Author(s):  
Akira Sakakura ◽  
Yudai Fujii ◽  
Ryota Nakao ◽  
Saki Sugihara ◽  
Keita Fujita ◽  
...  
Keyword(s):  
Amino Alcohol ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Danishefsky's Diene

AbstractAn enantioselective Diels–Alder reaction of 3-nitrocoumarins has been developed. A tryptophan-derived C 1-symmetric organoammonium thiourea catalyst promoted the reaction of 3-nitrocoumarins with Danishefsky’s diene to give the corresponding adducts with good enantioselectivity (up to 94% ee). One of the resulting adducts was converted into a chiral carbocyclic quaternary β-amino alcohol.

Synthesis and supramolecular organization of the iodide and triiodides of a polycyclic adamantane-based diammonium cation: the effects of hydrogen bonds and weak I⋯I interactions

CrystEngComm ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 2384-2395
Author(s):  
Ivan A. Mezentsev-Cherkes ◽  
Tatiana A. Shestimerova ◽  
Aleksei V. Medved'ko ◽  
Mikhail A. Kalinin ◽  
Alexey N. Kuznetsov ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Building Blocks ◽  
Supramolecular Organization ◽  
Supramolecular Architectures

Adamantane-like divalent building blocks and iodide or polyiodide anions combine into supramolecular architectures with the help of various noncovalent forces ranging from strong hydrogen bonds to secondary and weak I⋯I interactions.

Role of non-covalent interactions in the supramolecular architectures of mercury(ii) diphenyldithiophosphates: An experimental and theoretical investigation

2021 ◽  
Vol 45 (4) ◽  
pp. 2249-2263
Author(s):  
Pretam Kumar ◽  
Snehasis Banerjee ◽  
Anu Radha ◽  
Tahira Firdoos ◽  
Subash Chandra Sahoo ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
Supramolecular Organization ◽  
Π Interactions ◽  
Supramolecular Architectures ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The H-bond, spodium bond and CH⋯π interactions playing an important role in the supramolecular organization of two mercury(ii) diphenyldithiophosphate complexes have been discussed.

Crystal structure and two-level supramolecular organization of glycinium triiodide

2019 ◽  
Vol 68 (8) ◽  
pp. 1520-1524 ◽  
Author(s):  
T. A. Shestimerova ◽  
M. A. Bykov ◽  
Z. Wei ◽  
E. V. Dikarev ◽  
A. V. Shevelkov
Keyword(s):  
Crystal Structure ◽  
Supramolecular Organization
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