Construction of Porous Organic Nanostructures Using Cooperative Self-Assembly for Lipase-Catalyzed Inclusion of Gastrodigenin

2017 ◽  
Vol 1 (1) ◽  
pp. 175-182 ◽  
Author(s):  
Sagar Biswas ◽  
Rohit G. Jadhav ◽  
Apurba K. Das
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinping Hu ◽  
Jinbang Hu ◽  
Hongbing Wang ◽  
Kongchao Shen ◽  
Huan Zhang ◽  
...  

AbstractIntensive efforts have been devoted to surface Ullmann-like coupling in recent years, due to its appealing success towards on-surface synthesis of tailor-made nanostructures. While attentions were mostly drawn on metallic substrates, however, Ullmann dehalogenation and coupling reaction on semimetal surfaces has been seldom addressed. Herein, we demonstrate the self-assembly of 2, 7-dibromopyrene (Br2Py) and the well controllable dehalogenation reaction of Br2Py on the Bi(111)–Ag substrate with a combination of scanning tunnelling microscopy (STM) and density functional theory calculations (DFT). By elaborately investigating the reaction path and formed organic nanostructures, it is revealed that the pristinely inert bismuth layer supported on the silver substrate can initiate Ullmann-like coupling in a desired manner by getting alloyed with Ag atoms underneath, while side products have not been discovered. By clarifying the pristine nature of Bi–Ag(111) and Ullmann-like reaction mechanisms, our report proposes an ideal template for thoroughly exploring dehalogenative coupling reaction mechanisms with atomic insights and on-surface synthesis of carbon-based architectures.


2011 ◽  
Vol 35 (4) ◽  
pp. 784 ◽  
Author(s):  
Andrew K. Maerz ◽  
Drew A. Fowler ◽  
Andrew V. Mossine ◽  
Miten Mistry ◽  
Harshita Kumari ◽  
...  

2015 ◽  
Vol 57 (1) ◽  
pp. 62-78
Author(s):  
N. THAMWATTANA

Recently, organic nanostructures have attracted much attention, and amongst them peptide nanotubes are of interest in many fields of application including medicine and nanobiotechnology. Peptide nanotubes are formed by self-assembly of cyclic peptides with alternating L- and D-amino acids. Due to their biodegradability, flexible design and easy synthesis, many applications have been proposed such as artificial transmembrane ion channels, templates for nanoparticles, mimicking pore structures, nanoscale testing tubes, biosensors and carriers for targeted drug delivery. The mechanisms of an ion, a water molecule and an ion–water cluster entering into a peptide nanotube of structure cyclo[(-D-Ala-L-Ala-)$_{4}$] are explored here. In particular, the Lennard-Jones potential and a continuum approach are employed to determine three entering mechanisms: (i) through the tube open end, (ii) through a region between each cyclic peptide ring and (iii) around the edge of the tube open end. The results show that while entering the nanotube by method (i) is possible, an ion or a molecule requires initial energy to overcome an energetic barrier to be able to enter the nanotube through positions (ii) and (iii). Due to its simple structure, the D-, L-Ala cyclopeptide nanotube is chosen in this model; however, it can be easily extended to include more complicated nanotubes.


2012 ◽  
Vol 134 (40) ◽  
pp. 16759-16764 ◽  
Author(s):  
Aparna Deshpande ◽  
Chun-Hong Sham ◽  
Justice M. P. Alaboson ◽  
Jonathan M. Mullin ◽  
George C. Schatz ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (122) ◽  
pp. 100457-100463 ◽  
Author(s):  
Yusen Luo ◽  
Zheng Xue ◽  
Yongjun Li ◽  
Huibiao Liu ◽  
Wensheng Yang ◽  
...  

Controllable nano/microstructures from 0D to 1D were fabricated by adjusting the growth rate. The difference in symmetry between two molecules results in distinct self-assembly behaviours and different optical properties.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


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