scholarly journals Mineral Vesicles and Chemical Gardens from Carbonate-Rich Alkaline Brines of Lake Magadi, Kenya

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 467 ◽  
Author(s):  
Melese Getenet ◽  
Juan Manuel García-Ruiz ◽  
Cristóbal Verdugo-Escamilla ◽  
Isabel Guerra-Tschuschke
Keyword(s):  
Self Assembly ◽  
Metal Salt ◽  
Recent Observation ◽  
Soda Lakes ◽  
Soda Lake ◽  
Alkaline Solutions ◽  
One Pot ◽  
Rock Interaction ◽  
Lake Magadi ◽  
Chemical Gardens

Mineral vesicles and chemical gardens are self-organized biomimetic structures that form via abiotic mineral precipitation. These membranous structures are known to catalyze prebiotic reactions but the extreme conditions required for their synthesis has cast doubts on their formation in nature. Apart from model solutions, these structures have been shown to form in serpentinization-driven natural silica-rich water and by fluid-rock interaction of model alkaline solutions with granites. Here, for the first time, we demonstrate that self-assembled hollow mineral vesicles and gardens can be synthesized in natural carbonate-rich soda lake water. We have synthesized these structures by a) pouring saturated metal salt solutions, and b) by immersing metal salt pellets in brines collected from Lake Magadi (Kenya). The resulting structures are analyzed by using SEM coupled with EDX analysis, Raman spectroscopy, and powder X-ray diffraction. Our results suggest that mineral self-assembly could have been a common phenomenon in soda oceans of early Earth and Earth-like planets and moons. The composition of the obtained vesicles and gardens confirms the recent observation that carbonate minerals in soda lakes sequestrate Ca, thus leaving phosphate behind in solution available for biochemical reactions. Our results strengthens the proposal that alkaline brines could be ideal sites for “one-pot” synthesis of prebiotic organic compounds and the origin of life.

scholarly journals Enzyme-free synthesis of natural phospholipids in water

2019 ◽  
Author(s):  
Luping Liu ◽  
Yike Zou ◽  
Ahanjit Bhattacharya ◽  
Dongyang Zhang ◽  
Susan Q. Lang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Soda Lakes ◽  
Building Blocks ◽  
Alkaline Solutions ◽  
Artificial Cells ◽  
Proton Gradients ◽  
Aqueous Synthesis ◽  
Acidic Solutions ◽  
Membrane Bound ◽  
Living Organisms

AbstractAll living organisms synthesize phospholipids as the primary constituent of their cell membranes. While phospholipids can spontaneously self-assemble in water to form membrane-bound vesicles, their aqueous synthesis requires pre-existing membrane-embedded enzymes. This limitation has led to models in which the first cells used simpler types of membrane building blocks and has hampered integration of phospholipid synthesis into artificial cells. Here we demonstrate that a combination of ion pairing and self-assembly of reactants allows high-yielding synthesis of cellular phospholipids in water. Acylation of 2-lysophospholipids using cationic thioesters occurs in mildly alkaline solutions resulting in the formation of cell-like membranes. A variety of membrane-forming natural phospholipids can be synthesized. Membrane formation takes place in water from natural alkaline sources, such as soda lakes and hydrothermal oceanic vents. When formed vesicles are transferred to more acidic solutions, electrochemical proton gradients are spontaneously established and maintained.

scholarly journals Controlling the Shape and Chirality of an Eight-crossing Molecular Knot

2020 ◽  
Author(s):  
John P. Carpenter ◽  
Charlie McTernan ◽  
Jake L. Greenfield ◽  
Roy Lavendomme ◽  
Tanya K. Ronson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Self Assembly ◽  
Metal Salt ◽  
Molecular Machines ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
And Topology ◽  
Simple Pair ◽  
And Control

<p>The knotting of biomolecules impacts their function, and enables them to carry out new tasks. Likewise, complex topologies underpin the operation of many synthetic molecular machines. The ability to generate and control more complex knotted architectures is essential to endow these machines with more advanced functions. Here we report the synthesis of a molecular knot with eight crossing points, consisting of a single organic loop woven about six templating metal centres, <i>via</i> one-pot self-assembly from a simple pair of dialdehyde and diamine subcomponents and a single metal salt. The structure and topology of the knot were established by NMR spectroscopy, mass spectrometry and X-ray crystallography. Upon demetallation, the purely organic strand relaxes into a symmetric conformation, whilst retaining the topology of the original knot. This knot is topologically chiral, and may be synthesised diastereoselectively through the use of an enantiopure diamine building block.<b></b></p>

scholarly journals Controlling the Shape and Chirality of an Eight-crossing Molecular Knot

2020 ◽  
Author(s):  
John P. Carpenter ◽  
Charlie McTernan ◽  
Jake L. Greenfield ◽  
Roy Lavendomme ◽  
Tanya K. Ronson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Self Assembly ◽  
Metal Salt ◽  
Molecular Machines ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
And Topology ◽  
Simple Pair ◽  
And Control

<p>The knotting of biomolecules impacts their function, and enables them to carry out new tasks. Likewise, complex topologies underpin the operation of many synthetic molecular machines. The ability to generate and control more complex knotted architectures is essential to endow these machines with more advanced functions. Here we report the synthesis of a molecular knot with eight crossing points, consisting of a single organic loop woven about six templating metal centres, <i>via</i> one-pot self-assembly from a simple pair of dialdehyde and diamine subcomponents and a single metal salt. The structure and topology of the knot were established by NMR spectroscopy, mass spectrometry and X-ray crystallography. Upon demetallation, the purely organic strand relaxes into a symmetric conformation, whilst retaining the topology of the original knot. This knot is topologically chiral, and may be synthesised diastereoselectively through the use of an enantiopure diamine building block.<b></b></p>

Flow Chemistry Controls Both Self-Assembly and the Entrapped Oscillatory Cargo in Belousov-Zhabotinsky Driven Polymerization-Induced Self-Assembly

2019 ◽  
Author(s):  
Liman Hou ◽  
Marta Dueñas-Diez ◽  
Rohit Srivastava ◽  
Juan Perez-Mercader
Keyword(s):  
Self Assembly ◽  
Flow Chemistry ◽  
Batch Reactors ◽  
Equilibrium Conditions ◽  
One Pot ◽  
Bz Reaction ◽  
Polymer Vesicles ◽  
Simultaneous Control ◽  
Novel Method ◽  
Continuously Stirred Tank Reactor

<p></p><p>Belousov-Zhabotinsky (B-Z) reaction driven polymerization-induced self-assembly (PISA), or B-Z PISA, is a novel method for the autonomous one-pot synthesis of polymer vesicles from a macroCTA (macro chain transfer agent) and monomer solution (“soup”) containing the above and the BZ reaction components. In it, the polymerization is driven (and controlled) by periodically generated radicals generated in the oscillations of the B-Z reaction. These are inhibitor/activator radicals for the polymerization. Until now B-Z PISA has only been carried out in batch reactors. In this manuscript we present the results of running the system using a continuously stirred tank reactor (CSTR) configuration which offers some interesting advantages.Indeed, by controlling the CSTR parameters we achieve reproducible and simultaneous control of the PISA process and of the properties of the oscillatory cargo encapsulated in the resulting vesicles. Furthermore, the use of flow chemistry enables a more precise morphology control and chemical cargo tuning. Finally, in the context of biomimetic applications a CSTR operation mimics more closely the open non-equilibrium conditions of living systems and their surrounding environments.</p><p></p>

scholarly journals Precise Synthesis and Thin Film Self-Assembly of PLLA-b-PS Bottlebrush Block Copolymers

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1412
Author(s):  
Eunkyung Ji ◽  
Cian Cummins ◽  
Guillaume Fleury
Keyword(s):  
Thin Film ◽  
Block Copolymers ◽  
Self Assembly ◽  
Ring Opening ◽  
Periodic Structures ◽  
One Pot ◽  
Ordered Structures ◽  
Carbonyl Chloride ◽  
Thin Film Patterning ◽  
Nanoporous Templates

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope of photonic and membrane technologies. In this paper, we describe a two-step synthesis of poly(l-lactide)-b-polystyrene (PLLA-b-PS) BBCPs and their rapid thin-film self-assembly. PLLA chains were grown from exo-5-norbornene-2-methanol via ring-opening polymerization (ROP) of l-lactide to produce norbornene-terminated PLLA. Norbonene-terminated PS was prepared using anionic polymerization followed by a termination reaction with exo-5-norbornene-2-carbonyl chloride. PLLA-b-PS BBCPs were prepared from these two norbornenyl macromonomers by a one-pot sequential ring opening metathesis polymerization (ROMP). PLLA-b-PS BBCPs thin-films exhibited cylindrical and lamellar morphologies depending on the relative block volume fractions, with domain sizes of 46–58 nm and periodicities of 70–102 nm. Additionally, nanoporous templates were produced by the selective etching of PLLA blocks from ordered structures. The findings described in this work provide further insight into the controlled synthesis of BBCPs leading to various possible morphologies for applications requiring large periodicities. Moreover, the rapid thin film patterning strategy demonstrated (>5 min) highlights the advantages of using PLLA-b-PS BBCP materials beyond their linear BCP analogues in terms of both dimensions achievable and reduced processing time.

Chiroptical Probing of Lanthanide-Directed Self-Assembly Formation Using btp Ligands Formed in One-Pot Diazo-Transfer/Deprotection Click Reaction from Chiral Amines

2015 ◽  
Vol 22 (2) ◽  
pp. 486-490 ◽  
Author(s):  
Joseph P. Byrne ◽  
Miguel Martínez-Calvo ◽  
Robert D. Peacock ◽  
Thorfinnur Gunnlaugsson
Keyword(s):  
Self Assembly ◽  
Click Reaction ◽  
Chiral Amines ◽  
One Pot

One-pot synthesis of a TiO2–CdS nano-heterostructure assembly with enhanced photocatalytic activity

RSC Advances ◽  
2015 ◽  
Vol 5 (44) ◽  
pp. 34942-34948 ◽  
Author(s):  
Sayantan Mazumdar ◽  
Aninda J. Bhattacharyya
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Cadmium Sulfide ◽  
Self Assembly ◽  
Cost Effective ◽  
One Pot ◽  
One Pot Synthesis ◽  
Cost Effective Method

An unprecedented morphology of a titanium dioxide (TiO2) and cadmium sulfide (CdS) self-assembly obtained using a ‘truly’ one-pot and highly cost effective method with a multi-gram scale yield is reported here.

scholarly journals Determination of important enzymes and antimicrobial resistances of gram-positive haloalkaliphilic bacteria isolated from Salda Lake

2021 ◽  
Vol 38 (3) ◽  
pp. 375-382
Author(s):  
Pınar Çağlayan
Keyword(s):  
Bacillus Subtilis ◽  
Soda Lakes ◽  
Soda Lake ◽  
16S Rrna Gene Sequencing ◽  
Extreme Environment ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Haloalkaliphilic Bacteria ◽  
Rrna Gene Sequencing

As an extreme environment, soda lakes harbor various haloalkaliphilic microorganisms. Salda Lake is one of the natural soda lake (pH˃9) in Turkey. Haloalkaliphiles are unique microorganisms in their ability to live in high alkaline and high saline conditions, and play an important role in biodegradation and bioremediation of hydrocarbons. Hence, the aims of this study were to isolate haloalkaliphilic bacteria from water sample of Salda Lake, to identify these isolates by both conventional and molecular methods, to screen their industrially important enzymes, and to investigate their antimicrobial resistance profiles. Six isolates were identified as Bacillus horneckiae, Bacillus subtilis, Bacillus paramycoides, Bacillus pumilus, Staphylococcus epidermidis, Bacillus haynesii according to 16S rRNA gene sequencing analysis. The industrially important enzymes (amylase, cellulase, pullulanase, lipase, urease, protease, caseinase, oxidase, catalase) were produced by haloalkaliphilic isolates. These enzymes maybe used in alkaline and saline industrial processes. Although Bacillus subtilis was susceptible to all antibiotics, other isolates showed resistance to at least one antibiotic. The resistance against antibiotics were found as ampicillin/sulbactam 83%, amoxycillin/clavulanic acid 83%, ampicillin 67%, mupirocin 67%, chloramphenicol 50%, tetracycline 50%, imipenem 50%, meropenem 50%, cefadroxil 17%. These bacteria may have develope resistance to antibiotics that entering their natural environment in different ways.

scholarly journals PhotoATRP Induced Self-Assembly (PhotoATR-PISA) Enables Simplified Synthesis of Responsive Polymer Nanoparticles in One-Pot

2020 ◽  
Author(s):  
Ali Shahrokhinia ◽  
Randall Scanga ◽  
Priyanka Biswas ◽  
James Reuther
Keyword(s):  
Self Assembly ◽  
Glycidyl Methacrylate ◽  
Uv Light ◽  
Copper Catalyst ◽  
Crosslinking Agent ◽  
Polymer Nanoparticles ◽  
One Pot ◽  
Responsive Polymer ◽  
Catalyst Systems ◽  
First Time

<p><b>ABSTRACT:</b> Photo-controlled atom transfer radical polymerization (PhotoATRP) was implemented, for the first time, to accomplish polymerization induced self-assembly (PISA) mediated by UV light (λ = 365 nm) using ppm levels (ca. < 20 ppm) of copper catalyst at ambient temperature. Using Cu<sup>II</sup>Br<sub>2</sub>/tris(pyridin-2-ylmethyl)amine (TPMA) catalyst systems, PISA was per-formed all in one-pot starting from synthesis of solvophilic poly(oligo(ethylene oxide) methyl ether methacrylate) (POEGMA) blocks to core-crosslinked nanoparticles (NPs) utilizing poly(glycidyl methacrylate) (PGMA) and N,N-cystamine bismethacrylamide (CBMA) as the solvophobic copolymer and crosslinking agent, respectively. Sequential chain-extensions were performed for PGMA demonstrating capabilities for accessing multi-block copolymers with temporal control via switching the UV light on and off. Further, core-crosslinking of PISA nanoparticles was performed via the slow incorporation of the CBMA enabling one-pot crosslinking during the PISA process. Finally, the disulfide installed in the CBMA core-crosslinks allowed for the stimuli-triggered dissociation of nanoparticles using DL-dithiothreitol at acidic pH.</p>

Sign in / Sign up

Export Citation Format

Share Document