Laboratory Synthesis Research Articles

State-of-the-Art Biocatalysis.

The use of enzyme-mediated reactions has transcended ancient food production to the laboratory synthesis of complex molecules. This evolution has been accelerated by developments in sequencing and DNA synthesis technology, bioinformatic and protein engineering tools, and the increasingly interdisciplinary nature of scientific research. Biocatalysis has become an indispensable tool applied in academic and industrial spheres, enabling synthetic strategies that leverage the exquisite selectivity of enzymes to access target molecules. In this Outlook, we outline the technological advances that have led to the field’s current state. Integration of biocatalysis into mainstream synthetic chemistry hinges on increased access to well-characterized enzymes and the permeation of biocatalysis into retrosynthetic logic. Ultimately, we anticipate that biocatalysis is poised to enable the synthesis of increasingly complex molecules at new levels of efficiency and throughput.

Complex structures synthesized in shock processing of nucleobases – implications to the origins of life

Abstract Nucleobases are nitrogenous bases composed of monomers that are a major constituent of RNA and DNA, which are an essential part of any cellular life on the Earth. The search for nucleobases in the interstellar medium remains a major challenge, however, the recent detection of nucleobases in meteorite samples and laboratory synthesis in simulated analogue experiments have confirmed their abiotic origin and a possible route for their delivery to the Earth. Nevertheless, cellular life is based on the interacting network of complex structures, and there is substantial lack of information on the possible routes by which such ordered structures may be formed in the prebiotic environment. In the current study, we present the evidence for the synthesis of complex structures due to shock processing of nucleobases. The nucleobases were subjected to the reflected shock temperature of 3500–7000 K (estimated) and pressure of about 15–34 bar for over ~2 ms timescale. Under such extreme thermodynamic conditions, the nucleobases sample experiences superheating and subsequent cooling. Electron microscopic studies of shock processed residue show that nucleobases result in spontaneous formation of complex structures when subjected to extreme conditions of shock. These results suggest that impact shock processes might have contributed to the self-assembly of biologically relevant structures and the origin of life.

Data-driven enhancement of cubic phase stability in mixed-cation perovskites

Mixing cations has been a successful strategy in perovskite synthesis by solution-processing, delivering improvements in the thermodynamic stability as well as in the lattice parameter control. Unfortunately, the relation between a given cation mixture and the associated structural deformation is not well-established, a fact that hinders an adequate identification of the optimum chemical compositions. Such difficulty arises since local distortion and microscopic disorder influence structural stability and also determine phase segregation. Hence, the search for an optimum composition is currently based on experimental trial and error, a tedious and high-cost process. Here, we report on a machine-learning-reinforced cubic-phase-perovskite stability predictor that has been constructed over an extensive dataset of first-principles calculations. Such a predictor allows us to determine the cubic phase stability at a given cation mixture regardless of the various cations’ pair and concentration, even assessing very dilute concentrations, a notoriously challenging task for first-principles calculations. In particular, we construct machine learning models, predicting multiple target quantities such as the enthalpy of mixing and various octahedral distortions. It is then the combination of these targets that guide the laboratory synthesis. Our theoretical analysis is also validated by the experimental synthesis and characterization of methylammonium–dimethylammonium-mixed perovskite thin films, demonstrating the ability of the stability predictor to drive the chemical design of this class of materials.

The Development of Reaction Cascades to Synthesize Dimeric Coccinellid Alkaloids.

Over the course of the past decade, our group has been intensely interested in achieving the laboratory synthesis of varied members of the coccinellid alkaloid family of natural products. These compounds, produced by varied species of ladybugs throughout the world as defensive agents, include several polycyclic members that can formally be considered as either monomeric or dimeric with architectures that contain between 3 and 7 ring systems along with an array of stereocenters. As a result of their fascinating structures, many groups have achieved syntheses of varied monomeric members using a variety of synthetic strategies and tactics. However, no efforts to synthesize any of the dimeric structures had been reported at the time we began our studies, and only a modest amount of study had been performed as relates to their biosynthesis, with little knowledge of how the larger structures might actually arise in Nature. In this Account, we provide an overview of our general synthetic considerations to achieve a global synthesis of the collection, efforts that have led to date to the formal and total synthesis of 12 different members, 4 at the dimer level. Critical was (1) the identification of a key, common intermediate to enable access to a large number of monomeric substructures in short order, (2) careful thinking as to how the larger structures might arise biosynthetically to fuel building block design, and (3) the development of several reaction cascades that rapidly assembled the majority of their molecular complexity in single-pot operations. Key discoveries in the program include the finding that when efforts to achieve intermolecular dimerizations fail with advanced intermediates, attempts to couple more functionalized fragments earlier and then fold them into the desired structure can be an effective strategy. We also highlight suggestive evidence that a non-natural isomer we originally prepared from one of those cascades may, in fact, be a natural product. And, in particular, we will focus on how two key cascades were developed, as a result of synthetic challenges at varied points in our explorations, which proved capable of forging multiple bonds, rings, and stereocenters in the target structures. One of these includes a designed event that combined 9 different chemical reactions in a single pot and may prove useful for the synthesis of other targets.

Tailoring the properties of 2-D rGO-PPy-ZnS nanocomposite as emissive layer for OLEDs

The integration of semi-conductive materials into the polypyrrole (PPy) matrix tends to be an effective way to improve PPy's properties. Herein we report the laboratory synthesis of rGO-PPy-ZnS (rPZ) nanocomposites through in-situ oxidative polymerization processes. The structural and morphological verification of nanocomposites was carried out by XRD, FESEM and TEM. At the dominant wavelength, the Photoluminescence spectra display cyan color with a high rate of e−-h+ recombination. The decrease in band gap (1.48 eV) and refractive index (2.52) of rPZ showing surface conductivity. The CCT and Duv value shows the light level above the black body curve and the color purity is 55.5%. The current density has increased by 115%, indicating an increase in conductivity. The decrease in the optical band gap, and improved conductivity with increased recombination frequency verified that the as-prepared rGO-PPy-ZnS (rPZ) nanocomposite can be used in OLED devices as an emissive layer.

Design of C-H-N-O based new hetero-cyclic high energy density molecules: a theoretical survey

Theoretical study of C-H-N-O based new high energy density molecules is modeled with well-known FOX-7 (1, 1 - dinitro 2, 2 - diamino ethylene) moiety. We have designed some new hetero-cyclic molecules which can serve as a potential high energy density molecule. We have reported the optimized structures, frequency calculations, thermal stability, impact sensitivity, natural bond orbital analysis and detonation properties of these molecules. A thorough analysis has been performed with the crystal density, the energy of activation for nitro (C-NO2) to nitrito (C-ONO) conversion and the C-NO2 bond dissociation energy of these molecules. Atoms in molecules (AIM) analysis has been done in order to get the stability of the weakest C-NO2 bond and the covalent character of the bonds. The electronic structure calculation has been performed at the B3LYP level of theory with aug-cc-pVDZ basis set by using G16 quantum chemistry package. These designed molecules have found to possess superior detonation properties than FOX-7 molecule and thus suggest for laboratory synthesis by expert experimentalists.

Laboratory Synthesis and Titrations of IronIIchloride-FeCl<sub>2</sub> and IronII Ethoxide-Fe(OEt)<sub>2</sub> Using Ethanol-90° - Hexane and Sodium Ethoxide-Na(OEt)

Laboratory synthesis of IronIIchloride-FeCl2 at approximately 200[°C] to 250[°C] using hydrochloric acid-HCl-(33%) and fine iron filament (purity>99%) was done with respecting the reaction stoichiometric. A titration procedure with NaOH-0.05N was established and allowed to titrate the FeCl2 synthesized in solution. Thus, the mass yield against raw materials (Iron and HCl) was 67.22[%]. Then, this synthesized FeCl2 solution suffered an evaporation-crystallization-drying thermic treatment procedure which efficiency evaluated with NaOH-0.05N titration was up to 98[%]. Secondly, laboratory synthesis procedure of IronIIEthoxide-Fe(OEt)2 or FeO2C4H10 by reflux during 150[mn] at approximately 90[°C] to 115[°C] (maximally) using the previous synthesized FeCl2, sodium ethoxide-Na(OEt) and ethanol with pure hexane as solvent was carried out. The molar ratios (Iron/Ethanol) and (Ethanol/Hexane/Na(OEt)/Iron) were respectively (0.4775/1) and (1/2.5/0.96/0.4775) and permitted to acquire a heterogeneous phases which extraction with a washing-extracting mixed solvent; composed with Ethanol 90°-Pure Hexane-Toluene and another solvent composed only with Ethanol90°-Pure Hexane without ethanol such as the molar ratios of (Ethanol/Hexane), (Hexane/Toluene), (Ethanol/Toluene) and (Ethanol/Hexane)/Na(OEt) were respectively 1.27, 20.19, 26.55 and 14.02; followed by a crystallization procedure permitted to obtain pure IronIIEthoxide-Fe(OEt)2 liquid phases on top and solid grey graphite fine powders with eventually the FeCl2 representative-by-product on the bottom solution which concentrations were quantified and evaluated by a titration procedure using NaOH-0.05N and hexane as additive in titrated solution. It was noticed that the concentration of pure IronIIEthoxide-Fe(OEt)2 in liquid phases increased from the top to the bottom between respectively 1.458E-2 [mol/L] to 1.667E-1 [mol/L]. Then, an evaporation-crystallization procedure to concentrate the previous heterogeneous phases was established and carried out in order to crystalize a large part of the IronIIEthoxide-Fe(OEt)2 to the solid grey graphite fine powders, the mass yield quantified by the previous titration was up to 97[%]. The grey graphite fine powders was filtered and washed with a washing procedure using water and pure hexane such as (H2O/FeCl2) and (Hexane/H2O) molar ratios were respectively 221 and 14 which efficacy to retain alkenes-ethylene and to extract FeCl2 was very high respectively 99.15[%] and 97.07[%] as molars rates with 86.08[%] retention rate of Fe(OEt)2. Finally, the washed grey graphite fine powders suffered a thermic treatment which permitted to increase its purity 99.75[%] with 75[%] as porosity evaluated with acetone.

Molecular modelling of compounds used for corrosion inhibition studies: a review.

Molecular modelling of organic compounds using computational software has emerged as a powerful approach for theoretical determination of the corrosion inhibition potential of organic compounds. Some of the common techniques involved in the theoretical studies of corrosion inhibition potential and mechanisms include density functional theory (DFT), molecular dynamics (MD) and Monte Carlo (MC) simulations, and artificial neural network (ANN) and quantitative structure-activity relationship (QSAR) modeling. Using computational modelling, the chemical reactivity and corrosion inhibition activities of organic compounds can be explained. The modelling can be regarded as a time-saving and eco-friendly approach for screening organic compounds for corrosion inhibition potential before their wet laboratory synthesis would be carried out. Another advantage of computational modelling is that molecular sites responsible for interactions with metallic surfaces (active sites or adsorption sites) and the orientation of organic compounds can be easily predicted. Using different theoretical descriptors/parameters, the inhibition effectiveness and nature of the metal-inhibitor interactions can also be predicted. The present review article is a collection of major advancements in the field of computational modelling for the design and testing of the corrosion inhibition effectiveness of organic corrosion inhibitors.

Updating Levothyroxine Synthesis for the Modern Age.

Synthesis of levothyroxine sodium, the sodium salt of a synthetic levoisomer of thyroxine, revolutionized the management of hypothyroidism and related symptoms. However, the primary synthetic route to this active pharmaceutical ingredient (API) is more than 70+ years old with low-yielding steps and obsolete reagents. It lacks experimental data on intermediates, making laboratory and large-scale synthesis of this API difficult and time-consuming. Here, we describe an improved synthesis of levothyroxine using commonly available modern reagents. By modifying and replacing low yielding and/or unproductive steps of Chalmers synthesis, we were able to achieve higher overall yields (39-51%) consistently. Key modifications include an alternative path to the selective N-acetylation step that yielded 5 in a pure and consistent fashion. Our improved methodology, coupled with detailed experimental data, provides a practical alternative to existing methods that can be conveniently implemented to synthesize Levothyroxine sodium in fine chemical settings.

Nature‐Inspired, Computer‐Assisted Optimization of Hierarchically Structured Zeolites

AbstractZeolite catalysis is often affected by transport limitations, which significantly influence overall performance. Introducing wide pores as molecular transport highways can reduce transport limitations, control the product distribution, and mitigate effects of catalyst deactivation. Nevertheless, the importance to rationally design the meso‐ and macropore space remains underappreciated. This article reviews multiscale modelling approaches to optimize overall catalytic performance. It provides a general methodology and rules of thumb to guide catalyst synthesis with optimal pore network characteristics. Inspiration is taken from nature, such as the structure of leaves and tissues, with similar requirements and associated features. In optimal hierarchically structured zeolites, the added macro‐/mesopore volume fraction, connectivity, crystal size, and minimum wide pore size are crucial. The broad pore size distribution is secondary. No uncontrolled diffusion limitations should exist within the zeolite crystals. Surface barriers, however, can significantly affect, even dominate overall transport. Understanding their origin and ways to control them is an emergent research area. Synthesis methods to realize hierarchically structured zeolites are briefly reviewed. Significant gaps exist between laboratory synthesis methods and industrial requirements. Zeolite catalysis could benefit from computer‐assisted design of their hierarchical pore network, embracing principles used by natural transport networks for scalable efficiency, selectivity, and robustness.

Methods and Cost Estimation for the Synthesis of Nanosized Lithium Sulfide

Lithium sulfide (Li2S) is an alternative cathode material for lithium‐sulfur batteries. It can mitigate the volume expansion problem encountered by the sulfur cathode, in addition, as a fully lithium‐inserted cathode, it can be paired with lithium‐free anodes or be assembled into anode‐free batteries. However, commercially available Li2S powder delivers poor electrochemical performances due to the significant potential barrier during the first charging process, and therefore developing inexpensive synthesis route for nanosized Li2S with small diameter and low charging overpotential becomes the key to the construction of practical Li2S cathode. Herein, the preparation methods for Li2S nanoparticles are summarized, including laboratory synthesis methods and potential large‐scale preparation routes; traditional industrial synthesis methods for commercially available Li2S are also attached as references. In particular, the scalability of these methods is mentioned, and the costs of the resulted Li2S products are also estimated and compared with the currently used cathode materials for Li‐ion batteries. In the end, the commercially worthwhile research pathways for Li2S synthesis as well as the perspective on the practical production of Li2S are discussed. Useful guidance for the selection of practical Li2S synthesis routes is also provided.

Solvothermal synthesis of CuFeS2 nanoflakes as a promising electrode material for supercapacitors

The present work describes the electrochemical energy storage performance of CuFeS2 (Chalcopyrite), which is well known for its high electrical conductivity, natural abundance, and low cost. The laboratory synthesis method for CuFeS2 nanoflakes by facile one step solvothermal method is successfully accomplished. The as-synthesized CuFeS2 nanoflakes are subjected to both Physical and chemical characterization, as well as electrochemical characterization. CuFeS2 sample has been coated over carbon cloth substrate for the fabrication of flexible electrode for supercapacitor. The Cu1+ and Fe3+ ions offer a synergistic contribution in the redox mechanism and substantiate an eminent electrochemical performance for supercapacitor. Galvanometric Charge Discharge (GCD) profile of CuFeS2 electrode in three electrode system manifests a high specific capacitance of 219 F g−1 at 1 A g−1 in an aqueous medium of 2 M KOH electrolyte with the potential range of -0.5 to 0.5 V. Further in two electrode system, the symmetric supercapacitor based on CuFeS2 electrode exhibits a high specific capacitance of 120 F g−1 at a current density of 1 A g−1 in aqueous 2 M KOH electrolyte. The symmetric supercapacitor based on CuFeS2 electrode delivers a maximum specific energy of 16 Wh Kg−1 at a specific power of 1146 W kg−1with a capacitive retention of 94% over 6000 cycles. These factors inclusively promote CuFeS2 as a promising electrode material for supercapacitor application.

Nickel/Cobalt‐Catalyzed Reductive Hydrocyanation of Alkynes with Formamide as the Cyano Source, Dehydrant, Reductant, and Solvent

AbstractA Ni/Co co‐catalyzed reductive hydrocyanation of various alkynes was developed for the production of saturated nitriles. Hydrocyanic acid is generated in situ from safe and readily available formamide. Formamide played multiple roles as a cyano source, dehydrant, and reductant for the NiII pre‐catalyst and vinyl nitriles, along with acting as the co‐solvent in this reaction. Detailed mechanistic investigation supported a pathway via hydrocyanation of C≡C bond and the subsequent reduction of C=C bond. Wide substrate scope, the employment of a cheap and stable nickel salt as pre‐catalyst, a safe cyano source and convenient experimental operation render this hydrocyanation practical for the laboratory synthesis of saturated nitriles.magnified image

Aryl Amination Using Soluble Weak Base Enabled by a Water-Assisted Mechanism

The amination of aryl halides has become one of the most commonly practiced C-N bond-forming reactions in pharmaceutical and laboratory syntheses. The widespread use of strong or poorly soluble inorganic bases for amine activation nevertheless complicates the compatibility of this important reaction class with sensitive substrates as well as applications in flow and automated synthesis, to name a few. We report a palladium-catalyzed C-N coupling using Et3N as a weak, soluble base, which allows a broad substrate scope that includes bromo- and chloro(hetero)arenes, primary anilines, secondary amines, and amide type nucleophiles together with tolerance for a range of base-sensitive functional groups. Mechanistic data have established a unique pathway for these reactions in which water serves multiple beneficial roles. In particular, ionization of a neutral catalytic intermediate via halide displacement by H2O generates, after proton loss, a coordinatively unsaturated Pd-OH species that can bind amine substrate triggering intramolecular N-H heterolysis. This water-assisted pathway operates efficiently with even weak terminal bases, such as Et3N. The use of a simple, commercially available ligand, PAd3, is key to this water-assisted mechanism by promoting coordinative unsaturation in catalytic intermediates responsible for the heterolytic activation of strong element-hydrogen bonds, which enables broad compatibility of carbon-heteroatom cross-coupling reactions with sensitive substrates and functionality.

Regulating the reactivity of black phosphorus via protective chemistry.

Rationally regulating the reactivity of molecules or functional groups is common in organic chemistry, both in laboratory and industry synthesis. This concept can be applied to inorganic nanomaterials, particularly two-dimensional black phosphorus (BP) nanosheets. The high reactivity of few-layer (even monolayer) BP is expected to be "shut down" when not required and to be resumed upon application. Here, we demonstrate a protective chemistry-based methodology for regulating BP reactivity. The protective step initiates from binding Al3+ with lone pair electrons from P to decrease the electron density on the BP surface, and ends with an oxygen/water-resistant layer through the self-assembly of hydrophobic 1,2-benzenedithiol (BDT) on BP/Al3+ This protective step yields a stabilized BP with low reactivity. Deprotection of the obtained BP/Al3+/BDT is achieved by chelator treatment, which removes Al3+ and BDT from the BP surface. The deprotective process recovers the electron density of BP and thus restores the reactivity of BP.

Studying of analgesic and anti-inflammatory activity of 2,4-dioxobutanoic acid hydrazine derivatives

Objective. To study the analgesic and anti-inflammatory activity of water-soluble hydrazine derivatives of 2,4-dioxobutanoic acids, as well as to determine the relationship between the structure of substances and their biological effects.
 Materials and methods. The laboratory synthesis methods were applied to obtain 2-hydrazine derivatives of 2,4-dioxobutanoic acids. The compounds were tested for biological activity using a hot plate test in mice and an acute inflammatory reaction caused by carrageenan-induced paw edema in rats.
 Results. The analgesic activity of four compounds is comparable to that of nimesulide. One of the substances obtained is found to exhibit higher anti-inflammatory activity than nimesulide during the 1st and 3rd hours of the experiment. Two compounds with a combination of high analgesic and anti-inflammatory activity were identified. The effect of certain radicals in the structure of the substances on the activities studied was discovered.
 Conclusions. The revealed relationship between the structure of original compounds and their biological activities can be used in the further synthesis and search for new domestic pharmaceutical substances with investigated effects.

Гидроксипроизводные левоглюкозенона в реакциях энантиоселективного восстановления 1,3-дифенилпропан-1-она

The enantioselective reduction of prochiral ketones is an important method for the preparation of enanti-enriched secondary alcohols, which can serve as starting materials for optically active compounds. Chiral metal hydride reagents, such as lithium aluminum hydride (LiAlH4) and sodium borohydride (NaBH4), modified with chiral ligands, have been developed to effect enantioselective reduction. However, in most cases, derivatives are used to obtain chiral hydride reagents, which are rare and hardly available. Therefore, the search for more accessible and effective derivatives suitable for the modification of hydride reagents is an urgent task. Levoglucosenone is an optically pure enone of carbohydrate nature, readily available by pyrolysis of any cellulose-containing materials. Levoglucosenone is considered a promising bioplatform for both laboratory synthesis and industrial use. The prospect of the development of chemistry of levoglucosenone and its derivatives in industry makes it possible to pay attention to these compounds from the point of view of studying their possibilities as chiral inducers or auxiliaries. In this work, we studied the possibilities of chiral induction in the reduction reactions of 1,3-diphenylpropan-1-one with hydride reagents obtained by replacing hydrogens in LiAlH4 and NaBH4 with hydroxy derivatives of levoglucosenone. The reduction of 1,3-diphenylpropan-1-one with chiral aluminum hydride reagents proceeded with low enantioselectivity, mainly with a predominance of (S)-1,3-diphenylpropan-1-ol. It was found that the enantiomeric purity of the S-stereomer decreases with an increase in the substitution of hydrogen atoms in LiAlH4 by hydroxy derivatives of levoglucosenone. Reduction of 1,3-diphenylpropan-1-one with reagents obtained by partial neutralization of NaBH4 with hydroxy derivatives of levoglucosenone, on the contrary, predominantly leads to the formation of (R)-1,3-diphenylpropan-1-ol. The addition of AcOH and Bu4NCl to NaBH4 has a positive effect on the optical frequency of the R-alcohol. At the same time, enantioselectivity in the reactions was almost absent upon reduction of 1,3-diphenylpropan-1-one with reagents obtained by partial neutralization of BH3. The best results of enantioselective reduction were shown by unsaturated alcohols: (1S,4S,5R) -6,8-dioxabicyclo[3.2.1]oct-2-en-4-ol and (1S,4S,5R)-4-methyl-6,8-dioxabicyclo[3.2.1]oct-2-en-4-ol, of which (1S,4S,5R)-6,8-dioxabicyclo[3.2.1]oct-2-en-4-ol was the most effective. It is likely that an increase in the enantioselectivity of reactions carried out in the presence of hydroxy derivatives of levoglucosenone is possible by obtaining more bulky chiral ligands, provided that the double bond is retained.

Thermoregulatory Strategies of Diving Air-Breathing Marine Vertebrates: A Review

The aquatic habitat of marine “air-breathing” vertebrates provides a significant thermoregulatory challenge due to the high thermal conductivity of water. In addition to temperature changes across their range, air-breathing vertebrates experience temperature changes on the timescale of seconds to minutes as they perform dives to access two critical resources: air at the surface and food at depth. In response to these challenges, air-breathing vertebrates have developed morphological and physiological adaptations that align with their life histories and phylogenies and contribute to homeostasis. However, the physiological and behavioral mechanisms used to maintain thermal balance while diving is still poorly understood. The cardiovascular system is integral to the physiological responses associated with the dive response, exercise, digestion, and thermoregulation. The adjustments required to meet one physiological demand may not be compatible with another and can result in a potential conflict between the various physiological demands imposed on air-breathing divers. We reviewed the literature on thermoregulation while diving in an effort to synthesize our current understanding of the thermoregulatory strategies of diving air-breathing marine vertebrates. Studies have demonstrated that thermoregulatory strategies can involve the temporal separation of two conflicting responses, a compromise in the performance of one response over another, or coordination of synergistic responses. We hope that a review and synthesis of both laboratory and field studies will stimulate future research efforts at the intersection of thermoregulation and diving physiology. Expanding the use of physiological biologgers, particularly to understudied species, will enhance our understanding of how these animals coordinate various physiological demands to maintain homeostasis in a thermally challenging environment.

Influence of Inorganic Bases on the Structure of Titanium Dioxide-Based Microsheets.

Laboratory synthesis of microsheets of titanium dioxide from titanyl sulfate involves the use of ammonia solution, whereas another inorganic base is most likely to be employed at the industrial level, as ammonia is a toxic agent and therefore should be avoided according to European Union (EU) regulations. Selected nontoxic bases such as sodium, potassium, and lithium hydroxides have been tested as an alternative to ammonia solution to obtain amorphous and crystalline TiO2-based microsheets. The final products obtained at each step of the procedure (samples lyophilized and annealed at 230 and 800 °C) were analyzed with electron and atomic force microscopy, X-ray powder diffraction, thermal analysis, and Fourier transform infrared (FTIR) and Raman spectroscopies to determine their morphology and phase composition. The differences in the morphology of the obtained products were described in detail as well as phase and structural composition throughout the process. It was found that, in the last step of the synthesis, microsheets annealed at 800 °C were built of small rods and oval or platy crystalline particles depending on the base used. The temperature of formation of anatase, rutile, and alkali-metal titanates in correlation with the ionic radius of the alkali metal present in the sample was discussed.

Roadmap to Building a Cell: An Evolutionary Approach.

Laboratory synthesis of an elementary biological cell from isolated components may aid in understanding of the fundamental principles of life and will provide a platform for a range of bioengineering and medical applications. In essence, building a cell consists in the integration of cellular modules into system’s level functionalities satisfying a definition of life. To achieve this goal, we propose in this perspective to undertake a semi-rational, system’s level evolutionary approach. The strategy would require iterative cycles of genetic integration of functional modules, diversification of hereditary information, compartmentalized gene expression, selection/screening, and possibly, assistance from open-ended evolution. We explore the underlying challenges to each of these steps and discuss possible solutions toward the bottom-up construction of an artificial living cell.