Bio-inspired Synthesis Research Articles

Synthesis of Carbon Nanospheres Through Carbonization of Areca nut.

We demonstrate a bio-inspired one-pot synthesis of carbon nanospheres with micro-porosity achieved from a promising carbon-rich source (Areca nut) using direct pyrolysis in nitrogen atmosphere at 550 °C in a tube-furnace without adding any catalysts. The resultant carbon spheres are highly monodispersed, uniformly shaped and possess good absorption behaviour (10.5 mg · g−1) for methylene blue (MB).

Role of cellulose functionality in bio-inspired synthesis of nano bioactive glass

In search of abundant cheaper natural polymer for bio-inspired bioactive glass nanoparticles synthesis, cellulose and its derivatives have been considered as a template. Different templates explored in the present studies are pure cellulose, methyl cellulose and amine grafted cellulose. To the best of our knowledge, for the first time of the considered templates, pure cellulose and amine grafted cellulose results in in situ nano particulate composite formation while interestingly methyl cellulose proves to be an excellent sacrificial template for the synthesis of uniform bioglass nanoparticles of diameter in the range of 55nm. Further, viscoelastic measurements were carried out using dynamic mechanical analyzer. Herein, an attempt has been made to establish structure-mechanical relationship based on the templates. Moreover, in vitro bioactivity is also observed to be affected by the nature of the template molecule used for the synthesis of bioactive glass.

Iron supported on bioinspired green silica for water remediation.

Iron has been used previously in water decontamination, either unsupported or supported on clays, polymers, carbons or ceramics such as silica. However, the reported synthesis procedures are tedious, lengthy (involving various steps), and either utilise or produce toxic chemicals. Herein, the use of a simple, rapid, bio-inspired green synthesis method is reported to prepare, for the first time, a family of iron supported on green nanosilica materials (Fe@GN) to create new technological solutions for water remediation. In particular, Fe@GN were employed for the removal of arsenate ions as a model for potentially toxic elements in aqueous solution. Several characterization techniques were used to study the physical, structural and chemical properties of the new Fe@GN. When evaluated as an adsorption platform for the removal of arsenate ions, Fe@GN exhibited high adsorption capacity (69 mg of As per g of Fe@GN) with superior kinetics (reaching ∼35 mg As per g sorbent per hr) - threefold higher than the highest removal rates reported to date. Moreover, a method was developed to regenerate the Fe@GN allowing for a full recovery and reuse of the adsorbent in subsequent extractions; strongly highlighting the potential technological benefits of these new green materials.

Bioinspired enantioselective synthesis of crinine-type alkaloids via iridium-catalyzed asymmetric hydrogenation of enones.

A bioinspired enantioselective synthesis of crinine-type alkaloids has been developed by iridium-catalyzed asymmetric hydrogenation of racemic cycloenones. The method features a biomimetic stereodivergent resolution of the substrates bearing a remote arylated quaternary stereocenter. Using this protocol, 24 crinine-type alkaloids and 8 analogues were synthesized in a concise and rapid way with high yield and high enantioselectivity.

Bio-inspired synthesis of PEGylated polypyrrole@polydopamine nanocomposites as theranostic agents for T1-weighted MR imaging guided photothermal therapy.

Polypyrrole nanoparticle (PPy) based theranostic agents for magnetic resonance imaging (MRI) guided photothermal therapy (PTT) have received increasing attention in recent years. However, the limitations of cost and biocompability still offer us opportunities to improve these agents. Considering the versatile character of polydopamine (PDA), PEGylated PPy@Fe3+-chelated PDA nanocomposites (PPDEs) were designed and prepared in an easy way. PPDE with a uniform core-shell structure could be obtained by adjusting the ratio of dopamine and PPys. In this nanocomplex, the shells confer the nanoparticles with good biocompability and MRI signal enhancing ability. Moreover, the PPy cores play a role in photothermal ablation of tumors. Compared with pure PDA nanoparticles, the PPDEs have higher NIR absorbance and better photothermal capability benefitting from the high photothermal conversion of the cores. Additionally, the obtained PPDEs provide significant MRI signal enhancement for both in vitro and in vivo imaging with high longitudinal relaxivity (r1 = 5.055 mM-1 s-1). After intravenous injection, the PPDEs exhibited valid tumor accumulation, as revealed by MRI and verified by biodistribution analysis. Under NIR irradiation, the PPDEs showed highly effective photothermal ablation of 4T1 cells. Notably, excellent biocompability of the PPDEs was confirmed by a relevant MTT assay and histologic analysis. This work achieved an example of exploiting the inherent advantages of PPy and PDA within a single unit and exploring its potential for T1 MRI-guided PTT.

Singlet oxygen formation in bio-inspired synthesis of a hollow Ag@AgBr photocatalyst for microbial and chemical decontamination

Singlet oxygen has been identified as a contributor to the degradation of contaminants using biosynthesised hollow Ag@AgBr catalysts.

High-value compounds from microalgae with industrial exploitability - A review.

From the past several years, algal biotechnology has gained noticeable interests among research-based organizations and industrial sectors. Recent studies have provided considerable evidence that microalgae-derived bioactive compounds could play a vital role in bio- and non-bio sectors of the modern world. Microalgae-based industrial exploitability ranges from basic biomass-based food and feeds nutraceuticals to high-value pharmaceuticals, cosmeceuticals, ecological and biomedical applications. With ever increasing scientific knowledge, social and environmental awareness, bio-inspired synthesis of microalgae-based green products, and recent advancements in algal biotechnology will extend the utilization of microalgae into new areas. Microalgae offer high biodiversity with an enormous potential to produce structurally complex yet bioactive compounds which are either impossible or difficult to produce via synthetic routes. In this paper, a range of value-added bioactive compounds from microalgae with industrial potentialities has been reviewed. The contribution ended with a critical description of the main research gaps and envisioned with future considerations to progress further in this exciting era of research.

Optimization of Different Reaction Conditions for the Bio-Inspired Synthesis of Silver Nanoparticles Using Aqueous Extract of Solanum nigrum Leaves

Optimization of Different Reaction Conditions for the Bio-Inspired Synthesis of Silver Nanoparticles Using Aqueous Extract of Solanum nigrum Leaves One of the significant goals in nanotechnology is to explore different ways for synthesis of nanoparticles with the ability to control and reduce costs and environmental pollutions. Bio-inspired synthesis of nanoparticles using plant extracts has resulted in creation of a new branch of nanotechnology. Silver nanoparticles are among the most widely used nanoparticles. The current research work investigate the findings of optimization of different experimental variables like ratio of plant leaf extract and silver nitrate, reaction time, temperature and pH on silver nanoparticles synthesized using aqueous leaf extract of Solanum nigrum. The formation of dark brown color confirmed the synthesis of silver nanoparticles. The bio-inspired synthesis of silver nanoparticles was found to be optimum at aqueous extract and silver nitrate ratio of 5:95, reaction time 4 hours, temperature 70°C and pH 7. The silver nanoparticles thus formed under optimized parameters were then characterized using transmission electron microscopy that revealed that the nanoparticles are almost spherical in shape with a mean particle size of 17.54 nm. It can be concluded from the finding that good modification of the bioprocess parameters improves potential of desired nano-particles for particular applications.

Size and shape regulated synthesis of silver nanocapsules for highly selective and sensitive ultralow bivalent copper ion sensor application

The development of highly robust, quantitative, sensitive and naked eye colorimetric sensing of bivalent copper ions using bio-inspired synthesis of size and shape controlled silver nanocapsules (AgNCs) is reported herein.

Harnessing the main event of drimentines biosynthesis: bio-inspired synthesis and biological evaluation of Δ8'-isodrimentine A and related compounds

Harnessing the main event of drimentines biosynthesis: bio-inspired synthesis and biological evaluation of Δ8'-isodrimentine A and related compounds

Controlling the bio-inspired synthesis of silica

The influence of different parameters on the silicification procedure using lysozyme is reported. When polyethoxysiloxane (PEOS), an internally crosslinked silica reservoir, is used, regular structures with a narrow size distribution could be obtained only via introducing the silica precursor in two steps including initial dropping and subsequent addition of residual oil phase in one portion. We found that mixing sequence of mineralizing agents in the presence of a positively charged surfactant plays a key role in terms of silica precipitation when tetraethoxyorthosilicate (TEOS) is the oil phase. In contrast, well-mineralized crumpled features with high specific surface area could be synthesized in the presence of PEOS as a silica precursor polymer, regardless of mixing sequence. Moreover, introducing sodium dodecyl sulfate (SDS) as a negatively charged surfactant resulted in regular silica sphere formation only in combination with hexylene glycol (MPD) as a specific co-solvent. Finally, it is demonstrated that by inclusion of different nanoparticles even more sophisticated hybrid materials can be generated.

Preparation of an N-sec-alkyl 2,6-disubstituted aniline: a key intermediate in the divergent synthesis of S-Metolachlor metabolites

A simple method to prepare a 2,6-disubstituted aniline containing a N-sec-alkyl group and a carbonyl on one ortho substituent is reported. This method was used to accomplish the first synthesis of side chain oxidized ethylsulfonic acid (ESA) and oxanilic acid (OXA) metabolites of S-Metolachlor (S-Moc) herbicide. The 2,6-disubstituted aniline functionality was installed by a Sugasawa reaction of readily available ortho-toluidine. The N-sec alkyl group was introduced by a Mitsunobu alkylation of the nosyl-activated 2-acetyl-6-methyl-substituted aniline. This crucial step enabled access to the key 2,6-disubstituted aniline intermediate which was used in the divergent synthesis of S-Moc metabolites. A bioinspired synthesis of the keto-ESA metabolite was achieved in one step from the hydroxyl-ESA metabolite using a ruthenium-catalyzed oxidation. [Display omitted]

ChemInform Abstract: Bioinspired Synthesis of Magnetite Nanoparticles

AbstractReview: 230 refs.

Bio-inspired gold nanoparticles synthesis and their anti-biofilm efficacy

Gold nanoparticles (AuNPs) are ‘smart nanomaterials’ with a variety of applications in the different fields. The conventional methods used for AuNPs have some drawbacks and therefore, search of an alternative ‘green method’ is of high importance. In this study, Acinetobacter baumannii AB01 isolated from an infected apple sample was used as a green route for AuNPs synthesis. Effect of various physicochemical parameters such as pH, temperature, cell density and gold chloride salt concentrations on AuNPs synthesis was studied. These AuNPs were further characterized by UV–Vis spectrophotometer, transmission electron microscopy (TEM), energy dispersive spectroscopy, X-ray diffraction and dynamic light scattering. TEM images study showed presence of an extracellular polymeric substance around cells of A. baumannii AB01. The synthesized biogenic AuNPs were tested for their antibacterial activity by well diffusion method. Anti-biofilm efficacy of AuNPs was tested on the glass slide surfaces against the biofilms of Pseudomonas aeruginosa, Vibrio cholera and Brevibacterium linens and visualised by using a fluorescence microscopy. Biofilm formation was reduced about 60–80 % when compared with control biofilm (without AuNPs). Effect of different AuNPs concentrations on biofilm formation in microtiter plates was studied by 96-well plate assay. The bacterial biofilm inhibition (%) was increased with increasing concentrations of AuNPs.

Oxygen separation membrane derived from aquatic weed: A novel bio-inspired approach to synthesize BaBi0.2Co0.35Fe0.45O3-δ perovskite from water hyacinth (Eichhornia crassipes)

In recent years, bio-inspired synthesis processes have drawn increasing research interest as a new tool for designing next generation advanced functional materials with unparalleled advantages. Bio-inspired process offers unique microstructures which are difficult to engineer through conventional synthesis methodologies. The present study aims to develop a bio-templating process of synthesizing BaBi0.2Co0.35Fe0.45O3−δ (BBCF) perovskite type oxygen separation membrane mimicking the interior of water hyacinth's (Eichhornia crassipes) petioles. In Indian sub-continent water hyacinth is considered as one of the worst aquatic weed whose removal is necessary from natural water reservoir to save aquatic environment. The idea of using such water pollutant to produce engineered microstructure for improving material's functionality is the philosophy behind the present study. The exo-templating of water hyacinth results in interesting microstructure and enhanced the physical properties of BBCF membrane in terms of oxygen permeation flux. The novel, simple method may be extended to produce any multifunctional advanced material with a spectacular microstructure and unique properties.

Bioinspired Synthesis of Hierarchically Porous MoO2/Mo2C Nanocrystal Decorated N-Doped Carbon Foam for Lithium–Oxygen Batteries

The lithium oxygen (Li–O2) battery is one of the most promising technologies among various electrochemical energy storage systems. The challenge to develop a high-performance Li–O2 battery lies in exploring an air electrode with optimal porous structure and high efficient bifunctional electrocatalyst. The present work demonstrates a bioinspired synthesis route for the preparation of high performance Li–O2 air electrode materials that are made out of N-doped carbon foams decorated with heteronanostructured MoO2/Mo2C nanocrystals (MoO2/Mo2C@3D NCF). Here, recombinant proteins (ELK16-FLAG) facilitated the self-assembly of metal precursors and provided a carbon source for Mo2C formation. The as-prepared MoO2/Mo2C@3D NCF showed superior electrocatalytic activity in both oxygen evolution reaction and oxygen reduction reaction mechanisms with a high round-trip efficiency of 89.1% (2.77 V/3.11 V) at 100 mA g–1 as well as exceptional rate performances and good cyclability in Li–O2 battery. The desirable electroche...

Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for "Mineral Plastics".

Given increasing environmental issues due to the large usage of non-biodegradable plastics based on petroleum, new plastic materials, which are economic, environmentally friendly, and recyclable are in high demand. One feasible strategy is the bio-inspired synthesis of mineral-based hybrid materials. Herein we report a facile route for an amorphous CaCO3 (ACC)-based hydrogel consisting of very small ACC nanoparticles physically cross-linked by poly(acrylic acid). The hydrogel is shapeable, stretchable, and self-healable. Upon drying, the hydrogel forms free-standing, rigid, and transparent objects with remarkable mechanical performance. By swelling in water, the material can completely recover the initial hydrogel state. As a matrix, thermochromism can also be easily introduced. The present hybrid hydrogel may represent a new class of plastic materials, the "mineral plastics".

A Bioinspired Synthesis of (±)‐Rubrobramide, (±)‐Flavipucine, and (±)‐Isoflavipucine

AbstractA biomimetic synthesis of naturally occurring lactams rubrobramide, flavipucine, and isoflavipucine is described. The key step is a regioselective Darzens reaction between isobutyl glyoxal and an α‐bromo‐β‐ketoamide. The construction of the core tricyclic ring system of rubrobramide was achieved by a cascade reaction in a single step from an α,β‐epoxy‐γ‐lactam. Furthermore, the absolute configuration of naturally occurring (+)‐rubrobramide was determined by vibrational circular dichroism. (±)‐Flavipucine and (±)‐isoflavipucine were synthesized from an epoxyimide, which was prepared by reaction of isobutyl glyoxal with a protected α‐bromo‐β‐ketoamide. Deprotection of the epoxyimide and formation of the pyridone ring gave (±)‐flavipucine, which was converted into (±)‐isoflavipucine by thermal isomerization.

A Bioinspired Synthesis of (±)-Rubrobramide, (±)-Flavipucine, and (±)-Isoflavipucine.

A biomimetic synthesis of naturally occurring lactams rubrobramide, flavipucine, and isoflavipucine is described. The key step is a regioselective Darzens reaction between isobutyl glyoxal and an α-bromo-β-ketoamide. The construction of the core tricyclic ring system of rubrobramide was achieved by a cascade reaction in a single step from an α,β-epoxy-γ-lactam. Furthermore, the absolute configuration of naturally occurring (+)-rubrobramide was determined by vibrational circular dichroism. (±)-Flavipucine and (±)-isoflavipucine were synthesized from an epoxyimide, which was prepared by reaction of isobutyl glyoxal with a protected α-bromo-β-ketoamide. Deprotection of the epoxyimide and formation of the pyridone ring gave (±)-flavipucine, which was converted into (±)-isoflavipucine by thermal isomerization.

An alternative total synthesis of bolivianine

An alternative total synthesis of bolivianine in twelve steps is herein reported on the basis of our previous successful bioinspired total synthesis. The present total synthesis features straightforward transformation from an aldol product to the butenolide of the target molecule, and stereoselective Diels-Alder cycloaddition to construct ring E, as well as the final spontaneous IMHDA process.