Academic literature on the topic 'Bio-Sourced molecules'

After the period of halogenated compounds, the period of nano-structured systems, and that of phosphorus (and nitrogen)-based additives (still in progress), following the increasingly demanding circular economy concept, about ten years ago the textile flame retardant world started experiencing the design and exploitation of bio-sourced products. Indeed, since the demonstration of the potential of such bio(macro)molecules as whey proteins, milk proteins (i.e., caseins), and nucleic acids as effective flame retardants, both natural and synthetic fibers and fabrics can take advantage of the availability of several low-environmental impact/“green” compounds, often recovered from wastes or by-products, which contain all the elements that typically compose standard flame-retardant recipes. The so-treated textiles often exhibit flame-retardant features that are similar to those provided by conventional fireproof treatments. Further, the possibility of using the same deposition techniques already available in the textile industry makes these products very appealing, considering that the application methods usually do not require hazardous or toxic chemicals. This review aims to present an overview of the development of bio-sourced flame retardants, focusing attention on the latest research outcomes, and finally discussing some current challenging issues related to their efficient application, paving the way toward further future implementations.

Biological molecules can be obtained from natural sources or from commercial waste streams and can serve as effective feedstocks for a wide range of polymer products. From foams to epoxies and composites to bulk plastics, biomolecules show processability, thermal stability, and mechanical adaptations to fulfill current material requirements. This paper summarizes the known bio-sourced (or bio-derived), environmentally safe, thermo-oxidative, and flame retardant (BEST-FR) additives from animal tissues, plant fibers, food waste, and other natural resources. The flammability, flame retardance, and—where available—effects on polymer matrix’s mechanical properties of these materials will be presented. Their method of incorporation into the matrix, and the matrices for which the BEST-FR should be applicable will also be made known if reported. Lastly, a review on terminology and testing methodology is provided with comments on future developments in the field.

One of the main areas of interest of synthetic organic chemistry is the rapid construction of small molecules with proven diverse biological activities for the development of new strategies to cure human health. In particular, the development of novel synthetic strategies is the most important option for reaching the molecular scaffolds of active molecules of natural origin. Balsacone A and asebogenin are compounds that exhibit a wide variety of important biological activities. In this respect, it has become very important to develop new strategies for the construction of biologically active natural and synthetic balsacone analogues. In particular, balsacone derivatives with hydroxy-substituted dihydrochalcone skeletons can be isolated from plant sources or obtained by hemi-syntheses using bio-sourced precursors. An efficient synthetic strategy to synthetically obtain balsacone A is the aim of the present study that considers the limited natural availability of these molecules as well as other factors, such as cost and time. Starting with phloroglucinol, a nine-step synthesis of the precursor of balsacone A was achieved at a 10% overall yield. Furthermore, asebogenin, which has a dihydrochalcone structure and plays a key role in the synthesis of balsacone A, was synthesised with a good yield.

We present a novel near-ambient-temperature approach to telechelic renewable polyesters by exploiting the unique properties of supercritical CO 2 (scCO 2 ). Bio-based commercially available monomers have been polymerized and functional telechelic materials with targeted molecular weight prepared by end-capping the chains with molecules containing reactive moieties in a one-pot reaction. The use of scCO 2 as a reaction medium facilitates the effective use of Candida antarctica Lipase B (CaLB) as a catalyst at a temperature as low as 35°C, hence avoiding side reactions, maintaining the end-capper functionality and preserving the enzyme activity. The functionalized polymer products have been characterized by 1 H nuclear magnetic resonance spectroscopy, matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry, gel permeation chromatography and differential scanning calorimetry in order to carefully assess their structural and thermal properties. We demonstrate that telechelic materials can be produced enzymatically at mild temperatures, in a solvent-free system and using renewably sourced monomers without pre-modification, by exploiting the unique properties of scCO 2 . The macromolecules we prepare are ideal green precursors that can be further reacted to prepare useful bio-derived films and coatings.

The aim of this work is to develop new organic bio-sourced inhibitors that are ecofriendly and biodegradable. These natural inhibitors are organic, non-toxic molecules derived from plant extracts, containing numerous secondary metabolites, and are capable of being highly effective in protecting metals against corrosion. This study concerns the extraction, characterization and electrochemical study of natural organic compounds extracted from a species of Sargassum abundant on the coasts of Martinique, Sargassum fluitans III. The objective is to inhibit the corrosion of carbon steel. Electrochemical impedance spectroscopy (EIS) and linear polarization (LP) techniques have led to new experimental results showing inhibitor efficacy. The results obtained show that this plant extract could serve as an effective inhibitor for the C38 steel in acidic media. Studies on the phytochemicals of the crude extract were also carried out. Electrochemical studies, on each chemical families present, were also established to find the main constituents responsible for corrosion inhibition properties of the algae extract. The adsorption of Sargassum fluitans III extract on the C38 steel surface, obeys the Langmuir adsorption isotherm.

: This study involved analyzing bio-molecules including protein, glycogen and lipids in parasites as well as in both the infected and non-infected intestine of the host. The worms were sourced from the intestinal region of the freshwater fish Clarias batrachus and underwent a washing and other necessary processes. The dry weight was recorded after subjecting the samples to a temperature range of 50-60°C for duration of 24 hours. During the comparison between cestode parasites and the host intestine, it was observed that Lytocestus sp. displayed reduced concentration of protein and glycogen in comparison to both the infected and non-infected segments of the host's intestine. Moreover, the lipid concentration in the parasite exceeded that found in the host intestine, regardless of infection status. Author noticed that concentration of protein, glycogen, and lipids were notably high in the non-infected region compared to the infected section within the host intestine.

LEDs are the foundation of lighting and display products surrounding us. While they have obtained great success in the commercial market, related research and development activities remain highly active aiming to enhance factors such as energy efficiency, stability, and environmental sustainability. Currently, commercial LED products are comprised of two key components: an indium gallium nitride e LED backlight with emission centered at 450 nm to cover the blue region of the visible spectrum, and powder inorganic phosphors on top converting blue light into longer wavelengths (e.g., green and red) to tune the emission of the device. A drawback of inorganic phosphors is that scattering of the emission from the micron-sized phosphor powders leads to substantial backscattering and subsequent absorption of the emission into the LED chip, and reabsorption losses in the phosphor itself, both of which reduce the overall light output of the final LED device. Organic dyes possess environmental advantages over inorganic phosphors because they are pi-conjugated molecules made from abundant elements (C, H, N, O, etc.) and are potentially bio-sourced. In this talk, I will present dyes that have been developed from theobromine, derived from cacao beans. When blended within an industrial polymer, poly(styrene-butadiene-styrene) (SBS), their enhanced solubility enables the formation of highly transparent films, crucial for reducing scattering loss in LEDs. Furthermore, resultant dye-SBS films achieved photoluminescence quantum yields (PLQYs) of around 90% under ambient conditions. Taking advantage of their transparency and solution processability, we fabricated a waveguide with this theobromine-dye-SBS composite, which was subsequentially assembled into an edge-lit LED device of no glare and enhanced aesthetics.

Surfactants are amphiphilic molecules with the ability to modify the surface tension between two surfaces. They can be obtained by various methods, the main one being synthetic, from petroleum-based substrates. Their universal use in a wide range of fields has created a global market and, consequently, ecological, and economic expectations for their production. Biocatalyzed processes, involving enzymes, can address this objective with processes complying with the principles of green chemistry: energy saving, product selectivity, monodispersity, and reduction in the use of solvents, with energy eco-efficiency. For example, fatty-acid carbohydrate esters are biobased surfactants that can be synthesized by lipases. In this work, we were interested in the synthesis of D-glucose lauric ester, which presents interesting properties described in the literature, with Aspergillus niger lipase, rarely described with sugar substrates. We optimized the synthesis for different parameters and reaction media. This lipase appeared to be highly selective for 6-O-lauroyl-D-glucopyranose. However, the addition of DMSO (dimethyl sulfoxide) as a co-solvent displays a duality, increasing yields but leading to a loss of selectivity. In addition, DMSO generates more complex and energy-intensive purification and processing steps. Consequently, a bio-sourced alternative as co-solvent with 2MeTHF3one (2-methyltetrahydrofuran-3-one) is proposed to replace DMSO widely described in the literature.

Biodegradable membranes with innovative antifouling properties are emerging as possible substitutes for conventional membranes. These types of membranes have the potential to be applied in a wide range of applications, from water treatment to food packaging and energy production. Nevertheless, there are several existing challenges and limitations associated with the use of biodegradable membranes in large scale applications, and further studies are required to determine the degradation mechanisms and their scalability. Biodegradable membranes can be produced from either renewable natural resources or synthesized from low-molecular monomers that increase the number of possible structures and, as a result, greatly expand the membrane application possibilities. This study focused on bio-sourced and synthesized biodegradable polymers as green membrane materials. Moreover, the article highlighted the excellent antifouling properties of biodegradable membranes that assist in improving membrane lifetime during filtration processes, preventing chemical/biological disposal due to frequent cleaning processes and ultimately reducing the maintenance cost. The industrial and biomedical applications of biodegradable membranes were also summarized, along with their limitations. Finally, an overview of challenges and future trends regarding the use of biodegradable membranes in various industries was thoroughly analyzed.

Le manque d'innovations thérapeutiques a récemment atteint un niveau critique par rapport aux traitements antibiotiques. Cette question, corrélée à l’apparition de bactéries multirésistantes, a mis en évidence la nécessité de nouvelles approches pour la découverte d’antibiotiques innovants. En conséquence, le projet BIOANTIBIO a été proposé.Les deux principales applications initialement envisagées pour les composés les plus actifs sont:• Additifs pour la formulation de matériaux innovants (par exemple, peintures et revêtements) afin de garantir leur durabilité en stockage (en collaboration avec IFMAS).• Médicaments : agents antibactériens et antifongiques, en particulier pour le développement d’agents antimicrobiens contre les bactéries résistantes aux médicaments, destinés à la protection de la santé humaine.L'utilisation de molécules naturelles pour développer de nouvelles classes d'antifongiques ou d'antimicrobiens peut être difficile. Néanmoins, on sait que la nature inspire les chimistes dans la synthèse de molécules aux propriétés biologiques et dans le cadre de ce projet, nous avons démontré que même l’acide pyroglutamique, composé biosourcé bien connu, devait encore être exploité en tant que motif phare de la chimie du laboratoire
The lack of therapeutic innovations has recently reached a critical level, considering antibiotic treatments. This issue, correlated with the appearance of multidrug-resistant bacteria underlined the need for new approaches towards the discovery of innovative antibiotics. As a consequence, the BIOANTIBIO project was proposed.The two main initially envisioned applications for the most active compounds being:• Additives for the formulation of innovative materials (eg paints and coatings) in order to guarantee their durability in storage (working in collaboration with IFMAS).• Drugs: antibacterial and antifungal agents, particularly for the development of antimicrobial agents against drug-resistant bacteria for human health protection.Employing natural molecules to develop novel antifungal or antimicrobial classes can be challenging. Nevertheless, nature is known to inspire chemists in the synthesis of molecules with improved biological properties and within this project we have demonstrated that even the well known pyroglutamic acid is still to be exploited as a scaffold

Les organogels sont des gels supramoléculaires ou gels physiques formés à partir d’organogélateurs dans des solvants organiques. Ces organogélateurs ou gélateurs de faible poids moléculaire (LMOGs) sont de petites molécules organiques (< 2000 Da) capables de s’auto-assembler. Cela conduit à la formation de structures anisotropes, principalement des fibres, qui forment un réseau fibrillaire auto-assemblé enchevêtré (SAFiN), dont le mécanisme d’assemblage est dirigé par des interactions non covalentes. L’objectif de cette thèse est de développer de nouveaux organogélateurs à partir de briques biosourcées. Dans un premier temps, nous avons synthétisé des molécules à base d’acide tannique. En faisant varier la nature des groupements et les longueurs de chaine, nous avons ainsi adapté la solubilité des molécules et cartographié une famille de molécules qui n'a pas démontré de propriétés intéressantes. Par la suite, nous avons synthétisé des molécules à base de FDCA contenant des fonctions amides. En variant la nature de l’amine et les longueurs de chaine, nous avons ainsi découvert une nouvelle famille d’organogélateurs
Organogels are supramolecular gels or physical gels formed from organogelators in organic solvents. These organogelators or low molecular weight organogelators (LMOGs) are small organic molecules (< 2000 Da) capable of self-assembly. This leads to the formation of elongated structures, mainly fibers, which form an entangled self-assembled fibrillar network (SAFiN), whose assembly mechanism is driven by non-covalent interactions. The objective of this thesis is to develop new organogelators from biobased building blocks. In a first step, we synthesized molecules based on tannic acid. By varying the nature of the groups and the chain lengths, we adapted the solubility of the molecules and mapped a family of molecules that, however, did not show interesting properties. Subsequently, we synthesized FDCA-based molecules containing amide functions. By varying the nature of the amine and the chain lengths, we discovered a new family of organogelators

Les produits naturels (PNs) ont perdu en popularité depuis l'introduction des petites molécules synthétiques il y a plusieurs années. De nombreuses raisons expliquent ce choix, telles que les difficultés d'accès et d'approvisionnement, la complexité de la chimie des PNs et l'avènement de la chimie combinatoire. Cependant, les PNs offrent de nombreuses propriétés intéressantes par rapport aux molécules synthétiques conventionnelles, ce qui leur confère à la fois des avantages et des inconvénients dans le contexte de la recherche de principes actifs. En général, les PNs se caractérisent par un plus grand nombre de carbones sp3 et de centres stéréogènes, une grande diversité de squelettes et une grande complexité structurelle. La moitié des médicaments approuvés par la FDA depuis 1994 étant des PNs ou des dérivés hémisynthétiques, et étant donnée la récente stagnation de la recherche et du développement de nouveaux médicaments, il devient de plus en plus évident que les produits naturels doivent être utilisés dans le processus de découverte de médicaments en tant que source d'inspiration.Par conséquent, de nombreuses stratégies émergent aujourd'hui pour la construction de chimiothèques inspirées par la nature, selon les stratégies "top-down" et "bottom-up". Dans les approches "bottom-up", la complexité est créée à partir de réactifs simples. En revanche, les approches "top-down" consistent à apporter des modifications structurelles à un produit naturel déjà complexe.Le travail présenté décrit deux approches différentes pour enrichir la chimiothèque de notre unité de recherche avec des composés dérivés de PNs. Une stratégie hémisynthétique "top-down" a été planifiée pour obtenir des dérivés de la lactucine et de la 11β,13-dihydrolactucine, deux lactones sesquiterpéniques extraites des racines de chicorée. 36 dérivés esters ont été synthétisés en trois étapes (synthèse classique), ainsi que deux bibliothèques de dérivés aminés (en utilisant la synthèse parallèle). Tous les composés ont ensuite été testés contre Mycobacterium tuberculosis et certaines molécules ont montré des activités prometteuses (CMI < 1,2 µM).D'autre part, une stratégie "bottom-up" a permis la synthèse de deux analogues de l'antibiotique naturel hygromycine A. Pour cette approche nous sommes partis de réactifs simples disponibles dans le commerce et avons appliqué une stratégie de déaromatisation dans le processus de synthèse.L'ensemble de ces travaux nous a permis d'explorer un espace chimique plus large, d'accroître la diversité structurelle de notre chimiothèque et de découvrir de nouveaux "hits". Nous pourrons également ainsi identifier de nouvelles cibles antibactériennes
Natural products (NPs) have declined in popularity since the introduction of synthetic small molecules several years ago. Many are the reasons behind this choice, such as difficulties in access and supply, complexities of NP chemistry and the advent of combinatorial chemistry. However, NPs offer many interesting properties compared to conventional synthetic molecules, which confer both advantages and challenges for the drug discovery process. Usually, NPs are characterized by a higher number of sp3 carbons and stereogenic centres, large scaffold diversity and structural complexity. With half of the drugs approved by the FDA since 1994 being NPs or hemisynthetic derivatives and the recent stagnation in new drug research and development, it is becoming more and more evident that NPs should be reintroduced in the drug discovery process as a source of inspiration.Therefore, many strategies are now emerging for the construction of nature-inspired chemical libraries, such as “top-down” and “bottom-up” strategies. In “bottom-up” approaches, complexity is created starting from simple building blocks. On the other hand, “top-down” approaches are assumed to make structural modifications to an already complex NP.Our presented work describes two different approaches to enrich the chemical library of our research unit with NP-derived compounds. A “top-down” semisynthetic strategy was planned to obtain derivatives of lactucin and 11β,13-dihydrolactucin, two sesquiterpene lactones extracted from chicory roots. Thirty-six ester derivatives were synthesized in three steps (classical synthesis), together with two amine derivative libraries (using parallel synthesis). All the compounds were then tested against Mycobacterium tuberculosis and some promising hits were found (MICGFP < 1.2 μM). On the other hand, a “bottom-up” strategy allowed the synthesis of two analogues of the known natural antibiotic hygromycin A. This approach started from simple commercially available building blocks and employed a dearomatization strategy in the synthetic process.Together, we explored a broader chemical space, increased the structural diversity of our chemical library and discovered new potential antibacterial hits. Moreover, this work paves the way for the discovery of new antibacterial targets

This chapter describes the use of ocean- or marine-sourced biomass for the production of renewable materials and chemicals. Algae and waste from the fisheries can be used to provide a range of chemicals including biopolymers (carbohydrates), pigments, proteins (and amino acids), lipids and minerals. This chapter highlights the use of algae to produce phycocolloids (carrageenans, agarose and alginates), waste crustacean shells to produce chitin, chitosan and related small molecules, and waste mollusc shells to produce biorenewable calcium carbonate. In many cases, green chemistry and engineering approaches are employed. Examples include the use of catalysts (both chemical and bio-catalysts) and the use of alternative solvents (water, supercritical fluids and ionic liquids). Furthermore, consideration of the overall sustainability of current fishing and aquaculture practices is encouraged and the use of by-products for adding commercial viability to this sector of the economy is outlined.

Natural steroids are organic compounds that play important physiological roles in various organisms. They are the key components of a cell, which act as important signalling molecules engaging in stress response, metabolic activities, reproduction, inflammation, and behavioural uniformities. Naturally, the human body embraces a cluster of steroids in the form of biological hormones, namely, sex hormones, adrenal cortical hormones and bile acids. Steroidal derivatives can imitate human hormones and exhibit their activities by boosting enzymes that the body lacks. Clinically, it is evident that the distribution of synthetic steroids is high in pharmaceutical use for hormonal anomalies, but they provide adverse side effects over long term usage. Steroids work as immunosuppressants to control many autoimmune disorders concerned with inflammation, but they also reduce the activity of the immune system, which is the body’s natural defence against infection and illness. Replacement of natural steroids sourced from herbal plants, marine invertebrates, bacteria, algae, and fungi has a medicinal value that aids in the treatment of various ailments. Apart from hormonal functions, bio-derived steroids also display a safe and copious pharmacological profile for anti-oxidant, anti-inflammatory, anti-carcinogenic, anti-neoplastic, neuroprotective, and cardioprotective activities. This chapter discusses the prevalence of various naturally available steroids in different entities and their suitable applications in various fields.

PLA (Poly Lactic Acid) is a bio-sourced and a biodegradable polymer. It represents an interesting substitute for some petrochemical based polymers, especially because of its wide range of applications in the biomedical, agriculture and packaging fields. Unfortunately, PLA exhibits slow crystallization kinetics, limiting the amount of crystallinity in the final product, which is a handicap in order to extend its use. Many authors have investigated the crystallization of polymers; nevertheless several physical mechanisms remain not yet understood. This work aims a complete characterization of PLA in order to improve the understanding of its crystallization kinetics. The quiescent crystallization was investigated using Differential Scanning Calorimetry (DSC) measurements in isothermal and non-isothermal conditions for PLA and PLA with 5wt % talc. The flow effect on crystallization was studied using a thermocontrolled hot-stage shearing device (Linkam) coupled with an optical microscope. The number of activated nuclei and the growth rate were measured as functions of temperature. In addition, the linear viscoelastic properties were obtained from a rheometer with plate-plate geometry. The enhancement of the crystallization was quantified and analyzed in terms of the half crystallization time t1/2. This characteristic time t1/2 is found to be drastically decreased by both the talc and the flow which promote supplementary nucleation leading to various crystalline microstructures. The flow is known to orient and stretch molecules leading to an extra nucleation. An original description of this phenomenon is proposed using two characteristic Weissenberg numbers; based on the definition of Rousse and reptation times. Finally, we have proposed a semi-empirical model to quantify the thermal and flow contributions on the crystallization.

PLA (Poly Lactic Acid) is a bio-sourced and biodegradable polymer. It represents an alternative for polymers issued from petrochemical synthesis. Unfortunately, the crystallization kinetics of PLA is very slow and limits the possibility to extend its application in several industrials domains. The enhancement of the PLA crystallization kinetic can be obtained by addition of nucleating agents of by ordering the molecular chains during flow, as in processing conditions. During processing of thermoplastic polymer experiences several thermomechanical conditions influencing drastically its final properties and mechanical behavior. During injection molding process, macromolecules are oriented and ordered due to the shear and elongation imposed by the melt flow in the mold during the filling step. As a consequence, supplementary nucleation is created in the polymer, leading to the acceleration of the crystallization kinetics. In this work, we propose to analyze and to quantify the role of the flow, the temperature kinetics and the nucleating agent on injected PLA parts structure and their mechanical behavior. A parametric analysis of the relationship between the polymer, its structure and the processing condition will be presented. The competition (sometimes antagonism) between several parameters, as the shear rate, the temperature kinetics and the nucleating agent will be highlighted.

Birch tree barks are regarded as waste in the pulp and papermaking industry and used as fuel. However, this material presents a source that contains many bio-based chemicals suitable for applications ranging from pharmaceuticals, plastics and composites, coatings, and antifeedants. Among the mixture of bio-derived chemicals in birch barks, triterpenoids, such as betulin, betulinic acid, and lupeol, can be present up to 30% weight of dry bark mass. They are highly valued for their anti-tumor, HIV, and inflammatory responses. In our presented work, triterpenoid mixtures were extracted through a Soxhlet extractor using the barks from locally sourced river birch trees (Betula nigra) with an average yield of 10.6% (dry bark mass). The extracted materials were characterized using the Nuclear Magnetic Resonance (NMR), Advanced Polymer Chromatography (APC), High-Performance Liquid Chromatography (HPLC), and hydroxyl number titration to assess the identity, average molecular weight, triterpenoid content, and the number of reactive sites, respectively. The extracts have been used to synthesize bio-based polymers with promising thermal and mechanical properties using minimal processing steps. Birch bark extract naturally contains many potential reactive sites and thus making it advantageous for synthesizing polymers without requiring multiple purification steps. We demonstrate the potentials for increasing the utility of birch bark, contributing to sustainability challenges in materials science and engineering.