Additional Functional Groups Research Articles

Structural Modifications on Dopamine Molecules toward Polydopamine Applications

Polydopamine (PDA) is a synthetic material synthesized through the oxidative self‐polymerization of dopamine under alkaline conditions. This material emulates the adhesive properties of mussel foot proteins, allowing the formation of robust and stable organic coatings on various surfaces. Researchers have attempted to identify and improve the surface‐coating properties of PDA by incorporating additional organic functional groups. This review explores the structural modifications of dopamine molecules at the organic chemistry level, with a focus on changes in the catechol moiety and aliphatic amines, and examines their impact on the applications of PDA. The flexibility of these modifications underscores their importance for optimizing PDA coatings for a wide range of applications.

Structural and Pasting Properties of Lentil Starch: A Comprehensive Review

ABSTRACTLentils are highly nutritious as they are rich in both proteins and starch, making them a crucial component of the human diet. This review article focuses on the morphology, microstructure, and pasting properties of lentil starch (LS). The LS exhibits poor crystallinity due to its high amylose‐to‐amylopectin ratio as reflected in its pasting behavior. The shapes of the LS granule range a wide variety, starting from huge ovals to small rounds, as captured in the scanning electron microscope (SEM). Fourier transform infrared (FTIR) spectroscopy displays the arrangement of starch molecules at the vicinity of the granule surface and detects the presence of additional functional groups in the modified starches. X‐ray diffraction (XRD) demonstrates both the qualitative and quantitative alterations in the crystalline domains of starch granules effectively. Nuclear magnetic resonance (NMR), in particular 13C CP/MAS have successfully examined the structural order of amylolyzed LS concentrations and amylose–lipid complex at the molecular level. This review might be of interest to the professionals involved in food and pharmaceuticals on product development using lentil as one of the ingredients in their formulations.

Interferometric analysis of the opto‐mechanical properties for polyamide‐6 antimicrobial fibers

AbstractPolyamide‐6 fibers were modified for use as antimicrobial fibers using two complementary methods: grafting with polyacrylic acid and silver nanoparticle treatment. The grafted samples exhibited different grafting yields of 7%, 8.8%, 10%, and 20.7%. Subsequently, two grafted samples (7% and 20.7% yields) were treated with silver nanoparticles (Ag NPs). The grafting process and the silver nanotreament were successfully confirmed using FTIR spectroscopy and SEM microscopy. Shake‐ flask method was used to study the cell viability of nanotreated samples. A two‐beam Mach–Zehnder interferometer was used to characterize the opto‐mechnaical and structural properties of the modified samples. For this purpose, a mechanical drawing device was equipped with the interferometer. The results indicated that with increasing grafting yield, optical properties decreased in both directions of light vibration. A fitting method was employed to calculate intrinsic optical properties that help to determine structural properties. Mechanical properties, including tensile strength and elongation at break, were also examined. Treatment of the grafted samples with silver nanoparticles improved their optical, mechanical, and antimicrobial properties. These findings confirmed that the PA‐6‐g‐PAA 20.7%‐t‐Ag NPs sample is suitable for various medical applications. Figures and tables are provided for illustration.Highlights PA‐6 fiber has been modified for medical applications by complementary processes. Grafting process introduced additional functional groups and enhanced ductility. Ag nano‐treatment gives the grafted PA‐6 fiber good antimicrobial activity. Interferometry precisely characterizes structural and opto‐mechanical properties. PA‐6‐g‐PAA20.7%‐t‐Ag NPs sample has good mechanical and antimicrobial properties.

Safety of a feed additive consisting of vitamin B2/riboflavin produced with Eremothecium ashbyi CCTCCM 2019833 for all animal species (Hubei Guangji Pharmaceutical Co., Ltd).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of a feed additive consisting of vitamin B2/riboflavin produced with Eremothecium ashbyi CCTCCM 2019833 intended for use as a nutritional additive (functional group: vitamins, pro-vitamins and chemically well-defined substances having similar effects) for all animal species. The characterisation, safety and efficacy of the additive have been already assessed previously; however, the FEEDAP Panel could not conclude on the safety of the additive for the target species, consumers and the users due to lack of reliable toxicological data. In the present assessment, the applicant submitted new genotoxicity and repeated dose oral toxicity studies. After the assessment of the data newly submitted, the FEEDAP Panel concluded that the use of the feed additive in animal nutrition under the conditions of use proposed is of no safety concern for the target species and the consumer. The additive is not a skin/eye irritant nor a skin sensitiser, but it is considered a respiratory sensitiser.

Di‐o‐Quinones Bearing an Additional Coordination Function in m‐Dioxyarylene Linker as Potential Building Blocks for Coordination‐Driven Self‐Assembly

AbstractBis‐dioxolene ligands 1–5, linked by m‐dioxyarylene spacers were synthesized. Such ligands are considered as potential building blocks for coordination‐driven design of cage‐like units by self‐assembly mechanism. The peculiarity of new species is in presence of additional functional group in the linker such as pyridinyl (1), ester (2–3), and carboxyl (4–5) that add the possibilities for ordering modes during the design of coordination polymers. Di‐o‐quinones 1–2 were synthesized by reaction of 4‐chloro‐3,6‐di‐tert‐butyl‐o‐quinone (4‐Cl‐3,6‐Q) with pyridine‐3,5‐diol and methyl 3,5‐dixydroxybenzoate, respectively, in presence of base. The preparation of di‐o‐quinone 5 turned to be a multistage process where di‐catechols 3–4 were isolated as intermediates.

Structural and electronic tuning of single-benzene fluorophores with simple methylations

Recent advancements in the development of low molecular-weight fluorophores have led to the study of a single-benzene fluorophore (SBF) containing both electron-withdrawing and electron-donating groups within an aromatic ring, resulting in unique photophysical properties. In this study, we explored the modulation of emissions by adjusting the electron-donating properties via the simple methylation of the 2,5-diamino or 2,5-dihydroxy terephthalate structure. Introducing additional functional groups under both symmetrical and unsymmetrical conditions demonstrated changes in the photophysical properties, which was not only owing to the structural variations in the location and number of methyl groups but also due to alterations in the electron-donating properties. The observed effects appeared to be owing to the interactions between the amine and ester groups, as confirmed via single-crystal X-ray diffraction. Finally, hydrolysis of the ester to the corresponding carboxylic acid resulted in various emission wavelengths at different pH values via protonation and deprotonation. This study provides valuable insights for predicting the structural and electronic effects of additional functional groups in SBF.

Nickel‐Catalyzed Reductive Protocol to Access Silacyclobutanes with Unprecedented Functional Group Tolerance

AbstractWhile significant progress has been made in the area of transition metal‐catalyzed ring‐opening and formal cycloaddition reactions of 1,1‐disubstituted silacyclobutanes (SCBs), synthesizing these SCBs—particularly those bearing additional functional groups—continues to present synthetic challenges. In this context, we present a novel Ni‐catalyzed reductive coupling reaction that combines 1‐chloro‐substituted silacyclobutanes with aryl or vinyl halides and pseudohalides, thereby obviating the need for organometallic reagents. This method facilitates the generation of 1,1‐disubstituted silacyclobutanes with a remarkable tolerance for various functional groups. This approach serves as a complementary and more step‐economical alternative to the commonly used yet moisture‐ and air‐sensitive nucleophilic substitution reactions involving Grignard or lithium reagents. Our initial mechanistic studies indicate that this reaction is initiated by oxidative cleavage of the Si−Cl bond in 1‐chlorosilacyclobutanes, which represents a distinct mechanism from the previously documented reductive coupling processes involving carbon electrophiles and chlorosilanes.

Online in-situ modification of biochar for the efficient removal of elemental mercury and co-benefit of SO2/NO removal

In this study, non-thermal plasma discharge was proposed for online in-situ modification of biochar injected into coal-biomass co-combustion flue gas, aiming to achieve the combined removal of elemental mercury (Hg0), NO, and SO2 from flue gas. After plasma discharge, the pore structure of biochar was slightly improved whereas the surface morphology of biochar was almost unchanged. After plasma discharge under O2, SO2, and HCl atmospheres, the oxygen, sulfur, and chlorine contents of biochar were obviously increased. More exactly, additional functional groups were formed on the modified biochar surface, such as CO, C(O)OC, CS, and CCl. Compared with raw biochar, the biochar modified under HCl, SO2, O2, H2O and CO2 atmospheres exhibited higher Hg0 removal efficiency, and longer modification time resulted in better Hg0 removal performance. The optimal modification atmosphere and reaction temperature were the simulated flue gas (SO2 + HCl + CO2 + O2 + H2O + NO + N2) and 20 ℃-100 ℃, respectively. The modified biochar exhibited excellent resistance to SO2 and H2O. The addition of HCl, CO2, NO, and O2 contributed to Hg0 removal. The removal efficiency of NO and SO2 attained a maximum of 100 %. The Hg0 removal mechanism was further revealed, where CO, C(O)OC, CS, and CCl served as active components.

Developing microalgae harvesting: Enhanced efficiency with magnetite-urea nanocomposites for sustainable astaxanthin biorefinery

Harvesting costs, accounting for 15–30 % of total expenses, are a major bottleneck in microalgae biorefinery due to low cell density and energy-intensive processes. This study investigates Fe3O4-Urea (Fe@urea) nanocomposites (NCs) to replace conventional methods and improve the harvesting efficiency (HE) of Chlorella zofingiensis, known for its high lipid and astaxanthin content. Urea-coated magnetite nanoparticles (NPs) with additional functional groups significantly improved harvesting performance across all pH levels compared to conventional Fe3O4 NPs. HE was evaluated using both optical density and cell counting methods, with the latter proving superior results by eliminating interference from unreacted salts and debris. Optimization of nanocomposite concentrations and culture pH with Fe@urea achieves 95 % HE at 800 mg L−1 and pH 3–4. The Langmuir and Freundlich models confirmed the nanocomposite's multifaceted capabilities. Characterization techniques included SEM, FTIR, EDX, zeta potential analysis, and TEM. This innovative approach can revolutionize large-scale microalgae biorefineries, enhancing sustainable biofuel and bioproduct production and supporting the Sustainable Development Goal of Affordable and Clean Energy (SDGs 7).

Safety and efficacy of a feed additive consisting of Saccharomyces cerevisiae NCYC R618 (Benesacc®) for chickens for fattening and other poultry species for fattening and reared for laying (Global Nutritech Biyoteknoloji Ltd. Sti).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Saccharomyces cerevisiae NCYC R618 as a zootechnical feed additive (functional group: gut flora stabiliser) for chickens for fattening and other poultry species for fattening and reared for laying. The additive has never been authorised. The strain under assessment S. cerevisiae (NCYC R618) qualifies for the qualified presumption of safety (QPS) and, consequently, the FEEDAP Panel concluded that the product is safe for the target species, the consumers and the environment. The FEEDAP Panel could not conclude on the skin and eye irritation or skin sensitisation potential of the additive. The additive should be considered a respiratory sensitiser. Due to the lack of sufficient data, the Panel cannot conclude on the efficacy of the additive under the proposed conditions of use.

Assessment of the feed additive consisting of propionic acid for all terrestrial animal species for the renewal of its authorisation (Eastman Chemical B.V., Perstorp AB, Dow Europe GmbH, BASF SE).

Propionic acid is currently authorised as a technological additive (functional group: silage additives) for all animal species. The applicants requested for the renewal of the authorisation of propionic acid when used as a feed additive for all terrestrial animal species. The applicants have provided evidence that the additive in the market complies with the conditions of the authorisation. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) confirms that the use of propionic acid under the current authorised conditions of use is safe for the target species, the consumers and the environment. Regarding user safety, the additive is corrosive to the skin and any exposure to users is considered a risk. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of tartrazine for its use in baits for freshwater fish (GIFAP).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of tartrazine as sensory additive (functional group: (a) colourants: (i) substances that add or restore colour in feedingstuffs). Tartrazine is intended to be incorporated in fishing baits up to a maximum of 30 mg/kg in complementary feed in order to colour them and attract fish in freshwater (ponds, rivers), for both recreational and competitive fishing. The additive is not intended for use in aquaculture. Tartrazine is already authorised for use with cats and dogs, ornamental fish, grain-eating ornamental birds and small rodents. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the use of tartrazine in the preparation of baits for freshwater fish under the proposed conditions of use is of no concern for the target animals. The use of tartrazine as a feed additive under the proposed conditions of use is considered safe for the consumer and the environment. Regarding the user safety, the additive should be considered a dermal and respiratory sensitiser. Inhalation and dermal exposure are considered a risk. The FEEDAP Panel could not conclude on the irritation potential of the additive. In absence of data, no conclusion can be reached on the efficacy of tartrazine in freshwater fish baits.

Safety and efficacy of a feed additive consisting of lutein-rich extract of Tagetes erecta L. for turkeys for fattening (EW Nutrition).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of lutein-rich extract of Tagetes erecta L. as sensory additive (functional group: Colourants (ii) substances which, when fed to animals, add colours to food of animal origin) for turkeys for fattening. The additive is already authorised for use in feed for chickens for fattening and minor poultry for fattening and laying hens and minor poultry for laying. The FEEDAP Panel concluded that the use of lutein-rich extract of T. erecta is safe for turkeys for fattening when used up to the maximum proposed use level of 80 mg total carotenoids/kg complete feed. The Panel concluded that the use of lutein-rich extract of T. erecta in feed for turkeys for fattening under the proposed conditions of use would not be of concern for the consumer, considering also its use in other poultry for fattening and for laying hens. Regarding user safety, the lutein-rich extract of T. erecta extract is irritant to skin and eyes and any exposure is considered a risk. The conclusions on user safety reached for the lutein-rich extract of T. erecta would, in principle, apply to preparations made with it. The use of the additive in feed for turkeys for fattening under the proposed conditions of use is safe for the environment. The FEEDAP Panel concluded that the additive has the potential to colour the skin of turkeys for fattening at the proposed conditions of use.

Safety and efficacy of a feed additive consisting of fumaric acid for all animal species for the renewal of its authorisation and extension of use (Life SUPPLIES NV)

Abstract Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for the renewal of the authorisation of fumaric acid as a technological and sensory additive (functional groups: preservative and flavouring compounds, respectively) and for a new use of the additive as a technological additive (functional group: acidity regulator) for all animal species. The applicant provided evidence that the additive currently in the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that fumaric acid remains safe under the authorised conditions of use for the terrestrial animals, consumers and the environment. However, the Panel cannot conclude on the safety for the aquatic animals under all authorised condition of use. Fumaric acid is irritant to skin, eyes and respiratory tract, and should be considered a skin and respiratory sensitiser due to the presence of nickel. The Panel also considers that the new use of the additive as an acidity regulator under proposed conditions of use would not introduce risks not already considered. There is no need to assess the efficacy of the additive in the context of the renewal of the authorisation (for its use as preservative and flavouring compound). The Panel is not in the position to conclude on the efficacy of fumaric acid as an acidity regulator in feed.

Interlayer Space Engineering-Induced Pseudocapacitive Zinc-Ion Storage in Holey Graphene Oxide-Bearing Vertically Oriented MoS2 Nano-Wall Array Cathode for Aqueous Rechargeable Zn Metal Batteries.

Transition metal dichalcogenides, particularly MoS2, are acknowledged as a promising cathode material for aqueous rechargeable zinc metal batteries (ARZMBs). Nevertheless, its lack of hydrophilicity, poor electrical conductivity, significant restacking, and restricted interlayer spacing translate into inadequate capacity and rate performance. Herein, the unique porous structure and additional functional groups present in holey graphene oxide (hGO) are taken advantage of to dictate the vertical growth pattern of oxygen-doped MoS2 nanowalls (O-MoS2/NW) over the hGO surface. Compared to conventional graphene oxide (GO), the presence of nano-pores in hGO facilitates the homogeneous dispersion of Mo precursors and provides stronger interaction sites, promoting the uniform vertical alignment of O-MoS2/NW. The synergistic interaction between O-MoS2-NW and hGO translates to enhanced electron conductivity, efficient electrolyte penetration, enhanced interlayer spacing, reduced restacking, and enhanced surface area. As a consequence of precise control of various factors that decide the overall battery performance, a high discharge capacity (227mAhg-1 at 100mAg-1) cathode material with significantly lower charge transfer resistance (66Ω) compared to pristine O-MoS2 (153Ω) is developed. These findings underscore the potential of hGO as a multifunctional platform for nanoengineering high-performance cathode materials for the next generation of efficient and durable ARZMBs.

A systematical comparation of Cu (II) adsorption behavior and mechanism between biomass fly ash and biogas residue pyrolysis char

Biomass fly ash (BFA) and biogas residues are the main by-products of biomass direct-fired power generation and biogas production. This study compares the Cu(II) adsorption mechanisms of BFA and biogas residue pyrolysis char (BRPC) through systematic tests. BFA exhibited a significantly higher adsorption capacity (75.34 mg/g) than BRPC (42.80 mg/g). The pseudo-first-order kinetic model best described BFA, while the Elovich model was optimal for BRPC. Both materials fit the Freundlich isotherm model. BFA's superior mineral co-precipitation and ion-exchange capacity are due to its rich mineral content, particularly calcium. BRPC benefits from an additional functional group complex adsorption due to its pyrolytic charcoal content. Variations in pore structure of BFA and BRPC did not demonstrate a significant effect on the adsorption. The results of this study provide essential data support for the potential of high-value utilization of BFA and BRPC and the innovative modification of high-performance biomass-based heavy metal adsorbent materials.

Betaketothioesters in organocatalysis: Harnessing nucleophilic reactivity, the fluorophobic effect, and expanding the substrate repertoire

The use of thioesters as nucleophiles marks a considerable change in organic synthesis. This new method, propelled by gentle enolization with minimal catalyst loading, results in enantiomeric excesses surpassing 95 % under ambient conditions, accomplishing total conversion in merely 6 h. Remarkably, this method eliminates the need for additional functional groups in nitroalkenes for efficient chirality transfer from the organocatalyst. The exceptional reactivity of thioesters, combined with their water tolerance, enables reactions utilizing the hydrophobic effect, resulting in reaction times as short as 15 min and products with slightly enhanced stereoselectivity compared to analogous reactions in dichloromethane. Additionally, reactions performed in perfluorinated solvents outpace their homogenous counterparts in organic solvents, delivering products in shorter time with comparable stereoselectivity. This work highlights the rare utilization of the fluorous effect in organocatalysis. Simple squaramides also exhibit remarkable catalytic activity in the reactions of beta-keto thioesters with alpha-bromo nitroalkenes. As little as 0.1 mol% of the catalyst leads to product formation with an 86 % yield (qNMR) and 93 % enantiomeric excess. Upscaling the reaction does not significantly affect the enantiomeric excess but leads to a slight decrease in yield from 82 % to 77 %. It has been demonstrated that thioesters react more rapidly than their ketoester counterparts, and the two-step reaction leading to dihydrofuran ring closure is entirely accomplished by extending the reaction time, eliminating the need for additional base. The examples presented here expand the range of substrates derived from carboxylic acid esters in catalytic reactions, suggesting the potential for the synthesis of challenging reactions in analogs of alkoxyl esters. Additional KS-DFT calculations shed more light on the reaction paths, rationalizing the observed stereochemical outcomes.

High-performance removal of methylene blue dye using porous lignin extracted from sugarcane bagasse by deep eutectic solvent

This study evaluated the ability of triethyl benzyl ammonium chloride/lactic acid deep eutectic solvent extracted lignin (TEBAC/LA-DES-L) to adsorb methylene blue (MB) without additional functional group modification. The structure and morphology of TEBAC/LA-DES-L were characterized using SEM, BET, FT-IR, and TGA techniques. Various factors influencing MB adsorption, such as extraction temperature, solution pH, adsorbent dose, initial MB concentration, adsorption time, and reaction temperature, were investigated. The Redlich-Peterson isotherm displayed a good fit for the experimental data, with a maximum adsorption capacity of 85.16 mg/g. Kinetic analysis suggested that the adsorption process followed the pseudo-second-order model, with adsorption occurring in <100 min on DES-L-4 h. The mechanism of MB adsorption on DES-L-4 h was attributed to electrostatic attraction, hydrophobic interactions, and hydrogen bonding forces. Overall, DES-L-4 h demonstrated high adsorption capacity and rapid adsorption rate, making it a promising adsorbent for effectively removing cationic dyes from wastewater.

Anion exchange recovery of rhenium from industrial liquors followed by direct synthesis of a rhenium halide salt

In the present study, the sorption of perrhenate ions from sulfuric acid liquors was studied using three types of polymer ion exchange resins. An anion exchange resin type 1 (a copolymer of 2-methyl-5-vinylpyridine with divinylbenzene (VP-DVB)) as well as two polyfunctional resins containing anion and cation exchange functional groups, namely, type 2 (a carboxylated VP-DVB with pyridine-2-carboxylic acid (picolinic acid) functional group) and type 3 (an aminophosphorylated VP-DVB with pyridine-2-[(methylamino)methyl]phosphonic acid functional group), were studied. The resins before and after rhenium sorption were characterized by FT-IR spectroscopy and XPS spectroscopy. The incorporation of additional acidic functional groups into the polymer matrix of the VP-DVB resins led to a slight decrease in the rhenium anion exchange capacity. At the same time, polyfunctional resins make it possible to strip rhenium with hydrochloric acid. A completely new process for the preconcentration of rhenium as a halide compound, which will contribute to the low-cost production of metallic rhenium, can be implemented using these new polyfunctional resins. Column sorption experiments using real uranium leach liquors demonstrated an exchange capacity of 33.2 mg of Re per gram of resin and a concentration factor in the eluate of ∼2500. The possibility of anion exchange recovery of rhenium from uranium leach liquors by Type 3 resin followed by direct precipitation of potassium hexachlororhenate from hydrochloric acid desorption liquor was demonstrated. The present study provided a new resin for rhenium recovery with excellent adsorption and elution characteristics, which is a promising candidate for practical applications.

Allenamides as a Powerful Tool to Incorporate Diversity: Thia-Michael Lipidation of Semisynthetic Peptides and Access to β-Keto Amides.

Lipopeptides are an important class of biomolecules for drug development. Compared with conventional acylation, a chemoselective lipidation strategy offers a more efficient strategy for late-stage structural derivatisation of a peptide scaffold. It provides access to chemically diverse compounds possessing intriguing and non-native moieties. Utilising an allenamide, we report the first semisynthesis of antimicrobial lipopeptides leveraging a highly efficient thia-Michael addition of chemically diverse lipophilic thiols. Using chemoenzymatically prepared polymyxin B nonapeptide (PMBN) as a model scaffold, an optimised allenamide-mediated thia-Michael addition effected rapid and near quantitative lipidation, affording vinyl sulfide-linked lipopeptide derivatives. Harnessing the utility of this new methodology, 22 lipophilic thiols of unprecedented chemical diversity were introduced to the PMBN framework. These included alkyl thiols, substituted aromatic thiols, heterocyclic thiols and those bearing additional functional groups (e.g., amines), ultimately yielding analogues with potent Gram-negative antimicrobial activity and substantially attenuated nephrotoxicity. Furthermore, we report facile routes to transform the allenamide into a β-keto amide on unprotected peptides, offering a powerful "jack-of-all-trades" synthetic intermediate to enable further peptide modification.