Long Alkyl Chains Research Articles

Using modified raw materials to fabricate electrospun, superhydrophobic poly(lactic acid) multiscale nanofibrous membranes for air-filtration applications

Nanofiber filtration materials are of considerable interest owing to their excellent interception capability for particulate matter (PM). However, numerous obstacles, such as highly complex manufacturing techniques, a short service life, low efficiency, and poor uniformity, hinder the large-scale production and utilization of these materials. In this work, multiscale modified poly(lactic acid) nanofibrous membranes (diameters: ∼49.9 and ∼223.22 nm) were fabricated by attaching long-chain alkyl groups with low surface energy to raw materials via chemical grafting and subsequently using the modified poly(lactic acid) for needleless electrospinning. This modification method facilitates the stable preparation process required for large-scale production. The membranes have small pores (∼340 nm in diameter) with a narrow pore-size distribution, superhydrophobicity (water contact angle: 155°), relatively high tensile strength (20.36 MPa), high filtration efficiency (>98.500% for PM0.3), and low resistance (<0.032% of atmospheric pressure), and they can maintain a filtration efficiency above 90.000% after 50 blowback cycles. Moreover, for particles with a diameter of <0.3 μm, the composites exhibit an initial filtration efficiency of 99.995%, which only decreases to 98.000% after 10 washing cycles. Therefore, this work presents a promising solution for the large-scale production of high-efficiency air filters.

Molecular design and experimental study on the alkylation of benzene with C6 olefin dimer with Lewis acidic monoamine ionic liquids and its sulfonate surfactant properties

Long-chain alkyl benzene (LAB), conventionally manufactured by petrochemical routes, is an important intermediate for the synthesis of high-value chemicals, especially detergents and oil displacement agents. The preparation of LAB from coal-based olefins has attracted extensive research interest. In this work, the alkylation activity of four Lewis acidic monoamine chloroaluminate ionic liquids (LAMCILs), designed by AlCl3 and monoamine hydrochloride with alkyl chains of different lengths, was predicted by quantum chemical calculations using the synthesis of 1-methyl-1-butylheptylbenzene (MBHB) with benzene and C6 olefin dimer as a model reaction. The HOMO*-LUMO* gap indicated that the alkylation activity was enhanced with increasing alkyl chain length of the organic amine molecules in the LAMCILs, in the following order: [n-C6H13NH3]Cl-AlCl3 > [n-C4H9NH3]Cl-AlCl3 > [n-C3H7NH3]Cl-AlCl3 > [C2H5NH3]Cl-AlCl3. These four LAMCILs were successfully synthesized and used to catalyze the alkylation of benzene with the C6 olefin dimer. The experimental results are consistent with the calculated results. The UV/VIS characterization showed that their Hammett acidity function (H0) increased as the alkyl chain of organic monoamine molecules in the LAMCILs extended. Therefore, a two-way correlation between the HOMO*-LUMO* gap, MBHB yield and Hammett acidity function can be established. Furthermore, the effect on the yield of MBHB was investigated by the method of metal chloride modified [n-C4H9NH3]Cl-AlCl3 ionic liquids. The results showed that the CuCl2-modified [n-C4H9NH3]Cl-AlCl3 ionic liquid had better catalytic activity in this study. Under optimal reaction conditions, the conversion of the C6 olefin dimer and selectivity toward MBHB reached 100 % and 91.34 %, respectively. Finally, the surfactant properties of sodium 1-methyl-1-butylheptylbenzene sulfonate (SMBHBS) were examined, and the results indicated that its surfactant properties were basically comparable to those of commercial LAS.

Mechanism of defect passivation achieved by chemical interaction in inverted perovskite solar cells

A variety of defects exist in the solution-processed polycrystalline perovskites, resulting in photovoltaic output losses and degradation. Chemical interaction is a promising way to realize the passivation of defects. Herein, cetyl pyridinium bromide (CPB) containing both pyridine units and long-chain alkyl groups was introduced in the perovskite precursor solution as a passivation agent. Experimental results show that pyridine unit in CPB formed coordination with uncoordinated Pb2+, which also interact with N–H in MAPbI3. Meanwhile, long-chain alkyl groups in CPB had interaction with MAI and PbI2 in MAPbI3. Thus, trace amount of CPB in the precursor solution improved the optoelectronic properties of perovskite films and suppressed non-radiative carrier recombination in perovskite solar cell (PSC). CPB-modified perovskite films exhibit a lower trap-state density and stronger carrier migration capability. It enables the significant enhancement of PCE values of the p-i-n structured PSC from 18.27 % to 20.53 %, accompanied by the improved stability. Our work exhibits more possibility between passivating additive and PSC performance.

STEARIN AS A STARTING MATERIAL FOR THE SYNTHESIS OF BIOLOGICALLY ACTIVE IONIC LIQUIDS

For the first time, the possibility of using widely available stearin for the production of fatty acid-derived ionic liquids (ILs) has been shown. New amphiphilic ILs based on imidazolium, pyridinium, and quaternary ammonium cations containing long-chain alkyl substituents were obtained. The synthesized compounds are shown to have biological activity comparable to known antimicrobial compounds. ILs with one alkyl substituent have higher cytotoxicity and antimicrobial activity compared to disubstituted derivatives.

Influence of blending cycloalkanes on the energy content, density, and viscosity of Jet-A

This work focuses on the influence of addingvarious cyclohexanes on the volumetric and gravimetric energy content, density, and kinematic viscosity of Jet A. Mixtures of Jet-A and alkylcyclohexanes with varying alkyl-chain lengths, degrees of branching, and number of rings at 5, 10, 15, 30, and 60 % wt./wt. were examined. Among the alkylcyclohexanes under study, addition of the compounds with the longest alkyl chains, i.e., n-hexylcyclohexane and n-heptylcyclohexane, were identified as compounds with the potential to increase both the specific and energy density of the mixtures. Contrasting results obtained for 1,2,3-trimethylcyclohexane (decreasing specific energy and increasing density) and 1,3,5-trimethylcyclohexane (decreasing energy density and kinematic viscosity) revealed the importance of the relative position of the substituents in cycloalkanes. More sterically hindered isomers and less symmetrical structures were associated to higher density and kinematic viscosity values. C9-cycloalkanes were identified as potential molecules to decrease the kinematic viscosity of blending mixtures. Branched structures in C12-cycloalkanes, such as 1,3-diisopropylcyclohexane and 1,4-diisopropylcyclohexane, were found to decrease gravimetric energy. However, additions higher than 15 % wt./wt. of branched cycloalkanes were also associated with increments of the volumetric energy content to values similar when linear alkyl-chain cycloalkanes of the same carbon number were added into the mixture. Decalin withcis-stereochemistry exhibited greater energy density, density, and kinematic viscosity thantrans-stereochemistry. JP-10 additions provided slightly higher energy densities but lower specific energies thancis-decalin. At low mass additions (<10 % wt./wt.), tricyclic compounds, such as tetradecahydroanthracene and adamantane, caused the largest increases in the energy density and density of the mixtures. Tetradecahydroanthracene increased the specific energy by +0.26 % and the volumetric energy by +1.40 % when added at 5 and 10 % wt./wt., respectively. However, larger mass additions (>10 % wt./wt.) of adamantane into Jet-A are not possible due to solubility conditions. Additions of JP-10 (28 % wt./wt.), cis-decalin (40 % wt./wt.), or trans-decalin (50 % wt./wt.) into Jet-A are proposed to maximize energy content (∼+3.5 %) while meeting density and kinematic viscosity requirements. These results broaden the understanding of cycloalkanes as potential key compoundsof sustainable aviation fuels withhigher energy content and minimal environmental impact.

Ultrasound and microwave-assisted extraction of silkworm pupae (Bombyx mori) oil and its quality characterisation

Abstract This study aimed to investigate the effect of Ultrasound-Assisted Extraction (USAE) and Microwave-Assisted Extraction (MWAE) methods on the quality parameters and yield of silkworm pupae oil. The selected key independent variables that impact the extraction process, such as power levels, liquid-solid (L/S) ratio, and time for the extraction of SPO (silkworm pupae oil), were optimised. The extracted silkworm pupa oil was further characterised for oil quality, thermal behaviour using DSC (Differential Scanning Calorimeter), colour values and fatty acid profile for its suitability for various food applications. USAE resulted in a maximum oil yield of 36.60 ± 0.20% at 400 W with an L/S ratio of 6 ml/g at 20 min pulsation time. The fatty acid profile of SPO through GC-MS revealed significant amounts of linoleic acid and linolenic acid (6.50% and 67.18%) in USAE, followed by MWAE (34.40 ± 0.20%). Further, the FTIR spectra revealed high-intensity bands ranging between 2300-3000 cm−1, associated with functional groups from long-chain alkyl groups and triglycerides. It was observed that SPO had Omega-3 and Omega-6 long chain fatty acids and triglycerides which are essential for human health. Antioxidant activity exhibited high free radical scavenging in USAE (27.46 ± 0.15%) followed by MWAE (26.63 ± 0.15%). The morphology of SEM images of USAE exhibits microstructural damage to cells resulting in the release of more oil. DSC thermograph displayed that crystallisation and melting curve temperatures for USAE and MWAE were lower than SXLE (soxhlet extraction) alone due to higher amounts of unsaturated fatty acids. SPO extracted using USAE exhibited higher oil yield with significant antioxidant capacity and good thermal properties for its application in food products.

Side-chain functionality driven thermoresponsive and semicrystalline poly(L-glutamate)s and self-assembly

The appropriate functionalization of synthetic polypeptides is the key to introduce stimuli-responsiveness and amphiphilicity for generating self-assembled nanostructures (micelles, vesicles, etc.) with promising applications in the areas of drug/gene delivery and tissue engineering. This work presents a way to functionalize poly(L-glutamate)s with long chain alkyl groups and to study the semicrystalline as well as solution-phase behavior such as thermoresponsiveness, self-aggregation etc. of the resultant polypeptides. The ring opening polymerization (ROP) of the as-synthesized γ-propargyl-L-glutamate N-carboxyanhydride produce poly(L-glutamate) (PGlu-Pr) with pendant propargyl group, which is clicked with long-chain alkyl azides via Cu-catalyzed alkyne-azide-cycloaddition (Cu-AAC) reaction to give alkyl-grafted poly(L-glutamate)s [PGlu–Cn(s), n = 10, 12, 16, 20]. The helical secondary conformation predominates for PGlu-Pr and PGlu–Cn(s) in both solution phase and in solid state and the extent of helicity decreases with increase in the length of alkyl chains. The corresponding control monomeric analogs, alkyl grafted L-glutamates (Glu–Cn)s, show formation of birefringent crystals due to the presence of the long alkyl chains as examined by differential scanning calorimetry (DSC) and polarized optical microscopy. Whereas PGlu–Cn(s) having n ≥ 12 show feeble crystallinity in their solid state. Interestingly, the solutions of PGlu–Cn(s) in CHCl3 and THF show upper critical solution temperature (UCST)-type thermoresponsive properties with tunable cloud point, but no such property is observed for Glu–Cn(s). Self-assembly of PGlu–Cn(s) in these solvents generates vesicular nanoaggregates as confirmed by the dynamic light scattering and transmission electron microscopy. These nanoaggregates can encapsulate organic dye (Eosin B) as studied by fluorescence and confocal microscopy.

Detoxification of coal-tar pitch by alkylation method and toxicity evaluation by chemical index, fumes and water-soluble substances

Coal-tar pitch (CTP) output in China has consistently exceeded 7 million tons annually since 2011. CTP contains 16 toxic polycyclic aromatic hydrocarbons (PAHs) that are preferentially monitored by the American Environmental Protection Agency (EPA). As a result, the widespread and extensive use of CTP is restricted. Consequently, finding ways to reduce the toxicity of CTP has become an urgent concern. In the paper, the reaction conditions were optimized using model compounds (naphthalene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, benzo [a]pyrene) of CTP. Subsequently, the CTP was modified through alkylation reaction using 1-dodecene, and the detoxification effect was evaluated based on chemical index, fumes, and water-soluble substances. The total content of 16 toxic PAHs in the modified CTP (MCTP) decreased by 75.56% compared to the original CTP. The toxicity equivalent quotient (TEQ) of the MCTP was reduced by more than 65% according to different environmental standards. The content of the 16 PAHs detected in MCTP fumes released at 140 °C decreased by 80.89%, while in water-soluble substances it decreased by 64.04% and 76.67% at 30 °C and 60 °C, respectively. These results strongly indicate the effectiveness of the alkylation method in reducing the toxicity of CTP. However, in order to develop more environmentally-friendly materials, it is necessary to explore more efficient catalysts and cheaper modifiers, which will be the focus of our future research. Novelty StatementThis study investigated the toxicity inhibition of CTP to reduce the content of PAHs by alkylation method. The modification process was analyzed using model compounds to understand the potential reaction pathways. The objective of toxicity inhibition was achieved by creating low-toxicity and long-chain alkyl substitutes. Additionally, the toxicity of CTP and MCTP was assessed by introducing fumes and water-soluble substances.

Interfacial Water Tuning by Intermolecular Spacing for Stable CO2 Electroreduction to C2+ Products.

Electroreduction of CO2 to multi-carbon (C2+ ) products is a promising approach for utilization of renewable energy, in which the interfacial water quantity is critical for both the C2+ product selectivity and the stability of Cu-based electrocatalytic sites. Functionalization of long-chain alkyl molecules on a catalyst surface can help to increase its stability, while it also tends to block the transport of water, thus inhibiting the C2+ product formation. Herein, we demonstrate the fine tuning of interfacial water by surface assembly of toluene on Cu nanosheets, allowing for sustained and enriched CO2 supply but retarded water transfer to catalytic surface. Compared to bare Cu with fast cathodic corrosion and long-chain alkyl-modified Cu with main CO product, the toluene assembly on Cu nanosheet surface enabled a high Faradaic efficiency of 78 % for C2+ and a partial current density of 1.81 A cm-2 . The toluene-modified Cu catalyst further exhibited highly stable CO2 -to-C2 H4 conversion of 400 h in a membrane-electrode-assembly electrolyzer, suggesting the attractive feature for both efficient C2+ selectivity and excellent stability.

The structure effect on the physicochemical properties of Gemini surfactants used as viscosity reducer for heavy oil

The structure of surfactants is a key factor affecting their physicochemical properties. Our earlier work synthesized Gemini surfactants CEA-n with different structures. In this paper, the effects of polyether chain length, spacer groups number and the hydrophobic alkyl chain length of surfactants CEA-n on the interfacial properties, wettability, rheological properties and emulsion stability were fully studied in detail, and the effects of surfactant structure on their temperature tolerance and salt resistance properties were explored. The results showed that the variation of polyether chain length of surfactant molecules had the greatest impact on the interfacial tension (IFT), and the surfactants with longer alkyl chains had better interfacial film strength. The wettability of various surfactant systems was investigated by the sessile drop method, and the contact angle decreased remarkably from 92.6° to 17.9° in a short time (300 s) after adding surfactant CEA-6. Judging from the fluid type, each heavy oil emulsion system exhibited pseudoplastic fluid characteristics, and dilute shear phenomenon was observed in the range of 0–50 s−1 with an increasing shear ratio. The particle size, dispersibility and coalescence of the heavy oil O/W emulsion droplets of each system were observed through the microscopic images of the emulsions, and the factors affecting the stability of the emulsions were systematically studied by bottle test. It was found that the increase of oil-water ratio, surfactant concentration and mixing speed would improve the stability of O/W emulsions, while high temperature would accelerate the demulsification process. All these results established the structure-property relationship of surfactant molecules.

Exploring phosphoryl oxygen basicity in U(VI) complexation: A comparative study from trialkyl phosphate to phosphine oxide.

The conventional argument that extraction efficiency depends on the "basicity of the phosphoryl oxygen" is thoroughly examined in this study. The analysis involves studying the electronic structures of various ligands, such as phosphate, phosphonate, phosphinate, and phosphine oxide, as well as variations in their alkyl chain length, and their corresponding uranium complexes. The studies revealed a significant amount of destabilizing strain and steric repulsion for ligands having longer alkyl chains upon complexation. A considerable amount of stabilizing orbital and dispersion interactions compensate for these repulsions, forming stable complexes. Dispersion interactions become more significant upon chain elongation and are mainly responsible for the preference for U(VI) metal ions by ligands with lengthy alkyl chain units. The preference of phosphine oxide ligands for U(VI) is analyzed within the context of enhanced orbital interactions resulting from the energetically close donor (ligand) and acceptor (metal nitrate) orbitals. Additionally, dispersion-based interactions also become significant, especially with larger chain lengths. The electronegative environment around the phosphorus atom, along with the existence of low-dipole moment structures, is also examined in relation to their possible role in solvent extraction and their influence on the selectivity of ligands for uranyl species.

Transport properties of imidazolium-based room temperature ionic liquids in confinement of slit charged carbon nanopores: New insights from molecular simulations

The paper presents a study of the behavior of room-temperature ionic liquids with different alkyl chain lengths and anion types in slit negatively charged carbon nanopores of various widths (1–15 nm) using all-atom molecular dynamics simulations. The structure of the confined ionic liquids is investigated using number, mass, and charge density profiles and radial distribution functions. The paper also discusses such characteristics as mean squared displacement of ions in all directions, self-diffusion coefficients of cations and anions in the bulk, their temperature dependences, electrical conductivity. Some energy characteristics are obtained by quantum chemical calculations. It is established that there is a bulk region in the pore center for all the confined ionic liquids, starting from the pore width of 7 nm. The sums of the cationic and anionic self-diffusion coefficients of different ionic liquids can be arranged as follows: D[OMIM][BF4] < D[EMIM][BF4] < D[OMIM][NTf2] < D[EMIM][NTf2]. Due to layering structure inside the pore, the dynamics of the ions is heterogeneous. It is shown that the RTILs with longer alkyl chains have lower electrical conductivities regardless of temperature. The opposite effect associated with the species size is observed for RTILs with different anions.

Effect of pendant ester groups on gas transport property of 6FDA-BAPP/6FAP copolyimide membrane

Despite the various methods that have been developed, controlling the microstructure of polyimide membranes to achieve excellent separation performance based on target gases remains a challenge. One such method involves rearranging polyimides containing ortho-hydroxyl groups into polybenzoxazoles at temperatures above 400 °C, which can effectively distort the backbones and improve gas diffusion. However, this approach is limited by the extremely high conversion temperatures required and low conversion degrees achieved. The esterification process of the polyimide, which contains ortho-hydroxyl groups to the imide ring, represents a simple and effective approach to enhance the membrane's competitiveness in gas separation without undergoing thermal rearrangement at high temperatures. The polyimide was prepared by the polycondensation of 4,4'-(Hexafluoro isopropylidene) diphthalic anhydride (6FDA), 2,2-double (4,4-amino phenoxy) propane (BAPP), and 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (6FAP). Microstructures and gas transport coefficients were analyzed when the esterification of 6FDA-BAPP/6FAP was conducted using acetic anhydride and caproic anhydride. In CO2/N2 separation, a-6FDA-BAPP/6FAP exhibits CO2 permeability of 1279.41 ± 66.93 Barrer and perm-selectivity of 40.80 ± 2.27, owing to the significantly improved affinity to CO2. The membrane of c-6FDA-BAPP/6FAP exhibit the further improved CO2 permeability and deteriorated perm-selectivity, due to a leveling effect on the diffusion of CO2 and N2 caused by the pendant caproates with longer alkyl chains. The results confirmed that the gas separation performance of polyimide membrane containing ortho-hydroxyl groups is sensitive to the pendant group.

Micelle conformation of sodium alkyl sulfate surfactants with different hydrophobic chain length: A molecular dynamics study

Based on all-atom molecular dynamics (MD) simulation, micelle properties and microstructures of sodium alkyl sulfate (SAS) with different hydrophobic chain length in explicit aqueous solution are investigated. With the growth of hydrophobic alkyl chain (C8 ∼ C16), the shape of micelle gradually transform from spherical micelle into ellipsoidal or cylindrical aggregate. Longer hydrophobic tail chains collapse inside the micelle and results the smaller exposed surface, which leads to the decreased solvent accessible surface area (SASA) and hydrogen bond. The conformation of C8 ∼ C14 micelles is solid sphere or ellipsoid and the effect of expanding space by the hydrophobic tail chains is dominant. And the hydrophobic tail chains of C16 micelle collapse inside the micelle and extend to the micelle shell but do not expose to the surface of the micelle. The motion of shorter alkyl chain in micelle is restrictive and longer alkyl chain is active. Longer hydrophobic alkyl chain prompts the SAS molecules to move form aqueous solution to form micelle spontaneously due to the increase of entropy.

Ionothermal Approach to Homo- and Heteroleptic Alkylation of Tellurido Mercurate Clusters for Assembly in Lamellar Crystal Structures.

The selective methylation and butylation of chalcogenido metalate clusters by utilizing imidazolium-based ionic liquids turned out to be not only a comparably mild but at the same time also the only known method for postsynthetic alkylation of such species in order to increase their solubility. For additional impact on the crystal structures, selective alkylation with longer alkyl chains was addressed by utilizing the ionic liquid (C10C1Im)[BF4] (C10 = decyl group at position 1 and C1 = methyl group at position 3 of the cation's Im = imidazolium ring) for ionothermal syntheses of functionalized tellurido mercurate clusters. Herein, we report three novel compounds, two of which comprise cluster anions that exhibit a selective organic functionalization of their terminal telluride ligands upon in situ alkylation with the ionic liquid: [Hg6Te6(Te2)2(TeDec)2]6- (in 1; Dec = decyl) represents the first decylated chalcogenido metalate cluster. A unique heteroleptic functionalization, combining methylation and decylation, was achieved for the second cluster, [Hg6Te6(Te2)2(TeDec)(TeMe)]6- (in 2; Me = methyl). The third cluster is purely inorganic, but based on the same cluster core architecture: [Hg4Te2(Te2)2(Te3)2]4- (in 3) comprises a tritelluride unit instead of two HgTeR groups (R = Me, Dec). As a consequence of the long alkyl chains, both at the cluster and at the charge-compensating cations, all three crystal structures are characterized by lamellar assemblies of cations and anions. For further comparison of the properties of the organometallic versus purely inorganic compounds, vibrational and optical properties of crystalline samples of the compounds comprising clusters 1 and 3 were studied by means of infrared, Raman, and UV-visible spectroscopy. The results clearly show the effect of the presence of an organic decoration (in 1) relative to its absence (in 3), reflected by a red shift of the band gap energy (1 → 3) and a replacement of the Te-C bands (in 1) with bands for tritelluride units (in 3).

Hydrophobic/hydrophilic separation performance evaluation of a mixed-mode ionic liquid embedded stearyl thioglycolate functionalized silica stationary phase

In this work, a novel imidazolium ionic liquid embedded multifunctional chromatographic stationary phase (Sil-AVI-ST) was synthesized by the radical-mediated thiol-ene click reaction. A wide range of samples including hydrophilic sulfonamides, vitamins and nucleosides/bases as well as hydrophobic phthalates, bisphenols, alkylphenols and steroid hormones were selected to evaluate the separation ability of the newly obtained Sil-AVI-ST. As expected, an efficient separation of the above tested analytes was successfully achieved in different chromatographic modes. It was proved that multiple stationary phase-analyte interaction forces promoted the selective separation. The Sil-AVI-ST column provided multiple retention mechanisms, enabling the efficient separation of diverse analytes with different polarity. More importantly, embedding a polar ligand (1-allyl-3-vinyl-imidazolium) could improve the separation efficiency of long-chain alkyl bonded stationary phases for hydrophilic analytes, and the developed Sil-AVI-ST column could also realize the detection of hydrophobic analytes under water-rich conditions, which is impossible for the conventional hydrophobic columns. Therefore, the newly prepared Sil-AVI-ST stationary phase has a good practical application potential.

Discovery of Novel Tetramethylpyrazine Containing Chalcone Derivatives as Anti-Inflammatory Agents.

Chalcones are precursors of flavonoids and exhibit a broad spectrum of pharmacological activity. As anti-inflammatory agents, two series of chalcone derivatives and chalcone-based oximes were synthesized and characterized. To integrate the tetramethylpyrazine moiety into these novel molecules, the multifunctional natural chemical ligustrazine was employed. A variety of newly synthesized ligustrazine-based chalcones were utilized as precursors for the synthesis of new oximes and their inhibitory activity against COX-1, COX-2, and LOX-5 enzymes were compared. The conversion of ketones to their oxime derivatives increased the effectiveness of COX-1 and COX-2 inhibition. Due to the substituted ether groups, oxime derivative 5d had the lowest IC50 values of 0.027 ± 0.004 μM and 0.150 ± 0.027 μM for COX-1 and COX-2 isoenzymes, respectively. Notably, the oxime derivative's highest effectiveness is conferred by the presence of methoxymethoxy or hydroxy groups at the C-3 and C-4 positions on the phenyl ring. The 6b derivative with a long alkyl chain ether group was shown to be the most powerful 5-LOX inhibitor. All compounds were also assessed for their ability to inhibit nitric oxide generation and LPS-induced IL-6, IL-1β, and TNF-α production in RAW 264.7 macrophages. Finally, in order to determine the structural effects responsible for the binding mechanism of compounds, they were docked into the binding sites of COX-1, COX-2, and 5-LOX, which revealed an inhibitory mechanism of action and demonstrated the relevance of various types of interactions. The findings showed that these novel compounds had a significant impact on antiinflammatory actions.

Narcissus pseudonarcissus L. (Amaryllidaceae) bulb metabolite profiling and biological activities

Various metabolomics approaches have greatly contributed to the study of natural products from medicinal plants. Among thousands of plant species, Narcissus pseudonarcissus L. (Amaryllidaceae) is reputed for its ornamental, industrial, and medicinal applications. This plant is also used traditionally for microbial infections, inflammations, skin complaints, and cancers. Long ago, N. pseudonarcissus has gained considerable research interest thanks to its diverse alkaloids that have been widely studied. However, the non-alkaloidal principles and different bioactivities of this plant were poorly deliberated in previous works. Therefore, this work evaluates the biological potential of N. pseudonarcissus bulbs′ total ethanol extract (TEE) and its derived fractions (I‒IV), along with exploring the overlooked non-alkaloidal metabolites of this amaryllid. Overall, GC‒MS-based analysis of the bulbs led to the identification of varied metabolites, e.g., long-chain alkyl amines, alkylbenzenes, long-chain hydrocarbons, fatty acid derivatives, and phenylpropanoids. Most of these phytochemicals are first characterized herein in either the genus Narcissus or the family Amaryllidaceae. Additionally, the acidic EtOAc fraction (II) exhibited the highest scavenging potential of the 2,2′-diphenyl-1-picrylhydrazyl radical and the greatest ferric reducing power, possibly due to its relatively higher contents of phenolics and flavonoids that were also estimated herein. On the other hand, the basic EtOAc fraction (III) exerted the maximum anti-proliferative actions against Caco-2 (colon) and Mcf-7 (breast) tumor cells, while all of the tested fractions were inactive against HepG-2 (liver) cancer cells. Finally, different N. pseudonarcissus fractions demonstrated varied inhibitory activities against a group of pathogenic bacteria and fungi. Among them, fractions II and III were further observed as good synergists with some standard antimicrobial agents, even against some resistant microbial strains. These data could support the reported use of N. pseudonarcissus in traditional medical systems and help widen its future phytochemical and biological prospection.

High-efficiency fungal pathogen intervention for seed protection: new utility of long-chain alkyl gallates as heat-sensitizing agents.

Control of food-contaminating fungi, especially pathogens that produce mycotoxins, is problematic since effective method for intervening fungal infection on food crops is often limited. Generally Regarded As Safe (GRAS) chemicals, such as natural compounds or their structural derivatives, can be developed as antimicrobial agents for sustainable food/crop production. This study identified that long-chain alkyl gallates, i.e., octyl-, nonyl-, and decyl gallates (OG (octyl 3,4,5-trihydroxybenzoic acid), NG, DG), can function as heat-sensitizing agents that effectively prevent fungal contamination. Out of twenty-eight candidate compounds and six conventional antifungal agents examined, the heat-sensitizing capacity was unique to the long-chain alkyl gallates, where OG exhibited the highest activity, followed by DG and NG. Since OG is a GRAS compound classified by the United States Food and Drug Administration (FDA), further in vitro antifungal studies were performed using OG. When OG and mild heat (57.5°C) were co-administered for 90 seconds, the treatment achieved > 99.999% fungal death (> 5 log reduction). Application of either treatment alone was significantly less effective at reducing fungal survival. Of note, co-application of OG (3 mM) and mild heat (50°C) for 20 minutes completely prevented the survival of aflatoxigenic Aspergillus flavus contaminating crop seeds (Brassica rapa Pekinensis), while seed germination rate was unaffected. Heat-sensitization was also determined in selected bacterial strains (Escherichia coli, Agrobacterium tumefaciens). Altogether, OG is an effective heat-sensitizing agent for control of microbial pathogens. OG-mediated heat sensitization will improve the efficacy of antimicrobial practices, achieving safe, rapid, and cost-effective pathogen control in agriculture/food industry settings.

Digital Light Processing 3D Printing of Soft Semicrystalline Acrylates with Localized Shape Memory and Stiffness Control.

Multimaterial three-dimensional (3D) printing of objects with spatially tunable thermomechanical properties and shape-memory behavior provides an attractive approach toward programmable "smart" plastics with applications in soft robotics and electronics. To date, digital light processing 3D printing has emerged as one of the fastest manufacturing methods that maintains high precision and resolution. Despite the common utility of semicrystalline polymers in stimuli-responsive materials, few reports exist whereby such polymers have been produced via digital light processing (DLP) 3D printing. Herein, two commodity long-alkyl chain acrylates (C18, stearyl and C12, lauryl) and mixtures therefrom are systematically examined as neat resin components for DLP 3D printing of semicrystalline polymer networks. Tailoring the stearyl/lauryl acrylate ratio results in a wide breadth of thermomechanical properties, including tensile stiffness spanning three orders of magnitude and temperatures from below room temperature (2 °C) to above body temperature (50 °C). This breadth is attributed primarily to changes in the degree of crystallinity. Favorably, the relationship between resin composition and the degree of crystallinity is quadratic, making the thermomechanical properties reproducible and easily programmable. Furthermore, the shape-memory behavior of 3D-printed objects upon thermal cycling is characterized, showing good fatigue resistance and work output. Finally, multimaterial 3D-printed structures with vertical gradation in composition are demonstrated where concomitant localization of thermomechanical properties enables multistage shape-memory and strain-selective behavior. The present platform represents a promising route toward customizable actuators for biomedical applications.