Decanoate Research Articles

Mesoporous silica-grafted deep eutectic solvent-based mixed matrix membranes for wastewater treatment: Synthesis and emerging pollutant removal performance

Abstract Nano-enhanced membrane technology and deep eutectic solvents (DESs) have demonstrated effectiveness in addressing emerging environmental pollutants. This research centers on purifying water by removing heavy metals employing membranes enhanced with mesoporous silica and DES. Various DESs, including hexanoic acid, octanoic acid, and decanoic acid, were synthesized using tetrabutylammonium bromide (TBABr) as a base. The study combined a polysulfone-based membrane with mesoporous silica, aiming for efficient indigenous crafting to remove heavy metals. Mesoporous silica was blended with the synthesized DES solution, creating diverse membranes for heavy metal separation. The study characterized these membranes using various techniques such as scanning electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and contact angle measurements. Surface mapping confirmed the integration of silicon-based DES, reducing the membrane surface roughness from 4 to 1.4 nm. By adjusting the carboxylic acid chain length with TBABr and adding mesoporous silica, leaching ratios were reduced from 4.2 to 2.3%. Silica-grafted DES-based membranes exhibited a progressive increase in flux from 2.6 to 26.67 L/m2 h. The synthesized silicon-based membranes demonstrated outstanding performance, achieving rejection rates exceeding 80% for chromium and arsenic, maintaining an impressive 90% flux recovery ratio even at high flux rates. This study will envision the potential of nano-enhanced membrane technology utilizing DES for sustainable water purification and wastewater treatment applications to achieve the sustainable development goal (SDG) of clean water and sanitation (SDG-6).

An inverse method for the estimation of the vapor and liquid diffusivity coefficient of conventional and phase change material based hemp concrete

This study proposes a method for fast estimation of the hydric properties, including liquid and vapor diffusivities, of three distinct materials: a conventional biosourced insulating material (hemp concrete) and two innovative hybrid composites (hemp concrete with capric acid and hemp concrete with lauric acid). To estimate these parameters, an approach based on an inverse method has been developed. It involves minimizing the quadratic difference between numerical and experimental values of relative humidity, using the Nelder-Mead algorithm by assuming an exponential evolution of the liquid and vapor diffusivities. An unsteady-state experiment has been conducted in a climatic chamber during 18 days to provide experimental data for parameters’ estimation. The obtained maximum root mean square error (RMSE) for all the samples is 4.4% that is a satisfactory approximation given the model assumptions and the experimental uncertainties (±2%). The estimated parameters allow calculating all investigated materials’ liquid and vapor diffusivities. The validation of the approach is achieved by comparing its results with those from the existing literature.

A novel antimicrobial peptide with broad-spectrum and exceptional stability derived from the natural peptide Brevicidine

The global issue of antibiotic resistance is increasingly severe, highlighting the urgent necessity for the development of new antibiotics. Brevicidine, a natural cyclic lipopeptide, exhibits remarkable antimicrobial activity against Gram-negative bacteria. In this study, a comprehensive structure-activity relationship of Brevicidine was investigated through 20 newly synthesized cyclic lipopeptide analogs, resulting in the identification of an optimal linear analog 22. The sequence of analog 22 consisted of five d-amino acids and four non-natural amino acid 2,5-diaminovaleric acid (Orn) and conjugated with decanoic acid at N-terminal. Compared to Brevicidine, analog 22 was easier to synthesize, and exerted broad spectrum antimicrobial activity and excellent stability (t1/2 = 40.98 h). Additionally, analog 22 demonstrated a rapid bactericidal effect by permeating non-specifically through the bacterial membranes, thereby minimizing the likelihood of inducing resistance. Moreover, it exhibited remarkable efficacy in combating bacterial biofilms and reversing bacterial resistance to conventional antibiotics. Furthermore, it effectively suppressed the growth of bacteria in vital organs of mice infected with S. aureus ATCC 25923. In conclusion, analog 22 may represent a potential antimicrobial peptide for further optimization.

Synthetic cap rate indices (1991-Covid era)

We introduce a method that combines Euclidean distancing and OLS techniques to project synthetic capitalization rate indices (‘SCXs’) for metropolitan statistical areas in the US. SCXs are projected independently of market prices, asset specific characteristics and geographic location (ex-ante). In contrast to market cap rates, driven by geographic proximity and market comparables, our new method is driven by economic proximity. We find SCXs provide better forward guidance than market cap rates for commercial real estate (‘CRE’) defaults and CRE values before and during the Covid pandemic. Our method establishes CRE benchmark cap rate indices across property types that explicitly connect CRE valuation at the MSA level to macroeconomic indicators through economic proximity.

The Gas Chromatography Mass Spectrometry Analysis of an Ayurvedic Formulation Amruthadi Kashaya

Amruthadi Kashaya is a Ayurvedic formulation mentioned in the book Arogya Kalpadruma for the treatment of Pandu (anaemic syndrome), Kamala (jaundice) and Raktapitha (bleeding disorders). The Yoga contains six drugs namely Amrutha (Tinospora cordifolia), Vasa (Adhatoda vasica), Yashtimadhu (Glycyrrhiza glabra), Tiktha (Solanum anguivi), Ela (Elettaria cardamomum), Pichumantha (Azadirachta indica). This Kashaya is rich in phytoconstituents, such as phenolics, terpenoids, and lipids, which are known for their many biological benefits, including anti-inflammatory, anti-cancer, and antioxidant effects. The purpose of the current study is to use Gas Chromatography Mass Spectrometry (GCMS) analysis to identify the different types of bio molecules that are present in this Kashaya. Kashaya was prepared according to standard protocol. It was concentrated in the rotary vacuum evaporator, and the total soluble solid (TSS) obtained was used for GCMS analysis. The GCMS of Kashaya showed the presence of bio molecules such as 7 Hexadecanoic acid, methyl ester, Methyl tetradecanoate, Diethyl Phthalate, Dodecanoic acid, methyl ester, Methyl stearate, à-Terpineol, Methyl 8-methylnonanoate, 3-Cyclohexene-1-methanol, à, à,4-trimethyl-, acetate, Decanoic acid, methyl ester, 1,6,10-Dodecatrien-3-ol,3,7,11-trimethyl-, (E)-, Ethyl iso-allocholate, Spiro [2,4] hepta-4,6-diene, Butylated Hydroxytoluene, 9-Hexadecenoic acid, methyl ester, (Z) etc. à-Terpineol, 7-Hexadecenoic acid, methyl ester, Butylated hydroxytoluene, Nerolidyl acetate have antioxidant activity likewise some of the bio molecules have anti-inflammatory, antibacterial, anticancer activity. It is concluded that Ayurvedic formulation Amruthadi Kashaya contains many bio molecules having therapeutic actions.

An Update on the Role and Potential Molecules in Relation to Ruminococcus gnavus in Inflammatory Bowel Disease, Obesity and Diabetes Mellitus.

Ruminococcus gnavus (R. gnavus) is a gram-positive anaerobe commonly resides in the human gut microbiota. The advent of metagenomics has linked R. gnavus with various diseases, including inflammatory bowel disease (IBD), obesity, and diabetes mellitus (DM), which has become a growing area of investigation. The initial focus of research primarily centered on assessing the abundance of R. gnavus and its potential association with disease presentation, taking into account variations in sample size, sequencing and analysis methods. However, recent investigations have shifted towards elucidating the underlying mechanistic pathways through which R. gnavus may contribute to disease manifestation. In this comprehensive review, we aim to provide an updated synthesis of the current literature on R. gnavus in the context of IBD, obesity, and DM. We critically analyze relevant studies and summarize the potential molecular mediators implicated in the association between R. gnavus and these diseases. Across numerous studies, various molecules such as methylation-controlled J (MCJ), glucopolysaccharides, ursodeoxycholic acid (UDCA), interleukin(IL)-10, IL-17, and capric acid have been proposed as potential contributors to the link between R. gnavus and IBD. Similarly, in the realm of obesity, molecules such as hydrogen peroxide, butyrate, and UDCA have been suggested as potential mediators, while glycine ursodeoxycholic acid (GUDCA) has been implicated in the connection between R. gnavus and DM. Furthermore, it is imperative to emphasize the necessity for additional studies to evaluate the potential efficacy of targeting pathways associated with R. gnavus as a viable strategy for managing these diseases. These findings have significantly expanded our understanding of the functional role of R. gnavus in the context of IBD, obesity, and DM. This review aims to offer updated insights into the role and potential mechanisms of R. gnavus, as well as potential strategies for the treatment of these diseases.

Fabrication and evaluation of polyurethane supported form‐stable PCMs

AbstractThe current research is oriented towards the development and assessment of the properties of the form‐stable phase change materials (PCMs), comprising of the thermoset polymer matrix (polyurethane, PU) enclosing capric acid (CA) as an active thermal energy storage (TES) component. The Fourier Transform Infrared Spectroscopy (FTIR) and Field‐Emission Scanning Electron Microscopy (FE‐SEM) have been used to characterize the chemical nature and morphological details of the developed PU‐based PCMs (PUPCMs). TES attributes and thermal stability of the resultant PCMs are evaluated by thermo‐analytical techniques such as Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). A thermal reliability test has been conducted to determine the phase change efficiency of the prepared PCMs. PUPCMs have been found to be suitable for TES applications, such as passive space heating or cooling building applications.

Natural soda lakes provide compatible conditions for RNA and membrane function that could have enabled the origin of life.

The origin of life likely occurred within environments that concentrated cellular precursors and enabled their co-assembly into cells. Soda lakes (those dominated by Na+ ions and carbonate species) can concentrate precursors of RNA and membranes, such as phosphate, cyanide, and fatty acids. Subsequent assembly of RNA and membranes into cells is a long-standing problem because RNA function requires divalent cations, e.g. Mg2+, but Mg2+ disrupts fatty acid membranes. The low solubility of Mg-containing carbonates limits soda lakes to moderate Mg2+ concentrations (∼1 mM), so we investigated whether both RNAs and membranes function within these lakes. We collected water from Last Chance Lake and Goodenough Lake in Canada. Because we sampled after seasonal evaporation, the lake water contained ∼1 M Na+ and ∼1 mM Mg2+ near pH 10. In the laboratory, nonenzymatic, RNA-templated polymerization of 2-aminoimidazole-activated ribonucleotides occurred at comparable rates in lake water and standard laboratory conditions (50 mM MgCl2, pH 8). Additionally, we found that a ligase ribozyme that uses oligonucleotide substrates activated with 2-aminoimidazole was active in lake water after adjusting pH from ∼10 to 9. We also observed that decanoic acid and decanol assembled into vesicles in a dilute solution that resembled lake water after seasonal rains, and that those vesicles retained encapsulated solutes despite salt-induced flocculation when the external solution was replaced with dry-season lake water. By identifying compatible conditions for nonenzymatic and ribozyme-catalyzed RNA assembly, and for encapsulation by membranes, our results suggest that soda lakes could have enabled cellular life to emerge on Earth, and perhaps elsewhere.

Effect of Carboxyl Group Position on Assembly Behavior and Structure of Hydrocarbon Oil-Carboxylic Acid Compound Collector on Low-Rank Coal Surface: Sum-Frequency Vibration Spectroscopy and Coarse-Grained Molecular Dynamics Simulation Study.

In this work, the assembly behavior and structure of a compound collector with different carboxyl group positions at the low-rank coal (LRC)-water interface were investigated through coarse-grained molecular dynamics simulation (CGMD) combined with sum-frequency vibration spectroscopy (SFG). The choice of compound collector was dodecane +decanoic acid (D-DA) and dodecane +2-butyl octanoic acid (D-BA). CGMD results showed that the carboxyl group at the carbon chain's middle can better control the assembly process between carboxylic acid and D molecules. SFG research found that the carboxyl group at the carbon chain's termination had a greater impact on the displacement of the methyl/methylene symmetric stretching vibration peak, while the carboxyl group at the carbon chain's middle had a greater impact on the displacement of the methyl/methylene asymmetric stretching vibration peak. The spatial angle calculation results revealed that the methyl group's orientation angle in the D-BA molecule was smaller and the carboxyl group's orientation angle in the BA molecule was bigger, indicating that D-BA spread more flatly on the LRC surface than D-DA. This meant that the assembled structure had a larger effective adsorption area on the LRC surface. The flotation studies also verified that the assembly behavior and structure of D-BA with the carboxyl group at the carbon chain's middle at the LRC-water interface were more conducive to the improvement of flotation efficiency. The study of interface assembly behavior and structure by CGMD combined with SFG is crucial for the creation of effective compound collectors.

Insight into the role of hydrogen bond donor in deep eutectic solvents

Deep eutectic solvent (DES) is considered as one of the green solvents with bright prospect in this century. Its excellent performance is closely related to the hydrogen bonds formed between hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD). Through changing the type of HBD and adjusting its molar fraction, it makes a difference to the intensity of the hydrogen bonds. In this work, tetrabutylammonium chloride (TBAC) was chosen as HBA, decanoic acid (DEC) and octanoic acid (OC) were chosen as HBD. With the molar ratios ranging from 3:1 to 1:3, seven TBAC-DEC-based DES and seven TBAC-OC-based DES were synthesized. Based on the study of the structural characteristics and the thermophysical properties, such as the eutectic point, the thermal stability, the density and the viscosity, the effect of HBD on DES was investigated. The increased HBD destroyed the orderly configuration of DES. Meanwhile, the elongation of the HBD’s alkyl chain enhanced the interaction between the components. Moreover, the mass-connectivity-based model and the hard sphere model were introduced to predict the density and viscosity, respectively. Both of the two models exhibited good predictivity, with the average absolute relative deviation less than 0.2 % and 5 %, respectively.

Molecular Mechanisms Underlying Medium-Chain Free Fatty Acid-Regulated Activity of the Phospholipase PlaF from Pseudomonas aeruginosa.

PlaF is a membrane-bound phospholipase A1 from Pseudomonas aeruginosa that is involved in remodeling membrane glycerophospholipids (GPLs) and modulating virulence-associated signaling and metabolic pathways. Previously, we identified the role of medium-chain free fatty acids (FFAs) in inhibiting PlaF activity and promoting homodimerization, yet the underlying molecular mechanism remained elusive. Here, we used unbiased and biased molecular dynamics simulations and free energy computations to assess how PlaF interacts with FFAs localized in the water milieu surrounding the bilayer or within the bilayer and how these interactions regulate PlaF activity. Medium-chain FFAs localized in the upper bilayer leaflet can stabilize inactive dimeric PlaF, likely through interactions with charged surface residues, as has been experimentally validated. Potential of mean force (PMF) computations indicate that membrane-bound FFAs may facilitate the activation of monomeric PlaF by lowering the activation barrier for changing into a tilted, active configuration. We estimated that the coupled equilibria of PlaF monomerization-dimerization and tilting at the physiological concentration of PlaF lead to the majority of PlaF forming inactive dimers when in a cell membrane loaded with decanoic acid (C10). This is in agreement with a suggested in vivo product feedback loop and gas chromatography-mass spectrometry profiling results, indicating that PlaF catalyzes the release of C10 from P. aeruginosa membranes. Additionally, we found that C10 in the water milieu can access the catalytic site of active monomeric PlaF, contributing to the competitive component of C10-mediated PlaF inhibition. Our study provides mechanistic insights into how medium-chain FFAs may regulate the activity of PlaF, a potential bacterial drug target.

The Development and Characterization of Novel Ionic Liquids Based on Mono- and Dicarboxylates with Meglumine for Drug Solubilizers and Skin Permeation Enhancers.

In this study, we synthesized a family of novel ionic liquids (ILs) with meglumine (MGM) as cations and tartaric acid (TA), azelaic acid (AA), geranic acid (GA), and capric acid (CPA) as anions, using pharmaceutical additives via simple acid-base neutralization reactions. The successful synthesis was validated by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and powder X-ray diffraction (PXRD). Thermal analysis using differential scanning calorimetry confirmed the glass transition temperature of MGM-ILs to be within the range of -43.4 °C--13.8 °C. We investigated the solubilization of 15 drugs with varying pKa and partition coefficient (log P) values using these ILs and performed a comparative analysis. Furthermore, we present MGM-IL as a new skin permeation enhancer for the drug model flurbiprofen (FRP). We confirmed that AA/MGM-IL improves the skin permeation of FRP through hairless mouse skin. Moreover, AA/MGM-IL enhanced drug skin permeability by affecting keratin rather than stratum corneum lipids, as confirmed by ATR-FTIR. To conclude, MGM-ILs exhibited potential as drug solubilizer and skin permeation enhancers of drugs.

In Vitro Evaluation of Essential Oils and Saturated Fatty Acids for Repellency against the Old-World Sand Fly, Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae).

The sand fly, Phlebotomus papatasi (Scopoli, 1786), is a major vector for Leishmania major in the Middle East, which has impacted human health and US military operations in the area, demonstrating the need to develop effective sand fly control and repellent options. Here, we report the results of spatial repellency and avoidance experiments in a static air olfactometer using the female P. papatasi testing essential oils of Lippia graveolens (Mexican oregano), Pimenta dioica (allspice), Amyris balsamifera (amyris), Nepeta cataria (catnip), Mentha piperita (peppermint), and Melaleuca alternifolia (tea tree); the 9-12 carbon saturated fatty acids (nonanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid); and the synthetic repellents DEET and IR3535. The materials applied at 1% exhibited varying activity levels but were not significantly different in mean repellency and avoidance from DEET and IR3535, except in regards to nonanoic acid. Some materials, particularly nonanoic and undecanoic acids, produced sand fly mortality. The observed trends in mean repellency over exposure time included the following: (1) P. dioica oil, M. alternifolia oil, decanoic acid, undecanoic acid, DEET, and IR3535 exhibited increasing mean repellency over time; (2) oils of N. cataria, A. balsamifera, M. piperita, and dodecanoic acid exhibited relatively constant mean repellency over time; and (3) L. graveolens oil and nonanoic acid exhibited a general decrease in mean repellent activity over time. These studies identified the essential oils of N. cataria and A. balsamifera as effective spatial repellents at reduced concentrations compared to those of DEET. Additional research is required to elucidate the modes of action and potential synergism of repellents and essential oil components for enhanced repellency activity.

Thermal Properties and Characterization of n-Decanol-Capric Acid/Expanded Graphite/Boron Nitride for Thermal Energy Storage

To find a low temperature phase change material (PCM) that can be applied to the middle constant temperature chamber of the three chamber refrigerator, this study proposes a binary eutectic PCM of n-decanol and capric acid as a base liquid, expanded graphite as a support material, and boron nitride as a thermal conductivity enhanced particle to modify the material. The composite PCM with suitable phase change temperature and high phase change latent heat is prepared by the solution blending method. The leakage rate experiment determines the maximum adsorption ratio of expanded graphite to be 92 %. The chemical structure, microstructure and thermodynamic properties are characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, thermal conductivity analyzer and thermogravimetric analyzer. The results show that the n-decanol and capric acid binary eutectic PCM is fully wrapped in the porous structure of expanded graphite, and boron nitride thermal conductivity enhanced particles are well adsorbed on the surface and pores of expanded graphite. The n-decanol and capric acid phase change material, boron nitride thermal conductivity enhanced particles and expanded graphite support material are only physically combined and no chemical reaction occurred. The phase change temperature of CPCM-2 with 3 % boron nitride thermal conductivity enhanced particles is -3.68 °C, the phase change latent heat is 129.2 J/g, and the thermal conductivity is 0.75 W/m·K. It has good thermal stability and reliability in the application temperature range.

Evidence of Heritability in Prebiotically Realistic Membrane-Bound Systems.

The vesicles of short chain amphiphiles have been demonstrated to grow and divide. Here, we explored whether vesicle populations show evidence of heritability. We prepared 1:1 decanoic acid:decylamine vesicles with or without a detergent and in either water or prebiotic soup, a mixture of compounds that might have been present on early Earth. The mixtures were subjected to transfer with dilution, where, after 24 h of incubation (one generation), we transferred 10% of the mix into a 90% volume of a fresh vesicle-containing solution. This was continued for 30 generations. Samples with a history of transfers were compared to no-transfer controls (NTCs), initiated each generation using the same solutions but without 10% of the prior generation. We compared the vesicle size distribution and chemical composition of the transfer samples and NTCs and compared their fluorescence signals in the presence of Nile Red dye. We observe changes in the vesicle size but did not detect differences in the chemical composition. In the samples with detergent and soup, we observed irregular changes in the Nile Red fluorescence, with a tendency for parent and offspring samples to have correlated values, suggestive of heritability. This last result, combined with evidence of temporal autocorrelation across generations, suggests the possibility that vesicles could respond to selection.

Enzymatic synthesis of structured lipids from sacha inchi (Plukenetia volubilis) oil with capric acid via acidolysis reaction in stirred tank and packed bed mini reactors

The present study describes an efficient and sustainable synthesis method for producing functional triglycerides (FTs) by conducting an acidolysis reaction of sacha inchi (Plukenetia volubilis) oil with capric acid (C10), catalyzed by Rhizopus oryzae (RO) lipase immobilized in low-cost corn cob powder, to obtain medium-large-medium chain (MLM) triglycerides. Initially, acidolysis reactions were performed between sacha inchi oil, C10, and the immobilized enzyme in a stirred tank at various temperatures (35 °C, 45 °C, 55 °C, and 59 °C), different molar ratios (1:2, 1:3, 1:4 oil:fatty acid), and various hydrolytic enzyme activities (83.6, 124, and 217 IU/mg). Subsequently, to optimize the degree of incorporation, the best condition from the stirred tank reactions (45 °C, 1:3 M ratio, and 217 U of hydrolytic activity) was selected, considering the highest nutritional quality of the lipid in terms of the migration of the sn2 position, and was tested in a packed bed reactor with a spatial time of 112 min, residence time of 107 min, and a flow rate of 0.5 mL/min. The highest incorporation degree achieved in packed bed reactor was 36% at 45 °C. Afterward, it was developed for the best condition an integrative platform for the recycling of the RO lipase immobilized in low-cost corn cob powder (up to four successive cycles without any make up). Subsequent assays on the functional triglycerides revealed atherogenic and thrombogenicity lipid index values of 0.04 ± 0.10 and 4.15 ± 0.05, respectively, which were lower than those of pure sacha inchi oil, indicating the potential to enhance the nutritional quality of the oil through C10 incorporation.

No Effects of Decanoic Acid on Locomotor Activity and Antioxidant Defences in an Experimental Animal Model of Attention-Deficit/Hyperactivity Disorder.

Medium-chain triglycerides such as decanoic acid (C10), which is one of the fatty acids that constitute dietary fats, are of substantial interest for their potential therapeutic effects on neuropsychiatric disorders. However, the effects of C10 on attention-deficit/hyperactivity disorder (ADHD) remain to be studied. We explored the effects of C10 on behavioural activity and antioxidant defences in an experimental animal model of ADHD. To establish an experimental animal model of ADHD, neonatal rats were subjected to unilateral striatal lesions using 6-hydroxydopamine (6-OHDA). The rats sequentially underwent open-field and Y-maze tests before treatment [postnatal day 25 (PN25)]. After the subcutaneous administration of either vehicle or C10 solution (250 mg/kg) for 14 days, the behavioural tests were repeated on PN39. Next, we examined the effects of C10 on the expression of the constitutive antioxidant enzymes catalase and glutathione peroxidase-1/2 and the phase II transcription factor nuclear factor erythroid 2-related factor 2 in four different regions of the rat brain. Injection of 6-OHDA unilaterally into the striatum resulted in elevated locomotor activity on PN39. The administration of C10 for a period of 14 days did not alter the locomotor hyperactivity. Moreover, the administration of C10 had no significant effects on the expression of proteins related to antioxidant defences in the hippocampus, prefrontal cortex, striatum or cerebellum of both control and lesioned rats. The lack of significant effects of C10 in our study may depend on the dose and duration of C10 administration. Further exhaustive studies are needed to verify the efficacy and effects of different doses and treatment durations of C10 and to explore the underlying mechanisms.

Targeted Isolation of Antibiofilm Compounds from Halophytic Endophyte Bacillus velezensis 7NPB-3B Using LC-HR-MS-Based Metabolomics.

The discovery of new natural products has become more challenging because of the re-isolation of compounds and the lack of new sources. Microbes dwelling in extreme conditions of high salinity and temperature are huge prospects for interesting natural metabolites. In this study, the endophytic bacteria Bacillus velezensis 7NPB-3B isolated from the halophyte Salicornia brachiata was screened for its biofilm inhibition against methicillin-resistant Staphylococcus aureus (MRSA). The fractionation of the crude extract was guided by bioassay and LC-HRMS-based metabolomics using multivariate analysis. The 37 fractions obtained by high-throughput chromatography were dereplicated using an in-house MS-Excel macro coupled with the Dictionary of Natural Products database. Successive bioactivity-guided separation yielded one novel compound (1), a diketopiperazine (m/z 469.258 [M - H]-) with an attached saturated decanoic acid chain, and four known compounds (2-5). The compounds were identified based on 1D- and 2D-NMR and mass spectrometry. Compounds 1 and 5 exhibited excellent biofilm inhibition properties of >90% against the MRSA pathogen at minimum inhibition concentrations of 25 and 35 µg/mL, respectively. The investigation resulted in the isolation of a novel diketopiperazine from a bacterial endophyte of an untapped plant using an omics approach.

Volatilome, Microbial, and Sensory Profiles of Coffee Leaf and Coffee Leaf-Toasted Maté Kombuchas.

Kombucha is a fermented beverage traditionally made from the leaves of Camelia sinensis. The market has drastically expanded recently, and the beverage has become more elaborated with new, healthy food materials and flavors. Pruning and harvesting during coffee production may generate tons of coffee leaves that are discarded although they contain substantial amounts of bioactive compounds, including those found in maté tea and coffee seeds. This study characterized the changes in volatilome, microbial, and sensory profiles of pure and blended arabica coffee leaf tea kombuchas between 3-9 days of fermentation. Acceptance was also evaluated by consumers from Rio de Janeiro (n = 103). Kombuchas (K) were prepared using black tea kombucha starter (BTKS) (10%), sucrose (10%), a symbiotic culture of Bacteria and Yeasts (SCOBY) (2.5%), and a pure coffee leaf infusion (CL) or a 50:50 blend with toasted maté infusion (CL-TM) at 2.5%. The RATA test was chosen for sensory profile characterization. One hundred volatile organic compounds were identified when all infusions and kombucha samples were considered. The potential impact compounds identified in CL K and CL-TM K were: methyl salicylate, benzaldehyde, hexanal, nonanal, pentadecanal, phenylethyl-alcohol, cedrol, 3,5-octadien-2-one, β-damascenone, α-ionone, β-ionone, acetic acid, caproic acid, octanoic acid, nonanoic acid, decanoic acid, isovaleric acid, linalool, (S)-dihydroactinidiolide, isoamyl alcohol, ethyl hexanoate, and geranyl acetone. Aroma and flavor descriptors with higher intensities in CL K included fruity, peach, sweet, and herbal, while CL-TM K included additional toasted mate notes. The highest mean acceptance score was given to CL-TM K and CL K on day 3 (6.6 and 6.4, respectively, on a nine-point scale). Arabica coffee leaf can be a co-product with similar fingerprinting to maté and black tea, which can be explored for the elaboration of potentially healthy fermented beverages in food industries.

Study on the compounding of cysteine modified Schiff base and decanoic acid as corrosion inhibitors for bronze with patina

This study employed a combined experimental and theoretical approach to investigate the synergistic corrosion inhibition and mechanism of l-cysteine (CYB)-modified Schiff bases (Schiff bases) and decanoic acid (HC10) as environmentally friendly corrosion inhibitors on corroded bronze in a 3.5 wt% NaCl solution. Surface and electrochemical analysis techniques were used to assess the inhibitor effectiveness, permeability and quantify solution reinforcement effect through compressive testing. Additionally, quantum chemical calculations based on density functional theory (DFT), molecular dynamics simulations (MD), and x-ray photoelectron spectroscopy (XPS) were employed to validate the mechanism of synergistic corrosion inhibition. The results indicate that the two molecules cooperate to impede corrosion via competitive adsorption, while also displaying high permeability and reinforcement properties.