Buffalo worm (Alphitobius diaperinus) proteins: Structural properties, proteomics and nutritional benefits.

Biophysical methods such as circular dichroism (CD) and differential scanning calorimetry (DSC) have been minimally used to characterize insect-derived proteins. This study examines the insect Alphitobius diaperinus as a potential protein source. Techniques such as alkaline solubilization coupled to isoelectric precipitation and Osborne fractionation were used to obtain protein concentrates and fractions (albumins, globulins, prolamins, glutelins). SDS-PAGE results showed dominant protein bands at 78.3, 73.3, 49.3, 34.5, 32.0, and 10.3 kDa. All fractions had over 60 % α-helix and ß-sheet structures, indicating stable conformations. Prolamins showed high surface hydrophobicity and thermal stability. Nutritionally, glutelins exhibited the highest concentration of essential amino acids (68.75 g/100 g protein), and demonstrated superior In vitro protein-digestibility (84.04 %) as well as the highest In vitro protein-digestibility corrected amino acid score (73.11 %). Therefore, this study characterized the structural-function relationship of A. diaperinus proteins and collectively assessed their suitability and safety for human consumption.

Toxicological impacts of plastic microfibers from face masks on Artemia salina: An environmental assessment using Box-Behnken design.

An increase in global plastic manufacturing and subsequent disposal has resulted in widespread increase in microplastic pollution. Particularly, the post-COVID surge in face mask usage has introduced significant volumes of synthetic plastic microfibers into the environment, posing new ecological risks. Present study examines the toxicological impacts of face mask derived microfibers on Artemia salina, a key marine zooplankton species, using the Box-Behnken design to assess the effects of microfiber dosage (0.1 mg/L- 5 mg/L), salinity (0.5 ppt-30 ppt), temperature (10 °C-45 °C), and cyst stocking density (10 cysts/L-100 cysts/L) on hatching efficiency and swimming competencies. Results demonstrated that higher microfiber dosages (2.5 mg/L-5 mg/L) significantly reduced the hatching efficiencies and swimming competencies, while temperature and cyst density also modulated these effects. Additionally, survival assays indicated a significant reduction in survival rates with increasing microfiber concentrations, attributed to the bioaccumulation, oxidative stress and developmental deformities in the organism. The study further explores the leaching of chromophoric dissolved organic matter and turbidity, revealing a direct correlation with microfiber dosage and exposure duration. These findings underscore the urgent need for mitigation strategies to address microfiber pollution and protect aquatic ecosystems. Data presented from the research provides valuable insights into the environmental impacts of plastic microfiber contamination, emphasizing the necessity for continued investigation into effective solutions for managing plastic waste.

Chitosan-coated liposomal systems for delivery of antibacterial peptide LL17-32 to Porphyromonas gingivalis.

Periodontal disease is triggered by surface bacterial biofilms where bacteria are less susceptible to antibiotic treatment. The development of liposome-based delivery mechanisms for the therapeutic use of antimicrobial peptides is an attractive alternative in this regard. The cationic antimicrobial peptide LL-37 (human cathelicidin) is well-known to exert antibacterial activity against P orphyromonas gingivalis, a keystone oral pathogen. However, the antibacterial activity of the 16-amino acid fragment (LL17-32) of LL-37, is unknown. In addition, there are still gaps in studies using liposomal formulations as delivery vehicles of antibacterial peptides against this pathogen. This study was designed to examine the influence of the different types of liposomal formulations to associate and deliver LL17-32 to act against P. gingivalis. Chitosans of varying Mw and degree of acetylation (DA) were adsorbed at the surface of soya lecithin (SL) liposomes. Their bulk (average hydrodynamic size, ζ-potential and membrane fluidity) and ultrastructural (d-spacing, half-bilayer thickness and the water layer thickness) biophysical properties were investigated by a panel of techniques (DLS, SAXS, M3-PALS, fluorescence spectroscopy and TEM imaging). Their association efficiency, in vitro release, stability, and efficacy in killing the periodontal pathogen P. gingivalis were also investigated. All liposomal systems possessed spherical morphologies and good shelf-life stabilities. Under physiological conditions, chitosan formulations with a high DA demonstrated enhanced stability in comparison to low DA-chitosan formulations. Chitosans and LL17-32 both decreased SL-liposomal membrane fluidity. LL17-32 exhibited a high degree of association with SL-liposomes without in vitro release. In biological studies, free LL17-32 or chitosans alone, demonstrated microbicidal activity against P. gingivalis, however this was attenuated when LL17-32 was loaded onto the SL-liposome delivery system, presumably due to the restrained release of the peptide. A property that could be harnessed in future studies (e.g., oral mucoadhesive slow-release formulations).

Study of the Thermal Phase Transition of Poly(N,N-diethylacrylamide-co-N-ethylacrylamide) Random Copolymers in Aqueous Solution.

N-alkyl-substituted polyacrylamides exhibit a thermal coil-to-globule transition in aqueous solution driven by an increase in hydrophobic interactions with rising temperature. With the aim of understanding the role of N-alkyl substituents in the thermal transition, this study focuses on the molecular interactions underlying the phase transition of poly(N,N-diethylacrylamide-co-N-ethylacrylamide) random copolymers. Poly(N,N-diethylacrylamide) (PDEAm), poly(N-ethylacrylamide) (PNEAm), and their random copolymers were synthesized by free radical polymerization and their chemical structure characterized spectroscopically. It was found that the values of the cloud-point temperature increased with PNEAm content, and particle aggregation processes took place, increasing the negative charge density on their surface. The cloud-point temperature of each copolymer decreased with respect to the theoretical values calculated assuming an absence of interactions. It is attributed to the formation of intra- and interchain hydrogen bonding in aqueous solutions. These interactions favor the formation of more hydrophobic macromolecular segments, thereby promoting the cooperative nature of the transition. These results definitively reveal the dominant mechanism occurring during the phase transition in the aqueous solutions of these copolymers.

Encapsulation of short-chain bioactive peptides (BAPs) for gastrointestinal delivery: a review.

The majority of known peptides with high bioactivity (BAPs) such as antihypertensive, antidiabetic, antioxidant, hypocholesterolemic, anti-inflammatory and antimicrobial actions, are short-chain sequences of less than ten amino acids. These short-chain BAPs of varying natural and synthetic origin must be bioaccessible to be capable of being adsorbed systemically upon oral administration to show their full range of bioactivity. However, in general, in vitro and in vivo studies have shown that gastrointestinal digestion reduces BAPs bioactivity unless they are protected from degradation by encapsulation. This review gives a critical analysis of short-chain BAP encapsulation and performance with regard to the oral delivery route. In particular, it focuses on short-chain BAPs with antihypertensive and antidiabetic activity and encapsulation methods via nanoparticles and microparticles. Also addressed are the different wall materials used to form these particles and their associated payloads and release kinetics, along with the current challenges and a perspective of the future applications of these systems.

A comparative study of the digestion behavior and functionality of protein from chia (Salvia hispanica L.) ingredients and protein fractions.

Protein derived from chia (Salvia hispanica L.), characterized by a balanced amino acid composition, represents a potentially healthier and environmentally friendly alternative poised for innovation within the plant-based food sector. It was hypothesized that the growing location of chia seeds and processing techniques used might influence protein digestion patterns, which in turn could affect the biological functions of the digestion products. To examine this hypothesis, we assessed the gastrointestinal fate of degummed-defatted flour (DDF), protein concentrate (PC), and isolated albumin (Alb) and globulin (Glo) fractions. Furthermore, we compared the antioxidant and anti-inflammatory activities of the resulting digesta by means of in vitro and cellular assays. Post-gastrointestinal digestion, the PC exhibited elevated levels of soluble protein (7.6 and 6.3 % for Mexican and British PC, respectively) and peptides (24.8 and 27.9 %, respectively) of larger molecular sizes compared to DDF, Alb, and Glo. This can be attributed to differences in the extraction/fractionation processes. Leucine was found to be the most prevalent amino acids in all chia digesta. Such variations in the digestive outcomes of chia protein components significantly influenced the bioactivity of the intestinal digestates. During gastrointestinal transit, British Glo exhibited the best reactive oxygen species (ROS) inhibition activity in oxidative-stressed RAW264.7 macrophages, while Mexican digesta outperformed British samples in terms of ROS inhibition within the oxidative-stressed Caco-2 cells. Additionally, both Mexican and British Alb showed effectively anti-inflammatory potential, with keratinocyte chemoattractant (KC) inhibition rate of 82 and 91 %, respectively. Additionally, Mexican PC and Alb generally demonstrated an enhanced capacity to mitigate oxidative stress and inflammatory conditions in vitro. These findings highlight the substantial potential of chia seeds as functional food ingredients, resonating with the shifting preferences of health-conscious consumers.

The Rosetta Stone of interactions of mucosa and associated bacteria in the gastrointestinal tract.

PURPOSE OF REVIEW: Gut microbiota-mucosa-epithelial cells co-exist in an intricate three-way relationship that underpins gut homeostasis, and ultimately influences health and disease conditions. The O-glycans of mucin glycoproteins have been uncovered as a centrepiece of this system, although understanding the phenomena at play at the molecular level has been challenging and subject to significant traction over the last years. The purpose of this review is to discuss the recent advances in the phenomena that mediate microbiota and mucus multidirectional interactions in the human gut. RECENT FINDINGS: The mucus biosynthesis and degradation by both commensal and pathogenic bacteria is under tight regulation and involves hundreds of carbohydrate-active enzymes (CAZy) and transporters. The fucosylation of O-glycans from mucin-2 seems to dictate binding by pathogenic species and to influence their virulence. Less clear is the influence of O-glycans in quorum sensing and biofilm formation. We have reviewed the advances in the in vitro models available to recreate the phenomena that capture the physiological context of the intestinal environment, emphasising models that include mucus and other aspects relevant to the physiological context. SUMMARY: The recent findings highlight the importance of merging advances in analytical (glycans analysis) and omics techniques along with original robust in vitro models that enable to deconstruct part of the high complexity of the living gut and expand our understanding of the microbes-mucosa relationships and their significance in health and disease.

Characterisation of locust bean gum with asymmetric flow field-flow fractionation (AF4) and light scattering.

We present a detailed characterisation of locust bean gum (LBG), an industrially significant galactomannan, utilising asymmetric flow field-flow fractionation (AF4) and light scattering. Molecular weight and size determination of galactomannans is complicated by their tendency to aggregate, even in dilute solutions; AF4 allows us to confirm the presence of aggregates, separate these from well-dispersed polymer, and characterise both fractions. For the dispersed polymer, we find Mw=9.2×105 g mol-1 and Rg,z=82.1 nm; the distribution follows Flory scaling (Rg∼Mν) with ν∼ 0.63, indicating good solvent conditions. The aggregate fraction exhibited radii of up to 1000 nm and masses of up to 3×1010 g mol-1. Furthermore, we demonstrate how both fractions are influenced by changes to filtration procedure and solvent conditions. Notably, a 200 nm nylon membrane effectively removes the aggregated fraction; we present a concentration-dependent investigation of solutions following this protocol, using static and dynamic light scattering, which reveals additional weak aggregation in these unfractionated samples. Overall, we demonstrate that AF4 is highly suited to LBG characterisation, providing structural information for both well-dispersed and aggregated fractions, and expect the methods employed to apply similarly to other galactomannans and associating polymer systems.

On the Fractionation and Physicochemical Characterisation of Self-Assembled Chitosan-DNA Polyelectrolyte Complexes.

Chitosan is extensively studied as a carrier for gene delivery and is an attractive non-viral gene vector owing to its polycationic, biodegradable, and biocompatible nature. Thus, it is essential to understand the chemistry of self-assembled chitosan-DNA complexation and their structural and functional properties, enabling the formation of an effective non-viral gene delivery system. In this study, two parent chitosans (samples NAS-032 and NAS-075; Mw range ~118-164 kDa) and their depolymerised derivatives (deploy nas-032 and deploy nas-075; Mw range 6-14 kDa) with degrees of acetylation 43.4 and 4.7%, respectively, were used to form polyelectrolyte complexes (PECs) with DNA at varying [-NH3+]/[-PO4-] (N/P) molar charge ratios. We investigated the formation of the PECs using ζ-potential, asymmetric flow field-flow fractionation (AF4) coupled with multiangle light scattering (MALS), refractive index (RI), ultraviolet (UV) and dynamic light scattering (DLS) detectors, and TEM imaging. PEC formation was confirmed by ζ-potential measurements that shifted from negative to positive values at N/P ratio ~2. The radius of gyration (Rg) was determined for the eluting fractions by AF4-MALS-RI-UV, while the corresponding hydrodynamic radius (Rh), by the DLS data. We studied the influence of different cross-flow rates on AF4 elution patterns for PECs obtained at N/P ratios 5, 10, and 20. The determined rho shape factor (ρ = Rg/Rh) values for the various PECs corresponded with a sphere morphology (ρ ~0.77-0.85), which was consistent with TEM images. The results of this study represent a further step towards the characterisation of chitosan-DNA PECs by the use of multi-detection AF4 as an important tool to fractionate and infer aspects of their morphology.

Derivatized chitosan-oil-in-water nanocapsules for trans-cinnamaldehyde delivery.

trans-Cinnamaldehyde, known for its bacterial anti-quorum sensing activity when applied at sublethal concentrations, has gained traction given its potential use against multidrug resistant bacteria. In this work, trans-cinnamaldehyde-loaded oil-in-water nanocapsules coated with chitosan, N,N,N-trimethyl chitosan chloride, N-(2-(N,N,N-trimethylammoniumyl)acetyl) chitosan chloride or N-(6-(N,N,N-trimethylammoniumyl)hexanoyl)chitosan chloride were obtained. All the formulated nanocapsules showed a Z-average hydrodynamic diameter ~ 160 nm and ζ-potential higher than +40 mV. N,N,N-trimethyl chitosan-coated oil-in-water nanocapsules showed the greatest trans-cinnamaldehyde association efficiency (99.3 ± 7.6) % and total payload release (88.6 ± 22.5) %, while N-(6-(N,N,N-trimethylammoniumyl)hexanoyl)chitosan chloride chitosan-coated oil-in-water nanocapsules were the only formulations stable in phosphate buffer saline PBS (pH 7.4) upon incubation at 37 °C for 24 h. Future work should address the stability of the developed nanocapsules in culture media and their biological performance.

Investigating on the toxicity and bio-magnification potential of synthetic glitters on Artemia salina.

Our research aims to assess the toxic impacts of polyethylene terephthalate (PET) glitters on Artemia salina as a model zooplankton. The mortality rate was assessed using a Kaplan Maier plot as a function of various microplastic dosages. The ingestion of microplastics was confirmed by their presence in digestive tract and faecal matter. Gut wall damage was confirmed by dissolution of basal lamina walls and an increase in the secretory cells. A significant decrease in the activities of cholinesterase (ChE) and glutathione-S-transferase (GST) were noted. A decrease in catalase activity could be correlated to an increase in the generation of reactive oxygen species (ROS). Cysts incubated in presence of microplastics exhibited delay in their hatching into 'umbrella' and 'instar' stages. The data presented in the study would be useful for scientists working on discovering new sources of microplastics, related scientific evidences, image data and model of study.

Improved Antioxidant and Mechanical Properties of Food Packaging Films Based on Chitosan/Deep Eutectic Solvent, Containing Açaí-Filled Microcapsules.

The development of biobased antioxidant active packaging has been valued by the food industry for complying with environmental and food waste concerns. In this work, physicochemical properties for chitosan composite films as a potential active food packaging were investigated. Chitosan films were prepared by solution casting, plasticized with a 1:2 choline chloride: glycerol mixture as a deep eutectic solvent (DES) and incorporated with 0-10% of optimized açaí oil polyelectrolyte complexes (PECs). Scanning electron microscopy and confocal laser scanning microscopy revealed that the chitosan composite films were continuous and contained well-dispersed PECs. The increased PECs content had significant influence on the thickness, water vapor permeability, crystallinity (CrD) and mechanical and dynamic behavior of the films, as well as their antioxidant properties. The tensile strength was reduced in the following order: 11.0 MPa (control film) > 0.74 MPa (5% DES) > 0.63 MPa (5% DES and 5% PECs). Films containing 2% of PECs had an increased CrD, ~6%, and the highest elongation at break, ~104%. Films with 1% of PECs displayed the highest antioxidant properties against the ABTS and DPPH radicals, ~6 and ~17 mg TE g-1, respectively, and highest equivalent polyphenols content (>0.5 mg GAE g-1). Films with 2% of particles were not significantly different. These results suggested that the chitosan films that incorporated 1-2% of microparticles had the best combined mechanical and antioxidant properties as a potential material for food packaging.

Biotechnologically produced chitosans with nonrandom acetylation patterns differ from conventional chitosans in properties and activities.

Chitosans are versatile biopolymers with multiple biological activities and potential applications. They are linear copolymers of glucosamine and N-acetylglucosamine defined by their degree of polymerisation (DP), fraction of acetylation (FA), and pattern of acetylation (PA). Technical chitosans produced chemically from chitin possess defined DP and FA but random PA, while enzymatically produced natural chitosans probably have non-random PA. This natural process has not been replicated using biotechnology because chitin de-N-acetylases do not efficiently deacetylate crystalline chitin. Here, we show that such enzymes can partially N-acetylate fully deacetylated chitosan in the presence of excess acetate, yielding chitosans with FA up to 0.7 and an enzyme-dependent non-random PA. The biotech chitosans differ from technical chitosans both in terms of physicochemical and nanoscale solution properties and biological activities. As with synthetic block co-polymers, controlling the distribution of building blocks within the biopolymer chain will open a new dimension of chitosan research and exploitation.

Short-time acoustic and hydrodynamic cavitation improves dispersibility and functionality of pectin-rich biopolymers from citrus waste.

Pectin is a valuable biopolymer used as a natural, clean label additive for thickening and gelling. However, industry faces issues with dispersibility and stability of pectin formulations. To address these issues, the effect of short processing time (30-180 s) with hydrodynamic (HC) and acoustic cavitation (AC) on the dispersibility and gelling functionality of mandarin pectin-rich polysaccharide (M-PRP) was investigated. Short-time processing with HC and AC did not affect polymer composition. HC, but not AC, decreased polydispersity index (PDI) from 0.78 to 0.68 compared to the control. Electron and atomic force microscopy showed that HC and AC decreased aggregation of fibrous and matrix polymers. Both treatments increased apparent viscosity significantly from 0.059 Pa s to 0.30 Pa s at 10 -s. The pectin dispersions showed good gelling capacity upon addition of calcium (final conc. 35 mM). HC and AC treatments for 150 s led to gels that were 7 and 4 times stronger (as measured by peak force) than the control with more homogeneous, less porous structures. In conclusion, short-time HC and AC can improve the dispersibility and functionality of citrus pectin without affecting composition, and are promising technologies to facilitate the use of pectin in industry applications.

Chitosan/cyclodextrin surface-adsorbed naringenin-loaded nanocapsules enhance bacterial quorum quenching and anti-biofilm activities.

Pathogenic bacteria use quorum sensing (QS), a cell-to-cell communication process that relies on small signaling molecules, to regulate the genetic expression that leads to several essential virulence factors such as bioluminescence, biofilm formation, bacterial motility, among other. Naringenin (NAR), a bitter and colorless flavanone ubiquitous in herbs and fruits, has been shown to inhibit QS activity in P. aeruginosa by decreasing the production of pyocyanin and elastase. In this study, to evaluate the anti-QS activity of naringenin against an E. coli Top 10 biosensor, we developed a novel core-corona nanocapsule formulation comprising surface co-adsorbed ß-cyclodextrin (Captisol®) and chitosan loaded with NAR. The results showed that both the nanocapsule (NC) and nanoemulsion (NE) formulations, NAR payload associated with high efficiency , namely ~ 92.88 and ~ 67.98%, respectively. These formulations remained stable for 24 h and showed a biphasic controlled release profile in bacterial M9 medium. Captisol® was effectively immobilized on the NC's surface, resulting in a surface charge inversion from positive (~ + 42 mV) to negative (~ -32 mV) Î¶-potential. The biosensor assay revealed that NC outperformed NE in quenching the QS response and the incorporation of naringenin at the NC's multifunctional surface enhanced this bioactivity. Cytotoxicity assays showed that when NAR was associated in NC (188 µM) it was not cytotoxic to Caco2 cells, by contrast with its free form, thus highlighting the cytoprotective effect of the developed formulation. Biofilm formation was inhibited up to ~ 60% in NAR-loaded NC (188 µM), indicating the synergistic effect of positively charged chitosan with the bioactivity of NAR while harnessing the NC's high surface area-to-volume ratio.

Aptamer-based detection of fumonisin B1: A critical review.

Mycotoxin contamination is a current issue affecting several crops and processed products worldwide. Among the diverse mycotoxin group, fumonisin B1 (FB1) has become a relevant compound because of its adverse effects in the food chain. Conventional analytical methods previously proposed to quantify FB1 comprise LC-MS, HPLC-FLD and ELISA, while novel approaches integrate different sensing platforms and fluorescently labelled agents in combination with antibodies. Nevertheless, such methods could be expensive, time-consuming and require experience. Aptamers (ssDNA) are promising alternatives to overcome some of the drawbacks of conventional analytical methods, their high affinity through specific aptamer-target binding has been exploited in various designs attaining favorable limits of detection (LOD). So far, two aptamers specific to FB1 have been reported, and their modified and shortened sequences have been explored for a successful target quantification. In this critical review spanning the last eight years, we have conducted a systematic comparison based on principal component analysis of the aptamer-based techniques for FB1, compared with chromatographic, immunological and other analytical methods. We have also conducted an in-silico prediction of the folded structure of both aptamers under their reported conditions. The potential of aptasensors for the future development of highly sensitive FB1 testing methods is emphasized.

Aptamer-Target-Gold Nanoparticle Conjugates for the Quantification of Fumonisin B1.

Fumonisin B1 (FB1), a mycotoxin classified as group 2B hazard, is of high importance due to its abundance and occurrence in varied crops. Conventional methods for detection are sensitive and selective; however, they also convey disadvantages such as long assay times, expensive equipment and instrumentation, complex procedures, sample pretreatment and unfeasibility for on-site analysis. Therefore, there is a need for quick, simple and affordable quantification methods. On that note, aptamers (ssDNA) are a good alternative for designing specific and sensitive biosensing techniques. In this work, the assessment of the performance of two aptamers (40 and 96 nt) on the colorimetric quantification of FB1 was determined by conducting an aptamer-target incubation step, followed by the addition of gold nanoparticles (AuNPs) and NaCl. Although MgCl2 and Tris-HCl were, respectively, essential for aptamer 96 and 40 nt, the latter was not specific for FB1. Alternatively, the formation of Aptamer (96 nt)-FB1-AuNP conjugates in MgCl2 exhibited stabilization to NaCl-induced aggregation at increasing FB1 concentrations. The application of asymmetric flow field-flow fractionation (AF4) allowed their size separation and characterization by a multidetection system (UV-VIS, MALS and DLS online), with a reduction in the limit of detection from 0.002 µg/mL to 56 fg/mL.

Chitosan coatings reduce fruit fly (Anastrepha obliqua) infestation and development of the fungus Colletotrichum gloeosporioides in Manila mangoes.

BACKGROUND: Mangoes are tropical fruits appreciated worldwide but are extremely perishable, being susceptible to decay, pest infestation and fungal diseases. Using the flavorful and highly valued 'Manila' cultivar, we examined the effect of second-generation chitosan coatings on shelf-life, phenolic compound variation, phytohormones, pest infestation by fruit flies (Anastrepha obliqua) and anthracnose disease caused by the fungus Colletotrichum gloeosporioides. RESULTS: We observed almost total elimination of A. obliqua eggs with 10 and 20 g L-1 chitosan in diluted acetic acid and a five- to sixfold reduction in anthracnose damage. Treatment with 20 g L-1 chitosan also extended the shelf-life. External (skin) and internal (pulp) discoloration processes were delayed. Fruit firmness was higher when compared with control and acetic acid treatments, and total soluble solids were lower in chitosan-treated fruit. Targeted and non-targeted metabolomics analyses on chitosan-coated fruit identified some phenolic compounds related to the tannin pathway. In addition, abscisic acid and jasmonic acid in the peel were downregulated in chitosan-coated mango peels. Both phytohormones and phenolic content may explain the reduced susceptibility of mangoes to anthracnose development and A. obliqua egg eclosion or larval development. CONCLUSIONS: We conclude that chitosan coatings represent an effective postharvest treatment that significantly reduces anthracnose disease, inhibits A. obliqua egg eclosion and significantly extends 'Manila' mango shelf-life, a key factor currently inhibiting large-scale commercialization of this valuable fruit. © 2020 Society of Chemical Industry.

Screening of Bacterial Quorum Sensing Inhibitors in a Vibrio fischeri LuxR-Based Synthetic Fluorescent E. coli Biosensor.

A library of 23 pure compounds of varying structural and chemical characteristics was screened for their quorum sensing (QS) inhibition activity using a synthetic fluorescent Escherichia coli biosensor that incorporates a modified version of lux regulon of Vibrio fischeri. Four such compounds exhibited QS inhibition activity without compromising bacterial growth, namely, phenazine carboxylic acid (PCA), 2-heptyl-3-hydroxy-4-quinolone (PQS), 1H-2-methyl-4-quinolone (MOQ) and genipin. When applied at 50 µM, these compounds reduced the QS response of the biosensor to 33.7% ± 2.6%, 43.1% ± 2.7%, 62.2% ± 6.3% and 43.3% ± 1.2%, respectively. A series of compounds only showed activity when tested at higher concentrations. This was the case of caffeine, which, when applied at 1 mM, reduced the QS to 47% ± 4.2%. In turn, capsaicin, caffeic acid phenethyl ester (CAPE), furanone and polygodial exhibited antibacterial activity when applied at 1mM, and reduced the bacterial growth by 12.8% ± 10.1%, 24.4% ± 7.0%, 91.4% ± 7.4% and 97.5% ± 3.8%, respectively. Similarly, we confirmed that trans-cinnamaldehyde and vanillin, when tested at 1 mM, reduced the QS response to 68.3% ± 4.9% and 27.1% ± 7.4%, respectively, though at the expense of concomitantly reducing cell growth by 18.6% ± 2.5% and 16% ± 2.2%, respectively. Two QS natural compounds of Pseudomonas aeruginosa, namely PQS and PCA, and the related, synthetic compounds MOQ, 1H-3-hydroxyl-4-quinolone (HOQ) and 1H-2-methyl-3-hydroxyl-4-quinolone (MHOQ) were used in molecular docking studies with the binding domain of the QS receptor TraR as a target. We offer here a general interpretation of structure-function relationships in this class of compounds that underpins their potential application as alternatives to antibiotics in controlling bacterial virulence.