Commercial Compounds Research Articles

Recovery of antioxidant from Decapterus Macarellus waste using wet rendering method

In Malaysia, Decapterus Maruadsi is widely used as the main ingredient in food products such as ‘keropok lekor’ and fish cracker. The wastes generated from the fish snack industry are underutilized and most are discarded into the sea, generating considerable environmental pollution. The recovery of antioxidants in the fish wastes could lead to the development of a very exciting and promising alternative source of commercial antioxidant compounds. The objective of the present work is to investigate the effect of temperature, type of solvent, extraction time, and ratio of sample to solvent loading in the extraction of antioxidants from Decapterus Maruadsi waste using the wet rendering method. The collected fish waste of Decapterus Maruadsi was pre-treated and then subjected to a wet rendering treatment at 0–60 °C for 30–150 min with ratio of sample to solvent loading of between 1:10 and 9:10 (w/v). The presence of antioxidant in the extract was analyzed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Total Phenolic Compound (TPC) assays. Based on the results of this study, wet rendering treatment performed for 90 min at 30 °C with a ratio of sample to solvent loading of 3:10 produced an extract with the highest concentration of active antioxidant compounds. Besides, only N-Acetyl-glutamic acid was identified with LCMS QTOF analysis. These results suggest that the fish waste of Decapterus Maruadsi can be exploited to become a source of antioxidants for food and pharmaceutical applications.

Towards discovery of inhibitors of the undecaprenyl-pyrophosphate phosphatase BacA by virtual high-throughput screening

Increasing resistance to common antibiotics is becoming a major challenge that requires the development of new antibacterial agents. Peptidoglycan is an essential heteropolymer of the bacterial envelope that ensures the integrity and shape of all bacteria and is also an important target for antibiotics. The biosynthesis of peptidoglycan depends on a lipid carrier, undecaprenyl phosphate. As a byproduct of peptidoglycan polymerization, the lipid carrier is released as undecaprenyl pyrophosphate, which must be recycled to allow new polymerization cycles. To this end, it undergoes a dephosphorylation process catalyzed by the membrane phosphatase BacA, which is specific and highly conserved in bacteria. In the present study, we identified small molecules displaying inhibitory potency towards BacA. We began by preparing a commercial compound library, followed by high-throughput virtual screening by ensemble docking using the 3D structure of BacA and molecular dynamics snapshots to account for the flexibility of the protein. Of 83 compounds computationally selected and tested in a biochemical assay, one sulfamoylthiophene molecule showed significant inhibition of the undecaprenyl pyrophosphate dephosphorylation activity catalyzed by BacA. Subsequently, an additional 33 scaffold analogs were selected and acquired, of which 6 compounds exhibited BacA inhibition. The IC50 values of these compounds ranged from 42 to 366 μM. In addition, significant antibacterial activity against Escherichia coli was observed in TolC/PAP2-depleted strains. We believe that the overall strategy followed in this study and the identified class of inhibitors provide a solid foundation for the further development of potent BacA-targeted inhibitors and the discovery of novel antibacterial compounds.

Torrefaction of cellulose, hemicelluloses and lignin extracted from woody and agricultural biomass in TGA-GC/MS: Linking production profiles of volatile species to biomass type and macromolecular composition

The production of volatile species in torrefaction of cellulose, hemicellulose and lignin extracted from woody and agricultural biomass was quantified as a function of temperature. The novel coupling of TGA to GC/MS through a heated storage loop system allowed sampling volatile species released at 11 different temperatures in a single torrefaction experiment between 200 and 300 °C, at 3 °C.min−1. The results showed that the use of extracted fractions obtained from different biomass samples led to the detection of a higher number of species (23) than in previous studies with commercial compounds, obtaining a higher degree of detail in the characterization of the production of volatile species in torrefaction. Volatile species were generally released in this study from lower temperatures than those previously reported for commercial compounds. This may be due to the better preservation of cellulose, hemicellulose and lignin properties in extracted fractions thanks to the optimized extraction procedure. Volatile species production profiles were assessed based on the formation mechanisms proposed in the literature and the production of polysaccharide-based fractions was shown to be correlated to their sugar composition. Finally, production profiles allow identifying the temperature range to enhance the production of a given volatile species in torrefaction.

Insights into a rapid screening method for anti-cucumber mosaic virus compounds

Cucumber mosaic virus (CMV) is a detrimental plant virus in agricultural production. Traditionally, the half-leaf method using Nicotiana glutinosa has been used for screening agrochemicals to control CMV. However, this forms a time-consuming experimental bottleneck. In this study, we constructed a rapid screening model for anti-CMV compounds using CMV. In short, purified CMV particles were labeled through amine reactions and then subjected to binding studies with commercial compounds. The relative gene expression levels were then confirmed. Additionally, the rapid screening model results were verified using synthesized compounds. The commercial compounds ningnanmycin, ribavirin, and moroxydine hydrochloride bound to CMV with dissociation constants of 0.012, 2.870, and 0.069 μM, respectively, and they significantly inhibited expression of the gene for the CMV coat protein in CMV-infected tobacco leaves. This rapid screening model was assessed using our synthetic compounds N12, N16, and N18 through binding, which were shown to have dissociation constants 0.008, 0.025, and 70.800 μM, respectively, as well as via gene expression studies. Thus, a rapid method for screening anti-CMV commercial compounds and our synthetic compounds was constructed and confirmed.

Evaluation of homeopathic medicine in rats subjected to a hypercaloric diet and stress

Introduction: The factors related to obesity are complex, involving biologic, environmental and neuropsychological mechanisms[1-3]. Among the factors which influence the gain of weight, we can consider the stressful factors. Aims: The aim of this experiment was to evaluate the influence of the commercial homeopathic product compound by Fucus vesiculosus 1cH, Thyroidinum 5cH and Calcarea carbonica 5cH (Besomed®) in the gain of weight in animals submitted to hypercaloric diet and stress. Materials and Methods 40 male freshly weaned Wistar rats, ingesting hypercaloric food, were divided into 4 groups, being two groups submitted to stress by standstill, being one group treated and the other one for control (vehicle) and two more groups without stress being one treated and the other one for control. All were given the drink water ad libidum, in blind, for 2 months. The general activity was evaluated by the Open Field method in 2 steps, one after stress and one after 1 month of treatment. The weekly gain of weight was measured during the whole period of treatment. The data were analyzed by the ANOVA method of two ways followed by the Bonferroni test[4], being p≤0,05. Results: The treatment with Besomed® was effective in reducing only the gain of weight in the animals submitted to stress (p≤0,05); the evaluation of general activity in the Open Field showed increase in the time of freezing of these same animals after receiving the stressful stimulus. Discussion: The medicine is used as auxiliary in obesity treatment, and has the same both endogenous highdiluted molecules as the medicine used by similarity, which is the case of Calcarea carbonica, which, among others is indicated for obesity and hyperlipidemia[5], being observed in this study that the homeopathic complex group gained less weight than the other groups. Stress is capable of disturbing the physiological and psychological homeostasia of an individual, and when the stress is caused by standstill, it may induce behavior of the anxious type. There are also studies relating anxiety and feeding behavior in chronically stressed[6] individuals, showing that consuming a hypercaloric diet induces an anxious behavior[7] in male rats. In this study was not observed any change in the motor activity of animals which passed stress, however the time of freezing of the animals which took Besomed® was the lowest (p≤0,05) after stress, if compared to the control groups, demonstrating the absence of an anxious behavior. Conclusion: The medicine evaluated was effective in reducing weight and in inducing an adaptive behavior only in the stressed animals, reducing the evaluated parameters to the same levels observed in the control group.

Biosurfactant activity of indigenous Bacillus sp. ES4.3 isolated from endemic breeding sites of dengue hemorrhagic fever vector in Surabaya, East Java, Indonesia

Abstract. Nafidiastri FA, Susetyo RD, Nurhariyati T, Supriyanto A, Geraldi A, Ni’matuzahroh, Fatimah, Salamun. 2021. Biosurfactant activity of indigenous Bacillus sp. ES4.3 isolated from endemic breeding sites of dengue hemorrhagic fever vector in Surabaya, East Java, Indonesia. Biodiversitas 22: 5375-5381. Bacillus spp. have shown the ability to results a variety of commercial bioactive compounds such as proteins, peptides, and lipopeptides (LPs). Some of the LPs produced by Bacillus spp. are surfactin, iturin, and fengicin. This study aimed to determine the name of the indigenous Bacillus sp. ES4.3, the biosynthesis surfactin gene, and the potential activity for biosurfactant produced by entomopathogenic Bacillus sp. ES4.3 isolated from endemic breeding sites of ??Dengue Hemorrhagic Fever Vector in Surabaya, East Java, Indonesia. Genomic DNA of Bacillus sp. ES4.3 was detected by isolating the DNA and visualizing it by electrophoresis. Furthermore, the 16S rRNA gene was amplified by the Polymerase Chain Reaction (PCR) method. The resulting nucleotide sequences were analyzed to find the relationship between Bacillus sp ES4.3 with another bacteria using MEGA version 6 software. Detection of biosynthesis surfactin gene was carried out by PCR method using srfAD primers. Analysis of the homology level of the surfactin gene was performed using the NCBI BLASTn and BLASTp genetic analysis program. The indigenous Bacillus sp. ES4.3 had 97.66% closeness to the species Bacillus velezensis FZB42 and the surfactin gene showed a 100% ID with the surfactin biosynthesis thioesterase SrfA-D gene on the Bacillus amyloliquefaciens group. The biosurfactant activity was indicated by the formation of clear zones, emulsions, and a decrease in surface tension in the values ??of 21.38 mN/m from the NB medium control and 33.74 mN/m from the distilled water control. The ability of B. velezensis ES4.3 to hemolyzed and reduce surface tension indicated the presence of biosurfactant that can disrupt stability and damage the midgut of Aedes aegypti. Thus, B. velezensis ES4.3 has the potential to be developed as a biocontrol in disease vectors.

Hepatic Glucose Metabolism and Its Disorders in Fish.

Carbohydrate, which is the most abundant nutrient in plant-sourced feedstuffs, is an economically indispensable component in commercial compound feeds for fish. This nutrient can enhance the physical quality of diets and allow for pellet expansion during extrusion. There is compelling evidence that an excess dietary intake of starch causes hepatic disorders, thereby further reducing the overall food consumption and growth performance of fish species. Among the severe metabolic disturbances are glycogenic hepatopathy (hepatomegaly caused by the excessive accumulation of glycogenin hepatocytes) and hepaticsteatosis (the accumulation of large vacuoles of triacylglycerols in hepatocytes). The development of those disorders is mainly due to the limited ability of fish to oxidize glucose and control blood glucose concentration. The prolonged elevations of blood glucose increase glucose intake by the liver, and excess glucose is stored either as glycogen through glycogenesis in hepatocytes or as triglycerides via lipogenesis in tissues, depending on the species. In some fish species(e.g., largemouth bass), the liver has a low ability to regulate glycolysis, gluconeogenesis, and glycogen breakdown in response to high starch intake. For most species of fish, the liver size increases with lipid or glycogen accumulation when they have a high starch intake. It is a challenge to develop the same set of diagnostic criteria for all fish species as their physiology or metabolic patterns differ. Although glycogenic hepatopathy appears to be a common disease in carnivorous fish, it has been under-recognized in many studies. As a result, understanding these diseases and their pathogeneses in different fish species is crucial for manufacturing cost-effective pellet diets to promote the health, growth,survival, and feed efficiency of fish in future.

Potential effects of dietary chitosan against lead-induced innate immunotoxicity and oxidative stress in Nile tilapia (Oreochromis niloticus)

Urbanization and industrialization have led to heavy metals in aquatic environments. These metals are toxic, nondegradable, and persistent. Lead (Pb) is an immunotoxicant that can adversely affect animal health, even at low levels. Chitosan (CHI) is an eco-friendly compound with exceptional antibacterial and immunostimulant characteristics. This study investigated the effect of dietary CHI on the antioxidant defense system and innate immune responses of tilapia (Oreochromis niloticus) against the cytotoxic effect of prolonged Pb exposure. The results indicated dietary CHI could nullify the toxicity of prolonged Pb exposure in fish by substantially activating the antioxidant defense system capacity and fish innate immune responses. In addition, CHI minimized the alterations in the histology of fish organs. The findings suggest that chitosan can be a commercial, eco-friendly immunostimulant and bioactive compound for mitigating the effects of heavy metal toxicity in aquaculture.

Identification of novel positive allosteric modulators of GLP1R that stimulate its interaction with ligands and Gα subunits

Glucagon-like peptide-1 (GLP-1) is a major incretin hormone that enhances the release of insulin from pancreatic β-cells by activating the glucagon-like peptide-1 receptor (GLP1R), which belongs to secretin-like class B of G protein-coupled receptors (GPCRs). Owing to the absence of small molecule agonist drugs to GLP1R, focus has been placed on chemical modulators that bind to the allosteric site of GLP1R. In this study, we identified novel small-molecule positive allosteric modulators of GLP1R from a chemical library consisting of commercial drug compounds using an assay system that measures the direct interaction between a purified GLP1R and its ligand, exendin-4. Two newly identified compounds, benzethonium and tamoxifen, significantly enhanced the affinity of peptide ligands for GLP1R although they lacked agonist activity by themselves. In addition, benzethonium augmented the ligand-induced accumulation of cAMP in GLP1R-transfected HEK293T cells. These compounds significantly increased the affinity of GLP1R to the alpha-subunit of G proteins, suggesting that they stabilize GLP1R in a conformation with a higher affinity to peptide ligand as well as G proteins. These compounds may lead to the design of an orally active positive allosteric modulator for GLP1R.

From Lignin to Valuable Aromatic Chemicals: Lignin Depolymerization and Monomer Separation via Centrifugal Partition Chromatography.

Lignin has long been recognized as a potential feedstock for aromatic molecules; however, most lignin depolymerization methods create a complex mixture of products. The present study describes an alkaline aerobic oxidation method that converts lignin extracted from poplar into a collection of oxygenated aromatics, including valuable commercial compounds such as vanillin and p-hydroxybenzoic acid. Centrifugal partition chromatography (CPC) is shown to be an effective method to isolate the individual compounds from the complex product mixture. The liquid–liquid extraction method proceeds in two stages. The crude depolymerization mixture is first subjected to ascending-mode extraction with the Arizona solvent system L (pentane/ethyl acetate/methanol/water 2:3:2:3), enabling isolation of vanillin, syringic acid, and oligomers. The remaining components, syringaldehyde, vanillic acid, and p-hydroxybenzoic acid (pHBA), were resolved by using ascending-mode extraction with solvent mixture comprising dichloromethane/methanol/water (10:6:4) separation. These results showcase CPC as an effective technology that could provide scalable access to valuable chemicals from lignin and other biomass-derived feedstocks.

Potential Novel Thioether-Amide or Guanidine-Linker Class of SARS-CoV-2 Virus RNA-Dependent RNA Polymerase Inhibitors Identified by High-Throughput Virtual Screening Coupled to Free-Energy Calculations.

SARS-CoV-2, or severe acute respiratory syndrome coronavirus 2, represents a new pathogen from the family of Coronaviridae that caused a global pandemic of COVID-19 disease. In the absence of effective antiviral drugs, research of novel therapeutic targets such as SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) becomes essential. This viral protein is without a human counterpart and thus represents a unique prospective drug target. However, in vitro biological evaluation testing on RdRp remains difficult and is not widely available. Therefore, we prepared a database of commercial small-molecule compounds and performed an in silico high-throughput virtual screening on the active site of the SARS-CoV-2 RdRp using ensemble docking. We identified a novel thioether-amide or guanidine-linker class of potential RdRp inhibitors and calculated favorable binding free energies of representative hits by molecular dynamics simulations coupled with Linear Interaction Energy calculations. This innovative procedure maximized the respective phase-space sampling and yielded non-covalent inhibitors representing small optimizable molecules that are synthetically readily accessible, commercially available as well as suitable for further biological evaluation and mode of action studies.

Three-Dimensional RAW264.7 Cell Model on Electrohydrodynamic Printed Poly(ε-Caprolactone) Scaffolds for In Vitro Study of Anti-Inflammatory Compounds

Inflammation plays an essential role in the human immune system, and anti-inflammatory compounds are important to promote health. However, the in vitro screening of these compounds is largely dependent on flat biology. Herein, we report our efforts in establishing a 3D inflammation murine macrophage model. Murine macrophage RAW 264.7 cells were cultured on poly(ε-caprolactone) (PCL) scaffolds fabricated through an electrohydrodynamic jetting 3D printer and their behavior were examined. Cells on PCL scaffolds showed a 3D shape and morphology with multilayers and a lower proliferation rate. Moreover, macrophages were not activated by scaffold material PCL and 3D microenvironment. The 3D cells showed greater sensitivity to lipopolysaccharide stimulation with higher production activity of nitric oxide (NO), nitric oxide synthases (iNOS), and cyclooxygenase-2 (COX-2). Additionally, the 3D macrophage model showed lower drug sensitivity to commercial anti-inflammatory drugs including aspirin, ibuprofen, and dexamethasone, and natural flavones apigenin and luteolin with higher IC50 for NO production and lower iNOS and COX-2 inhibition efficacy. Overall, the 3D macrophage model showed promise for higher accurate screening of anti-inflammatory compounds. We developed, for the first time, a 3D macrophage model based on a 3D-printed PCL scaffold that provides an extracellular matrix environment for cells to grow in the 3D dimension. 3D-grown RAW 264.7 cells showed different sensitivities and responses to anti-inflammatory compounds from its 2D model. The 3D cells have lower sensitivity to both commercial and natural anti-inflammatory compounds. Consequently, our 3D macrophage model could be applied to screen anti-inflammatory compounds more accurately and thus holds great potential in next-generation drug screening applications.

Interaction of various types of bisphenols with enzymes involved in melanin synthesis

ObjectivesBisphenol is one of the commercial chemical compounds which finds application in the manufacture of phenol, polyesters, polycarbonates, epoxy resins, etc. Bisphenol A is the most commonly found bisphenol derivative, although there are various analogues such as Bisphenol S, Bisphenol B, Bisphenol C, Bisphenol E, Bisphenol AF, which vary with their structures. Bisphenols majorly get into us by means of food as they are found in food packaging and beverage containers and can be easily absorbed by the body. They can make way into the body systems either by direct means like skin contact or by indirect means through food that is stored in a bisphenol-coated containers. Exposure of the human system to this compound may bring about mild to adverse ailments ranging from skin irritations to infertility. Pigmentation disorder is one such health condition that occurs due to melanocyte destruction and is caused by bisphenol exposures. They interact with various proteins and enzymes that have been involved in the melanocyte synthesis pathway, thereby disrupting their normal functions.MethodsIn silico analysis has been done to predict the interaction and other descriptive binding parameters when the bisphenol derivatives BPA. BPB, BPC, BPE, BPS and BPAF have been docked with some of the essential proteins for melanin synthesis such as tyrosinase, tyrosinase-related protein 1(TRP-1), dopachrome tautomerase/tyrosinase-related protein-2(TRP-2).ResultsThe interaction has been quantified with the binding energies, and the interacting amino acid residues have also been identified. The results showed strong interactions for both the proteins TRP-1 and TRP-2 with BPA. BPB, BPC, BPE, BPS and BPAF.ConclusionsThe risk and threats caused by the commercial products made of bisphenol are at higher levels, and thereby, the need for a safe and desirable alternative has been insisted.

Cobalt nanoparticles to enhance anaerobic digestion of cow dung: focusing on kinetic models for biogas yield and effluent utilization

The impacts of Co nanoparticles (NPs) on the anaerobic digestion (AD) of cow dung were investigated using kinetic models (modified Gompertze, logistic, and first-order) and experimental measurements. The deviation between the predicted and measured data for biogas yield with modified Gompertze and logistic models were 0.66–2.26% and 1.43–4.19%, respectively. The addition of Co NPs (1–3 mg/L) improved the hydrolysis rate (K) value by 66.66–144% compared with the control. Furthermore, the fertilizer efficiency of effluent with Co NPs was comparable to that of commercial NPK compound fertilizer. The combination of kinetic models and experimental measurements can effectively quantify the impact of Co NPs on AD performance and provide an informed choice for industrial production.

Nothing lasts forever: understanding microbial biodegradation of polyfluorinated compounds and perfluorinated alkyl substances.

SummaryPoly‐ and perfluorinated chemicals, including perfluorinated alkyl substances (PFAS), are pervasive in today’s society, with a negative impact on human and ecosystem health continually emerging. These chemicals are now subject to strict government regulations, leading to costly environmental remediation efforts. Commercial polyfluorinated compounds have been called ‘forever chemicals’ due to their strong resistance to biological and chemical degradation. Environmental cleanup by bioremediation is not considered practical currently. Implementation of bioremediation will require uncovering and understanding the rare microbial successes in degrading these compounds. This review discusses the underlying reasons why microbial degradation of heavily fluorinated compounds is rare. Fluorinated and chlorinated compounds are very different with respect to chemistry and microbial physiology. Moreover, the end product of biodegradation, fluoride, is much more toxic than chloride. It is imperative to understand these limitations, and elucidate physiological mechanisms of defluorination, in order to better discover, study, and engineer bacteria that can efficiently degrade polyfluorinated compounds.

Review of Achieved Purities after Li-ion Batteries Hydrometallurgical Treatment and Impurities Effects on the Cathode Performance

This paper is a product purity study of recycled Li-ion batteries with a focus on hydrometallurgical recycling processes. Firstly, a brief description of the current recycling status was presented based on the research data. Moreover, this work presented the influence of impurities such as Cu, Fe and Mg on recovered cathode materials performance. The impact of the impurities was described depending on their form (metallic or ionic) and concentration. This work also reviewed hydrometallurgical recycling processes depending on the recovered material, obtained purity and recovery methods. This purity data were obtained from both research and battery industry actors. Finally, the purity study was completed by collecting data regarding commercial battery-grade chemical compounds and active lithium cathode materials, including required purity levels and allowed impurity limitations.

Structure-based virtual screening for new lead compounds targeted Plasmodium α-tubulin

Aim. Search for new dinitroaniline and phosphorothioamide compounds, capable of selective binding with Plasmodium α-tubulin, affecting its mitotic apparatus. Methods. Structural biology methods of computational prediction of protein-ligand interaction: molecular docking, molecular dynamics and pharmacophore analysis. Selection of compounds based on pharmacophore characteristics and virtual screening results. Results. The protocol and required structural conditions for target (α-tubulin of P. falciparum) preparation and correct modeling of the ligand-protein interaction (docking and virtual screening) were developed. The generalized pharmacophore model of ligand-protein interaction and key functional groups of ligands responsible for specific binding were identified. Conclusions. Based on results of virtual screening, 22 commercial compounds were selected. Identified compounds proposed as potential inhibitors of Plasmodium mitotic machinery and the base of new antimalarial drugs.
 Keywords: malaria, Plasmodium, intermolecular interaction, dinitroaniline derived, phosphorothioamidate derived.

Hazard Evaluation of Metal–Organic Framework Synthesis and Scale-up: A Laboratory Safety Perspective

The undeniable rise of metal–organic framework (MOF) technology has opened the possibilities of these compounds for research and potential commercialization as alternative materials with a versatile number of applications that range from catalysis to greenhouse gases capture. However, there are several factors that constrain the direct scale-up of MOF from the laboratory to industrial plant scale given the insufficient knowledge about the overall safety in the synthesis process of more than 6000 existing MOF structures. This article discusses the findings of an overall hazard identification and analysis on the mainstream MOF synthesis process at the laboratory scale. One of the main motivations is to provide an insightful source of the safety practices and standards well-known in the chemical and petrochemical industries applied to the case study of the MOF synthesis process, as well as to prevent tragic incidents as the one reported in a research institute in March 2021. The intention is to encourage present and future MOF researchers to apply the techniques described in this article, or similar techniques, to their own laboratory practices therefore improving the overall practice of MOF synthesis. This work contributes to the overall advancement of MOF technology and the efforts for its commercial use at an industrial scale.

Effects of Ethanolic Extract of Kiam Wood/Cashew Bark and Commercial Phenolic Compounds Oxidized Under Alkaline Condition on Gel Property of Gelatin from Cuttlefish Skin

The effect of ethanolic extracts of kiam wood (EKW) or cashew bark (ECB) and commercial phenolic compounds oxidized under alkaline condition (pH 9) on gel properties of gelatin extracted from cuttlefish skin was investigated. All the oxidized compounds increased gel strength (GS) of gelatin, in which the highest value was noticed for gels containing oxidized catechin (CH-G) and gallic acid (GA-G) (P<0.05). Among the ethanolic extracts, the gel added with EKW (EKW-G) had higher GS than that containing ECB gel (ECB-G) (P<0.05). Both extracts yielded gels with similar GS to those added with oxidized ferulic and tannic acids (P>0.05). Lightness and free amino group content of gels were decreased with the addition of oxidized compounds, regardless of their types. Gels added with oxidized compounds showed lower solubility and amino group content as compared to the control, indicating the formation of nondisulphide covalent bonds in the gel matrix. The treated samples showed a gel network with thicker strands and larger voids, compared with the control gel. Overall, oxidized EKW extract had a similar impact on the gel properties of gelatin to the oxidized phenolic compounds, especially catechin and gallic acids.

Predicting zebrafish (Danio rerio) embryo developmental toxicity through a non-conformational QSAR approach

For many years, the frequent use of synthetic chemicals in the manufacture of veterinary drugs and plague control products has raised negative effects on human health and other non-target organisms, promoting the need to employ a practical and suitable methodology for early risk identification of several thousand commercial compounds. The zebrafish (Danio rerio) embryo has been emerged as one sustainable animal model for measuring developmental toxicity, an endpoint that is included in the regulatory procedures to approve chemicals, avoiding conventional and costly toxicity assays based on animal testing. In this context, the Quantitative Structure-Activity Relationships (QSAR) theory is applied to develop a predictive model based on a well-defined zebrafish embryo developmental toxicity database reported by the ToxCast™ Phase I chemical library of the Environmental Protection Agency (U.S. EPA). By means of four freely available softwares, a set with 28,038 non-conformational descriptors that encode the largest amount of permanent structural features are readily calculated. The Replacement Method (RM) variable subset selection technique provided the best regression models. Thereby, a linear QSAR model with proper statistical quality (Rtrain2 = 0.64, RMSEtrain = 0.49) is established in agreement with the Organization for Economic Co-operation and Development principles, accomplishing each internal (loo, l15 % o, VIF and Y-randomization) and external (Rtest2,Rm2, QF12, QF22, QF32 and CCC) validation criterion. The present QSAR approach provides a useful computational tool to estimate zebrafish developmental toxicity of new, untasted or hypothetical compounds, and it can contribute to the general lack of QSAR models in the literature to predict this endpoint.