Ethyl Anthranilate Research Articles

Repellent effect of two anthranilates against the tropical bed bug Cimex hemipterus (Hemiptera: Cimicidae) demonstrated in laboratory assays.

The bites and blood sucking of bed bugs (Cimex spp.) (Hemiptera: Cimicidae) pose a serious threat to human physical and mental health. Application of an effective repellent can prevent or reduce bed bug bites. Previous studies on repellent screening mainly focused on Cimex lectularius L. In this study, we investigated the repellent effect of two safe food additives, ethyl anthranilate (EA) and butyl anthranilate (BA), against Cimex hemipterus (F.), and also explored the role of antennae and mouthparts on C. hemipterus perception of repellents. Both EA and BA had a strong repellent effect against tropical bed bugs and their repellency was similar or lower than that of N,N-diethyl-3-methyl benzoyl amide, depending on whether or not a CO2 source was present. EA had higher repellency than BA and exhibited repellency to C. hemipterus for 3 days when a CO2 source was present. C. hemipterus avoided resting on 20% EA- and BA-treated harborages. Applying 20% EA and BA on rabbit skin significantly reduced the blood intake of C. hemipterus within 2 h. C. hemipterus could perceive EA and BA after their antennae or mouthparts or both antennae and mouthparts were removed. Both EA and BA had strong repellency against C. hemipterus, with EA being more repellent. Ablation of antennae and mouthparts did not affect the perception of EA and BA by C. hemipterus. © 2023 Society of Chemical Industry.

UTILISATION OF CONICAL PRICKLES OF BOMBAX CEIBA BARK FOR MULTIFUNCTIONAL MOSQUITO REPELLENT COLOURATION OF COTTON

"The development of novel routes for the production of functional textiles is an urgent need. Natural dyes are a safe and sustainable choice for the colouration of textiles. To achieve the colouration of textiles with natural dyes, mordanting methods have been highly explored; the present work targets the functional natural dyeing of cotton by the in-situ development of azoic dye. The paper discusses a new application approach of a novel natural dye (derived from conical prickles of Bombax ceiba bark) to cotton using mosquito repellent ethyl anthranilate. The dye obtained from the extract of Bombax ceiba bark conical prickles (CPBCE) was further converted into azoic dye by reacting it with diazotised ethyl anthranilate. The developed coloured cotton fabric was endowed with mosquito repellence, antibacterial action, and UV protection. The colouration properties and fastness of dyed samples were examined using standard methods. Moreover, the dyed samples were also characterised using TGA (thermogravimetric analysis) and XRD (X-ray diffraction) analysis. Thus, 100% mosquito repellent properties, good antibacterial protection, and excellent UV protection were imparted to cotton."

Natural Repellents as a Method of Preventing Ant Damage to Microirrigation Systems.

Simple SummaryAnts play an essential role in most agroecosystems. However, these insects can occasionally be detrimental to agricultural microirrigation equipment by chewing on tubing parts and causing uneven water distribution along the crops. One of the alternatives traditionally proposed to avoid this damage is the incorporation of substances into the tube material that deter or reduce chewing activity. However, the few attempts made prior to this research were unsuccessful due to the unsuitability of the selected substances and the methods used to integrate them into the tubing. In this study, we assessed the protective efficacy of this method in pipes used for subsurface drip irrigation (SDI). Unlike traditional attempts, we selected nontoxic compounds previously proven to be repellent against ants and integrated them into drip tubing through complex processes such as plastic compounding, injection and extrusion. The use of this type of tubing in a crop where significant ant damage is often reported revealed minimum damage when compared to control tubing containing no repellent additives. This suggests the efficiency of this method in providing protection against ants, but further studies are recommended prior to the commercialization of the designed system.Ants are important because they damage agricultural equipment, including microirrigation systems. The aim of this research was to assess the efficiency of the incorporation of repellents in drip irrigation tubing as a method of protection against ant damage. Unlike previous studies, we tested a series of nontoxic compounds that are repellent to ants. First, we assessed their repellent effects on a local ant species via olfactometer trials. Then, the candidates showing the best results (cinnamon essential oil, p-anisaldehyde and ethyl anthranilate) were incorporated via compounding, injection and extrusion to polyethylene tubing to test their efficiency in the field. Field tests showed high damage levels in the control tubing containing no repellents, presumably caused by up to six different ant species (Cardiocondyla batesii, Plagiolepis pygmaea, P. schmitzii, Solenopsis sp., Tapinoma nigerrimum and Tetramorium semilaeve). In contrast, the pipes containing the three selected compounds remained almost intact, with the treatment including ethyl anthranilate showing no damage at all. These results suggest the strong repellent potential of the selected compounds, even when integrated into plastic, as well as the apparent success of the proposed methodology against the damage caused by ants. The diversity of damage-causing agents that exist in or above the soil strongly encourages further studies to determine the overall efficiency of repellents in protecting irrigation pipes.

Development of Mosquito Repellent, Antibacterial, Antioxidant and UV Protective Cotton Using a Novel Method of Azoic Dyeing with Terminalia Chebula

ABSTRACT With rising awareness regarding human and environmental safety, the use of sustainable resources for the functionalisation of natural textile fibers are highly demanded. The present study investigates a novel process for the development of multifunctional cotton using the azoic dyeing method. Preparation of azoic dyes was performed using ethyl anthranilate (EA), a safe mosquito-repellent, and Terminalia chebula natural dye as the coupling component. The novel method of in-situ azoic dyeing using Terminalia chebula and ethyl anthranilate for functional coloration of cotton is explored. The developed shades were found satisfactory in terms of fastness and color strength. The novel method resulted in mosquito-repellent cotton with 100% mosquito repellency, which was found durable until at least 20 washes. Additional functional properties such as antibacterial activity (more than 94%), antioxidant activity (>87%) and UV protection (UPF >50) were also confirmed.

Michael addition of ethyl anthranilate and phenyl monothioanthranilate to acetylenic esters: experimental and theoretical results

The reaction of ethyl anthranilate with DMAD and with methyl propiolate in dichloromethane in the presence of ethylaluminium dichloride as catalyst at room temperature gives a mixture of the respective E- and Z-intermediate derivatives which do not cyclize even on refluxing for several hours. On carrying out the reaction in refluxing methanol in the absence of the catalyst, only one stereochemical isomer is obtained which is Z-intermediate indicating conversion of less stable isomer into the thermodynamically more stable derivative under these conditions. The resulting product did not cyclize even on refluxing in methanol in the presence of montmorillonite K10 clay catalyst. The reaction of phenyl monothioanthranilate with DMAD and with methyl propiolate gives similar results. A theoretical investigation of the reaction of ethyl anthranilate with methyl propiolate at the B3LYP/6-31 + G(d) level reveals that it occurs in five steps.

Development of multifunctional polyester using disperse dyes based through a combination of mosquito repellents

Advancement of new protection methodologies to counter mosquito-borne diseases always remains a public intrigue. Among all reported and researched methods, mosquito repellent textiles may prove an effective product, as textiles being the basic need, cover most parts of the human body. This investigation focuses on the synthesis of novel mosquito repellent dyes from a combination of mosquito repellents like N, N‑diethyl-3-methyl benzamide (DEET) derivative, ethyl anthranilate, and 4‑hydroxy coumarin. Resultant dyes were analysed by FTIR, 1HNMR, UV spectroscopy, mass spectroscopy, and elemental analysis. The synthesized dyes were utilized for the dyeing of polyester. Dyed polyester demonstrated 100% mosquito repellency along with other functional properties such as antibacterial activity (>93%) and UV protection (UPF>124). The mosquito repellency was retained to a significant extent even after 20 washes. The synthesized dyes also displayed an efficient antioxidant activity and low algal toxicity. As most of the textiles are coloured, the synthesized novel disperse dyes can act as a tool for the multifunctional modification of polyester-based textile substrates.

Mosquito repellent thermal stability, permeability and air volatility

The effectiveness of mosquito repellents, whether applied topically on the skin or released from a wearable device, is determined by the evaporation rate. This is because a repellent has to be present in the form of a vapour in the vicinity of the exposed skin that needs protection. Therefore, gravimetric techniques were used to investigate the direct evaporation of selected liquid repellents, their permeation through polymer films, and their release from a microporous polyethylene matrix. Evaporation of a repellent into quiescent air is determined by its air permeability. This is a product of the vapour pressure and the diffusion coefficient, i.e. . It was found that repellents could be ranked in terms of decreasing volatility as: ethyl anthranilate > citriodiol > dimethyl phthalate > N,N-diethyl-meta-toluamide (DEET) > decanoic acid > ethyl butylacetylaminopropionate > Icaridin. Experimental SA values, at 50 °C, ranged from 0.015± 0.008 mPa m2 s-1 for the least volatile repellent (Icaridin) to 0.838± 0.077mPam2 s-1 for the most volatile (ethyl anthranilate). The release rate from microporous polyethylene strands, produced by extrusion-compounding into ice water baths followed a similar ranking. These strands featured an integral skin-like membrane that covered the extruded strands and controlled the release of the repellent at a low effective rate. The high thermal and thermo-oxidative stability together with the low volatility of the mosquito repellents ethyl butylacetylaminopropionate and Icaridin make them attractive candidates for long-lasting wearable mosquito-repellent devices. Such anklets/bracelets may have utility for outdoor protection against infective mosquito bites in malaria-endemic regions. © 2019 Society of Chemical Industry.

Visual test for the presence of the illegal additive ethyl anthranilate by using a photonic crystal test strip.

A test strip has been developed for the rapid detection of the illegal additive ethyl anthranilate (EA) in wine. The detection scheme is based on a combination of photonic crystal based detection and molecular imprinting based recognition. The resulting molecularly imprinted photonic crystal (MIPC) undergoes a gradual color change from green to yellow to red upon binding of EA. A semi-quantitative colorimetric card can be used to estimate the content of EA, either visually or by making use of an optical fiber spectrometer. A linear relationship was found between the Bragg diffraction peak shift and the concentration of EA in the range from 0.1mM to 10mM. The detection limit is 10μM. The test has been successfully used to screening for the presence of EA in grape wine. The test strip is selective, and can be re-used after re-activation. Graphical abstract Schematic representation of the fabrication and application of the molecularly imprinted photonic crystal (MIPC) based test trip. The resulting MIPC undergoes a gradual color change from green to yellow to red upon binding of the illegal wine additive ethyl anthranilate (EA).

Toxicity and repellency of two anthranilates against Aedes albopictus Skuse (Diptera: Culicidae)

The ability of Aedes albopictus Skuse to transmit several pathogens to humans makes it a very important mosquito with public health significance. Ecofriendly products as alternatives to synthetic chemicals for the control of mosquito vectors are needed. Therefore, the larvicidal and repellent effects of two nontoxic chemicals, butyl anthranilate (BA) and ethyl anthranilate (EA), at different concentrations were compared in A. albopictus. The repellency persistence of BA and three commercial mosquito repellent products (Liushen repellent spray, DKB Korean, Raid repellent spray) against A. albopictus was compared. The results showed that 0.1% concentrations of BA and EA solutions were highly toxic to A. albopictus larvae, and the mortality rate was >90% after 4 h of treatment. We found that BA was more repellent than EA, and at 0.1% BA and 1% EA, and the repellency rates were 53.62% and 38.47%, respectively. Overall, 5% BA presented a significantly longer repellency time than the three commercial repellent products against female A. albopictus. These results indicate that BA has significant larvicidal and repellent effects and can be exploited further for the development of ecofriendly alternatives to existing toxic chemicals currently used for mosquito control.

Safe chemical repellents to prevent the spread of invasive ants.

The red imported fire ant, Solenopsis invicta, is one of the most dangerous invasive species in the world. Fire ants can spread by hiding among plant material and soil that are transported from infested areas in vehicles and vessels. Therefore, efficient repellents may be used to prevent fire ants from infesting transported goods. Although some fire ant repellants have been identified, novel, cost-effective and environmentally friendly materials for fire ant control are still needed. Recent studies with other model insects have suggested readily available, non-toxic alternatives (e.g., anthranilates) to commercial repellents. We measured the repellent effects of the food additives ethyl anthranilate and butyl anthranilate against nesting by fire ant workers, and the results demonstrated that extremely low concentrations of these compounds can prevent fire ant nesting in pots. The tested compounds remained active at concentrations < 100 µL/L, which is many times lower than the minimum active concentration of any other proposed compound, including the established insect repellent N,N-diethyl-3-methylbenzamide (DEET). These inexpensive chemicals are safely used by the food and cosmetics industries, and their high efficiency differentiates them as the most promising chemicals for use in preventing the spread of fire ants; thus, these chemicals should be evaluated for further potential applications. © 2018 Society of Chemical Industry.

Protection against mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus using a novel insect repellent, ethyl anthranilate

Growing concern on the application of synthetic mosquito repellents in the recent years has instigated the identification and development of better alternatives to control different mosquito-borne diseases. In view of above, present investigation evaluates the repellent activity of ethyl anthranilate (EA), a non-toxic, FDA approved volatile food additive against three known mosquito vectors namely, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus under laboratory conditions following standard protocols. Three concentration levels (2%, 5% and 10% w/v) of EA were tested against all the three selected mosquito species employing K & D module and arm-in-cage method to determine the effective dose (ED50) and complete protection time (CPT), respectively. The repellent activity of EA was further investigated by modified arm-in-cage method to determine the protection over extended spatial ranges against all mosquito species. All behavioural situations were compared with the well-documented repellent N,N-diethylphenyl acetamide (DEPA) as a positive control. The findings demonstrated that EA exhibited significant repellent activity against all the three mosquitoes species. The ED50 values of EA, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus were found to be 0.96%, 5.4% and 3.6% w/v, respectively. At the concentration of 10% w/v, it provided CPTs of 60, 60 and 30min, respectively, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes. Again in spatial repellency evaluation, EA was found to be extremely effective in repelling all the three tested species of mosquitoes. Ethyl anthranilate provided comparable results to standard repellent DEPA during the study. Results have concluded that the currently evaluated chemical, EA has potential repellent activity against some well established mosquito vectors. The study emphasizes that repellent activity of EA could be exploited for developing effective, eco-friendly, acceptable and safer alternative to the existing harmful repellents for personal protection against different hematophagous mosquito species.

Exploration of ethyl anthranilate-loaded monolithic matrix-type prophylactic polymeric patch

Compromised stability of pharmaceutical formulations loaded with volatiles is a serious problem associated with devices designed to deliver volatile compounds. The present study has been focused to evaluate the stability potential of matrix-type polymeric patches composed of volatile ethyl anthranilate for prophylaxis against vector-borne diseases. Ethyl anthranilate-loaded matrix-type polymeric patches were fabricated by solvent evaporation method on an impermeable backing membrane and attached to temporary release liners. Stability testing of the polymeric patches was performed as per the International Conference on Harmonization (ICH) guidelines for 6 months under accelerated conditions. In addition, the quantification of residual solvents was also performed as per the ICH guidelines. After conducting the stability studies for 6 months, the optimized patches showed the best possible results with respect to uniformity of drug content, physical appearance, and other analytical parameters. Furthermore, the amount of residual solvent was found well below the accepted limit. Thus, the present report outlined the analytical parameters to be evaluated to ensure the stability of a certain devices consisting of volatile compounds.

Synthesis and reactivity with M(II) (M=Co and Cu) chloride of 1-[(2-carboxyethyl)benzene]-3-[benzothiazole]triazene

Reaction of ethyl anthranilate, sodium nitrite, and 2-aminobenzothiazole produces a new triazenide compound, 1-[(2-carboxyethyl)benzene]-3-[benzothiazole]triazene (HL), which has been characterized by X-ray crystallography and NMR spectrum. In the presence of Et3N, reaction of HL and CuCl2 · 2H2O or CoCl2 · 6H2O in THF/methanol affords a tetranuclear copper(II) complex [Cu4L4(µ-OMe)4] · 4THF (1) and a cobalt(III) complex [CoL′3] (2) (L′ is 1-[benzothiazole] triazene ion), accompanied by C–N bond cleavage of HL. They are characterized by X-ray crystallography and magnetic susceptibility measurement. Magnetic studies indicate significant antiferromagnetic coupling between the copper(II) centers for 1. The value obtained for the coupling constant J is −585 cm−1.

Synthesis and antimicrobial activity of 5-substituted-2-phenyl-3-(o-carboethoxyphenyl)iminomethyl indoles and their derivatives

5-Substituted indole-3-carboxaldehydes (1a-c) on reaction with ethyl anthranilate (2) in ethanol under reflux for 8 h in presence of catalytic amount of concentrated hydrochloric acid gave 5-substituted-2-phenyl-3-(o-carboxyphenyl)iminomethyl indoles (3a-c), which on further reaction with hydrazine hydrate in ethanol under reflux for 5 h yielded 5-substituted-2-phenyl-3-(o-carboethoxyhydrazidophenyl)iminomethyl indoles (4a-c). Compounds (4a-c) on reaction with acetyl acetone/ethyl acetoacetate and ethylcyanoacetate in ethanol under reflux conditions for 5 h in presence of catalytic amount of glacial acetic acid furnished 5-substituted-2-phenyl-3-[o-carboxy-(3',5'-dimethylpyrazol/3'-methyl-pyrazol-5'-one/3'-aminopyrazol-5'-one-1'-)ylphenyl]iminomethyl indoles (5a-c), (6a-c) and (7a-c), respectively. All the newly synthesized compounds have been tested for their antimicrobial activity against E. coli, S. aureus, P. vulgaris, A. niger and C. albicans. Some of the compounds exhibited good activity against all the microorganisms tested.

Synthesis and Single Crystal X-Ray Structure of Bis[4-oxo-3- (2-ethoxycarbonylphenyl)-3,4-dihydroquinazolin-2-yl]disulfide

Diethyl 2,2´-thiocarbonyl-bis(azanediyl)dibenzoate was synthesized from the reaction of ethyl anthranilate with thiophosgene. Its treatment with sodium ethoxide in ethanol at room temperature gave ethyl 2-(4-oxo-2-thioxo-1,2-dihydroquinazolin-3(4H)-yl) benzoate, whereas in the presence of ethyl nitroacetate and under the same reaction conditions, the corresponding bis(quinazolin)disulfide was formed. Its structure was confirmed by IR, 1H and 13C NMR spectroscopy elemental analysis and single crystal X-ray structure determination.

Quantification of Selected Aroma-Active Compounds in Pinot Noir Wines from Different Grape Maturities

Effect of grape maturity on aroma-active compounds in Pinot noir wine was investigated using stir bar sorptive extraction-gas chromatograph-mass spectrometry (SBSE-GC-MS). High correlation coefficient (> 0.95) and low standard deviation (< 10%) were obtained for all aroma-active compounds of interest. Two vintages of Pinot noir wines with three different grape maturities each were analyzed. Statistical analysis showed that both grape maturity and growing year significantly affected the aroma composition of the final wine. Analysis of wine samples from the same vintage indicated that grape maturity could affect aroma compounds in different ways, based on their biochemical formation in the wines. For most short-chain fatty acid esters, there were no obvious trends with grape maturity, however, the concentrations of ethyl 2-methylpropanoate and ethyl 3-methylbutanoate consistently decreased with grape maturity. The decreasing trend was also observed for other esters including ethyl cinnamate, ethyl dihydroxycinnamate, and ethyl anthranilate, with the exception of ethyl vanillate, while C13 norisoprenoids, monoterpenes, and guaiacols had increasing trends with grape maturation.

Synthesis of 2‐Substituted and 2,3‐Disubstituted Quinazolin‐4‐ones Containing a Sterically Hindered Phenol Residue.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Aroma compounds in Oregon Pinot Noir wine determined by aroma extract dilution analysis (AEDA)

AbstractThe aroma profiles of Oregon Pinot Noir wines were investigated with aroma extract dilution analysis (AEDA). The wines were extracted with pentane‐diethyl ether, the aromas were distilled using solvent‐assisted flavour evaporation (SAFE) and separated into acidic/water‐soluble and neutral/basic fractions. In the acidic/water‐soluble fraction, 2‐phenylethanol and 3‐methyl‐1‐butanol showed the highest AEDA values, followed by 2‐methylpropanoic acid, butanoic acid, 2‐methylbutanoic acid, 3‐methylbutanoic acid, 2‐methylpropanol, hexanol, trans‐3‐hexenol, cis‐3‐hexenol, benzyl alcohol, 3‐methylthio‐1‐propanol, 3‐ethylthio‐1‐propanol, linalool and geraniol (all with FD ≥ 64). In the neutral/basic fraction, ethyl 2‐methylpropanoate, ethyl butanoate, 3‐methylbutyl acetate, ethyl hexanoate, and benzaldehyde had very high AEDA values (all with FD ≥ 64), followed by ethyl 3‐methylbutanoate, 3‐methylbutyl 2‐methylpropanoate, ethyl octanoate, ethyl decanoate, benzyl acetate, phenylethyl formate, phenylethyl acetate, ethyl dihydrocinnamate, ethyl anthranilate, 3‐methylthio‐1‐propanal, citronellal, whisky lactone and γ‐nonalactone (all with FD ≥ 16). Overall, the results indicated that there is no single compound that characterizes the aroma of Pinot Noir, and that the characteristic aroma comes from a blend of numerous compounds. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Synthesis of 2-Substituted and 2,3-Disubstituted Quinazolin-4-ones Containing a Sterically Hindered Phenol Residue

A series of 2-substituted and 2,3-disubstituted quinazolin-4-ones containing a 3,5-di(tert-butyl)-4-hydroxyphenyl group has been synthesized. They were prepared by the condensation of carboxylic acid imino ester hydrochlorides containing the indicated fragment with ethyl anthranilate and also by the reaction of azomethines, N-acylhydrazones, or the 4-phenylthiosemicarbazone of 3,5-di(tert-butyl)-4-hydroxybenzaldehyde with 2-methyl-4H-2,1-benzoxazin-4-one.

Bilirubin-IXbeta is a marker of meconium, like zinc coproporphyrin.

Because meconium accumulates continuously in the fetal intestine, analysis of the postnatally excreted material could yield important information of intrauterine metabolism and maturation. Therefore, a study of the bilirubin pigments in meconium and in the first neonatal stools was carried out. Meconium and stools from 37 neonates of various gestational ages were collected carefully, and stored at -20 degrees C, protected by aluminium foil. Samples were defrosted, vortex mixed with an equal amount of dimethyl sulfoxide, centrifuged, and submitted to analysis by high-pressure liquid chromatography using newly developed methods to identify and to quantitate the bilirubin-IXalpha, -IXbeta, -IXgamma, and -IXdelta isomers. In addition, samples were also submitted to diazo coupling with ethyl anthranilate. Total coproporphyrins and zinc coproporphyrin were assayed for comparison. Unconjugated bilirubin-IXalpha and -IXbeta were detected in meconium but not the -IXgamma or the -IXbeta isomer. Bilirubin-IXbeta was the predominant pigment and comprised 63% to 96% of the unconjugated bilirubins in the first sample of meconium excreted. Its amount decreased rapidly during the first 5 days in full-term newborns, but this occurred more slowly in preterm neonates, especially in those with a gestational age less than 30 weeks. The decrease of bilirubin-IXbeta over time correlated with that of coproporphyrin. Bilirubin-IXbeta is the prevailing bile pigment in the first excreted sample of meconium. It gradually decreases after birth and can be considered a biochemical marker of meconium, like zinc coproporphyrin.