Chlorine Groups Research Articles

Separation of Sucralose in Food Samples using Amines as Background Electrolyte Supported with DFT Calculations

Background: Sucralose is a high intensity artificial sweetener and chemically known as 1,6-dichloro-1,6-dideoxy-β-D-fructofuranosyl-4-chloro-4-deoxy-α-D-galactopyranoside. It is used as a sweetener and flavour enhancer in foods and beverages. Due to its high stability at wider temperatures and pH, it made its applicability in various food products throughout the world. As per Joint FAO/WHO Expert Group on Food Additives (JECFA) in 1990, the daily intake of sucralose is 0-15 mg/kg body weight. The literature reports suggest that sucralose has a possible health threat due to the presence of chlorine groups, thereby leading to several illnesses. The growing interest in the use of sucralose (SCL) in the foods makes it necessary in developing a fast, reliable, cost effective and reproducible analytical method to determine SCL in food samples. The detection of sucralose and other carbohydrates like fructose, glucose and sucrose is a challenging task owing to its: (i) unavailability of the charged functions and (ii) lack of absorption of strong chromophoric nature in the UV region. Therefore, separation of non-absorbing neutral molecules needs a careful procedure with suitable electrolyte systems. Methodology: An indirect UV detection capillary electrophoretic method is described for the separation of sucralose in different food samples. It was achieved by nucleophile substitution (SN2) in the presence of amine as background electrolytes. The morpholine buffer showed good buffering capacity in terms of migration time (< 8.0 min) and baseline stability when compared to other amine buffers (ethylamine, piperidine, triethylamine). The analytical applications of proposed method showed by recovery percentages of sucralose in real and spiked samples on intra and inter-day basis at optimum experimental conditions of 0.2 M buffer concentration and pH 12.0 at 230 nm UV detection. Results: The selection of BGE, UV detection wavelength, buffer concentration, buffer pH, cassette temperature and applied voltage was optimized to enhance the sensitivity and selectivity of the separation method. Recoveries obtained were ranging from 96.87 to 98.82% for real samples and 94.45 to 98.06% for spiked samples, respectively. Linearity was studied in the range of 2-10 mM, and showed a correlation coefficient of 0.9942. LOD and LOQ were found to be 0.3804 mg L-1 and 1.5215 mg L-1 with % RSD (n = 5) ± 1.27 and 1.19% with respect to migration time and peak area. Furthermore, to better understand the separation of sucralose with amine buffers, were investigated computationally using HOMO-LUMO calculations. The obtained results showed that the band gap decreases in the presence of amine moiety irrespective of its nature. Conclusion: In the study, a novel background electrolytic system was successfully applied to separate sucralose using indirect UV detector with capillary electrophoresis. The FTIR results confirmed that the interaction of sucralose with different amine buffers to better understand the separation chemistry behind sucralose and amine complexes. Moreover, computational results indicate that the direction of charge transfer from the amine functionality to the glucofuranosyl ring in each amine derivative of sucralose confirms the strong interaction between sucralose and amines, which led to the baseline separation of sucralose in different food samples.

Convenient Access to Functionalized Non-Symmetrical Atropisomeric 4,4′-Bipyridines

Non-symmetrical chiral 4,4′-bipyridines have recently found interest in organocatalysis and medicinal chemistry. In this regard, the development of efficient methods for their synthesis is highly desirable. Herein, a series of non-symmetrical atropisomeric polyhalogenated 4,4′-bipyridines were prepared and further functionalized by using cross-coupling reactions. The desymmetrization step is based on the N-oxidation of one of the two pyridine rings of the 4,4′-bipyridine skeleton. The main advantage of this methodology is the possible post-functionalization of the pyridine N-oxide, allowing selective introduction of chlorine, bromine or cyano groups in 2- and 2′-postions of the chiral atropisomeric 4,4′-bipyridines. The crystal packing in the solid state of some newly prepared derivatives was analyzed and revealed the importance of halogen bonds in intermolecular interactions.

Inhibitory activities of anthraquinone and xanthone derivatives against transthyretin amyloidogenesis

Transthyretin is a tetrameric protein which functions as a transporter of thyroxine and retinol-binding protein. Misfolding and amyloid aggregation of transthyretin are known to cause wild-type and hereditary transthyretin amyloidosis. Stabilization of the transthyretin tetramer by low molecular weight compounds is an efficacious strategy to inhibit the aggregation pathway in the amyloidosis. Here, we investigated the inhibitory activities of anthraquinone and xanthone derivatives against amyloid aggregation, and found that xanthone-2-carboxylic acid with one chlorine or methyl group has strong inhibitory activity comparable with that of diflunisal, which is one of the best known stabilizers of transthyretin. X-ray crystallographic structures of transthyretin in complex with the compounds revealed that the introduction of chlorine, which is buried in a hydrophobic region, is important for the strong inhibitory effect of the stabilizer against amyloidogenesis. An in vitro absorption, distribution, metabolism and elimination (ADME) study and in vivo pharmacokinetic study demonstrated that the compounds have drug-like features, suggesting that they have potential as therapeutic agents to stabilize transthyretin.

Bioremediation of polyvinyl chloride (PVC) films by marine bacteria

Polyvinyl chloride (PVC) is the third one after polyethylene and polypropylene in the production demand. It intends to grow further, causing an increase in the risk of health and ecological problems due to environmental accumulation and incineration. In the present study, we determined the biodegradative abilities of marine bacteria for PVC. Three potential marine bacterial isolates, T-1.3, BP-4.3 and S-237 (Vibrio, Altermonas and Cobetia, respectively) were identified after preliminary screening. They led to active biofilm formation, viability and protein formation on the PVC surface. The highest weight loss (1.76%) of PVC films was exhibited by BP-4.3 isolate after 60 days of incubation. Remineralization of PVC film was confirmed by CO2 assimilation assay. Change in surface topography was confirmed by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The functional group peak intensity was decreased for the terminal chlorine group at the region 1000–1300 cm−1, which indicated the dechlorination. Thermogravimetric, tensile strength and contact angle analysis showed a decline in the mechanical properties and a rise in PVC film's hydrophilic nature after biodegradation. These results demonstrated promising evidence of PVC degradation by marine bacteria.

Isolation of a novel strain, Sphingorhabdus sp. YGSMI21 and characterization of its enantioselective epoxide hydrolase activity.

Sphingorhabdus sp. YGSMI21, a novel microbial strain with an enantioselective epoxide hydrolase activity, was isolated from tidal samples contaminated by accidental oil spills subjected to enriched culture with polycyclic aromatic hydrocarbon. This strain was able to optically decompose (R)-styrene oxide (SO) and showed 100% optical purity. In addition, it showed a good enantioselectivity for the derivatives of (S)-SO, (S)-2-chlorostyrene oxide (CSO), (S)-3-CSO and (S)-4-CSO. For (S)-2-CSO, (S)-3-CSO and (S)-4-CSO, 99.9%ee was obtained with the yield of 26.2%, 24.8%, and 11.0%, respectively, when using 10 mg cells of Sphingorhabdus sp. YGSMI21 at pH 8.0 with 4 mM racemic substrates at pH 8.0 and 25°C. The values obtained in this study for (S)-2-CSO, particularly the yield of 26.2%, is noteworthy, considering that obtaining an enantiomerically pure form is difficult. Taken together, Sphingorhabdus sp. YGSMI21 can be regarded as a whole-cell biocatalyst in the production of various (S)-CSO with the chlorine group at a different position.

Optimizing Fe-Based Metal-Organic Frameworks through Ligand Conformation Regulation for Efficient Dye Adsorption and C2 H2 /CO2 Separation.

Regulating the structure of metal-organic frameworks (MOFs) by adjusting the ligands reasonably is expected to enhance the interaction of MOFs on special molecules/ions, which has significant application value for the selective adsorption of guest molecules. Herein, two tricarboxylic ligands H3 L-Cl and H3 L-NH2 were designed and synthesized based on the ligand H3 TTCA by replacing part of the benzene rings with C=C bonds and modifying the chlorine and amino groups on the 4-position of the benzene ring. Two 3D Fe-MOFs (UPC-60-Cl and UPC-60-NH2 ) with the new topology types were constructed. As the C=C bonds of the ligands have flexible torsion angles, UPC-60-Cl features three types of irregular 2D channels, while UPC-60-NH2 has a cage with two types of windows on the surface. The synergistic effect of unique channels and modification of functional groups endows UPC-60-Cl and UPC-60-NH2 with high adsorption capacity for organic dyes. Compound UPC-60-Cl shows high adsorption capacity for CV (147.2 mg g-1 ), RHB (100.3 mg g-1 ), and MO (220.9 mg g-1 ), whereas UPC-60-NH2 exhibits selective adsorption of MO (158.7 mg g-1 ). Meanwhile, based on the diverse pore structure and modification of active sites, UPC-60-Cl and UPC-60-NH2 show the selective separation of equimolar C2 H2 /CO2 . Therefore, reasonable regulation of organic ligands plays a significant role in guiding the structure diversification and performance improvement of MOFs.

Investigation on the photophysical properties of Cu(I) complexes supported by N‐heterocyclic carbene ligands with electron‐donating/withdrawing groups on imidazolylidene unit

AbstractTwo new four‐coordinate Cu(I) complexes consisted of bidentate NHC ligand and diphosphine ligand were successfully synthesized and characterized. The electron‐donating methyl and electron‐withdrawing chlorine groups were introduced into the imidazolylidene unit of N‐heterocyclic carbene (NHC) ligands to investigate their influences on the photophysical properties of complexes. The red‐shifted low‐energy absorption bands indicate that both methyl and chlorine decreased the band gaps between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Theoretical calculation results show the methyl group raised the energy level of HOMO more than that of LUMO, while the chlorine substituent lowered the energy level of LUMO more than that of HOMO. Both these Cu(I) complexes show high emission efficiencies and microsecond‐scale emission lifetimes. The photophysical data at 77 K show that emissions of these complexes are the mixture of phosphorescence and thermally activated delayed fluorescence (TADF).

Chlorination of a Zeolitic-Imidazolate Framework Tunes Packing and van der Waals Interaction of Carbon Dioxide for Optimized Adsorptive Separation

Molecular separation of carbon dioxide (CO2) and methane (CH4) is of growing interest for biogas upgrading, carbon capture and utilization, methane synthesis and for purification of natural gas. Here, we report a new zeolitic-imidazolate framework (ZIF), coined COK-17, with exceptionally high affinity for the adsorption of CO2 by London dispersion forces, mediated by chlorine substituents of the imidazolate linkers. COK-17 is a new type of flexible zeolitic-imidazolate framework Zn(4,5-dichloroimidazolate)2 with the SOD framework topology. Below 200 K it displays a metastable closed-pore phase next to its stable open-pore phase. At temperatures above 200 K, COK-17 always adopts its open-pore structure, providing unique adsorption sites for selective CO2 adsorption and packing through van der Waals interactions with the chlorine groups, lining the walls of the micropores. Localization of the adsorbed CO2 molecules by Rietveld refinement of X-ray diffraction data and periodic density functional theory calculations revealed the presence and nature of different adsorption sites. In agreement with experimental data, grand canonical Monte Carlo simulations of adsorption isotherms of CO2 and CH4 in COK-17 confirmed the role of the chlorine functions of the linkers and demonstrated the superiority of COK-17 compared to other adsorbents such as ZIF-8 and ZIF-71.

Donor-acceptor carbon nitride with electron-withdrawing chlorine group to promote exciton dissociation

Carbon nitride (C3N4) is promising for photocatalytic hydrogen production, but photogenerated electrons and holes in C3N4 usually tend to exist as excitons due to intrinsic Coulomb interactions making its photocatalytic activity unsatisfactory. Herein, a well-designed intramolecular C3N4-based donor-acceptor (D-A) photocatalytic system was constructed to promote exciton dissociation. Due to its good chemical compatibility with melamine and appropriate sublimation property, 2-amino-4,6-dichloropyrimidine unit was chosen as the monomer to react with melamine to construct intramolecular D-A system (CNClx). The hydrogen evolution rate of CNCl0.15 is 15.3 times higher than that of bulk C3N4 under visible light irradiation, with apparent quantum efficiency of 13.6% at 420 nm. The enhanced activity is attributed to introduced electron-withdrawing −Cl group as terminal group in the resulted CNClx samples, which can build internal electric field to promote the exciton dissociation into free electron and hole. In addition, lower work function value of CNClx samples indicates that internal electric field can help free electrons and holes transfer to the surface of CNClx samples for photocatalytic reaction.

1,3,5‐Trichloro‐2,4,6‐Trinitrobenzene: The Elusive Impurity Standard

Abstract1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) is an insensitive high explosive synthesized in two steps; 1,3,5‐trichloro‐2,4,6‐trinitrobenzene (TCTNB) is the only intermediate. Due to solubility limitations, TATB is often dissolved in dimethylsulfoxide (DMSO) for liquid chromatography‐mass spectrometry (LC–MS) analyses; however, DMSO is capable of participating in a wide variety of reactions. Intending to use it as an impurity standard, TCTNB was dissolved in DMSO. A stark color change from colorless to yellow accompanied by wavelength and ion chromatogram changes occurred over 24 hours. Three compounds were identified as causing the color change. All three were present in both acetone and DMSO solutions, but, overtime the absorbance spectra of the DMSO solution changed indicating an underlying reaction occurs between these compounds and DMSO. The chemical formulas of impurities present in the TCTNB sample as well as reaction products are identified via quadrupole time of flight mass spectrometry. The chemical structures are also proposed. The combination of the solvent system, ionization technique, and halogenated/nitrated aromatic ring structures resulted in substitutions of both the chlorine and nitro groups to hydroxyl groups. Three proposed structures were closely related to TCTNB, but only one was detected at a consistent mass and absorbance wavelength in both acetone and DMSO. This compound had undergone a chlorine to hydroxyl substitution and should be utilized for TCTNB detection.

Facile one-pot sequential synthesis of novel diaryl urea derivatives and evaluation of their in vitro cytotoxicity on adenocarcinoma cells

Recently, the diarylurea scaffold has been used widely to design potential anticancer agents. Pursuing our design strategy based on the modification of sorafenib as the lead compound using de novo design approaches, a new series of diaryl urea derivatives were synthesized through an efficient sequential one-pot reaction and evaluated for their in vitro antiproliferative activities against A549 and HT-29 cell lines. Notably, compound 11j exhibited antiproliferative activity against HT-29 with an IC50 value of 17.87 µM. SAR analyses revealed that substitution of the core diaryl scaffold with chlorine and methyl groups, and linear elongation of the molecules by the introduction of a methylene spacer group could cooperatively improve antiproliferative activity. The most active compound 11j induced mild apoptosis in HT-29 cells assessed based on DAPI staining experiments. The results of molecular docking simulations showed that the novel compounds bind to VEGFR-2 in a similar fashion to that observed for sorafenib. Molecular docking calculations also revealed that the most active compound 11j can bind well to the active site of VEGFR-2 by forming various interactions similar to those known for sorafenib particularly the π–π interaction, which is almost unique to sorafenib and highly active derivatives.

Polyolefins with Intrinsic Antimicrobial Properties

Polyolefins with antimicrobial properties are generally prepared through blending or coating with antimicrobial agents. However, the nonpolar nature of polyolefins brings many issues including the difficulties in homogeneous mixing. In this contribution, we report the synthesis of polyolefins with intrinsic antimicrobial properties through three different routes. First, direct copolymerization of ethylene with nitrogen-containing comonomers affords some nitrogen-functionalized polyolefins with moderate antimicrobial properties. Subsequently, two postpolymerization functionalization routes enable the formation of imidazolium and various metal ion-functionalized polyolefins through the conversion of preinstalled chlorine and carboxylic-functional groups. In addition to high molecular weight and high functional group incorporation, these alternative routes generate polyolefins with excellent mechanical and antimicrobial properties. This work demonstrates the importance of different functional groups in determining the antimicrobial properties of polyolefin materials.

17.1 %‐Efficient Eco‐Compatible Organic Solar Cells from a Dissymmetric 3D Network Acceptor

AbstractTo elevate the performance of polymer solar cells (PSC) processed by non‐halogenated solvents, a dissymmetric fused‐ring acceptor BTIC‐2Cl‐γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X‐ray crystallographic data suggests that BTIC‐2Cl‐γCF3 has a 3D network packing structure as a result of H‐ and J‐aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB‐TF was used as a donor, the toluene‐processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non‐halogenated solvents. Compared to its symmetric counterparts BTIC‐4Cl and BTIC‐CF3‐γ, the dissymmetric BTIC‐2Cl‐γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo‐stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi‐transparent building integrated photovoltaics (ST‐BIPV).

17.1 %-Efficient Eco-Compatible Organic Solar Cells from a Dissymmetric 3D Network Acceptor.

To elevate the performance of polymer solar cells (PSC) processed by non-halogenated solvents, a dissymmetric fused-ring acceptor BTIC-2Cl-γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X-ray crystallographic data suggests that BTIC-2Cl-γCF3 has a 3D network packing structure as a result of H- and J-aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB-TF was used as a donor, the toluene-processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non-halogenated solvents. Compared to its symmetric counterparts BTIC-4Cl and BTIC-CF3 -γ, the dissymmetric BTIC-2Cl-γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo-stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi-transparent building integrated photovoltaics (ST-BIPV).

Single-Mode W-Type Optical Fiber Stable Against Bending and Radiation

It is shown that single-mode fluorosilicate optical fibers fabricated with the aid of modified chemical vapor deposition exhibit a significant decrease in the radiation resistance when 1 mol % GeO2 is introduced into the silica-glass core. Elimination of chlorine and OH group impurities in the silica glass of the core of the fluorosilicate single-mode fiber leads to a relatively low level of radiation-induced attenuation. Prior to radiation processing, the loss factors of optical fiber are 0.18 and 0.3 dB/km at wavelengths of 1.55 and 1.31 μm, respectively. The dependence of optical loss of such fibers on the bend diameter ranging from 6 to 12 mm is studied.

Pyridine clubbed coumarin analogues: Their synthesis and biological studies as antimicrobials and antioxidants

The major aim of this study is to develop the new class of coumarin candidate clubbed with dihydropyridine-3-carbonitrile with an improved potency as an antimicrobial and antioxidant agent. The key intermediate 6-nitro-4-methyl coumarin-yl chloro acetate 5 have been linked to the 6-(4-fluorophenyl)-2-oxo-4-phenyl-1,2-dihydro pyridine-3-carbonitrile IIa-j derivative to afford 4-methyl-6-nitro-2-oxo-2H-chromen-7-yl-2-(3-cyano-6-(4-fluoro phenyl)-4-(substituted-phenyl) pyridin-2-yl-oxy) acetates 7a-j via efficient organic transformations. All the new derivatives have been characterized by spectral studies (IR, 1H and 13C NMR and mass spectroscopy). In vitro antimicrobial activity have been carried out using the broth microdilution method and antioxidant potency using DPPH bioassays. Bioassay results reveal that compound 7e are equipotent against E. coli with MIC value 50 µg/ mL compared to standard drug ciprofoloxacin. A final analogue 7c with 4-chlorophenyl substituent indicated better antifungal potency against C. albicans with MIC value 100 µg/ mL compared to standard drug griseofulvin. In addition, newly synthesized analogues have been found to be significant scavengers of DPPH radical with IC50 values of 32.11 μg/mL. It has been observed that the potent antibacterial candidate has proved to possess significant antioxidant activity. The presence of chlorine and hydroxy group on phenyl ring plays an important role for the potency in above mentioned biological assay.

Unexpected chloro-functionalized ionic liquids-promoted selective conversion of cellulose into levulinic acid

A series of chloro-functionalized ionic liquids (CFILs) with chlorine groups (–Cl) on cations and chloride anions (Cl-) were synthesized and used as the promotion reagents for the selective conversion of cellulose into levulinic acid (LA) with the co-product of formic acid (FA). The co-operation between cations and anions of CFILs was investigated intensively through the variation of the structure of cations and the addition of salts with different anions. 3-(3-chloropropyl)-1-methyl-imidazolium chloride (IL-3) was the most appropriate additive, achieving up to 4.2%, 52.6%, and 58.7% of glucose, LA, and FA yields at 83.5% of cellulose conversion, respectively.

Removal of herbicide 1-chloro-2,4-dinitrobenzene (DNCB) from aqueous solutions by electrochemical oxidation using boron-doped diamond (BDD) and PbO2 electrodes

The electrochemical removal of the 1-chloro-2,4-dinitrobenzene (DNCB) herbicide, a potentially carcinogenic agent from aqueous solutions, was performed at PbO2 and BDD electrodes by bulk electrolysis under galvanostatic control (300 and 400 A m−2) and under two pH conditions (3 and 9). Results clearly indicated that a 62 % of mineralization was achieved with BDD anode at pH 3, while only a 46 % of electrochemical oxidation (EO) was achieved at PbO2 electrode. The mineralization current efficiency (MCE) depended on the electrode material, current density, and pH conditions; but, for both PbO2 and BDD, high MCE was achieved at pH 3 and 300 A m−2, obtaining 2.54 % and 1.99 % for BDD and PbO2, respectively. The EO pathway depended on the electrocatalytic properties of each one of the anodes to produce hydroxyl radicals which attacked the DNCB molecule as well as the deactivating effects of the chlorine and nitro groups attached to the aromatic ring on the DNCB structure. Finally, HPLC analyses also showed that phenolic intermediates as well as carboxylic acids were formed, at a different extent, during the electrolysis process on both electrodes.

Study on synergistic effect of ozone and monochloramine on the degradation of chloromethylisothiazolinone biocide

In this study, it was found that monochloramine induced the formation of reactive species during ozonation of chloromethylisothiazolinone (CMIT). CMIT was found recalcitrant to chloramine. However, chloramine promoted the degradation of CMIT by ozonation significantly. Hydroxyl radicals contributed most to CMIT degradation (87%) during ozone/chloramine synergistic oxidation process (SOP). The hydroxyl radical exposure during ozone/chloramine SOP was around 7.9 times higher than that of ozonation process. The hydroxyl radical yield of ozone/chloramine SOP was estimated to be 32%. The reaction mechanisms between ozone and chloramine were postulated to include the oxygen transfer reaction to form singlet oxygen, and the formation of hydroxyl radical by the insertion pathway or electron transfer pathway. Chloramine dosage and pH are essential influencing factors. The degradation of CMIT increased from 41% to 74% with increasing chloramine dosage (0–20 μM), and then decreased to 65% when chloramine dosage continually increased to 40 μM. Ozone/chloramine SOP showed better performance at acidic or neutral conditions than basic condition. Based on the intermediates identified, the degradation pathway of CMIT during ozone/chloramine SOP included the oxidation of sulfur atom and the substitution of chlorine group by hydroxyl group. The oxidation of sulfur atom induced lower toxicities of transformation products. The toxicities of hydroxylation products were lower to fish and algae, but higher to daphnia. Based on the GC-ECD results, only trichloromethane (1.94 μg/L) was detected after ozone/chloramine SOP, accounting for 0.17% (μM/μM) of the CMIT removal.

Larvicidal activity of substituted chalcones against Aedes aegypti (Diptera: Culicidae) and non-target organisms.

The expansion of Aedes aegypti (Diptera: Culicidae) population has increased the number of cases of arboviruses, in part due to the inefficiency and toxicity of the chemical control methods available to control this vector. We synthesized 19 chalcone derivatives and examined their activity against Ae. aegypti larvae in order to select larvicidal compounds that are non-toxic to other organisms. Seven chalcone derivatives (3a, 3e, 3f, 6a, 6c, 6d, and 6f) had lethal concentrations of substituted chalcones capable of killing 50% (LC50 ) values lower than 100 mg mL-1 at 24 h post-treatment, which is the dose that the World Health Organization recommends for the selection of promising larvicides. The type of substituent added to (E)-1,3-diphenylprop-2-en-1-one (3a) markedly affected the larvicidal activity. Addition of chlorine, bromine and methoxy groups to the aromatic rings reduced the larvicidal activity, while replacement of the B-ring (phenyl) by a furan ring significantly increased the larvicidal activity. The furan-chalcone (E)-3-(4-bromophenyl)-1-(furan-2-yl)prop-2-en-1-one (6c) killed Ae. aegypti larvae (LC50 = 6.66 mg mL-1 ; LC90 = 9.97 mg mL-1 ) more effectively than the non-substituted chalcone (3a) (LC50 = 14.43 mg mL-1 ; LC90 = 20.96 mg mL-1 ), and was not toxic to the insect Galleria mellonella, to the protozoan Tetrahymena pyriformis, and to the algae Chorella vulgaris. The substitution pattern of chalcones influenced their larvicidal activity. In the set of compounds tested, (E)-3-(4-bromophenyl)-1-(furan-2-yl)prop-2-en-1-one (6c) was the most effective larvicide against Ae. aegypti, with no clear signs of toxicity to other animal models. Its mechanism of action and effectiveness under field conditions remain to be determined.