Reactive Extraction Research Articles

Therapeutic potential and chemo-morphological characterization of silver nanoparticles synthesized using aqueous extracts of Monarda citriodora Cerv. ex Lag.

In present study, bioreduction of silver nitrate to silver nanoparticles was carried out using leaf extracts of Monarda citriodora plant. Different reaction parameters viz: inorganic silver salt (AgNO3) concentration, monarda extract concentration, pH and reaction time were varied to optimize the conditions for maximum recovery of silver nanoparticles. Monarda citriodora plant could efficiently bio-reduce silver ions. The efficiency of process increased with increasing salt concentration. Maximum recovery of AgNO3 was attained at 5 mM concentration with 5% concentration of MC leaf extract. The mixture incubated for 24 h at pH 8 gave maximum recovery. The images from scanning electron microscope (SEM) confirmed the dispersed state of silver nanoparticles. The energy-dispersive spectroscopy (EDX) graphs depicted that silver nanoparticles comprised 91.97% of silver mixed with some groups like N and Al acting as capping agents. Presence of organic groups like –OH was confirmed by Fourier transform infrared spectroscopy (FTIR) graphs. The x-ray diffractometer (XRD) peaks corroborated with presence of silver in mixture. Antimicrobial and anti-oxidant activities of nanoparticles were studied. From the results it was observed that silver nano-particles are potential agonistics to many microbial strains and also have efficient free radical scavenging properties when compared with ascorbic acid.

Recovery of Iron Resources from Wet-Process Phosphoric Acid and the Preparation of High Purity Ferrous Oxalate: Solvent Extraction and Photochemical Reaction

Recovery of Iron Resources from Wet-Process Phosphoric Acid and the Preparation of High Purity Ferrous Oxalate: Solvent Extraction and Photochemical Reaction

Equilibrium and kinetic investigation of reactive extraction of pyridine-2-carboxylic acid using corn oil as diluent

Equilibrium and kinetic investigation of reactive extraction of pyridine-2-carboxylic acid using corn oil as diluent

Removal of acrylic acid from aqueous solution utilizing tri-n-octyl amine or tributyl-phosphate in edible oils through reactive extraction

The separation of acrylic acid from its aqueous solutions with edible oils by reactive extraction method was investigated. Walnut oil, hazelnut oil, sesame oil, and safflower oil were used to prepare a relatively environmentally friendly and low-toxic organic phase. Tributyl phosphate (TBP) and tri-n-octyl amine (TOA) were chosen as extractants. In addition, a modifier (octanol, decanol, octyl acetate, methyl isobutyl ketone, 2-octanone, dimethyl phthalate) was added to the organic phase, and its effect on the extraction was investigated. The temperature effect (25, 45, and 65 °C), one of the parameters affecting the extraction process, was investigated. The results were presented as distribution coefficient (D), extraction efficiency (E%), and loading factor (Z). In the physical extraction experiments performed with edible oils, the extraction efficiency ranged between 14 and 21%, while it reached around 70% with TBP and above 90% with TOA in the reactive extraction. It was observed that the highest efficiency among the oils was obtained with safflower oil (71.88% for TBP and 92.68 % for TOA) for both extractants used. Moreover, using octanol as a modifier in the organic phase had a positive effect on the removal of acrylic acid from aqueous media by reactive extraction.

OPTIMIZATION OF THE METHOD OF QUANTITATIVE DEFINITIONS OF FLAVONOIDS IN THE RAW MATERIALS OF "MENYANTHIDIS TRIFOLIATAE LEAVES"

The aim of the study is to optimize the methodology of quantitative determination of flavonoids in the leaves of Menyanthidis trifoliatae. In official medicine, the leaves of Menyanthidis trifoliatae are used for anorexia and dyspeptic disorders.
 In the current regulatory documentation (State Pharmacopoeia of the Russian Federation), it is proposed to evaluate the quality of raw materials by the content of the amount of flavonoids in terms of rutin using spectrophotometry. This technique is based on the ability of flavonoids containing free aromatic hydroxyl groups to form colored products with diazotized sulfanilic acid. The disadvantage of this technique is the long and time-consuming stage of cleaning raw materials from certain groups of lipophilic substances, which can also react with diazotized sulfanilic acid to form colored products.
 We have proposed a selective method for the quantitative determination of flavonoids in the herb trifoliate by the method of spectrophotometry in terms of rutin. The technique is based on the ability of flavonoids to form stable colored complexes with aluminum chloride. We have selected the optimal conditions for extraction and complexation reaction of aluminum chloride with flavonoids of M. trifoliatae extract. The proposed method has been validated and is suitable for use in an analytical laboratory.

Validation of improved automated nucleic acid extraction methods for direct detection of polioviruses for global polio eradication

Polioviruses (PV), the main causative agent of acute flaccid paralysis (AFP), are positive-sense single-stranded RNA viruses of the family Picornaviridae. As we approach polio eradication, accurate and timely detection of poliovirus in stool from AFP cases becomes vital to success for the eradication efforts. Direct detection of PV from clinical diagnostic samples using nucleic acid (NA) extraction and real-time reverse transcriptase polymerase chain reaction (rRT-PCR) instead of the current standard method of virus isolation in culture, eliminates the long turn-around time to diagnosis and the need for high viral titer amplification in laboratories. An essential component of direct detection of PV from AFP surveillance samples is the efficient extraction of NA. Potential supply chain issues and lack of vendor presence in certain areas of the world necessitates the validation of multiple NA extraction methods. Using retrospective PV-positive surveillance samples (n=104), two extraction kits were compared to the previously validated Zymo Research Quick-RNA™ Viral Kit. The Roche High Pure Viral RNA Kit, a column-based manual extraction method, and the MagMaX™ Pathogen RNA/DNA kit used in the automated Kingfisher Flex system were both non-inferior to the Zymo kit, with similar rates of PV detection in pivotal rRT-PCR assays, such as pan-poliovirus (PanPV), poliovirus serotype 2 (PV2), and wild poliovirus serotype 1 (WPV1). These important assays allow the identification and differentiation of PV genotypes and serotypes and are fundamental to the GPLN program. Validation of two additional kits provides feasible alternatives to the current piloted method of NA extraction for poliovirus rRT-PCR assays.

Identification of Solvent Extraction of Au(III) by Cyanex 272 from Hydrochloric Acid Solutions

Bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) is known to selectively extract Au(III) from dilute to concentrated hydrochloric acid solutions. Therefore, Cyanex 272 can be employed in the separation of Au(III) from the hydrochloric acid leaching solutions of secondary resources containing gold metal. This work identified the extraction reaction of Au(III) by Cyanex 272 from the hydrochloric acid solutions. Au(III) extraction data was obtained by varying the concentrations of HCl (1-9 M), Au(III) (0.1-1 g/L) and Cyanex 272 (0.01-0.1 M). Among the three variables, it was found that HCl concentration had the most pronounced effect on the extraction of Au(III), which increased with HCl concentration. The extraction reaction of Au(III) by Cyanex 272 is proposed by applying slope analysis method to the extraction data. Comparison of Fourier transform infrared spectroscopy results for the fresh and loaded Cyanex 272 revealed no change in the chemical structure of Cyanex 272 after the extraction. Nuclear magnetic resonance spectroscopic data showed a change in the characteristic peaks of the phosphorus atom of Cyanex 272, indicating the formation of a coordinative bond between Au(III) and Cyanex 272. FT-IR and NMR data together with application of slope analysis clearly verified that molecular Cyanex 272 takes parts in the extraction of Au(III).

On the origin of selectivity in extracting and separating lanthanide ions by alkyl-nitrilotriacetamide

Extraction and separation technology forms an essential component of contemporary spent nuclear fuel reprocessing. Comprehending the underlying factors that drive extractant selectivity holds immense importance in crafting and advancing new extractants with optimal and desired performance. However, the majority of previous studies predominantly concentrated on organometallic complexes generated, while overlooked the entirety of the extraction process. In this study, we employ molecular dynamics (MD), extended tight-binding (xTB), and density functional theory (DFT) methods to comprehensively investigate the entire reaction process, with particular attention to overlooked aspects. Our findings reveal that the selectivity preference in the extraction reaction originates from the competition involved in the formation of metal complexes in both the aqueous and organic phases. Addressing the previously neglected aspects is crucial for providing clear guidance to enhance extraction selectivity. In the process, we have developed two driving force models and explained the origin of extraction selectivity. Model I is propelled by distinctions among organometallic complexes, whereas Model II is influenced by their similarities. Little is known about Model II since reported extractants fulfill Model I. Notably, we have discovered that the extraction and separation of La3+/Lu3+ using hexaocactyl-nitrilotriacetamide conforms to Model II, marking the first example and potentially introducing a novel approach to design selective extractants.

Efficient separation for yttrium and heavy rare earth elements using functionalized quaternary ammonium ionic liquids

Given the similar ionic radii of heavy rare earth elements (HREEs), sixteen functionalized ionic liquids (FILs) with potential extraction and separation properties were designed and prepared, also their feasibilities for yttrium (Y) separation from HREEs were evaluated. The results show that [N16MOP][HDA] is the optimal extractant for Y separation from other HREEs, achieving a Ho/Y separation factor of 2.82. The extraction reaction is based on an ion pair mechanism, where a HoCl3 molecule is extracted by two [N16MOP][HDA] molecules. Complete stripping of the loaded rare earth elements (REEs) can be achieved using 0.1 mol/L hydrochloric acid. Deionized water is used as a scrubbing agent, the average separation coefficient between Y and other HREEs during the scrubbing process is 2.5. After six cycles of continuous operation for 15 h, the organic phase maintains stable extraction and separation capabilities, demonstrating good recyclability and periodic stability. This study introduces a sustainable method for separating Y from HREEs using novel FILs, which is more efficient and consumes fewer chemical reagents. The results of this study indicate that the introduction of functionalized cation in FIL enhances the affinity and selectivity of HREEs. This provides valuable insights into the design of FIL-based extractents and their potential applications in sustainable rare earth separation.

Electrochemical synthesis in company with hydrogen production via renewable energy: Opportunities and challenges

Organic electromechanical synthesis is an eco-friendly and efficient method for material synthesis, effectively addressing the high energy consumption and pollution problems in the traditional chemical industry. By combining hydrogen production from water electrolysis with organic electromechanical synthesis, the reactive oxygen/hydrogen from water hydrolysis can be utilized to oxidize/reduce organic compounds, reducing energy consumption and producing valuable organic products. However, this strategy still faces challenges when implemented in the industry. This paper addresses major technical challenges in the field, providing new insights for future advancements. Firstly, when selecting anode reactions for hydrogen production, it is important to consider the value and market demand of the oxidation product to match the production scale. Secondly, the development of efficient electrocatalysts and electrodes is required to enhance the oxidation kinetics and mass transfer of organics at the current density levels of industrial hydrogen production (500–2000 mA cm−2). Thirdly, it is essential to improve the selectivity and Faraday efficiency of the anode target product to lower the cost of subsequent separation and purification. Fourthly, existing anion and oxygen ion exchange membranes lack corrosion resistance to organic matter, and new separator materials with high ion conductivity and stability are crucial for the electrolytic coupling system. Finally, when combining organic oxidation and water electrolysis, the complexity of product separation increases, and it is recommended to integrate distillation, extraction, membrane separation, and electrochemical reactions to improve process efficiency.

Optimization of HIV Sequencing Method Using Vela Sentosa Library on Miseq Ilumina Platform.

Genotypic testing is often recommended to improve the management of patients infected with human immunodeficiency virus (HIV). To help combat this major pandemic, next-generation sequencing (NGS) techniques are widely used to analyse resistance to antiretroviral drugs. In this study, we used a Vela Sentosa kit (Vela Diagnostics, Kendall, Singapore), which is usually used for the Ion Torrent personal genome machine (PGM) platform, to sequence HIV using the Illumina Miseq platform. After RNA extraction and reverse transcriptase-polymerase chain reaction (RT-PCR), minor modifications were applied to the Vela Sentosa kit to adapt it to the Illumina Miseq platform. Analysis of the results showed the same mutations present in the samples using both sequencing platforms. The total number of reads varied from 185,069 to 752,343 and from 642,162 to 2,074,028 in the Ion Torrent PGM platform and the Illumina Miseq platform, respectively. The average depth was 21,955 and 46,856 for Ion Torrent PGM and Illumina Miseq platforms, respectively. The cost of sequencing a run of eight samples was quite similar between the two platforms (about USD 1790 for Illumina Miseq and about USD 1833 for Ion Torrent PGM platform). We have shown for the first time that it is possible to adapt and use the Vela Sentosa kit for the Illumina Miseq platform to obtain high-quality results with a similar cost.

A Knockout of Poly(ADP-Ribose) Polymerase 1 in a Human Cell Line: An Influence on Base Excision Repair Reactions in Cellular Extracts.

Base excision repair (BER) is the predominant pathway for the removal of most forms of hydrolytic, oxidative, and alkylative DNA lesions. The precise functioning of BER is achieved via the regulation of each step by regulatory/accessory proteins, with the most important of them being poly(ADP-ribose) polymerase 1 (PARP1). PARP1's regulatory functions extend to many cellular processes including the regulation of mRNA stability and decay. PARP1 can therefore affect BER both at the level of BER proteins and at the level of their mRNAs. Systematic data on how the PARP1 content affects the activities of key BER proteins and the levels of their mRNAs in human cells are extremely limited. In this study, a CRISPR/Cas9-based technique was used to knock out the PARP1 gene in the human HEK 293FT line. The obtained cell clones with the putative PARP1 deletion were characterized by several approaches including PCR analysis of deletions in genomic DNA, Sanger sequencing of genomic DNA, quantitative PCR analysis of PARP1 mRNA, Western blot analysis of whole-cell-extract (WCE) proteins with anti-PARP1 antibodies, and PAR synthesis in WCEs. A quantitative PCR analysis of mRNAs coding for BER-related proteins-PARP2, uracil DNA glycosylase 2, apurinic/apyrimidinic endonuclease 1, DNA polymerase β, DNA ligase III, and XRCC1-did not reveal a notable influence of the PARP1 knockout. The corresponding WCE catalytic activities evaluated in parallel did not differ significantly between the mutant and parental cell lines. No noticeable effect of poly(ADP-ribose) synthesis on the activity of the above WCE enzymes was revealed either.

Molecular Characterisation of Traditional Cashew (Anacardium occidentale L.) Populations from Nachingwea and Newala Districts in Tanzania

This study assessed the genetic diversity of 120 selected cashew plants from Nachingwea and Newala traditional cashew populations, comprising of 60 cashew plants from each population. Eight Simple Sequence Repeats (SSR) makers were used to ascertain the extent of genetic variation within and between the two traditional cashew populations. Genomic DNA extraction and Polymerase Chain Reaction (PCR) were performed using standard protocols. The results showed that all SSR markers were polymorphic. Average Polymorphic Information Content (PIC), heterozygosity, number of alleles per locus, allelic frequency and Shannon’s Index were 0.540, 0.721, 3.391, 0.666 and 0.649, respectively. Analysis of molecular variance results showed that genetic variation within populations was 88% while genetic variation between populations was 12%, implying gene flow between the populations. The results further showed that the two cashew populations are genetically diverse and that Nachingwea traditional cashew population was genetically more diverse than Newala population. High genetic variation observed in the cashew populations shows that they are suitable for use in cashew breeding programmes. Thus, conservation of traditional cashew populations is recommended

Optimization and modelling of pravastatin recovery from aqueous solutions using reactive extraction methodology

AbstractThis research endeavour primarily aimed to optimize and establish a model for the recovery of pravastatin, a well‐known statin drug recognized for its cholesterol‐lowering properties, from aqueous solutions using reactive extraction. This study used the Box–Behnken design to investigate extraction parameters and create a concise model equation illustrating the relationship between variables and responses. The investigation showed a strong agreement between the model equation and experimental outcomes. It highlighted a positive correlation, demonstrating that higher concentrations of reactant and pravastatin led to notable improvements in extraction efficiency. Two out of 90 experiments had extraction efficiencies below 10%, both with constant factors except for solvent type, while 14 experiments exceeding 80% efficiency highlighted the positive impact of a 50% reactant concentration on extraction efficiency. According to a statistical second‐order polynomial, the predicted extraction efficiency stands at 75.14%. In the culminating phase of the study, optimal extraction conditions were meticulously determined, resulting in the identification of an optimal set of parameters: a pravastatin concentration of 35 mg · L−1, an adogen concentration of 20.91% (v/v), and a butanol phase ratio of 0.2% (v/v). Under optimal conditions, the experimental extraction efficiency reached 72.69%, closely aligning with values predicted through numerical optimization employing response surface methodology.

Protozoários zoonóticos em gatos diarréicos no centro-oeste do Brasil

Diarrhea, especially that of infectious origin, is a common problem in feline medicine. However, identifying a causative agent is difficult in routine clinical practice due to the many pathogens that lead to non-specific clinical signs. Among the various gastrointestinal parasites, protozoa, such as Giardia duodenalis (Lambl, 1859) and Cryptosporidium spp. (Tyzzer, 1907), pose a great threat because of their pathogenicity, prevalence in domestic animals, and zoonotic potential. This study aimed to report the occurrence of intestinal protozoa, G. duodenalis, and Cryptosporidium spp., in cats from Campo Grande, Mato Grosso do Sul, Brazil. Fecal samples and clinical and epidemiological data were obtained from 60 patients with diarrhea. Samples were subjected to DNA extraction and polymerase chain reaction (PCR) to identify the protozoa. Protozoa-positive samples were subjected to DNA sequencing and phylogenetic analysis. PCR assays revealed that one sample (1.67 %) was positive for G. duodenalis, and four samples (6.67 %) contained Cryptosporidium spp. G. duodenalis assemblage B and Cryptosporidium felis (Iseki, 1979) were identified through amplicon DNA sequencing and subsequent phylogenetic analysis. This is the first report of C. felis and G. duodenalis (assemblage B) in cats in Mato Grosso do Sul, central-western Brazil.

Efficient separation and recovery of Co and Ni from ammonium sulfate roasting‐water leaching solutions of oceanic cobalt‐rich crusts by sulfide precipitation and P507–Cyanex 272 synergistic extraction

AbstractOceanic cobalt‐rich crusts contain many valuable metals including Co, Ni, Cu, and Mn, of which Co and Ni are scarce metal resources on terrestrial land. Co, Ni, Cu, and Mn in cobalt‐rich crusts can be efficiently extracted by the ammonium sulfate roasting‐water leaching (ARWL) process, but separating and recovering Co and Ni from the leaching solution containing high concentrations of Mn is a challenging problem. In this study, a combination of sulfide precipitation and P507–Cyanex 272 synergistic extraction is proposed for the separation and recovery of Co and Ni from the ARWL solutions of oceanic cobalt‐rich crusts. Under the optimum sulfide precipitation conditions, Co and Ni were precipitated with 99.85% and 99.63% efficiency, respectively, while Mn was coprecipitated with only .79% efficiency. The Co–Ni mixed sulfides were dissolved by dilute sulfuric acid under oxidative conditions to obtain a solution containing 12.584 g/L Co, 11.012 g/L Ni, and a small amount of Mn. Subsequently, Co and Mn were extracted from this solution using P507–Cyanex 272 synergistic extraction, the single‐stage extraction efficiencies of Co and Mn were 95.76% and 99.73%, respectively, and the coextraction efficiency of Ni was 3.02%, under the conditions of a feed solution pH of 3.0, an extractant saponification degree of 70%, a total extractant concentration of 20% (P507 to Cyanex 272 ratio of 3:7), and an O/A ratio of 1.1:1. The results of the thermodynamic study showed that the reaction of Co extraction by this mixed extraction system was exothermic. Ni in the organic phase was washed with an H2SO4 concentration of .12 mol/L, followed by stripping of Co and Mn with an H2SO4 concentration of .6 mol/L. Mn in the stripping solution was removed by oxidative precipitation with (NH4)2S2O8, after which the Co3O4 product was obtained by precipitation with (NH4)2C2O4 and calcination. Similarly, NiC2O4·2H2O can be obtained from the raffinate by (NH4)2C2O4 precipitation. Finally, a flowsheet was developed for the separation and recovery of Co, Ni, Cu, and Mn from the ARWL solutions of oceanic cobalt‐rich crusts. The study provides a promising scheme for the recovery of various valuable metals from deep‐sea cobalt‐rich crusts or manganese nodules.

Recent Advances in Designing Catalysts and Reaction Systems for Electrochemical Synthesis of Ammonia

AbstractThe current industrial synthesis of ammonia involves an energy‐intensive Haber‐Bosch process, significantly contributing to a massive carbon footprint. An electrochemical synthetic pathway for nitrogen fixation has recently garnered significant attention. It allows ammonia production through a green process without generating harmful pollutants. However, due to the robust N≡N bond, the limited nitrogen solubility, and the competing reactions of hydrogen extraction, the synthesis of ammonia by electrochemical nitrogen reduction (e‐NRR) is far from achieving industrialization. The intrinsic properties of the catalyst, the gas‐solid‐liquid interface, and the specific design of reaction system are the key factors that affect e‐NRR performance. Therefore, this review discusses recent efforts in enhancing e‐NRR performance towards ammonia production with regards to catalyst design, reaction interface optimization, and modulation of the reaction system (including lithium mediated ammonia synthesis). Finally, various promising research strategies and remaining tasks are presented. It is anticipated that this review could be beneficial for the further development of highly efficient and selective e‐NRR to ammonia.

Narrownose smoothhound (Mustelus schmitti) shark liver: From a residue to a high added value biocompounds

The exploration of fishery wastes for the extraction of value-added biocompounds has become a topic of current interest. The aim of this work was to promote a circular economy model by obtaining oil by enzymatic hydrolysis from Mustelus schmitti livers and incorporating it into bread. The oil extraction reaction was carried out using Alcalase® 2.4 L at pH 8.0, 55 °C of temperature for 60 min. Fatty acid analysis showed that the oil was rich in ω-3 long chain fatty acids (LCω3PUFAs), with the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) being the main constituents (13 and 70 % of total PUFAs, respectively). Then, an external gelation method was developed to produce alginate capsulates loaded with the extracted oil. The encapsulation efficiency (EE) was 93.41 %. Finally, capsulated and unencapsulated fish oil were used to develop breads and more than 95 % of EPA and DHA were recovered after baking. Thus, 20 g of baked product can provide about 45 % of the recommended minimum daily intake of EPA plus DHA. The results suggest that it is possible to use the liver from the narrownose smoothhound (Mustelus schmitti) shark fishery to produce value-added products based on a circular economy.

Assessment of alcoholic extraction of Jatropha curcas L. oil for potential reactive extraction towards fatty esters

This work dealt with the extraction of Jatropha oil using methanol and ethanol as solvents to evaluate a potential integration of extraction-transesterification to produce fatty esters. For comparison purposes, additional extractions were carried out with n-hexane as industrial benchmark solvent. The effects of type of solvent, particle size (0.44–3.57 mm), and seed-to-solvent ratio (1:4, 1:6, and 1:8 w/v) were evaluated with respect to oil yield, efficiency, saponification index (SI, mgKOH/g) and acid value (AV, mgKOH/g). As expected, highest oil yield (50.4% wt.) was obtained using n-hexane, but with a low selectivity to saponifiable materials (SI ∼ 166). When using alcohols, oil yield (8–31% wt.) and efficiency (17–70%) were lower and the quality of the oil was poor (SI 32–176; AV 4–5). Results indicated that, differently from previously claimed, integrated alcoholic extraction with alkaline transesterification would not be suitable for fatty esters production. By using experimental data and the Hildebrandt solubility parameters, it was possible to fit a continuous model suitable for further optimization and solvent selection in Jatropha oil extraction. The model was validated by predicting expected SI and oil yield using an untested solvent (i.e. petroleum ether), and difference between model predictions and experimental observations were less than 3%.

Ecdysone receptor strongly influences larval–pupal–adult transition and melanization in Tuta absoluta

Abstract Background Tomato leaf miner (Tuta absoluta) is a quarantined pest that damages Solanaceae crops worldwide. The overuse of traditional pesticides negatively affects both human health and the environment. RNA interference (RNAi), based on double-stranded RNA (dsRNA) induction, can be beneficial in the control of Tuta absoluta; one of the key points of using this technique is the selection of target genes. Exploring the ecdysone receptors (EcR) associated with the growth and development of tomato leaf miners is an important research topic and the primary aim of this study. Methods In this study, RNA extraction, cDNA synthesis, gene cloning, bioinformatics analysis, and quantitative real-time polymerase chain reaction were used to obtain the full length, conserved domain, and relative expression levels of the EcR. RNAi was used to explore the effects of EcR on larval growth and development, pupal weight, and emergence rate. Results The full-length cDNA of T. absoluta TaEcR was 1859 bp, and the coding region including the ZnF_C4 and HOLI domains was relatively conserved. The relative expression of EcR in the early pupal stage was substantially higher than that in the other instars. Approximately 70% of TaEcR RNAi larvae died or pupated abnormally. In the few successful pupations, the pupa weights were substantially lower (36.44%) than those of the control group. The color of the pupae was abnormal, and they did not enter their normal black state; the emergence rate of pupae was reduced by 43.45% compared to that of the control group. Conclusion These results indicate that TaEcR inhibition can affect larval metamorphosis, pupation, melanism, eclosion abnormalities, and, ultimately, lead to death. The results of this study suggest that TaEcR may be a candidate factor for developing environmentally-friendly RNAi pesticides that have practical value in field control.