Publications by authors named "N Paroul"

27 Publications

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification.

Braz J Biol 2021 28;83:e244647. Epub 2021 Jun 28.

Programa de Pós-Graduação em Engenharia de Alimentos, Universidade Regional Integrada do Alto Uruguai e das Missões - URI Erechim, Erechim, RS, Brasil.

The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-1 were obtained for the essential oil and 4.36 μg mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-1 for the essential oil of citronella and 86.30 μg mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.
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http://dx.doi.org/10.1590/1519-6984.244647DOI Listing
July 2021

Production of benzyl cinnamate by a low-cost immobilized lipase and evaluation of its antioxidant activity and toxicity.

Biotechnol Rep (Amst) 2021 Mar 6;29:e00586. Epub 2021 Jan 6.

Food Engineering Department, Universidade Regional Integrada do Alto Uruguai e das Missões-URI Erechim, Av. sete de setembro, 1621, 99709-910, Erechim, RS, Brazil.

In this work was optimized the production of benzyl cinnamate by enzymatic catalysis using the immobilized lipase NS88011 and to evaluate its biological properties. The optimized condition for this system was 1:3 (acid:alcohol) molar ratio, 59 °C, biocatalyst concentration 4.4 mg.mL for 32 h, with a yield of 97.6 %. The enzyme stability study showed that the enzyme remains active and yields above 60 % until the 13 cycle (416 h), presenting a promising half-life. In the determination of the antioxidant activity of the ester, an inhibitory concentration necessary to inhibit 50 % of the free radical 2,2-diphenyl-1-picryl-hydrazyl DPPH (IC) of 149.8 mg.mL was observed. For acute toxicity against bioindicator , lethal doses (LD) of 0.07 and 436.7 μg.mL were obtained for the ester and cinnamic acid, showing that benzyl cinnamate had higher toxicity, indicating potential cytotoxic activity against human tumors.
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http://dx.doi.org/10.1016/j.btre.2021.e00586DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809389PMC
March 2021

Biological properties of functional flavoring produced by enzymatic esterification of citronellol and geraniol present in essential oil.

Nat Prod Res 2020 Aug 25:1-7. Epub 2020 Aug 25.

Food Engineering Department, Universidade Regional Integrada do Alto Uruguai e das Missões-URI Erechim, Erechim, RS, Brazil.

The chemical composition and biological properties of citronella essential oil were modified by enzymatic esterification reaction of the major monoterpenic alcohols with cinnamic acid. The almost complete conversion of geraniol and citronellol present in the citronella () essential oil, into geranyl (99%) and citronellyl (98%) cinnamates was obtained after 48 hours of reaction using a molar ratio of 3:1 (cinnamic acid/alcohol), lipase concentration (Novozym 435) of 15% (w/w) and 70 °C. The esterified oil showed higher antimicrobial activity against bacteria resistant to oxacillin and penicillin and also greater larvicidal activity against larvae compared to unesterified oil. The results concerning the evaluation of toxicity against and cytotoxicity against monkey kidney epithelial cells also showed the superiority of the esterified oil.
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http://dx.doi.org/10.1080/14786419.2020.1810032DOI Listing
August 2020

Electronic Nose Based on Carbon Nanocomposite Sensors for Clove Essential Oil Detection.

ACS Sens 2020 06 17;5(6):1814-1821. Epub 2020 Jun 17.

Food Engineering, URI-Erechim, Av. Sete de Setembro 1621, 99709-910 Erechim, Rio Grande do Sul, Brazil.

This work describes the development of an electronic nose (e-nose) based on carbon nanocomposites to detect clove essential oil (CEO), eugenol (EUG), and eugenyl acetate (EUG.ACET). Our e-nose system comprises an array of six sensing units modified with nanocomposites of poly(aniline), graphene oxide, and multiwalled carbon nanotubes doped with different acids, dodecyl benzene sulfonic acid, camphorsulfonic acid, and hydrochloric acid. The e-nose presented an excellent analytical performance to the detected analytes (CEO, EUG, and EUG.ACET) with high sensitivity and reversibility. The limit of detection was lower than 1.045 ppb, with response time (<13.26 s) and recovery time (<106.29 s) and low hysteresis. Information visualization methods (PCA and IDMAP) demonstrated that the e-nose was efficient to discriminate the different concentrations of analyte volatile oil compounds. PM-IRRAS measurements suggest that the doping mechanism of molecular architectures is composed of a change in the oscillation energy of the characteristic dipoles and changes in the molecular orientation dipoles C═C and C═O at 1615 and 1740 cm, respectively. The experimental results indicate that our e-nose system is promising for a rapid analysis method to monitor the quality of essential oils.
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http://dx.doi.org/10.1021/acssensors.0c00636DOI Listing
June 2020

(3Z)-5-Chloro-3-(Hydroxyimino)indolin-2-one attenuates hyperglycemia, increased hepatic glycogen content and hepatic damage induced by malathion acute exposure in rats.

Nutr Metab (Lond) 2019 5;16:61. Epub 2019 Sep 5.

1Universidade Federal do Pampa (UNIPAMPA) Campus Uruguaiana, Uruguaiana, RS CEP 97500-970 Brazil.

Background: Organophosphorus pesticides (OP's) are heavily constituted in agriculture, gardens, home and veterinary and although it is useful, there are concerns about the environment, safety and health of human and animals. In this study, we investigated the effects of a new oxime, (3Z)-5-Chloro-3-(Hydroxyimino)indolin-2-one (OXIME) against the alterations induced by malathion, an OP insecticide, acute exposure on markers of hepatic damage, glucose homeostasis, oxidative stress in rats cholinesterase (ChE) activity in rats.

Methods: Adult male Wistar rats were divided into four groups: Control; Malathion; OXIME; and Malathion+OXIME. Twelve hours after co-treatment with malathion (250 mg/kg, i.p.) and/or OXIME (50 mg/kg, i.g.), the plasma and liver samples were collected for biochemical analyses.

Results: The OXIME blocked the increase of plasma markers of hepatic function (AST and ALP) and the enzymatic inhibition of catalase and glutathione reductase in the liver of malathion-treated rats. Moreover, the hepatic cholinesterases inhibition induced by malathion acute exposure was suppressed by OXIME treatment. As assessed, a single dose of OXIME lowered the glycemia levels and hepatic glycogen content enhanced by malathion.

Conclusions: This study suggests promise effects of (3Z)-5-Chloro-3-(Hydroxyimino) indolin-2-one against the hyperglycemia and the hepatic damage induced by malathion acute exposure, as well as its use as a ChE activity reactivator.
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http://dx.doi.org/10.1186/s12986-019-0374-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6727524PMC
September 2019
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