Publications by authors named "N K Simas"

22 Publications

Ethyl Acetate Fraction and Isolated Phenolics Derivatives from Identified by UHPLC-DAD-ESI-MS with Pharmacological Potential for the Improvement of Obesity-Induced Endothelial Dysfunction.

Pharmaceutics 2021 Jul 29;13(8). Epub 2021 Jul 29.

Pharmacology of Bioactive Products Research Group, Federal University of Rio de Janeiro-Macaé Campus, Macaé 27930-560, RJ, Brazil.

Endothelial dysfunction in obesity plays a key role in the development of cardiovascular diseases, and it is characterized by increased vascular tonus and oxidative stress. Thus, this study aimed to investigate the vasodilatory and antioxidant activities of ethyl acetate fraction and subfractions. Vascular effects were investigated on aorta isolated from control and monosodium glutamate (MSG) induced-obese Wistar rats, and antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods. The ethyl acetate fraction (MMEAF) induced a concentration-dependent vasodilation on aortic rings through the NO pathway, with the involvement of histamine H1 and estrogen ERα receptors and showed potent antioxidant activity. In aorta of MSG obese rats, maximal relaxation to acetylcholine was increased in the presence of MMEAF (3 µg/mL), indicating that MMEAF ameliorated obesity-induced endothelial dysfunction. Quercetin and kaempferol aglycones and their correspondent glycosides, as well as caffeoylquinic acid derivatives, A-type procyanidin trimer, ursolic and oleanolic triterpenoid acids were identified in subfractions from MMEAF and seem to be the metabolites responsible for the vascular and antioxidant activities of this fraction.
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http://dx.doi.org/10.3390/pharmaceutics13081173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401510PMC
July 2021

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

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

Antinociceptive constituents from L. juice.

Nat Prod Res 2020 Jun 9:1-5. Epub 2020 Jun 9.

Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.

This work aimed to investigate the main components of methanol fractions (MFSC and MFSCf) from L. juice and their antinociceptive potential. After LC-ESI-MS and ESI-MS/MS analysis, phenolic compounds, such as dicaffeoylquinic acid, schaftoside, vicenin-2, stilbene glycoside and the major compound tricin-7(2″- α-L-rhamnopyranosyl)-α-D-galacturonide (), were identified. MFSC and MFSCf significantly inhibited nociceptive responses in classical mice pain models. The isolated flavone, , inhibited strongly the neurogenic phase in formalin test without interfering with the inflammatory one. The co-administration of the opioid antagonist, naloxone, significantly reversed the antinociceptive effects on the neurogenic phase of both methanol fractions and , demonstrating the involvement of the opioid system on the antinociceptive effect. This work describes for the first time the antinociceptive effect of flavonoids present in sugarcane juice, highlighting the isolation and the structural elucidation of tricin-7(2″-α-L-rhamnopyranosyl)-α-D-galacturonide through ESI-MS/MS, 1D- and 2D-NMR.
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http://dx.doi.org/10.1080/14786419.2020.1771708DOI Listing
June 2020

The presence of heavy metals in Avicennia schaueriana Stapf & Leechman ex Moldenke leaf and epicuticular wax from different mangroves around Sepetiba Bay, Rio de Janeiro, Brazil.

Environ Sci Pollut Res Int 2020 Jul 16;27(19):23714-23729. Epub 2020 Apr 16.

Laboratório de Anatomia Vegetal, Instituto de Biociências, Universidade Federal do Mato Grosso do Sul (UFMS), Campo Grande, MS, 79070-900, Brazil.

This study aimed to investigate the leaf epicuticular wax and the presence of heavy metals in leaves of Avicennia shaueriana, a halophyte found in Brazilian mangroves. We evaluated plants collected in mangroves located around Sepetiba Bay, Rio de Janeiro State. Heavy metals were analyzed by energy dispersive X-ray spectroscopy (EDS or EDX) and inductively coupled plasma optical emission spectrometry (ICP-OES). Chemical analysis of epicuticular wax was made by gas chromatography-mass spectrometry (GC-MS). We also evaluated the micromorphology of leaf surface using scanning electronic and light microscopy. The leaves from each mangrove presented alterations in wax layer. Fagarasterol (lupeol) in high quantity was the main triterpene identified in the leaf wax from plants collected in all mangroves: Coroa Grande (76.43%), Pedra de Guaratiba (38.91%), and Marambaia (62.56%). Al, Fe, Mn, and Zn were the main heavy metals detected in leaves from the three mangroves by ICP-OES. Thus, we show that that plants able to survive in the mangrove swamp can adapt to the exposure of heavy metals, accumulate them in their leaves, and be used in coastal area recovery projects as a phytoremediator.
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http://dx.doi.org/10.1007/s11356-020-08606-6DOI Listing
July 2020
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