Gerlon de Almeida Ribeiro Oliveira
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Gerlon de Almeida Ribeiro Oliveira has a total of 64 co-authors. Here are the top co-authors by number of shared publications:
- Luciano Morais Liao
Federal University of Goiás (UFG)
7 shared publications - Boniek Gontijo Vaz
Universidade Federal de Goiás
2 shared publications - Dâmaris Silveira
University of Brasilia
2 shared publications - Aline Lima de Oliveira
Laboratório de Ressonância Magnética Nuclear, Instituto de Química, Universidade de Brasília, Brasília 70910-900, DF, Brazil
1 shared publication - Aline Nazareth Martins
Univ Fed Goias, Inst Biol Sci, Lab Pharmacol Nat & Synthet Prod, Room 209,Esperanca Ave,Campus Samambaia, BR-74690900 Goiania, Brazil
1 shared publication - Allen Grayson Oliver
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
1 shared publication
Latest Publications
- 28 November 2024
- Published by Wiley in Magnetic Resonance in Chemistry
- Vol. 63 (2) , 155-166
Enhancing Forensic Laboratories Through University Collaboration: Obtaining Conclusive Reports and Reference Materials via NMR
Forensic laboratories play a pivotal role in identifying and quantifying drugs in police seizures, often using spectroscopic techniques in combination with chromatographic methods that rely on chemical reference substances (CRS). The demand for a wide variety of CRS is critical, not only for common drugs like cocaine but also for the rapidly increasing number of new psychoactive substances (NPS), which emerge weekly. However, acquiring CRS is costly and bureaucratic because of the restricted circulation of these substances. Nuclear magnetic resonance (NMR) offers a viable alternative to identifying and quantifying substances without the need for specific CRS for each analyte. Although NMR equipment is commonly available at universities, it is typically absent from police laboratories because of its high initial cost. This work highlights a successful partnership between a forensic laboratory and university‐based NMR facilities as a cost‐effective strategy for obtaining CRS. A case study involving four substances—cocaine, two recently scheduled NPS, metonitazene and dipentylone, and ADB‐5′Br‐BUTINACA—demonstrates the effectiveness of this collaboration. This partnership allowed the generation of conclusive reports for seized substances, providing early warnings about NPS and helping to prevent potential outbreaks and public health crises. Additionally, the strategy facilitated the acquisition of expensive CRS from samples that would otherwise be destroyed, at a reduced cost and within a shorter timeframe. Furthermore, this partnership enhances student training in advanced instrumental analysis and research, showcasing the benefits of collaboration between forensic and academic institutions.
- 28 November 2024
- Published by Wiley in Magnetic Resonance in Chemistry
- Vol. 63 (2) , 155-166
Enhancing Forensic Laboratories Through University Collaboration: Obtaining Conclusive Reports and Reference Materials via NMR
Forensic laboratories play a pivotal role in identifying and quantifying drugs in police seizures, often using spectroscopic techniques in combination with chromatographic methods that rely on chemical reference substances (CRS). The demand for a wide variety of CRS is critical, not only for common drugs like cocaine but also for the rapidly increasing number of new psychoactive substances (NPS), which emerge weekly. However, acquiring CRS is costly and bureaucratic because of the restricted circulation of these substances. Nuclear magnetic resonance (NMR) offers a viable alternative to identifying and quantifying substances without the need for specific CRS for each analyte. Although NMR equipment is commonly available at universities, it is typically absent from police laboratories because of its high initial cost. This work highlights a successful partnership between a forensic laboratory and university‐based NMR facilities as a cost‐effective strategy for obtaining CRS. A case study involving four substances—cocaine, two recently scheduled NPS, metonitazene and dipentylone, and ADB‐5′Br‐BUTINACA—demonstrates the effectiveness of this collaboration. This partnership allowed the generation of conclusive reports for seized substances, providing early warnings about NPS and helping to prevent potential outbreaks and public health crises. Additionally, the strategy facilitated the acquisition of expensive CRS from samples that would otherwise be destroyed, at a reduced cost and within a shorter timeframe. Furthermore, this partnership enhances student training in advanced instrumental analysis and research, showcasing the benefits of collaboration between forensic and academic institutions.
- Open Access
Does Trema micranthum (L.) Blume Produce Cannabinoids?
There are inconclusive claims in the scientific literature that the species Trema micranthum, widely distributed throughout the Brazilian territory, may produce phytocannabinoids, potentially serving as an alternative to Cannabis sativa. In this study, we conducted a comprehensive investigation to assess the presence of phytocannabinoids in two Trema micranthum samples collected in the Midwest region of Brazil. In trying to detect cannabinoids in T. micranthum, a recommended cannabis screening test was employed, the Fast Blue BB Salt (FBBBS) colorimetric assay, followed by thin-layer chromatography (TLC) and instrumental techniques: high-performance liquid chromatography coupled to diode array detector (HPLC-DAD) and gas chromatography coupled to mass spectrometry (GC-MS). When employed without chloroform extraction, the FBBBS reagent yielded positive results for extracts from all parts of T. micranthum (leaves, branches, fruits, and inflorescences). However, these initial positive results from the FBBBS test, suggesting the presence of cannabinoids, were not corroborated by FBBBS followed by chloroform extraction, TLC, or the instrumental techniques used in this study. These additional outcomes suggest that the positive FBBBS test results were likely due to the presence of other phenolic compounds rather than phytocannabinoids. For example, the presence of vitexin-like compounds in T. micranthum extracts might explain the positive FBBBS test results. Therefore, new assertions that T. micranthum produces cannabinoids will require the support of more selective experiments to avoid false-positive claims based on less selective screening tests.
Open AccessDoes Trema micranthum (L.) Blume Produce Cannabinoids?
There are inconclusive claims in the scientific literature that the species Trema micranthum, widely distributed throughout the Brazilian territory, may produce phytocannabinoids, potentially serving as an alternative to Cannabis sativa. In this study, we conducted a comprehensive investigation to assess the presence of phytocannabinoids in two Trema micranthum samples collected in the Midwest region of Brazil. In trying to detect cannabinoids in T. micranthum, a recommended cannabis screening test was employed, the Fast Blue BB Salt (FBBBS) colorimetric assay, followed by thin-layer chromatography (TLC) and instrumental techniques: high-performance liquid chromatography coupled to diode array detector (HPLC-DAD) and gas chromatography coupled to mass spectrometry (GC-MS). When employed without chloroform extraction, the FBBBS reagent yielded positive results for extracts from all parts of T. micranthum (leaves, branches, fruits, and inflorescences). However, these initial positive results from the FBBBS test, suggesting the presence of cannabinoids, were not corroborated by FBBBS followed by chloroform extraction, TLC, or the instrumental techniques used in this study. These additional outcomes suggest that the positive FBBBS test results were likely due to the presence of other phenolic compounds rather than phytocannabinoids. For example, the presence of vitexin-like compounds in T. micranthum extracts might explain the positive FBBBS test results. Therefore, new assertions that T. micranthum produces cannabinoids will require the support of more selective experiments to avoid false-positive claims based on less selective screening tests.
- 4 September 2023
- Published by Springer Nature in Inflammopharmacology
- Vol. 31 (5) , 2451-2465
Anti-inflammatory and antinociceptive effects, and safety toxicological profile of a new paracetamol analog, LQFM291
In the scope of a research program with the goal of developing treatments for inflammatory diseases, the pharmacological evaluation of LQFM291, designed by molecular hybridization from butylated hydroxytoluene and paracetamol, was described. The antioxidant profile of LQFM291 was evaluated by electrochemical measurement. Also, acute or repeated treatments with equimolar doses to paracetamol were used to evaluate the antinociceptive and/or anti-inflammatory activities of LQFM291 in animal models. The toxicologic potential of LQFM291 was also evaluated and compared to paracetamol through biochemical and histopathological analysis after the repeated treatment schedule. As a result of the acute treatment, paracetamol showed a similar antinociceptive effect in formalin test compared to LQFM291. Whereas, after the repeated treatment, when carrageenan-induced hyperalgesia and edema tests were performed, paracetamol showed a delayed antinociceptive and anti-inflammatory effect compared to LQFM291. Furthermore, as other advantages the LQFM291 showed a high redox capacity, a gastroprotective activity and a safety pharmacological profile without any liver or kidney damage. These effects can be related to the prevention of oxidative stress by reduction of protein and lipid peroxidation in gastric tissue, maintenance of glutathione levels in hepatic homogenate, and a systemic reduction of pro-inflammatory cytokine levels, which may characterize the LQFM291 as a more viable and effective alternative to relief pain and inflammatory signs in patients with chronic disorders.
- 4 September 2023
- Published by Springer Nature in Inflammopharmacology
- Vol. 31 (5) , 2451-2465
Anti-inflammatory and antinociceptive effects, and safety toxicological profile of a new paracetamol analog, LQFM291
In the scope of a research program with the goal of developing treatments for inflammatory diseases, the pharmacological evaluation of LQFM291, designed by molecular hybridization from butylated hydroxytoluene and paracetamol, was described. The antioxidant profile of LQFM291 was evaluated by electrochemical measurement. Also, acute or repeated treatments with equimolar doses to paracetamol were used to evaluate the antinociceptive and/or anti-inflammatory activities of LQFM291 in animal models. The toxicologic potential of LQFM291 was also evaluated and compared to paracetamol through biochemical and histopathological analysis after the repeated treatment schedule. As a result of the acute treatment, paracetamol showed a similar antinociceptive effect in formalin test compared to LQFM291. Whereas, after the repeated treatment, when carrageenan-induced hyperalgesia and edema tests were performed, paracetamol showed a delayed antinociceptive and anti-inflammatory effect compared to LQFM291. Furthermore, as other advantages the LQFM291 showed a high redox capacity, a gastroprotective activity and a safety pharmacological profile without any liver or kidney damage. These effects can be related to the prevention of oxidative stress by reduction of protein and lipid peroxidation in gastric tissue, maintenance of glutathione levels in hepatic homogenate, and a systemic reduction of pro-inflammatory cytokine levels, which may characterize the LQFM291 as a more viable and effective alternative to relief pain and inflammatory signs in patients with chronic disorders.
- Open Access
Improvement in Solubility–Permeability Interplay of Psoralens from Brosimum gaudichaudii Plant Extract upon Complexation with Hydroxypropyl-β-cyclodextrin
Psoralen (PSO) and 5-methoxypsoralen (5-MOP) are widely used drugs in oral photochemotherapy against vitiligo and major bioactive components of root bark extract of Brosimum gaudichaudii Trécul (EBGT), previously standardized by LC-MS. However, the exceptionally low water solubility of these psoralens can cause incomplete and variable bioavailability limiting their applications and patient adherence to treatment. Therefore, the purpose of this work was to investigate the effects of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex on the solubility and jejunal permeability of PSO and 5-MOP from EBGT. Characterization of inclusion complexes were evaluated by current methods in nuclear magnetic resonance studies on aqueous solution, Fourier transform infrared spectroscopy, thermal analysis, and scanning electron microscopy in solid state. Ex vivo rat jejunal permeability was also investigated and compared for both pure psoralens and plant extract formulation over a wide HP-β-CD concentration range (2.5 to 70 mM). Phase solubility studies of the PSO- and 5-MOP-HP-β-CD inclusion complex showed 1:1 inclusion complex formation with small stability constants (Kc < 500 M−1). PSO and 5-MOP permeability rate decreased after adding HP-β-CD by 6- and 4-fold for pure standards and EBGT markers, respectively. Nevertheless, the complexation with HP-β-CD significantly improved solubility of PSO (until 10-fold) and 5-MOP (until 31-fold). As a result, the permeability drop could be overcome by solubility augmentation, implying that the HP-β-CD inclusion complexes with PSO, 5-MOP, or EBGT can be a valuable tool for designing and developing novel oral drug product formulation containing these psoralens for the treatment of vitiligo.
Open AccessImprovement in Solubility–Permeability Interplay of Psoralens from Brosimum gaudichaudii Plant Extract upon Complexation with Hydroxypropyl-β-cyclodextrin
Psoralen (PSO) and 5-methoxypsoralen (5-MOP) are widely used drugs in oral photochemotherapy against vitiligo and major bioactive components of root bark extract of Brosimum gaudichaudii Trécul (EBGT), previously standardized by LC-MS. However, the exceptionally low water solubility of these psoralens can cause incomplete and variable bioavailability limiting their applications and patient adherence to treatment. Therefore, the purpose of this work was to investigate the effects of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex on the solubility and jejunal permeability of PSO and 5-MOP from EBGT. Characterization of inclusion complexes were evaluated by current methods in nuclear magnetic resonance studies on aqueous solution, Fourier transform infrared spectroscopy, thermal analysis, and scanning electron microscopy in solid state. Ex vivo rat jejunal permeability was also investigated and compared for both pure psoralens and plant extract formulation over a wide HP-β-CD concentration range (2.5 to 70 mM). Phase solubility studies of the PSO- and 5-MOP-HP-β-CD inclusion complex showed 1:1 inclusion complex formation with small stability constants (Kc < 500 M−1). PSO and 5-MOP permeability rate decreased after adding HP-β-CD by 6- and 4-fold for pure standards and EBGT markers, respectively. Nevertheless, the complexation with HP-β-CD significantly improved solubility of PSO (until 10-fold) and 5-MOP (until 31-fold). As a result, the permeability drop could be overcome by solubility augmentation, implying that the HP-β-CD inclusion complexes with PSO, 5-MOP, or EBGT can be a valuable tool for designing and developing novel oral drug product formulation containing these psoralens for the treatment of vitiligo.
- 7 February 2022
- Published by Springer Nature in Journal of Applied Electrochemistry
- Vol. 52 (4) , 729-742
Electrochemical determination of carbendazim in grapes and their derivatives by an ionic liquid-modified carbon paste electrode
- 7 February 2022
- Published by Springer Nature in Journal of Applied Electrochemistry
- Vol. 52 (4) , 729-742
Electrochemical determination of carbendazim in grapes and their derivatives by an ionic liquid-modified carbon paste electrode
- 12 March 2021
- Published by American Chemical Society (ACS) in Industrial & Engineering Chemistry Research
- Vol. 60 (11) , 4405-4419
Amine/Carboxylic Acid Ionic Liquid Composite Membranes for CO2 Separation
- 12 March 2021
- Published by American Chemical Society (ACS) in Industrial & Engineering Chemistry Research
- Vol. 60 (11) , 4405-4419
Amine/Carboxylic Acid Ionic Liquid Composite Membranes for CO2 Separation
- 2 June 2020
- Published by Elsevier in Journal of Molecular Structure
- Vol. 1219, 128559
Structural comparison of five new halogenated dihydroquinoline-4(1H)-ones
- 2 June 2020
- Published by Elsevier in Journal of Molecular Structure
- Vol. 1219, 128559
Structural comparison of five new halogenated dihydroquinoline-4(1H)-ones
- 18 April 2019
- Published by Springer Nature in Food Analytical Methods
- Vol. 13 (1) , 35-43
Evaluation of Lipoxygenase Activity in Common Beans by UV and NMR Spectroscopy: Proposal for a Complementary Technique for Enzymatic Studies
- 18 April 2019
- Published by Springer Nature in Food Analytical Methods
- Vol. 13 (1) , 35-43
Evaluation of Lipoxygenase Activity in Common Beans by UV and NMR Spectroscopy: Proposal for a Complementary Technique for Enzymatic Studies
- Open Access
- 1 September 2017
- Published by Springer Nature in Revista Brasileira de Farmacognosia
- Vol. 27 (5) , 663-672
Vouacapane diterpenoids isolated from Pterodon and their biological activities
- 1 September 2017
- Published by Springer Nature in Revista Brasileira de Farmacognosia
- Vol. 27 (5) , 663-672
Open AccessVouacapane diterpenoids isolated from Pterodon and their biological activities