Paula Homem de Mello
Químico formado pela Universidade Federal de Pernambuco (UFPE) em 1991. Com mestrado também pela UFPE (1994), doutorado pela Universidade da Florida (2001) e pós-doutorados pela Technische Universität München (Munique, Alemanha de 2002-2004) e pela Ecole Polytechnique Fédérale de Lausanne (Lausanne, Suíça de 2004-2006).
Atua em diversas áreas de Química Teórica com ênfase em dinâmica clássica e quântica de elétrons e núcleos. Principais aplicações versam sobre efeitos não adiabáticos em reações químicas, efeitos de tunelamento nuclear em compostos orgânicos e uso do método de dinâmica CPMD/QMMM para a descrição de reações químicas em sistemas biológicos.
Foi bolsista de doutorado no exterior e bolsista do programa PRODOC da CAPES. Durante o período de doutorado recebeu auxilio do Deutschen Forschungsgemeinschaft (DFG) e da Swiss National Science Foundation (SNSF).
2024
de Mello, Paula Homem; de Souza, Ana Clara Gonzalez; Melo, Diêgo Ulysses; Mol, Gabriel S; de Souza, Jhonathan Rosa; Carneiro, Leonardo M; Nobrega, Maíra G; Zanotto, Mateus; Corrêa, Raissa Lohanna GQ; de Oliveira, Hueder PM; Bartoloni, Fernando H; Aoto, Yuri A; Neto, Mauricio D. Coutinho; Orestes, Ednilsom
Design Bioinspirado de Corantes Journal Article
Em: Química Nova, vol. 48, iss. 3, pp. e-20250047, 2024.
Resumo | Links | BibTeX | Tags:
@article{nokey,
title = {Design Bioinspirado de Corantes},
author = {Paula Homem de Mello and Ana Clara Gonzalez de Souza and Diêgo Ulysses Melo and Gabriel S Mol and Jhonathan Rosa de Souza and Leonardo M Carneiro and Maíra G Nobrega and Mateus Zanotto and Raissa Lohanna GQ Corrêa and Hueder PM de Oliveira and Fernando H Bartoloni and Yuri A Aoto and Mauricio D. Coutinho Neto and Ednilsom Orestes},
url = {https://www.scielo.br/j/qn/a/RCr5ZtRt4bVGwZhp5nxGSjP},
doi = {https://doi.org/10.21577/0100-4042.20250047},
year = {2024},
date = {2024-09-06},
urldate = {2024-09-06},
journal = {Química Nova},
volume = {48},
issue = {3},
pages = {e-20250047},
publisher = {Sociedade Brasileira de Química},
abstract = {The history of the discovery, use, and development of dyes is closely linked to the history of humanity itself. Among the first records of human civilization are cave paintings made from, e.g., fruits, plants, minerals, and insects. Over the centuries, using different techniques, colors have been given to all types of materials and products, from clothing to food. The chemicals responsible for colors are dyes - a vast collection of molecules of the most varied compositions, but which have in common the absorption of light within the visible window of the electromagnetic spectrum. This article aims not only to review the properties of some classes of natural dyes, their origins, and their applications but also to describe the various computational chemistry methods involved in designing new bio-inspired molecules.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The history of the discovery, use, and development of dyes is closely linked to the history of humanity itself. Among the first records of human civilization are cave paintings made from, e.g., fruits, plants, minerals, and insects. Over the centuries, using different techniques, colors have been given to all types of materials and products, from clothing to food. The chemicals responsible for colors are dyes – a vast collection of molecules of the most varied compositions, but which have in common the absorption of light within the visible window of the electromagnetic spectrum. This article aims not only to review the properties of some classes of natural dyes, their origins, and their applications but also to describe the various computational chemistry methods involved in designing new bio-inspired molecules.
Sodré, Pedro Tendrih; Aguilar, Andrea M.; Alves, Wendel A.; Neto, Mauricio D. Coutinho
Intrinsic and environmental modulation of stereoselective aldol organocatalyzed reactions by proline-containing lipopeptides Journal Article
Em: RSC Advances, vol. 14, iss. 29, pp. 21035-21046, 2024.
Resumo | Links | BibTeX | Tags:
@article{nokey,
title = {Intrinsic and environmental modulation of stereoselective aldol organocatalyzed reactions by proline-containing lipopeptides},
author = {Pedro Tendrih Sodré and Andrea M. Aguilar and Wendel A. Alves and Mauricio D. Coutinho Neto},
url = {https://pubs.rsc.org/en/content/articlehtml/2024/ra/d4ra03222e},
doi = {10.1039/d4ra03222e},
year = {2024},
date = {2024-07-03},
urldate = {2024-07-03},
journal = {RSC Advances},
volume = {14},
issue = {29},
pages = {21035-21046},
abstract = {Proline, along with its derivatives, has been employed as an efficient organocatalyst for aldol reactions, with the ability to promote the creation of stereoselective C–C bonds. Even though the Houk–List transition state model is able to explain the stereoselectivity observed when proline is used as a catalyst, few studies investigate the role of microheterogeneous media in modulating the reaction outcome. In this work, molecular dynamics and electronic structure calculations were used to investigate the aldol reaction in the condensed phase. Our research focused on a lipopeptide compound incorporating the proline residue within the sequence PRWG-(C18H37), where P represents L-proline, R stands for L-arginine, W for L-tryptophan, and G for L-glycine. This sequence is covalently bonded to a hydrophobic segment formed by a long aliphatic chain, acting as an organocatalyst in an aqueous solution. This catalytic phase utilizes the complex chemical environment of the solution to achieve high selectivity. Our findings indicate a Houk–List-like mechanism, in which the amide acts as an H-bond donor, complemented by a mechanism in which the counter ion, trifluoracetic acid (TFA), acts as a proton shuttle. Both mechanisms demonstrated low energy barriers—12.23 and 1.42 kcal mol−1 for the (S,R) stereoisomer formation, computed using DLPNO-CCSD with def2-TZVPP basis set. Further, to explore the catalytic effect of the PRWG-(C18H37) lipopeptide in water, molecular dynamics simulations were conducted. It was observed that the micellar phase significantly enhances stereospecific encounters, favouring the experimentally observed ratio of (SR/SS) isomers, in contrast to reactions in a pure cyclohexanone medium. By quantifying the effects enabled by the supramolecular assembly, we were able to shed light on the factors that modify and enhance the stereoslectivity of the reaction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Proline, along with its derivatives, has been employed as an efficient organocatalyst for aldol reactions, with the ability to promote the creation of stereoselective C–C bonds. Even though the Houk–List transition state model is able to explain the stereoselectivity observed when proline is used as a catalyst, few studies investigate the role of microheterogeneous media in modulating the reaction outcome. In this work, molecular dynamics and electronic structure calculations were used to investigate the aldol reaction in the condensed phase. Our research focused on a lipopeptide compound incorporating the proline residue within the sequence PRWG-(C18H37), where P represents L-proline, R stands for L-arginine, W for L-tryptophan, and G for L-glycine. This sequence is covalently bonded to a hydrophobic segment formed by a long aliphatic chain, acting as an organocatalyst in an aqueous solution. This catalytic phase utilizes the complex chemical environment of the solution to achieve high selectivity. Our findings indicate a Houk–List-like mechanism, in which the amide acts as an H-bond donor, complemented by a mechanism in which the counter ion, trifluoracetic acid (TFA), acts as a proton shuttle. Both mechanisms demonstrated low energy barriers—12.23 and 1.42 kcal mol−1 for the (S,R) stereoisomer formation, computed using DLPNO-CCSD with def2-TZVPP basis set. Further, to explore the catalytic effect of the PRWG-(C18H37) lipopeptide in water, molecular dynamics simulations were conducted. It was observed that the micellar phase significantly enhances stereospecific encounters, favouring the experimentally observed ratio of (SR/SS) isomers, in contrast to reactions in a pure cyclohexanone medium. By quantifying the effects enabled by the supramolecular assembly, we were able to shed light on the factors that modify and enhance the stereoslectivity of the reaction.
2023
de Almeida, James M.; Ferreira, Conny Cerai; Bandeira, Lucas; Cunha, Renato D; Neto, Mauricio D. Coutinho; Mello, Paula Homem De; Orestes, Ednilsom; Nascimento, Regina Sandra Veiga
Em: The Journal of Physical Chemistry B, vol. 127, iss. 43, pp. 9356-9365, 2023.
Resumo | Links | BibTeX | Tags:
@article{nokey,
title = {Synergistic Interaction of Hyperbranched Polyglycerols and Cetyltrimethylammonium Bromide for Oil/Water Interfacial Tension Reduction: A Molecular Dynamics Study},
author = {James M. de Almeida and Conny Cerai Ferreira and Lucas Bandeira and Renato D Cunha and Mauricio D. Coutinho Neto and Paula Homem De Mello and Ednilsom Orestes and Regina Sandra Veiga Nascimento},
url = {https://pubs.acs.org/doi/full/10.1021/acs.jpcb.3c01707},
doi = {10.1021/acs.jpcb.3c01707},
year = {2023},
date = {2023-10-23},
urldate = {2023-12-23},
journal = {The Journal of Physical Chemistry B},
volume = {127},
issue = {43},
pages = {9356-9365},
abstract = {Applying surfactants to reduce the interfacial tension (IFT) on water/oil interfaces is a proven technique. The search for new surfactants and delivery strategies is an ongoing research area with applications in many fields such as drug delivery through nanoemulsions and enhanced oil recovery. Experimentally, the combination of hyperbranched polyglycerol (HPG) with cetyltrimethylammonium bromide (CTAB) substantially reduced the observed IFT of oil/water interface, 0.9 mN/m, while HPG alone was 5.80 mN/m and CTAB alone IFT was 8.08 mN/m. Previous simulations in an aqueous solution showed that HPG is a surfactant carrier. Complementarily, in this work, we performed classical molecular dynamics simulations on combinations of CTAB and HPG with one aliphatic chain to investigate further the interaction of this pair in oil interfaces and propose the mechanism of IFT decrease. Basically, from our results, one can observe that the IFT reduction comes from a combination of effects that have not been observed for other dual systems: (i) Due to the CTAB-HPG strong interaction, a weakening of their specific and isolated interactions with the water and oil phases occurs. (ii) Aggregates enlarge the interfacial area, turning it into a less ordered interface. (iii) The spread of individual molecules charge profiles leads to the much lower interfacial tension observed with the CTAB+HPG systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Applying surfactants to reduce the interfacial tension (IFT) on water/oil interfaces is a proven technique. The search for new surfactants and delivery strategies is an ongoing research area with applications in many fields such as drug delivery through nanoemulsions and enhanced oil recovery. Experimentally, the combination of hyperbranched polyglycerol (HPG) with cetyltrimethylammonium bromide (CTAB) substantially reduced the observed IFT of oil/water interface, 0.9 mN/m, while HPG alone was 5.80 mN/m and CTAB alone IFT was 8.08 mN/m. Previous simulations in an aqueous solution showed that HPG is a surfactant carrier. Complementarily, in this work, we performed classical molecular dynamics simulations on combinations of CTAB and HPG with one aliphatic chain to investigate further the interaction of this pair in oil interfaces and propose the mechanism of IFT decrease. Basically, from our results, one can observe that the IFT reduction comes from a combination of effects that have not been observed for other dual systems: (i) Due to the CTAB-HPG strong interaction, a weakening of their specific and isolated interactions with the water and oil phases occurs. (ii) Aggregates enlarge the interfacial area, turning it into a less ordered interface. (iii) The spread of individual molecules charge profiles leads to the much lower interfacial tension observed with the CTAB+HPG systems.
Corrêa, Raissa Lohanna GQ; de Moraes, Matheus Morato Ferreira; de Oliveira, Kléber Thiago; Aoto, Yuri A.; Neto, Mauricio D. Coutinho; de Mello, Paula Homem
Diving into the optoelectronic properties of Cu (II) and Zn (II) curcumin complexes: a DFT and wavefunction benchmark Journal Article
Em: Journal of Molecular Modelling, vol. 29, não 166, 2023.
Resumo | Links | BibTeX | Tags:
@article{nokey,
title = {Diving into the optoelectronic properties of Cu (II) and Zn (II) curcumin complexes: a DFT and wavefunction benchmark},
author = {Raissa Lohanna GQ Corrêa and Matheus Morato Ferreira de Moraes and Kléber Thiago de Oliveira and Yuri A. Aoto and Mauricio D. Coutinho Neto and Paula Homem de Mello},
url = {https://link.springer.com/article/10.1007/s00894-023-05560-1},
doi = {10.1007/s00894-023-05560-1},
year = {2023},
date = {2023-04-29},
urldate = {2023-04-29},
journal = {Journal of Molecular Modelling},
volume = {29},
number = {166},
abstract = {Context
Curcumin is a popular food additive around the world whose medicinal properties have been known since ancient times. The literature has recently highlighted several biological properties, but besides the health-related usages, its natural yellowish color may also be helpful for light-harvesting applications. This research aims to close a knowledge gap regarding the photophysical description of curcumin and its metallic complexes.
Methods
We conducted benchmark experiments comparing NEVPT calculations with several DFT functionals (B3LYP, M06-L, M06-2X, CAM-B3LYP, and ωB97X-D) for describing the UV spectra of curcumin and its metallo-derivative, curcumin-copper(II). Once we determined the most suitable functional, we performed tests with different basis sets and conditions, such as solvation and redox state, to identify their impact on excited state properties. These results are also reported for the curcumin-zinc(II) derivative. We found that the accuracy of DFT functionals depends strongly on the nature of curcumin’s excitations. Intra-ligand transitions dominate the absorption spectra of the complexes. Curcumin absorption is marginally affected by solvation and chelation, but when combined with redox processes, they may result in significant modifications. This is because copper cation changes its coordination geometry in response to redox conditions, changing the spectrum. We found that, compared to a NEVPT reference, B3LYP is the best functional for a general description of the compounds, despite not being appropriate for charge transfer transitions. M06-L was the best for LMCT transitions. However, compared with NEVPT2 and PNO-LCCSD(T)-F12 results, no functional achieved acceptable accuracy for MLCT transitions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Context
Curcumin is a popular food additive around the world whose medicinal properties have been known since ancient times. The literature has recently highlighted several biological properties, but besides the health-related usages, its natural yellowish color may also be helpful for light-harvesting applications. This research aims to close a knowledge gap regarding the photophysical description of curcumin and its metallic complexes.
Methods
We conducted benchmark experiments comparing NEVPT calculations with several DFT functionals (B3LYP, M06-L, M06-2X, CAM-B3LYP, and ωB97X-D) for describing the UV spectra of curcumin and its metallo-derivative, curcumin-copper(II). Once we determined the most suitable functional, we performed tests with different basis sets and conditions, such as solvation and redox state, to identify their impact on excited state properties. These results are also reported for the curcumin-zinc(II) derivative. We found that the accuracy of DFT functionals depends strongly on the nature of curcumin’s excitations. Intra-ligand transitions dominate the absorption spectra of the complexes. Curcumin absorption is marginally affected by solvation and chelation, but when combined with redox processes, they may result in significant modifications. This is because copper cation changes its coordination geometry in response to redox conditions, changing the spectrum. We found that, compared to a NEVPT reference, B3LYP is the best functional for a general description of the compounds, despite not being appropriate for charge transfer transitions. M06-L was the best for LMCT transitions. However, compared with NEVPT2 and PNO-LCCSD(T)-F12 results, no functional achieved acceptable accuracy for MLCT transitions.
Curcumin is a popular food additive around the world whose medicinal properties have been known since ancient times. The literature has recently highlighted several biological properties, but besides the health-related usages, its natural yellowish color may also be helpful for light-harvesting applications. This research aims to close a knowledge gap regarding the photophysical description of curcumin and its metallic complexes.
Methods
We conducted benchmark experiments comparing NEVPT calculations with several DFT functionals (B3LYP, M06-L, M06-2X, CAM-B3LYP, and ωB97X-D) for describing the UV spectra of curcumin and its metallo-derivative, curcumin-copper(II). Once we determined the most suitable functional, we performed tests with different basis sets and conditions, such as solvation and redox state, to identify their impact on excited state properties. These results are also reported for the curcumin-zinc(II) derivative. We found that the accuracy of DFT functionals depends strongly on the nature of curcumin’s excitations. Intra-ligand transitions dominate the absorption spectra of the complexes. Curcumin absorption is marginally affected by solvation and chelation, but when combined with redox processes, they may result in significant modifications. This is because copper cation changes its coordination geometry in response to redox conditions, changing the spectrum. We found that, compared to a NEVPT reference, B3LYP is the best functional for a general description of the compounds, despite not being appropriate for charge transfer transitions. M06-L was the best for LMCT transitions. However, compared with NEVPT2 and PNO-LCCSD(T)-F12 results, no functional achieved acceptable accuracy for MLCT transitions.
