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Ding Y, Liu H, Tekwani BL, Nanayakkara NPD, Khan IA, Walker LA, Doerksen RJ. Methemoglobinemia Hemotoxicity of Some Antimalarial 8-Aminoquinoline Analogues and Their Hydroxylated Derivatives: Density Functional Theory Computation of Ionization Potentials. Chem Res Toxicol 2016; 29:1132-41. [DOI: 10.1021/acs.chemrestox.6b00063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Yuanqing Ding
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Haining Liu
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Babu L. Tekwani
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - N. P. Dhammika Nanayakkara
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Ikhlas A. Khan
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Larry A. Walker
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Robert J. Doerksen
- National Center for Natural Products Research,
Research Institute
of Pharmaceutical Science, and ‡Department of BioMolecular Sciences, School
of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
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Goicoechea JM, McGrady JE. On the structural landscape in endohedral silicon and germanium clusters, M@Si12 and M@Ge12. Dalton Trans 2015; 44:6755-66. [PMID: 25636138 DOI: 10.1039/c4dt03573a] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Amongst the endohedral clusters of the tetrel elements, M@En, the 12-vertex species are unique in that three completely different geometries, the icosahedron (Ih, [Ni@Pb12](2-)), the hexagonal prism (HP, Cr@Si12) and the bicapped pentagonal prism (BPP, [Ru@Ge12](3-)) have been identified in stable molecules. We explore here the origins of this structural diversity by comparing stability patterns across isovalent and isoelectronic series, M@Si12, M@Ge12 and [M@Ge12](3-). The BPP structure dominates the structural landscape for high valence electron counts (57-60) while the HP has a rather narrower window of stability around the 54-56 count. Moreover the preference for an HP structure is unique to silicon: in no case is a rigorously D6h-symmetric structure the global minimum for M@Ge12. Distortions from the high-symmetry limits, where present, can be traced to degeneracies or near-degeneracies in the frontier orbital domains. In all cases the structure adopted is that which maximizes the delocalization of electron density between the metal and the cluster cage, such that both components attain stable electronic configurations.
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Affiliation(s)
- José M Goicoechea
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
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3
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Liu H, Ding Y, Walker LA, Doerksen RJ. Computational Study on the Effect of Exocyclic Substituents on the Ionization Potential of Primaquine: Insights into the Design of Primaquine-Based Antimalarial Drugs with Less Methemoglobin Generation. Chem Res Toxicol 2015; 28:169-74. [PMID: 25222923 PMCID: PMC4332040 DOI: 10.1021/tx500230t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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The effect of an
exocyclic substituent on the ionization potential
of primaquine, an important antimalarial drug, was investigated using
density functional theory methods. It was found that an electron-donating
group (EDG) makes the ionization potential decrease. In contrast,
an electron-withdrawing group (EWG) makes the ionization potential
increase. Among all the exocyclic positions, a substituent at the
5- or 7-position has the largest effect. This can be explained by
the contribution of the atomic orbitals at those positions to the
highest occupied molecular orbital (HOMO). In addition, a substituent
at the N8-position has a considerably large effect on the ionization
potential because this atom makes the second largest contribution
to the HOMO. These findings have potential implications for the design
of less hemotoxic antimalarial drugs. We suggest that it is worth
considering placement of an EWG at the 5-, 7-, or N8-positions of
primaquine in future drug discovery attempts.
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Affiliation(s)
- Haining Liu
- Department of BioMolecular Sciences and ‡the National Center for Natural Products Research, School of Pharmacy, University of Mississippi , University, Mississippi 38677, United States
| | - Yuanqing Ding
- Department of BioMolecular Sciences and ‡the National Center for Natural Products Research, School of Pharmacy, University of Mississippi , University, Mississippi 38677, United States
| | - Larry A Walker
- Department of BioMolecular Sciences and ‡the National Center for Natural Products Research, School of Pharmacy, University of Mississippi , University, Mississippi 38677, United States
| | - Robert J Doerksen
- Department of BioMolecular Sciences and ‡the National Center for Natural Products Research, School of Pharmacy, University of Mississippi , University, Mississippi 38677, United States
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