Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III)
- Managa, Muthumuni, Amuhaya, Edith K, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
- Authors: Managa, Muthumuni , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
Physicochemical and photodynamic antimicrobial chemotherapy studies of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines
- Osifeko, Olawale L, Durmuş, Mahmut, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Durmuş, Mahmut , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7255 , http://hdl.handle.net/10962/d1020264 , http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Description: The synthesis and photophysicochemical properties of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines (InPcs) are presented in this study. General trends are described for quantum yields of fluorescence, triplet, singlet oxygen and photodegradation as well as lifetimes of fluorescence and triplet state of these compounds. The complexes exhibited high singlet oxygen quantum yields (ФΔ) ranging from 0.44 to 0.66 in DMF, and from 0.44 to 0.69 in DMSO and ФΔ = 0.31 for the quartenized tetra substituted InPc which is soluble in water. The triplet quantum yields (ФT) ranged from 0.77 to 0.95 in DMF and from 0.77 to 0.94) in DMSO. The tetra substituted photosensitizers do not differ in their inactivation of bacteria with over 8 log reduction of viable bacteria when compared with the mono substituted photosensitizer which could only manage a 1 log reduction. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Full Text: false
- Date Issued: 2015
- Authors: Osifeko, Olawale L , Durmuş, Mahmut , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7255 , http://hdl.handle.net/10962/d1020264 , http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Description: The synthesis and photophysicochemical properties of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines (InPcs) are presented in this study. General trends are described for quantum yields of fluorescence, triplet, singlet oxygen and photodegradation as well as lifetimes of fluorescence and triplet state of these compounds. The complexes exhibited high singlet oxygen quantum yields (ФΔ) ranging from 0.44 to 0.66 in DMF, and from 0.44 to 0.69 in DMSO and ФΔ = 0.31 for the quartenized tetra substituted InPc which is soluble in water. The triplet quantum yields (ФT) ranged from 0.77 to 0.95 in DMF and from 0.77 to 0.94) in DMSO. The tetra substituted photosensitizers do not differ in their inactivation of bacteria with over 8 log reduction of viable bacteria when compared with the mono substituted photosensitizer which could only manage a 1 log reduction. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Full Text: false
- Date Issued: 2015
Applications of lead phthalocyanines embedded in electrospun fibers for the photoinactivation of Escherichia coli in water
- Osifeko, Olawale L, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:7304 , http://hdl.handle.net/10962/d1020381
- Description: Lead (II) pyridyloxyphthalocyanine (PbTpyPc) and its quaternized form (PbTepyPc) were synthesized and the photophysical behavior examined. Low fluorescence quantum yields (ΦF) of 0.01 and 0.02 were observed for PbTepyPc and PbTpyPc, respectively. The singlet oxygen quantum yields (ΦΔ) were 0.60 and 0.68, for PbTepyPc and PbTpyPc, respectively using DPBF as a quencher in DMF. Singlet oxygen production of the embedded sensitizers in electrospun fiber were quantified using ADMA and were found to be ΦΔ = 0.41 and ΦΔ = 0.21 for PbTepyPc and PbTpyPc, respectively. Photodynamic inactivation of Escherichia coli (E. coli) with the quaternized photosensitizer at 5 μM, totally inactivated the E. coli (with log CFU = 10 decrease). Only 0.4 log CFU decrease was obtained with PbTpyPc. The embedded non-quaternized photosensitizer (PbTpyPc) was less active on the gram negative bacteria but the quaternized photosensitizer (PbTepyPc) was effective towards inactivation of E. coli. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2014.05.010
- Full Text: false
- Date Issued: 2014
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:7304 , http://hdl.handle.net/10962/d1020381
- Description: Lead (II) pyridyloxyphthalocyanine (PbTpyPc) and its quaternized form (PbTepyPc) were synthesized and the photophysical behavior examined. Low fluorescence quantum yields (ΦF) of 0.01 and 0.02 were observed for PbTepyPc and PbTpyPc, respectively. The singlet oxygen quantum yields (ΦΔ) were 0.60 and 0.68, for PbTepyPc and PbTpyPc, respectively using DPBF as a quencher in DMF. Singlet oxygen production of the embedded sensitizers in electrospun fiber were quantified using ADMA and were found to be ΦΔ = 0.41 and ΦΔ = 0.21 for PbTepyPc and PbTpyPc, respectively. Photodynamic inactivation of Escherichia coli (E. coli) with the quaternized photosensitizer at 5 μM, totally inactivated the E. coli (with log CFU = 10 decrease). Only 0.4 log CFU decrease was obtained with PbTpyPc. The embedded non-quaternized photosensitizer (PbTpyPc) was less active on the gram negative bacteria but the quaternized photosensitizer (PbTepyPc) was effective towards inactivation of E. coli. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2014.05.010
- Full Text: false
- Date Issued: 2014
Graduation ceremony photographs
- Authors: Nyokong, Tebello
- Date: 2010-2012
- Type: still image
- Identifier: vital:7232 , http://hdl.handle.net/10962/d1006503
- Description: Photographs taken of Prof Tebello Nyokong's students during different graduation ceremonies 2010 - 2012.
- Full Text:
- Date Issued: 2010-2012
- Authors: Nyokong, Tebello
- Date: 2010-2012
- Type: still image
- Identifier: vital:7232 , http://hdl.handle.net/10962/d1006503
- Description: Photographs taken of Prof Tebello Nyokong's students during different graduation ceremonies 2010 - 2012.
- Full Text:
- Date Issued: 2010-2012
- «
- ‹
- 1
- ›
- »