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Development of a Hypoxia-Selective Near-Infrared Fluorescent Probe for Non-invasive Tumor Imaging

Research Abstract
A near-infrared fluorochrome, GPU-311, was designed, synthesized and evaluated for its application in non-invasive imaging of tumor hypoxia. Efficient synthesis was achieved by nucleophilic substitution and click chemistry ring using the bifunctional tetraethylene glycol linker 2 containing thiol and azide groups for the conjugation of the propargylated nitroimidazole 1 and the heptamethine cyanine dye 3 bearing a 2-chloro-1-cyclohexenyl ring. GPU-311 exhibited long excitation and emission wavelength (Ex/Em_785/802 nm) and a decent quantum yield (0.05). The water solubility and hydrophilicity of GPU-311 increased. After in-vitro treatment of SUIT-2/HRE-Luc pancreatic cancer cells with GPU-311, a higher level of fluorescence was observed selectively in hypoxia than in normoxia. However, in-vivo fluorescence imaging of a mouse xenograft model after GPU-311 administration revealed inadequate accumulation of GPU-311 in tumors due to its rapid elimination through the liver.
Research Authors
Bahaa Gamal Mohamed Youssif, Kensuke Okuda, Tetsuya Kadonosono, Ola Ibrahim Abdel Razek Salem, Alaa Arafat Mohamed Hayallah, Mostafa Ahmed Hussein, Shinae Kizaka-Kondoh, Hideko Nagasawa
Research Journal
Chem. Pharm. Bull
Research Rank
1
Research Vol
Vol. 60,No.3
Research Year
2012

2-Nitroimidazole-Tricarbocyanine Conjugate as a Near-Infrared Fluorescent Probe for in-Vivo Imaging of Tumor Hypoxia

Research Abstract
We developed a novel near-infrared (NIR) fluorescent probe, GPU-167, for in-vivo imaging of tumor hypoxia. GPU-167 comprises a tricarbocyanine dye as an NIR fluorophore and two 2-nitroimidazole moieties as exogenous hypoxia markers that undergo bioreductive activation and then selective entrapment in hypoxic cells. After treatment with GPU-167, tumor cells contained significantly higher levels of fluorescence in hypoxia than in normoxia. In-vivo fluorescence imaging specifically detected GPU-167 in tumors 24 h after administration. Ex-vivo analysis revealed that fluorescence showed a strong correlation with hypoxia inducible factor (HIF)-1 active hypoxic region. These data suggest that GPU-167 is a promising in-vivo optical imaging probe for tumor hypoxia.
Research Authors
Kensuke Okuda1, Yasuyuki Okabe1, Tetsuya Kadonosono2, Takahiro Ueno1, Bahaa G. M. Youssif, Shinae Kizaka-Kondoh, Hideko Nagasawa
Research Journal
Bioconj. Chem.
Research Rank
1
Research Vol
Vol.23
Research Year
2012

Antiparasitic Antioxidant Phenylpropanoids and Iridoid Glycosides from Tecoma mollis

Research Abstract
A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1-7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1-7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1-8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC50 value of 6.71 μg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum.
Research Authors
Wael M. Abdel-Mageed, Enaam Y. Backheet, Azza A. Khalifa, Zedan Z. Ibraheim, Samir A. Ross
Research Department
Research Journal
Fitoterapia
Research Member
Zedan Zeid Ibraheim Hammad
Research Rank
1
Research Vol
Vol. 83
Research Year
2012

Antiparasitic Antioxidant Phenylpropanoids and Iridoid Glycosides from Tecoma mollis

Research Abstract
A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1-7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1-7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1-8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC50 value of 6.71 μg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum.
Research Authors
Wael M. Abdel-Mageed, Enaam Y. Backheet, Azza A. Khalifa, Zedan Z. Ibraheim, Samir A. Ross
Research Department
Research Journal
Fitoterapia
Research Rank
1
Research Vol
Vol. 83
Research Year
2012

Antiparasitic Antioxidant Phenylpropanoids and Iridoid Glycosides from Tecoma mollis

Research Abstract
A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1-7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1-7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1-8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC50 value of 6.71 μg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum.
Research Authors
Wael M. Abdel-Mageed, Enaam Y. Backheet, Azza A. Khalifa, Zedan Z. Ibraheim, Samir A. Ross
Research Department
Research Journal
Fitoterapia
Research Rank
1
Research Vol
Vol. 83
Research Year
2012

Antiparasitic Antioxidant Phenylpropanoids and Iridoid Glycosides from Tecoma mollis

Research Abstract
A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1-7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1-7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1-8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC50 value of 6.71 μg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum.
Research Authors
Wael M. Abdel-Mageed, Enaam Y. Backheet, Azza A. Khalifa, Zedan Z. Ibraheim, Samir A. Ross
Research Department
Research Journal
Fitoterapia
Research Rank
1
Research Vol
Vol. 83
Research Year
2012

Crotonase Catalysis Enables Flexible Production of Functionalized Prolines and Carbapenams

Research Abstract
The biocatalytic versatility of wildtype and engineered carboxymethylproline synthases (CMPSs) is demonstrated by the preparation of functionalized 5-carboxymethylproline derivatives methylated at C-2, C-3, C-4, or C-5 of the proline ring from appropriately substituted amino acid aldehydes and malonyl-coenzyme A. Notably, compounds with a quaternary center (at C-2 or C-5) were prepared in a stereoselective fashion by engineered CMPSs. The substituted-5-carboxymethyl-prolines were converted into the corresponding bicyclic β-lactams using a carbapenam synthetase. The results demonstrate the utility of the crotonase superfamily enzymes for stereoselective biocatalysis, the amenability of carbapenem biosynthesis pathways to engineering for the production of new bicyclic β-lactam derivatives, and the potential of engineered biocatalysts for the production of quaternary centers.
Research Authors
Refaat B. Hamed, Luc Henry, J. Ruben Gomez-Castellanos, Jasmin Mecinović, Christian Ducho, John L. Sorensen, Timothy D. W. Claridge, Christopher J. Schofield
Research Department
Research Journal
J. Am. Chem. Soc.
Research Member
Research Rank
1
Research Vol
Vol. 134
Research Website
http://pubs.acs.org/doi/abs/10.1021/ja208318d
Research Year
2012

Hydroxy Vasntine, A New Pyrroloquinazoline Alkaloids Trisulcus (Forssk) Nees

Research Abstract
Hydroxy vasntine (1), a new pyrroloquinazoline alkaloidsalong with two known compounds: 7-hydroxy vasicine (2) and 7-hydroxy vasicine (3) were isolated from the aerial parts of Anisotes trisulcus (Forssk) Nees (Acanthaceae). Their structures were established by UV, IR, ID NMR, in addition to mass spectroscopic data and comparison with literature data. The different fractions were evaluated for their cytotoxic activity using the brine shrimp bioassay.
Research Authors
Mohamed A. El-Shanawany, Hanaa M. Sayed, Sabrin R. M. Ibrahim, Marwa A. A. Fayed
Research Department
Research Journal
J. Nat. Prod. Plant Resour
Research Member
Research Rank
1
Research Vol
Vol. 1,No. 4
Research Year
2011

Hydroxy Vasntine, A New Pyrroloquinazoline Alkaloids Trisulcus (Forssk) Nees

Research Abstract
Hydroxy vasntine (1), a new pyrroloquinazoline alkaloidsalong with two known compounds: 7-hydroxy vasicine (2) and 7-hydroxy vasicine (3) were isolated from the aerial parts of Anisotes trisulcus (Forssk) Nees (Acanthaceae). Their structures were established by UV, IR, ID NMR, in addition to mass spectroscopic data and comparison with literature data. The different fractions were evaluated for their cytotoxic activity using the brine shrimp bioassay.
Research Authors
Mohamed A. El-Shanawany, Hanaa M. Sayed, Sabrin R. M. Ibrahim, Marwa A. A. Fayed
Research Department
Research Journal
J. Nat. Prod. Plant Resour
Research Rank
1
Research Vol
Vol. 1,No. 4
Research Year
2011

Hydroxy Vasntine, A New Pyrroloquinazoline Alkaloids Trisulcus (Forssk) Nees

Research Abstract
Hydroxy vasntine (1), a new pyrroloquinazoline alkaloidsalong with two known compounds: 7-hydroxy vasicine (2) and 7-hydroxy vasicine (3) were isolated from the aerial parts of Anisotes trisulcus (Forssk) Nees (Acanthaceae). Their structures were established by UV, IR, ID NMR, in addition to mass spectroscopic data and comparison with literature data. The different fractions were evaluated for their cytotoxic activity using the brine shrimp bioassay.
Research Authors
Mohamed A. El-Shanawany, Hanaa M. Sayed, Sabrin R. M. Ibrahim, Marwa A. A. Fayed
Research Department
Research Journal
J. Nat. Prod. Plant Resour
Research Rank
1
Research Vol
Vol. 1,No. 4
Research Year
2011
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