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Abyssomicins from the South China Sea Deep-Sea Sediment Verrucosispora sp.: Natural Thioether Michael Addition Adducts as Antitubercular Prodrugs

Research Abstract
Our investigations into the anti-TB properties of the South China Sea deep-sea Verrucosispora sp. (MS100128) led to the isolation, identification, and anti-TB evaluation of new (1–3) and known (4–6, 10) abyssomicins. Structures were assigned to 1–3 on the basis of detailed spectroscopic analysis, biosynthetic considerations, mechanistic studies, and semisynthesis from the co-metabolite 5. Detailed analytical studies into abyssomicin Michael addition chemistry informed our understanding of the chemical reactivity, stability, and anti-TB properties of this rare structure class. We established 8 as a far more potent Michael acceptor than 5, and used this to rationalize its superior antibacterial properties. We transformed 5 into the Michael adduct 1 and used both in vitro and cell-based analytical studies to demonstrate that 1 can act as a prodrug, thus responding to oxidative activation to selectively deliver the anti-TB antibiotic 8. Our studies make a contribution beyond the specifics of the abyssomicin pharmacophore by drawing attention to the possible utility of thioether Michael addition adducts as a means to stabilize highly reactive Michael acceptors, thereby enhancing bioavailability and improving therapeutic potential. The thioether Michael adduct prodrug concept, inspired by abyssomicins from the South China Sea, offers a promising new approach to “chemically package” bioactive Michael acceptors, thus improving their chances of being developed into clinically useful drugs.
Research Authors
Qian Wang, Fuhang Song, Xue Xiao, Pei Huang, Li Li, Aaron Monte, Wael M. Abdel-Mageed, Jian Wang, Hui Guo, Wenni He, Feng Xie, Huanqin Dai, Miaomiao Liu, Caixia Chen, Hao Xu, Mei Liu, Andrew M. Piggott, Xueting Liu, Robert J. Capon, Lixin Zhang
Research Department
Research Journal
Angew. Chem. Int. Ed., DOI: 10.1002/anie.201208801
Research Rank
1
Research Vol
Vol. 52, No. 4
Research Year
2013

Bioconcentration of Fenitrothion in Freshwater Fish (Oreochromis niloticus)

Research Abstract
Fenitrothion is being increasingly used as an insecticide under intensive cultivation to control vegetables and fruits pests. The bioconcentration of fenitrothion 2 different groups of freshwater fish (Oreochromis niloticus) was investigated after 28 days of exposure. One tenth of the determined 96 h-LC50 concentrations applied to fish. Fenitrothion concentration was 3.85 mg kg-1 and the Bioconcentration Factors (BCFs) after the experimental period 28 days 675.43 for whole fish body while the concentration was 1.51 mg kg-1 with respective BCFs was reached 264.91 for muscle tissue were 1.61 after daily exposure during the experimental time 28 days. Results concluded that the fenitrothion has ability to fenitrothion bioconcentration factor was high in whole fish compared to muscle tissue.
Research Authors
Sherif H. Abd-Alrahman, Gamila A. M. Kotb, Manal E. A. Elhalwagy, Mounir M. Salem-Bekheit, Wael M. Abdel-Mageed, Awwad A. Radwan
Research Department
Research Journal
J. Anim. Vet. Adv.
Research Rank
1
Research Vol
Vol. 12, No. 12
Research Year
2013

Caesanines A-D, New Cassane Diterpenes with Unprecedented N Bridge from Caesalpinia sappan

Research Abstract
Serial antibacterial furanoditerpenes caesanines A-D (1-4), possessing a cassane-type diterpenoid skeleton with an unusual N bridge between C-19/C-20, were identified from a Chinese herb Caesalpinia sappan Linn. In addition, caesanine D (4) showed the first class of dicassane diterpenoid ethers. Their structures were determined by different spectroscopic methods and ECD calculation. Caesanines A and B exhibited strong activities against MRSA suggesting a promising entry point for the development of anti-infective drugs.
Research Authors
Jingyu Zhang, Wael M. Abdel-Mageed, Miaomiao Liu, Pei Huang, Wenni He, Li Li, Fuhang Song, Huanqin Dai, Xueting Liu, Jingyu Liang, Lixin Zhang
Research Department
Research Journal
Org. Lett., DOI: 10.1021/ol402058z
Research Rank
1
Research Vol
Vol. 15, No. 18
Research Year
2013

Nivetetracyclates A and B: Novel Compounds Isolated from Streptomyces niveus

Research Abstract
A high-throughput screening of a microbial natural product library led to the discovery of two novel compounds named nivetetracyclates A and B (1 and 2), which were produced by Streptomyces niveus designated as LS2151. The backbone of the compounds contains a hydrotetracyclate not previously reported from a natural source. The structures of the compounds were elucidated by spectroscopic methods. The nivetetracyclates exhibited activity against human HeLa cells.
Research Authors
Caixia Chen, Xueting Liu, Wael M. Abdel-Mageed, Hui Guo, Weiyuan Hou, Marcel Jaspars, Li Li, Feng Xie, Biao Ren, Qian Wang, Huanqin Dai, Fuhang Song, Lixin Zhang
Research Department
Research Journal
Org. Lett., DOI: 10.1021/ol4027733
Research Rank
1
Research Vol
Vol. 15, No. 22
Research Year
2013

Phytochemical Screening and Antimicrobial Activity of EthOH/Water Ziziphus jujuba Seeds Extracts

Research Abstract
The Ziziphus species (Rhamnaceae family) are considered to be multipurpose plants and have been used as foods, folklore medicines, the environmental protection plants. This study was conducted to isolated and evaluate the antimicrobial activity of ethanol extract of Ziziphus jujuba seeds against sixe bacterial strains by determining minimum inhibitory concentration (MIC) and analyzed their content by using chromatographic techniques to identify the principal bioactive phytochemicals. GC/MS analysis of ethanol extract of Ziziphus jujuba seed revealed the existence of 20 component, main components were 13-Heptadecyn-1-ol (12.95%), 7-Ethyl-4-decen-6-one (9.73%), Lineoleoyl chloride (8.54%), Linoleic acid (6.37%), 2,5-Octadecadiynoic acid, methyl ester (5.57%) and Palatinol A (4.81%). The results indicated that the ethanolic extract of Ziziphus jujuba seed contains a many bioactive components that could have advantage offer a platform of using Ziziphus jujuba seed as herbal alternative for the current synthetic antimicrobial agents.
Research Authors
Sherif H. Abd-Alrahman, Mounir M. Salem-Bekhit, Manal E.A. Elhalwagy, Wael M. Abdel-Mageed, Awwad A. Radwan
Research Journal
J. Pure Appl. Microbio.
Research Member
Awwad Abdoh Radwan Salama
Research Rank
1
Research Vol
Vol. 7 (Spl. Edn.)
Research Year
2013

Phytochemical Screening and Antimicrobial Activity of EthOH/Water Ziziphus jujuba Seeds Extracts

Research Abstract
The Ziziphus species (Rhamnaceae family) are considered to be multipurpose plants and have been used as foods, folklore medicines, the environmental protection plants. This study was conducted to isolated and evaluate the antimicrobial activity of ethanol extract of Ziziphus jujuba seeds against sixe bacterial strains by determining minimum inhibitory concentration (MIC) and analyzed their content by using chromatographic techniques to identify the principal bioactive phytochemicals. GC/MS analysis of ethanol extract of Ziziphus jujuba seed revealed the existence of 20 component, main components were 13-Heptadecyn-1-ol (12.95%), 7-Ethyl-4-decen-6-one (9.73%), Lineoleoyl chloride (8.54%), Linoleic acid (6.37%), 2,5-Octadecadiynoic acid, methyl ester (5.57%) and Palatinol A (4.81%). The results indicated that the ethanolic extract of Ziziphus jujuba seed contains a many bioactive components that could have advantage offer a platform of using Ziziphus jujuba seed as herbal alternative for the current synthetic antimicrobial agents.
Research Authors
Sherif H. Abd-Alrahman, Mounir M. Salem-Bekhit, Manal E.A. Elhalwagy, Wael M. Abdel-Mageed, Awwad A. Radwan
Research Department
Research Journal
J. Pure Appl. Microbio.
Research Rank
1
Research Vol
Vol. 7 (Spl. Edn.)
Research Year
2013

Antimicrobial Activity of Latex Silver Nanoparticles Using Calotropis procera

Research Abstract
Objective: To synthesize silver nanoparticles (AgNPs) by green methods using serum latex of Calotropis procera at 80°C and evaluate them against bacteria, dermatophytes and phytopathogenic fungi comparing with the activity of untreated latex. Methods: The synthesis of AgNPs was performed by mixing 3% latex serum extract with the same volume of silver nitrate (2 mmol/L) solution in round flask and heating in water bath at 80°C. Characterization of silver particles were determined using UV-vis spectrophotometer, transmission electron microscopy (TEM), X-ray diffraction and Fourier transform infrared spectroscopy. The antimicrobial activity of the green synthesized AgNPs was determined against bacteria, dermatophytes and phytopathogenic fungi and compared to the crude untreated latex by agar-well diffusion methods. Results: Biosynthesis of latex silver nanoparticles was successfully obtained by green method. The formation of AgNPs has been confirmed by UV-vis, TEM microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. TEM analysis showed that synthesized AgNPs are highly stable spherical shaped particles, well dispersed with a diameter ranged from 4 nm up to 25 nm and an average size of 12.33 nm. AgNPs showed strong antibacterial activity against Gram- negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Serratia sp.) and antifungal activity against Trichophyton rubrum, Candida albicans and Aspergillus terreus. Conclusions: It can be concluded that serum latex of Calotropis procera was found to display strong potential for the synthesis of AgNPs as antimicrobial agents through rapid reduction of silver ions (Ag+ to Ag0). The green synthesized AgNPs were found to show higher antimicrobial.
Research Authors
Nadia Hussein Mohamed, Mady Ahmed Ismail, Wael Moustfa Abdel-Mageed, Ahmed Abdelfattah Mohamed Shoreit
Research Department
Research Journal
Asian Pac. J. Trop. Biomed., doi: 10.12980/APJTB.4.201414B216
Research Rank
1
Research Vol
Vol. 4, No. 11
Research Year
2014

Antimicrobial Activity of Latex Silver Nanoparticles Using Calotropis procera

Research Abstract
Objective: To synthesize silver nanoparticles (AgNPs) by green methods using serum latex of Calotropis procera at 80°C and evaluate them against bacteria, dermatophytes and phytopathogenic fungi comparing with the activity of untreated latex. Methods: The synthesis of AgNPs was performed by mixing 3% latex serum extract with the same volume of silver nitrate (2 mmol/L) solution in round flask and heating in water bath at 80°C. Characterization of silver particles were determined using UV-vis spectrophotometer, transmission electron microscopy (TEM), X-ray diffraction and Fourier transform infrared spectroscopy. The antimicrobial activity of the green synthesized AgNPs was determined against bacteria, dermatophytes and phytopathogenic fungi and compared to the crude untreated latex by agar-well diffusion methods. Results: Biosynthesis of latex silver nanoparticles was successfully obtained by green method. The formation of AgNPs has been confirmed by UV-vis, TEM microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. TEM analysis showed that synthesized AgNPs are highly stable spherical shaped particles, well dispersed with a diameter ranged from 4 nm up to 25 nm and an average size of 12.33 nm. AgNPs showed strong antibacterial activity against Gram- negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Serratia sp.) and antifungal activity against Trichophyton rubrum, Candida albicans and Aspergillus terreus. Conclusions: It can be concluded that serum latex of Calotropis procera was found to display strong potential for the synthesis of AgNPs as antimicrobial agents through rapid reduction of silver ions (Ag+ to Ag0). The green synthesized AgNPs were found to show higher antimicrobial.
Research Authors
Nadia Hussein Mohamed, Mady Ahmed Ismail, Wael Moustfa Abdel-Mageed, Ahmed Abdelfattah Mohamed Shoreit
Research Journal
Asian Pac. J. Trop. Biomed., doi: 10.12980/APJTB.4.201414B216
Research Rank
1
Research Vol
Vol. 4, No. 11
Research Year
2014

Antimicrobial Activity of Latex Silver Nanoparticles Using Calotropis procera

Research Abstract
Objective: To synthesize silver nanoparticles (AgNPs) by green methods using serum latex of Calotropis procera at 80°C and evaluate them against bacteria, dermatophytes and phytopathogenic fungi comparing with the activity of untreated latex. Methods: The synthesis of AgNPs was performed by mixing 3% latex serum extract with the same volume of silver nitrate (2 mmol/L) solution in round flask and heating in water bath at 80°C. Characterization of silver particles were determined using UV-vis spectrophotometer, transmission electron microscopy (TEM), X-ray diffraction and Fourier transform infrared spectroscopy. The antimicrobial activity of the green synthesized AgNPs was determined against bacteria, dermatophytes and phytopathogenic fungi and compared to the crude untreated latex by agar-well diffusion methods. Results: Biosynthesis of latex silver nanoparticles was successfully obtained by green method. The formation of AgNPs has been confirmed by UV-vis, TEM microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. TEM analysis showed that synthesized AgNPs are highly stable spherical shaped particles, well dispersed with a diameter ranged from 4 nm up to 25 nm and an average size of 12.33 nm. AgNPs showed strong antibacterial activity against Gram- negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Serratia sp.) and antifungal activity against Trichophyton rubrum, Candida albicans and Aspergillus terreus. Conclusions: It can be concluded that serum latex of Calotropis procera was found to display strong potential for the synthesis of AgNPs as antimicrobial agents through rapid reduction of silver ions (Ag+ to Ag0). The green synthesized AgNPs were found to show higher antimicrobial.
Research Authors
Nadia Hussein Mohamed, Mady Ahmed Ismail, Wael Moustfa Abdel-Mageed, Ahmed Abdelfattah Mohamed Shoreit
Research Journal
Asian Pac. J. Trop. Biomed., doi: 10.12980/APJTB.4.201414B216
Research Rank
1
Research Vol
Vol. 4, No. 11
Research Year
2014

Dermacozines H−J Isolated from a Deep-Sea Strain of Dermacoccus abyssi from Mariana Trench Sediments

Research Abstract
Dermacoccus abyssi sp. nov. strains MT1.1 and MT1.2 are actinomycetes isolated from a Mariana Trench sediment at a depth of 10 898 m. The fermentation process using complex media led to the production of three new pigmented heteroaromatic (oxidized and reduced) phenazine compounds, dermacozines H−J (1−3). Extensive use was made of 1D and 2D NMR experiments and high-resolution MS to determine the structures of the compounds. The new dermacozines showed radical scavenging activity, and the highest activity was observed for dermacozine H (1), with an IC50 value of 18.8 μM.
Research Authors
Marcell Wagner, Wael M. Abdel-Mageed, Rainer Ebel, Alan T. Bull, Michael Goodfellow, Hans-Peter Fiedler, Marcel Jaspars
Research Department
Research Journal
J. Nat. Prod., dx.doi.org/10.1021/np400952d
Research Rank
1
Research Vol
Vol. 77, No. 2
Research Year
2014
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