In the course of our screening program for anti-Mycobacterium bovis bacillus Calmette-Guérin (BCG) and anti-Mycobacterium tuberculosis H37Rv (MTB H37Rv) agents from ourmarine natural product library, a newly isolated actinomycete strain, designated as MS449, was picked out for further investigation. The strain MS449, isolated from a sediment sample collected from South China Sea, produced actinomycin X2 and actinomycin D in substantial quantities, which showed strong inhibition of BCG and MTB H37Rv. The structures of actinomycins were elucidated by nuclear magnetic resonance and mass spectrometric analysis. The strain MS449 was taxonomically characterized on the basis of morphological and phenotypic characteristics, genotypic data, and phylogenetic analysis. The 16S rRNA gene sequence of the strain was determined and a database search indicated that the strain was closely associated with the type strain of Streptomyces avermitilis (99.7 % 16S rRNA gene similarity). S. avermitilis has not been previously reported to produce actinomycins. The marine-derived strain of Streptomyces sp. MS449 produced notably higher quantities of actinomycin X2 (1.92 mg/ml) and actinomycin D (1.77 mg/ml) than previously reported actinomycins producing strains. Thus, MS449 was considered of great potential as a new industrial producing strain of actinomycin X2 and actinomycin D.

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.

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.

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.

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.

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.

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.

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.

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.

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.