• Applied Biological Chemistry
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• v.38 no.2
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• pp.163-167
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• 1995

New twenty 2-(n-octyl)-3-(n-propyl)isothiourea derivatives(S) were synthesized which is modified from the insecticidal Buprofezine (Applaud) in the selective insecticidal activities in-vitro against Diamond-Back moth (Plutella Xylostella Linnaeus). The structure activity relationships(SAR) between the insecticidal activity$(pI_{50})$ and a various physicochemical parameters of the substituent(Z) of S were analyzed by the multiple regression technique. The activities would depend largely on the MR, ${\pi}$ and $L_1$ parameters. The SAR was rationalized by parabolic function of MR, ${\pi}$ and $L_1$ constant, where the optimal values of the constants were $L_1=5.22{{\AA}}$, $MR=15.70\;Cm^3/mol$ and ${\pi}=1.60$, respectively. The steric effects play an important role in determining insecticidal activity. The SAR suggest that the S derivatives having a substituents with a small breadth and an appropriate length as Z group showed potent activity. From the results, the iso-propyl group(Z) substituent (5) with three carbon atom was the most effective compound.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.44-52
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• 2006

New organotin(IV) derivatives with general formulae R_2SnL_2 and R_3SnL, where R = methyl, n-butyl, n-octyl and phenyl and HL is either 3-[N-(4-nitrophenyl)amido]-propenoic acid or 3-[N-(4-nitrophenyl)amido] propanoic acid have been synthesized in 1 : 2 and 1 : 1 molar ratio by different methods. The FTIR spectra clearly demonstrated that the organotin(IV) moieties react with [O,O] atoms of the ligands. The bonding and coordination behavior in these complexes are discussed on the basis of multinuclear (^1H,\,^{13}C,\,^{119}Sn) NMR and mass spectrometric studies. Antibacterial, and antifungal screening tests were performed for these compounds and reported here. These values were compared to those of the precursors and it was found that diorganotin(IV) complexes exhibit less activity as compared to triorganotin(IV) complexes . LD_{50} data were obtained by Brine Shrimp assay method. Insecticidal activity was performed for selective compounds by contact toxicity method.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.281-286
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• 2010

A Pseudomonas fluorescens strain was isolated and found to show antagonistic activity against phytopathogenic fungi and to possess a gene responsible for production of antibiotic 2,4-diacetylphloroglucinol. For the extension of biocontrol range, a gene for an Androetonus australis Hector insect toxin 1 (AaHIT1), one of the most known toxic insect-selective peptides, was designed and synthesized according to the preferred codon usage of Pseudomonas fluorescens, cloned, and transformed into the strain by pSUP106 vector, a broad-host-range plasmid. Bioassays indicated that the engineered strain was able to produce AaHIT1 with insecticidal activity, and at the same time retain the activity against plant pathogen. The experiments for nonplanted soil and rhizosphere colonization showed that, similar to the population of the wild-type strain, that of the engineered strain remained relatively constant in the first 10 days, and the subsequent 50 days, suggesting that AaHIT1 expression in the bacterial cell does not substantially impair its long-term colonization. It is first reported that a Pseudomonas fluorescens strain expressing an active scorpion neurotoxin has dual activity against phytopathogenic fungi and insects, making at attractive for agronomic applications.