• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3061-3065
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• 2009

A series of mono- and 1,1'-bis(heteroaryl)-substituted ferrocenes were prepared by employing Frielander reaction of acetyl- and 1,1'-diacetylferrocene with a series of o-aminoaldehydes. Reactions of 1,1'-diacetylferrocene with two equivalents of 1-aminonaphthalene-2-carbaldehyde and 8-aminoquinoline-7-carbaldehyde afforded a mixture of mono- and 1,1'-bis(heteroaryl)-substituted ferrocenes in a ratio of 1 : 3.1 - 3.8, while the reaction with 4-aminoacridine-3-carbaldehyde did not provide any characterizable product presumably due to the redox instability of the product induced by low reduction potential of benzo[b]-1,10-phenanthroline. Structural and optical properties of the compounds prepared were described.

• Interaction and multiscale mechanics
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• v.6 no.1
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• pp.31-50
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• 2013

A five parameter viscoelastic model is developed to study harmonic waves propagating in the non-homogeneous viscoelastic filaments of varying density. The constitutive relation for five parameter model is first developed and then it is applied for harmonic waves in the specimen. In this study, it is assumed that density, rigidity and viscosity of the specimen i.e., rod are space dependent. The specimen is non-homogeneous, initially unstressed and at rest. The method of non-linear partial differential equation has been used for finding the dispersion equation of harmonic waves in the rods. A simple method is presented for reflections at the free end of the finite non-homogeneous viscoelastic rods. The harmonic wave propagation in viscoelastic rod is also presented numerically with MATLAB.

• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.1988-1992
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• 2008

A series of new derivatives on the ring A of luotonin A were prepared by Friedländer condensation of 6,7,8,10- tetrahydropyrrolo[2,1-b]quinazoline-6,10-dione and suitably substituted 2-aminobenzaldehydes and 2- aminoacetophenones. Their inhibitory activities on topoisomerases and cytotoxicities against selected human cancer cell lines were evaluated. Among the compounds tested, 8-fluoroluotonin A showed similar inhibitory activity on topoisomerase I comparable to camptothecin while luotonin A and 9-hydroxyluotonin A showed 1.37 and 0.94 times stronger inhibitory activity, respectively, on topoisomerase II compared to etoposide. Some derivatives of luotonin A showed moderate cytotoxicity. The possible relationship between the inhibitory activity on Topo II and the cytotoxicity of luotonin A and its analogues, thus, cannot be ruled out.