Two novel cobalt(III) pyridine complexes (1) [Co(en)2(py)2]3+ and (2) [Co(en)2(mepy)2]3+ (en=ethylenediamine, py=pyridine, and mepy=methylpyridine) have been synthesized and characterized. The interaction of these complexes with calf thymus DNA was investigated by absorption, emission spectroscopy, viscosity measurements, DNA melting, and DNA photocleavage. Results suggest that the two complexes bind to DNA via groove mode and complex 2 binds more strongly to CT DNA than complex 1. Moreover, these Co(III) complexes have been found to promote the photocleavage of plasmid DNA pBR322 under irradiation at 365 nm, cytotoxicity results of complexes are also showing anticancer activity.

Three Ru(II) complexes, namely [Ru(bipy) 2-PRIP] 2? (1), [Ru(dmb) 2 PRIP] 2? (2), and [Ru(phen) 2 PRIP] 2?(3) (dmb = 4,4 0 -dimethyl-2,2 0 -bipyridine; PRIP = 2-(pyrrole) imidazo [4,5-f]-1,10-phenanthroline) have been synthesized and characterized by elemental analysis, mass spectra, IR, 1 H NMR and 13 C NMR. The DNA-binding properties of the three complexes with calf-thymus DNA (CT-DNA) were investigated by spectrophotometry, fluorescence methods and viscosity measurements. The results suggest that all three complexes bind to CT-DNA through intercalation. Also, when irradiated at 365 nm, the three complexes promote the photocleavage of plasmid pBR-322 DNA. Under comparable experimental conditions, complex 3 cleaves DNA more effectively than complexes 1 and 2.

A new furoquinoline alkaloid, 5-hydroxydictamnine, along with β-sitosterol was isolated from the heartwood of Atalantia monophylla. The structure of this alkaloid was established by chemical and spectral evidences together with a nuclear overhauser effect (NOE) experiment.

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