Syntheses and electrochemical behaviour of novel dmit or dmio (dithiolato) cobalt(iii) complexes with a η5-cyclopentadienyl or η5-pentamethylcyclopentadienyl ring

Four novel cobalt(III) complexes with a cyclopentadienyl or pentamethylcyclopentadienyl ring and dmit or dmio ligands were synthesized, and their electrochemical behaviour was investigated. All these complexes exhibited three one-electron transfer steps: one reduction and two oxidation steps. In addition, a novel organosulphur compound was afforded by electrochemical oxidation of dmit cobalt complex. Thus, these complexes may have considerable synthetic potential as precursors for electron reservoirs and organosulphur compounds.     

Comparison of reactivity of alkane hydroxylation with intact cells and cell- free extracts ofMethylosinus trichosporium OB3b

Kinetic studies for hydroxylation of a series of alkanes (methane, ethane and propane) with intact cells and cell-free extracts ofMethylosinus trichosporium OB3b were carried out.K _m values for alkane hydroxylation with cell-free extracts were lower than those with intact cells, suggesting that cytoplasm plays an important role in the solubility of alkanes to increase their concentration.     

Synthesis and antileukemic activity of (+-)-20-deoxyaminocamptothecin analogues

The camptothecin analogues (+-)-7-ethyl-10-methoxy-20-deoxyaminocamptothecin (2) and (+-)-7-ethyl-10-hydroxy-20-deoxyaminocamptothecin.HCl (3) were synthesized from indolizine compound 4 via Friedl?nder condensation to construct a pentacyclic ring system, and were tested in a P388 mouse antileukemia assay. Compounds 2 and 3 were more active and less toxic than (+)-camptothecin (1), and therefore had higher therapeutic ratios.