Moo Jin Jun

Synthesis, biodistribution and antitumor activity of hematoporphyrin-platinum(II) conjugates.

A new series of platinum(II) complexes of pegylated hematoporphyrin derivatives with controlled hydrophobic/hydrophilic balance were synthesized by introducing different kinds of poly(ethylene glycol) and amine ligands to the porphyrin ring. The antitumor activity of the porphyrin-platinum(II) conjugates was assayed in vitro and in vivo against leukemia L1210 cell line and various human tumor cell lines. The present complexes exhibited high antitumor activity and improved water solubility as well as considerable lipophilicity. In particular, complex 16 showed not only higher in vivo activity (T/C%=258) than cisplatin (T/C%=184) and carboplatin (T/C%=168), but also excellent solubility in water and organic solvent. The antitumor activity of complex 20 was superior to that of carboplatin against all human tumor cell lines tested. Moreover, some amphiphilic complexes (7 and 12) exhibited elevated tumor-localizing effect (tumor/muscle ratio>2).

The sterochemistry and absolute configurations of the metal complexes of novel optically active NSSN system tetradentate ligands. Cobalt(III) complexes of S,S′-bis(β-aminoethyl)-trans-1,2-dithiocyclohexane. Crystal and molecular structure of s-cis[Co(adch)Cl2]Cl·C2H5OH

Abstract A novel open-chain tetradentate ligand having the NSSN donor atom array, S,S′-bis(β-aminoethyl)-trans-1,2-dithiocyclohexane (adch), has been synthesized and the cobalt(III) complexes of [Co(adch)X2]+ (X = Cl−, NO−2, NCS−, X2 =CO2−3) have been prepared. Only the s-cis geometric isomers have been formed. From the reaction between Na3[ CO(CO3)3] and the reacemic adch ligand, the RR-adch ligand is coordinated to the cobalt(III) ion stereospecifically to give the Λ-s-cis-(δλδ)-[Co(adch)Cl2]+ enantiometer complex, while the SS-adch ligand stereospicifically to give the Λ-s-cis-(λδλ)[Co(adch)Cl2]+ enantiometer complex, which have been observed in the crystal structure of the [Co(adch)Cl2]Cl2·C2H5OH complex solved by single-crystal X-ray analysis. The unit cell contains both Λ and Δ complex isomer, two chloride ions and two ethanol molecules. The bond distances in A: CoS = 2.241 (2) and 2.232 (2), Co N = 1.963 (5) and 1.959 (6) CoCl = 2.262 (2) and 2.250 (2). The coordination geometry about the cobalt atom is a distorted octahedron.

LINKAGE ISOMERISM OF (DIAMINE)PLATINUM(II) COMPLEXES OF SULFUR-CONTAINING YLIDENEMALONATE LIGANDS

Abstract A 1 H NMR study has been carried out on (diamine)platinum(II) complexes of 1,3-dithian-2-ylidenemalonate (DTAYM) and 1,3-dithiepane-2-ylidenemalonate (DTEYM) ligands as anionic leaving group in aqueous solution. Only the O,S-chelated isomer was observed in solution for all the DTAYM complexes regardless of the kind of carrier ligand amine as was in the solid state. However, both O,S- and S,S′-chelated isomers were observed in solution for DTEYM complexes, which show linkage isomerism from the O,S-chelate to the thermodynamically more stable S,S′-chelate. The rate of linkage isomerism of the DTEYM complexes was found to be dependent on their amine co-ligands. Molecular dynamics of the DTAYM complexes was also discussed based on their temperature-dependent NMR spectra. The crystal structure of the S,S′-isomer of (NH 3 ) 2 Pt(DTEYM) · H 2 O was determined whereas that of the O,S-isomer could not be obtained due to its poor crystallinity.