Naoyuki Sano, Hironori Yoshino, Yoshiaki Sato, Hideo Honma, Christopher E.J. Cordonier and Ikuo Kashiwakura* Pages 957 - 965 ( 9 )
Background: We recently synthesized a compound in which 5-mercapto-1-methyltetrazole (MM4) was coordinated to tiopronin monovalent (TPN-Au(I)) and reported its cytotoxic activity against human leukemia cells in vitro.
Objective: We further synthesized other heterocyclic compounds coordinated with TPN-Au(I) and assessed their cytotoxic activity against hepatocellular carcinoma HepG2 and lung cancer cell line H1299 in vitro.
Methods: Seven kinds of compounds were synthesized by introducing a five-membered heterocyclic compound into TPN-Au(I). The number of viable cells was counted by a trypan blue dye exclusion assay. Fluorescence conjugated-Annexin V and propidium iodide were used for the apoptosis analysis.
Results: Seven compounds were successfully synthesized. Among these compounds, TPN-Au(I)-MTZ (3- mercapto-1,2,4-triazole), TPN-Au(I)-MMT (2-mercapto-5-methyl-1,3,4-thiadiazole), and TPN-Au(I)-MMTT (2-mercapto-5-methylthio-1,3,4-thiadiazole) effectively suppressed the proliferation and induced apoptosis in HepG2 cells. In addition, TPN-Au(I)-MMTT and TPN-Au(I)-MMT also showed effective cytotoxicity against H1299 cells.
Conclusion: The present results showed that introduction of some five-membered heterocyclic compounds, especially MMT and MMTT, to TPN-Au(I) improved the cytotoxicity against solid cancer cells.
Tiopronin monovalent (TPN-Au(I)), 5-membered heterocyclic compound, 3-mercapto-1,2,4-triazole (MTZ), 2-mercapto-5- methyl-1,3,4-thiadiazole (MMT), 2-mercapto-5-methylthio-1,4-thiadiazole (MMTT), cytotoxicity.