TY - JOUR
T1 - Cationic porphyrins bearing diazolium rings
T2 - Synthesis and their interaction with calf thymus DNA
AU - Tjahjono, Daryono H.
AU - Akutsu, Takehiro
AU - Yoshioka, Naoki
AU - Inoue, Hidenari
PY - 1999/10/18
Y1 - 1999/10/18
N2 - Two novel cationic porphyrins bearing five-membered rings at the meso- positions, meso-tetrakis(1,3-dimethylimidazolium-2-yl)porphyrin (H2TDMImP) and meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (H2TDMPzP), have been synthesized. These two compounds interact with calf thymus DNA (CTDNA) in different binding modes from that of meso-tetrakis(N-methylpyridinium-4- yl)porphyrin (H2TMPyP). H2TDMImP outside binds to the minor groove of CTDNA while H2TDMPzP intercalates into CTDNA. These two novel cationic porphyrins strongly bind to CTDNA even at high ionic strength and the binding constant of H2TDMPzP to CTDNA is comparable to that of H2TMPyP. The binding of H2TDMImP to CTDNA is enthalpically driven. The favorable free energy changes in binding of H2TDMPzP to CTDNA come from the large negative enthalpy changes accompanied by small positive entropy changes.
AB - Two novel cationic porphyrins bearing five-membered rings at the meso- positions, meso-tetrakis(1,3-dimethylimidazolium-2-yl)porphyrin (H2TDMImP) and meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (H2TDMPzP), have been synthesized. These two compounds interact with calf thymus DNA (CTDNA) in different binding modes from that of meso-tetrakis(N-methylpyridinium-4- yl)porphyrin (H2TMPyP). H2TDMImP outside binds to the minor groove of CTDNA while H2TDMPzP intercalates into CTDNA. These two novel cationic porphyrins strongly bind to CTDNA even at high ionic strength and the binding constant of H2TDMPzP to CTDNA is comparable to that of H2TMPyP. The binding of H2TDMImP to CTDNA is enthalpically driven. The favorable free energy changes in binding of H2TDMPzP to CTDNA come from the large negative enthalpy changes accompanied by small positive entropy changes.
KW - Binding constant
KW - Cationic porphyrin
KW - Imidazole
KW - Porphyrin-DNA complex
KW - Pyrazole
KW - Thermodynamic parameter
UR - http://www.scopus.com/inward/record.url?scp=0032850115&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032850115&partnerID=8YFLogxK
U2 - 10.1016/S0304-4165(99)00139-7
DO - 10.1016/S0304-4165(99)00139-7
M3 - Article
C2 - 10572955
AN - SCOPUS:0032850115
SN - 0304-4165
VL - 1472
SP - 333
EP - 343
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
IS - 1-2
ER -