Laboratory of Analytical Chemistry of Medicines

(a) Design of potent antioxidants.
(b)TEM and structual studies of cisplatine-DNA topology.
(c)Approach to understand mechanism of Aβ _1-42 aggregation.

Reactive oxygen species (ROS) such as the hydroxyl radical (HO . ), superoxide (O 2 -. ),and hydrogen peroxide (H 2 O 2 ) have high oxidative strength, abstract electrons andhydrogen radicals from biological targets, and cause oxidative damage in vitro (Fig. 1).

Recently, we showed that the aggregation of Aβ _1-42 is different in several pH solutions,and TEM images (x 28000) of Aβ self-assembly are represented in Fig. 2.

The aggregation model plays an important role in the design and synthesis of inhibitorsof Aβ aggregation.
cis-Diamminedichloroplatinum(II), Pt ^II (NH₃)₂ Cl₂ (cisplatin or cis-DDP) is a most usefulanti-cancer agent in cancer chemotherapy (see Fig. 3(A)). However, the trans-isomer(trans-DDP) of cis-DDP is clinically ineffective although it binds to DNA. We are interestedin the difference of anti-cancer activity (geometrical effect) of the two drugs. Figures 3(B)and (C) show the TEM images of trefoil DNA which produced under the DNAtopoisomerase I-reaction condition in living nucleus model (cis-DDP modified DNA-histone complex) and the topology 3₁ . The topological production caused by binding ofanti-cancer drug, cisplatin, to DNA-histone complex. The results may be a measure forthe development of new anti-cancer drugs.complex.

Basic study and Application of clay minerals.

The environmental purification and conservation by some clay minerals have beenresearched. Smectite group is mainly used on our study.