Gravar-mail: Binding Characteristics of (–)‐(R)‐2‐Aminomethylpyrrolidine(1,1‐cyclobutanedi‐carboxylato)‐2‐platinum(II) to DNA, RNA and Protein Molecules in HeLa Cells and Its Lethal Effect: Comparison with cis‐ and trans‐Diammmedichloroplatinums(II)