Ellipticin penetrates between the bases of DNA and interferes with DNA replication to produce anticancer effects.It is a molecule that has both π-conjugation, which is an essential feature of organic semiconductors, and hydrogen-bonding properties, which are often found in biomolecules.In general, molecules with hydrogen bonds have high thermodynamic stability, but high conduction properties are often not expected.

　This time, we created an ellipticin thin film with the same orientation direction by taking advantage of the high flatness for entering the DNA of ellipticin and the high crystallinity due to the strong hydrogen bonding property.Quantum chemistry calculation results show that this crystal has π-π interaction similar to that of organic semiconductors with excellent properties.In this process, hydrogen bonds are the driving force for the gathering of ellipticin molecules, and it was predicted that without hydrogen bonds, the intermolecular distance would be doubled and the electron interaction would be drastically reduced.On the other hand, it was confirmed from the calculation results that hydrogen bonds not only shorten the intermolecular distance but also have high electron transfer interaction through hydrogen bonds.

　As an experimental verification, when the conductivity of the thin film was measured using microwaves, the conductivity in the folding direction of the π-conjugated system was about 1.5 times higher than that in the hydrogen bonding direction.In addition, the estimated charge mobility and the measured conductivity were similar to those of the typical organic semiconductor pentacene, and elliptycin showed its excellent organic semiconductor characteristics.

　In the future, it plans to develop transistors using biomolecules and chemical sensors that detect ethyl acetate, which is a biological indicator compound for lung cancer.

Paper information:[Nature Communication] Repurposing DNA Binding Agents as H-bonded Organic Semiconductors