Quinhydrone is regarded as a donor-acceptor complex composed of hydroquinone and quinone. Here we show that 1,5-dibromo-2,6-naphthoquinhydrone shows electron transport in the transistors. The donor and acceptor frontier orbitals are approximately the same, but in addition to the strong acceptor ability of the quinone, enhancing and canceling contributions of the second bridge orbital result in monopolar transport.