Genes are the blueprints for the architectures of living organisms, providing the backbone of the information required for formation of proteins. Changes in genes lead to disorders, and these disorders could be rectified by reversing the mutations that caused them. Photochemical methods currently in use for site-directed mutagenesis employ the photoactive 3-cyanovinylcarbazole ( K) nucleotide incorporated in the oligodeoxyribonucleotide (ODN) backbone. The major drawback of this method, the requirement for high temperature, has been addressed, and deamination has previously been achieved at 37 °C but with low efficiency. Here, efficient deamination has been accomplished under physiological conditions by using a short complementary photoactive ODN with a 5'-phosphate group in the -1 position with respect to the target cytosine. It is hypothesized that the free phosphate group affects the microenvironment around the target cytosine by activating the incoming nucleophile through hydrogen bonding with the water molecule, thus facilitating nucleophilic attack on the cytosine C-4 carbon. The degree of deamination observed in this technique is high and the effect of the phosphate group is to accelerate the deamination reaction.

Herein, we report the major factor for deamination reaction rate acceleration, i.e., hydrophilicity, by using various 5-substituted target cytosines and by carrying out deamination at high temperatures. Through substitution of the groups at the 5′-position of the cytosine, the effect of hydrophilicity was understood. It was then used to compare the various modifications of the photo-cross-linkable moiety as well as the effect of the counter base of the cytosine to edit both DNA and RNA. Furthermore, we were able to achieve cytosine deamination at 37 °C with a half-life in the order of a few hours.

The effect of residual rice bran(HDRB) , obtained by compression, on the onset of diabetes was evaluated in KK-Ay/Ta mice. The HDRB contained approximately １ ０％ oil. However, the inclusion of HDRB in the diet, at a level corresponding to an ingestable amount of brown rice per day, did not increase the body weight. In mice fed an HDRB diet, the postprandial blood glucose levels reduced significantly, whereas insulin secretion decreased slightly. HDRB also contributed to a decrease in the levels of urinary ８-hydroxy-２′ -deoxyguanosine (８-OHdG) , which is an oxidative stress marker. Thus, the results of our short-term experiment suggest that the intake of HDRB produced by compression, at a level equivalent to the amount of brown rice consumed per day, is effective in controlling the onset of diabetes.