Tom Komatsu; Kenjiro Hanaoka; Alexander Adibekian; Kentaro Yoshioka; Takuya Terai; Tasuku Ueno; Mitsuyasu Kawaguchi; Benjamin F. Cravatt; Tetsuo Nagano
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AMER CHEMICAL SOC 135 (16) 6002 - 6005 0002-7863 2013/04 [Refereed]
Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2018/04 -2020/03
Author : Kawaguchi Mitsuyasu
Becuase I found that ENPP1 specifically recognizes and hydrolyzes mGMP groups in living cells, I tried to apply mGMP group to the approved anticancer drug and aimed to develop a compound that shows cytotoxicity in ENPP1 overexpressing cells. However, when we attempted to prodrug SN-38, it was found that the mGMP group was unstable on the synthesis. Considering the background of previous studies, the acidity of the prodrug group is considered to be a key factor in the synthesis of the prodrug. In the result of an investigation of reaction conditions, it was found that coumarin, which is less acidic than TG, is also possible to synthesize Cou-mGMP. By using this reaction condition, I think that I can synthesize various prodrug compounds having mGMP group.
In this study, we investigated the development of the fluorescence probe for NO which detects NO independent from oxygen tension in the milieu, but rather dependent on the reactivity of NO itself. We designed and synthesized various compounds bearing coumarin fluorophore moiety and nitronyl nitroxide (NN) moiety connected with various linkers, and examined the relevant combination and positions for NO detection. From the results, the compound in which NN was connected to the position 3 of the coumarin core structure showed good fluorescence response for NO. The probe was also found to show equivalent fluorescence responses both under aerobic and anaerobic conditions, meaning that the probe can detect NO independent from the oxygen tension.
Next, we tried to modify the probe so that it is more resistant from the reduction with ascorbic acid. It is found that the derivative with 4 ethyl groups showed the partial resistance against the reduction with ascorbic acid.
Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2015/04 -2017/03
Author : Kawaguchi Mitsuyasu
In general, sirtuin activity is detectable by a protease (eg. trypsin) coupled two-steps method. However, such method has several problems, cumbersome procedure, false-positive compounds on chemical screening.
In this study, focusing on interesting reports showing that sirtuin recognize and hydrolize long-chain fatty acyl groups, we hypothesized that sirtuin can hydrolize acyl groups of large quencher dyes. We exhibited that sirtuin activity is detectable by a FRET based novel fluorescence probe, SFP3, and applied this methodology for chemical screening. We identified novel scaffolds of SIRT6 inhibitor and activiator.