80963-08-2Relevant articles and documents
Macrocyclic BACE1 inhibitors with hydrophobic cross-linked structures: Optimization of ring size and ring structure
Otani, Takuya,Hattori, Yasunao,Akaji, Kenichi,Kobayashi, Kazuya
, (2021/11/22)
Based on the X-ray crystallography of recombinant BACE1 and a hydroxyethylamine-type peptidic inhibitor, we introduced a cross-linked structure between the P1 and P3 side chains of the inhibitor to enhance its inhibitory activity. The P1 and P3 fragments bearing terminal alkenes were synthesized, and a ring-closing metathesis of these alkenes was used to construct the cross-linked structure. Evaluation of ring size using P1 and P3 fragments with various side chain lengths revealed that 13-membered rings were optimal, although their activity was reduced compared to that of the parent compound. Furthermore, the optimal ring structure was found to be a macrocycle with a dimethyl branched substituent at the P3 β-position, which was approximately 100-fold more active than the non-substituted macrocycle. In addition, the introduction of a 4-carboxymethylphenyl group at the P1′ position further improved the activity.
[18F](2S,4S)-4-(3-Fluoropropyl)glutamine as a tumor imaging agent
Wu, Zehui,Zha, Zhihao,Li, Genxun,Lieberman, Brian P.,Choi, Seok Rye,Ploessl, Karl,Kung, Hank F.
, p. 3852 - 3866 (2016/10/13)
Although the growth and proliferation of most tumors is fueled by glucose, some tumors are more likely to metabolize glutamine. In particular, tumor cells with the upregulated c-Myc gene are generally reprogrammed to utilize glutamine. We have developed new 3-fluoropropyl analogs of glutamine, namely [18F](2S,4R)- and [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 3 and 4, to be used as probes for studying glutamine metabolism in these tumor cells. Optically pure isomers labeled with 18F and 19F (2S,4S) and (2S,4R)-4-(3-fluoropropyl)glutamine were synthesized via different routes and isolated in high radiochemical purity (>95%). Cell uptake studies of both isomers showed that they were taken up efficiently by 9L tumor cells with a steady increase over a time frame of 120 min. At 120 min, their uptake was approximately two times higher than that of L-[3H]glutamine ([3H]Gln). These in vitro cell uptake studies suggested that the new probes are potential tumor imaging agents. Yet, the lower chemical yield of the precursor for 3, as well as the low radiochemical yield for 3, limits the availability of [18F](2S,4R)-4-(3-fluoropropyl)glutamine, 3. We, therefore, focused on [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4. The in vitro cell uptake studies suggested that the new probe, [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4, is most sensitive to the LAT transport system, followed by System N and ASC transporters. A dualisotope experiment using L-[3H]glutamine and the new probe showed that the uptake of [3H]Gln into 9L cells was highly associated with macromolecules (>90%), whereas the [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4, was not (18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4, may be useful for testing tumors that may metabolize glutamine related amino acids.
Synthesis of optically pure 4-fluoro-glutamines as potential metabolic imaging agents for tumors
Qu, Wenchao,Zha, Zhihao,Ploessl, Karl,Lieberman, Brian P.,Zhu, Lin,Wise, David R.,Thompson, Craig B.,Kung, Hank F.
supporting information; scheme or table, p. 1122 - 1133 (2011/04/16)
A versatile synthetic route to prepare all four stereoisomeric 4-fluoro-glutamines was developed by exploiting a Passerini three-component reaction. The skeleton of 4-substituted glutamine derivatives was efficiently constructed. Subsequent four-step reactions, highlighted by a "neutralized" TASF fluorination, provided the desired products with high yields and excellent optical purity. The optically pure fluorine-18 labeled 4-fluoroglutamines were also successfully prepared using either a 18-crown-6/KHCO3 or K[222]/K2CO3 catalysis system. Preliminary cell uptake and inhibition studies using the 9L tumor cells ana SF188BC1-XL tumor cells (a glutamine addicted tumor derived from glioblastoma) provided strong evidence for their potential application in conjunction with positron emission tomography (PET) for in vivo imaging of tumors, which use glutamine as an alternative energy source.
