869116-13-2Relevant articles and documents
Synthesis of L-[5-11C]Leucine and L-α-[5-11C]Methylleucine via Pd0-mediated 11C-Methylation and Microfluidic Hydrogenation: Potentiality of Leucine PET Probes for Tumor Imaging
Takatani, Shuhei,Tahara, Tsuyoshi,Tsuji, Mieko,Ozaki, Daiki,Shibata, Nina,Hashizume, Yoshinobu,Suzuki, Masaaki,Onoe, Hirotaka,Watanabe, Yasuyoshi,Doi, Hisashi
, p. 3271 - 3279 (2021)
The efficient synthesis of L-[5-11C]leucine and L-α-[5-11C]methylleucine has been investigated using a continuous two-step sequence of rapid reactions consisting of Pd0-mediated 11C-methylation and microfluidic hydrogenation. The synthesis of L-[5-11C]leucine and L-α-[5-11C]methylleucine was accomplished within 40 min with a decay-corrected radiochemical yield of 15–38 % based on [11C]CH3I, radiochemical purity of 95–99 %, and chemical purity of 95–99 %. The Pd impurities in the injectable solution measured using inductively coupled plasma mass spectrometry met the international criteria for human use. Positron emission tomography scanning after an intravenous injection of L-[5-11C]leucine or L-α-[5-11C]methyl leucine in A431 tumor-bearing mice was performed. As a result, L-α-[5-11C]methylleucine was found to be a potentially useful probe for visualizing the tumor. Tissue distribution analysis showed that the accumulation value of L-α-[5-11C]methylleucine in tumor tissue was high [12±3% injected dose/g tissue (%ID/g)].
An improved large scale procedure for the preparation of N-Cbz amino acids
Pehere, Ashok D.,Abell, Andrew D.
experimental part, p. 1493 - 1494 (2011/05/16)
A simple and scalable method for the preparation of N-Cbz protected amino acids is presented which uses a mixture of aqueous sodium carbonate and sodium bicarbonate to maintain the appropriate pH during the addition of benzyl chloroformate. The method has been extended to other N-protections and is amenable to large scale preparation of an intermediate toward Zofenopril, an ACE inhibitor.
Chemoenzymatic synthesis of triazole-linked glycopeptides
Groothuys, Stan,Kuijpers, Brian H. M.,Quaedflieg, Peter J. L. M.,Roelen, Harlof C. P. F.,Wiertz, Roel W.,Blaauw, Richard H.,Van Delft, Floris L.,Rutjes, Floris P. J. T.
, p. 3146 - 3152 (2008/02/09)
Triazole-linked glycopeptides are prepared by C-terminal elongation of glycoamino acids with proteinogenic amino acids following a chemical or enzymatic coupling protocol. Two orthogonal routes for a chemoenzymatic strategy were explored, involving a click-reaction before amide bond formation or in reverse order. It was found that enzymatic peptide coupling under the influence of alcalase proceeds cleanly and in high yields, while the resulting dipeptides can be efficiently clicked to acetylene- or azide-containing sugars. Georg Thieme Verlag Stuttgart.
