[EN] TARGETED RADIOPHARMACEUTICALS FOR THE DIAGNOSIS AND TREATMENT OF PROSTATE CANCER [FR] PRODUITS RADIOPHARMACEUTIQUES CIBLÉS POUR LE DIAGNOSTIC ET LE TRAITEMENT DU CANCER DE LA PROSTATE
[EN] TARGETED RADIOPHARMACEUTICALS FOR THE DIAGNOSIS AND TREATMENT OF PROSTATE CANCER [FR] PRODUITS RADIOPHARMACEUTIQUES CIBLÉS POUR LE DIAGNOSTIC ET LE TRAITEMENT DU CANCER DE LA PROSTATE
Asymmetric Synthesis of β,β-Disubstituted Alanines via a Sequential C(sp2)–C(sp3) Cross-Coupling–Hydrogenation Strategy
作者:David A. Petrone、Jonathan Maturano、James Herbort、Erin E. Plasek、J. Mayeli Vivaldo-Nikitovic、David Sarlah
DOI:10.1021/acs.orglett.4c02376
日期:2024.7.26
allows access to a diverse array of valuable β,β-disubstituted alanine derivatives. This synthesis exhibits broad functional group tolerance, and permits efficient access to β-aryl-β-alkyl, and the more rarely reported β,β-dialkyl Ala derivatives with high yield and excellent enantioselectivity. This transformation has been exhibited on decagram quantity, and can be used to generate Fmoc aminoacid derivatives
AbstractWe prepared the two enantiomers of 3‐(3′‐quinolyl)‐alanine (Qla, 1) in multigram scale by asymmetric hydrogenation. These amino acids, protected as Fmoc derivatives, were then used in the solid‐phase synthesis of two new somatostatin 14 (SRIF‐14) analogues 8 a and 8 b, tetradecapeptides in which the tryptophan residue (Trp8) is replaced by one of the two enantiomers of 3‐(3′‐quinolyl)‐alanine (Qla8) and therefore lack the NH bond in residue 8. The selectivity of these new analogues for the somatostatin receptors, SSTR1–5, was measured. Substitution with L‐Qla8 yielded peptide 8 a, which was highly selective for SSTR1 and SSTR3, with an affinity similar to that of SRIF‐14. Substitution by D‐Qla gave the relatively selective analogue 8 b, which showed high affinity for SSTR3 and significant affinity for SSTR1, SSTR2 and SSTR5. The biological results demonstrate that bulky and electronically poor aromatic amino acids at position 8 are compatible with strong activity with SSTR1 and SSTR3. Remarkably, these high affinity levels were achieved with peptides in which the conformational mobility was increased with respect to that of SRIF‐14. This observation suggests that conformational rigidity is not required, and might be detrimental to the interaction with receptors SSTR1 and SSTR3. The absence of an indole N proton in Qla8 might also contribute to the increased flexibility observed in these analogues.