Recognition of alpha-amino acid derivatives by N,N'-dibenzylated S,S-(+)-tetrandrine.
Complexation of free and N-acetylated alpha-amino acid anions (Gly, Ala, Phe) and some structurally related guests by a dicationic cyclophane-type N,N'-dibenzylated chiral derivative of a bisisoquinoline macrocyclic alkaloid S,S-(+)-tetrandrine (DBT) has been studied by (1)H-NMR titrations in D(2)O. In contrast to other macrocyclic hosts like cyclodextrins and calixarenes, DBT shows highest affinity and large enantioselectivity (K(S)/K(R) >/=10) toward smaller N-acetylalanine and binds larger phenylalanine derivatives more weakly and non-selectively. With 1,2,3,4-tetrahydroisoquinoline-3-carboxylate, a rigid analog of phenylalanine, binding again becomes enantioselective with K(S)/K(R)= 3.8. The binding specificity of DBT is rationalized on the basis of molecular mechanics calculations.
Lara
Karen Ochoa
KO
Departamento de Investigación en Polímeros y Materiales, Universidade de Sonora, México.
Godoy-Alcantar
Carolina
C
Eliseev
Alexey V
AV
Yatsimirsky
Anatoly K
AK
D000107:Acetylation; D000470:Alkaloids / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D001593:Benzyl Compounds / Q000737:chemistry*; D044182:Benzylisoquinolines / Q000737:chemistry*; D047250:Calixarenes; D003505:Cyclodextrins / Q000737:chemistry; D017666:Deuterium Oxide / Q000737:chemistry; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry; D013237:Stereoisomerism
D000470:Alkaloids; D000596:Amino Acids; D000838:Anions; D001593:Benzyl Compounds; D044182:Benzylisoquinolines; D003505:Cyclodextrins; D010636:Phenols; C121325:calix(4)arene; D047250:Calixarenes; C009438:tetrandrine; D017666:Deuterium Oxide