97905-55-0Relevant articles and documents
Dog Coronary Artery Adenosine Receptor: Structure of the N6-Alkyl Subregion
Kusachi, Shozo,Thompson, Robert D.,Bugni, William J.,Yamada, Nobuyuki,Olsson, R. A.
, p. 1636 - 1643 (2007/10/02)
The moderately potent and stereoselective coronary vasoactivity of N6-adenosine (1) is the basis for the present study that maps the N6 region of the coronary artery adenosine receptor by means of the structure-coronary vasoactivity relationships of 81 analogues of 1 in the open-thorax dog.Stereoselectivity is a general property of N6-substituted adenosines that have a chiral center adjacent to N6.The activity ratio of 1 to its S diastereomer is 10, the result of the positive interaction with the receptor of the propyl C-3 group of the Rdiastereomer in combination with the steric hindrance exerted by this group of the S diastereomer.Replacing the benzyl moiety of 1 by an ethyl, phenyl, phenethyl, or naphthyl group lowers potency of the R diastereomer and, accordingly, the R/S ratio.Propyl C-1 interacts with a receptor region large enough to accommodate three methylene residues and the propyl C-3 residue with a separate region large enough to accommodate two.The receptor subregion that interacts with the propyl C-1 of 1 is more tolerant of bulk and of polar substituents than the subregion that interacts with propyl C-3.Evidence bearing on the possible contribution of N6 to activity, e.g. through hydrogen bonding, is ambiguous.These results support a provisional model of the N6-alkyl subregion.