Quantitative structure–stability relationships among inclusion complexes of cyclodextrins I: Barbituric acid derivatives

✍ Scribed by Antal Lopata; Ferenc Darvas; Ágnes Stadler-Szóke; József Szejtli

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 295 KB
• Volume: 74
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600740223

✦ Synopsis

Quantitative structure-stability relationships (QSSRs) are formulated for the inclusion complexation of 17 barbituric acid derivatives with alpha- and beta-cyclodextrin. The variation in the complex stability constants K alpha and K beta is found to be partly accounted for by the molar refractivity or the hydrophobicity of the substituent R1 at position 5 of the barbiturate ring. In addition, K alpha also depends upon whether or not R1 is branching or cyclic, and K beta also depends upon whether the guest molecule is a barbiturate or a thiobarbiturate. The results suggest that in alpha-cyclodextrin-barbiturate complexes the cyclodextrin cavity includes only R1, while in beta-cyclodextrin complexes both R1 and (part of) the barbiturate ring are included. This complexation model is compared with those proposed by other authors.