title: Structure, stability, and antiplatelet activity of O-acyl derivatives of salicylic acid and lipophilic esters of acetylsalicylate.
abstract: The anti-thrombotic activity of acetylsalicylic acid (ASA) has been shown to be due to specific irreversible acetylation of blood platelet cyclooxygenase. The aim of our study was to investigate the associations between the antiplatelet activities of derivatives of both ASA and salicylic acid (SA), as well as the structure, stability, and molecular properties of these compounds. Homologous series of O-acyl derivatives of salicylic acid (propionyl-, butyrylsalicylic acids, PSA, BSA) and lipophilic dodecyl (C12)-, hexadecyl (C16)-, and cholesteryl acetylsalicylates were synthesized and tested for structure-activity relationships. The molecular properties (heat of formation, molecular surface area, dipole moment) of ASA and SA derivatives obtained by theoretical calculations changed with the increasing length of the acyl or alkyl residue. The inhibition of whole blood platelet aggregation and the reduction in thromboxane (TX) generation by O-acyl derivatives were concentration-dependent and decreased along with increasing the length of acyl hain. These effects correlated with the extent of platelet reactivity and P-selectin expression inhibition in collagen-activated platelets. In contrast to ASA and O-acyl derivatives of SA, none of the lipophilic ASA derivatives had a significant inhibitory effect on platelet aggregation. In conclusion, all SA and ASA derivatives studied under in vitro conditions showed much lower antiplatelet activities than ASA itself, despite their higher affinity to plasma proteins or membrane components and their equivalent ability to acetylate protein free amino groups.We suggest the significance of the carboxylic group, dipole moment, geometry, and size of these pharmaceuticals in their ability to bind to the active site of cyclooxygenase and their antiplatelet efficacy.
authors: Department of Bioregulators, Institute of Pharmacology and Biochemistry, National Academy of Sciences, Grodno, Belarus.
authors: Ilya B
authors: IB
authors: Zavodnik
authors: Elena
authors: E
authors: Lapshina
authors: Elena
authors: E
authors: Sudnikovich
authors: Magdalena
authors: M
authors: Boncler
authors: Bogusława
authors: B
authors: Luzak
authors: Marcin
authors: M
authors: Rózalski
authors: Magdalena
authors: M
authors: Helińska
authors: Cezary
authors: C
authors: Watała
mesh_terms: D001241:Aspirin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D004355:Drug Stability; D004952:Esters / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D015394:Molecular Structure; D019007:P-Selectin / Q000037:antagonists & inhibitors; D010974:Platelet Aggregation / Q000187:drug effects*; D011485:Protein Binding; D020156:Salicylic Acid / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013931:Thromboxanes / Q000096:biosynthesis
chemical_list: D004952:Esters; D019007:P-Selectin; D013931:Thromboxanes; D020156:Salicylic Acid; D001241:Aspirin