Cyclization, amino acid coupling, docking-based virtual screening and SAR: showing a strategy of the structural modification for salvianic acid A

Aim Providing diverse modification remains to be a strategy for salvianic acid A.Materials and methods Based on the docking virtual screening, salvianic acid A was cyclized, then modified with amino acid to provide 19 derivatives (6a-s), and evaluated their effects on platelet aggregation, thrombus formation, and determine serum levels of P-selectin and GPIIb/IIIa in male SD rats.Results The in vitro evaluation showed that 6a-s effectively against platelet-activating factor (PAF) and adenosine diphosphate (ADP) induced platelet aggregation. The in vivo anti-arterial thrombosis assay showed that 30 nmol/kg of 6a-s significantly decreased thrombus weights of rats, (3R)-6,7-dihydroxy-1,1- dimethylisochromane-3-carboxyl-Lys (6h) possessed the strongest anti-arterial thrombotic activity. The in vivo thrombolytic assay showed that the activities of 30 nmol/kg of 6a-s were significantly higher than that of saline solution (NS), 6h had the strongest activity. The ELISA assay showed that 6a-s effectively decreased the serum P-selectin and GPIIb/IIIa level.Conclusion 6a-s can effectively inhibited PAF and ADP induced platelet aggregation in vitro, at 30 nmol/kg dose they significantly decreased the weight of thrombus and significantly increased the potential of dissolve the clots. Specially, 6h was particularly superior and could be a promising candidate for the afterward development. Additionally, the benefits of the 19 derivatives were associated with the serum level of P-selectin and GPIIb/IIIa.