Antiplatelet Aggregation and Vasodilation Effects of RGDS

In an attempt to demonstrate the biological activities of a short peptide.Arg-Gly-Asp- Ser (RGDS) was synthesized and used for bioassay,The data obtained here proved that RGDS ob- viously inhibited PAF- and/or ADP-induced platelet aggregation.The present paper revealed that RG- DS had vasodilative action and the cGMP accumulation may be one of the mechanisms of RGDS exer- ting bioactivities.

Dissolvable polymeric microneedles loaded with aspirin for antiplatelet aggregation

To reduce mucosal damage in the gastrointestinal tract caused by aspirin,we developed a dissolvable polymeric microneedle(MN)patch loaded with aspirin.Biodegradable polymers provide mechanical strength to the MNs.The MN tips punctured the cuticle of the skin and dissolved when in contact with the subcutaneous tissue.The aspirin in the MN patch is delivered continuously through an array of micropores created by the punctures,providing a stable plasma concentration of aspirin.The factors affecting the stability of aspirin during MNs fabrication were comprehensively analyzed,and the hydrolysis rate of aspirin in the MNs was less than 2%.Compared to oral administration,MN administration not only had a smoother plasma concentration curve but also resulted in a lower effective dose of antiplatelet aggregation.Aspirin-loaded MNs were mildly irritating to the skin,causing only slight erythema on the skin and recovery within 24 h.In summary,aspirin-loaded MNs provide a new method to reduce gastrointestinal adverse effects in patients requiring aspirin regularly.

Comparison on Anticoagulation and Antiplatelet Aggregation Effects of Puerarin with Heparin Sodium and Tirofiban Hydrochloride: An In Vitro Study

Objective： To detect the anticoagulation and antiplatelet effects of different concentrations of puerarin, heparin sodium and tirofiban hydrochloride on the blood samples of healthy volunteers by Sonoclot coagulation and platelet function analyzer. Methods： Peripheral blood samples were extracted from 20 healthy volunteers, followed by adding different concentrations of puerarin, heparin sodium and tirofiban hydrochloride. Samples were detected for activated clotting time（ACT）, clot rate（CR） and platelet function（PF） by Sonoclot coagulation and platelet function analyzer instrument. Results： For puerarin and heparin sodium, the values of ACT gradually increased, and the values of CR and PF gradually decreased with increasing in drug concentration. There was a linear（or log linear） relationship between ACT, CR, PF value and drug concentration（P〈0.01）. Corresponding to each value, a regression equation was obtained. For tirofiban hydrochloride, the values of ACT and CR had no significant changes, while PF values gradually decreased with concentration increasing. There was also a linear relationship between PF values and concentrations of tirofiban hydrochloride（P〈0.01）. Under the same ACT values, the puerarin corresponding CR values（CR = e^（-0.0062） ACT＋4.31, P〈2.2 e^（-16）） were always higher than the corresponding values（CR = e-^（0.0028） ACT＋2.79, P-value〈2.2 e^（-16）） of heparin sodium. For high concentrations of puerarin（e.g. 3.8 mg/600 μL） and tirofiban hydrochloride（e.g. 0.8 μg/600 μL）, PF values had no significant difference. However, PF values for high puerarin concentration had a larger variance. Conclusions： Puerarin has similar anticoagulant and antiplatelet effects with the heparin sodium, and may have a lower hemorrhage risk than heparin sodium when obtained the same anticoagulation effect in the concentration range of this experiment. In addition, for high concentration, puerarin had the same antiplatelet function as tirofiban hydrochloride but with a larger individual variability.

Antiplatelet aggregation activity of some ferrocenylphenylimine compounds

Platelet hyper-aggregability triggered death and disability due to cardiovascular diseases is increasing worldwide and becoming a global concern. Therefore, it is necessary to synthesize newer drugs for the management of platelet aggregation. In this study, we investigated the antiplatelet aggregation activity of a novel series of ferrocenylimine compounds(3–10), N-(3-nitro-2-hydroxylbenzylidene)-3-ferrocenylimine(3), N-(3-bromo-2-hydroxylbenzylidene)-3-ferrocenylimine(4), N-(3-bromo-5-chlorosalicylidene)-3-ferrocenylimine(5), N-(ferrocenylformidene)-3-ferrocenylimine(6), N-(3-nitro-2-hydroxylbenzylidene)-4-ferrocenylimine(7), N-(3-bromo-2-hydroxylbenzylidene)-4-ferrocenylimine(8), N-(3-bromo-5-chlorosalicyl)-4-ferrocenylimine(9), N-(ferrocenylformidene)-4-ferrocenylimine(10) on thrombin-and ADP-induced platelet aggregation. The synthesized ferrocenylimine compounds(3–10) were found to exhibit higher antiplatelet aggregation activity than their precursors, which are 3-ferrocenylaniline(compound 1) and 4-ferrocenylaniline(compound 2). Among the derivatives, compounds 5, 6 and 10 possessed excellent platelet aggregation inhibition against the agonists.

Antiplatelet Aggregation Effects of YIGSK and RGD Containing Peptides

Antiplatelet aggregation effects of YIGSK, RGDS, RGDV, RGDF, YIGSKRGDS, YIGSKRGDV and YIGSKRGDF were observed. By comparing their activities it was found that by coupling YIGSK and RGD containing peptides the antiplatelet aggregation effects of some of the compounds may be enhanced.

Synthesis and activity evaluation of some novel derivatives of 4,5,6,7-tetrahydrothieno [3,2-c]-pyridine

Two series of novel derivatives of4,5,6,7-tetrahydrothieno [3,2-c]pyridine were synthesized and structurally characterized by 1^H NMR and MS. Their in vivo antiplatelet aggregation activities were evaluated.

Two new nonacosanetriols from the pollen of Typha angustifolia

Chemical investigation of the pollen of Typha angustifolia Linn.has led to the isolation of two new nonacosanetriols,7,8,10- nonacosanetriol(1) and 7,9,10-nonacosanetriol(2).Their structures were elucidated by chemical reaction and spectral analysis. Compounds 1 and 2 exhibited weak activity of antiplatelet aggregation in vitro.