Mechanism Study of Endothelial Protection and Inhibits Platelet Activation of Low Molecular Weight Fucoidan from Laminaria japonica

Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline(0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. v WF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce v WF level in vascular endothelial injury rats and also significantly reduce v WF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and v WF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.

Hawanoids A–E, unprecedented diterpenoids with PAF-induced platelet aggregation inhibitory activities from the deep-sea-derived fungus Paraconiothyrium hawaiiense

Hawanoids A–E(1–5), five highly cyclized diterpenoids were isolated from the deep-sea-derived fungus Paraconiothyrium hawaiiense FS482. Compounds 1 and 2 possessed an unprecedented tetracyclo[6.6.2.0^(2,7).0^(11,15)]cetane carbon skeleton while 3 and 4 possessed an unusual 11,14-macrocyclic ether moiety in phomactin family. Their structures including the stereo-chemistry were determined through spectroscopic analysis, X-ray diffractions and computational calculations. The plausible biosynthetic pathway was proposed based on the predicted biosynthetic gene cluster. All of the isolated compounds exhibited inhibitory activities against PAF-induced platelet aggregation. The molecular docking study was carried out understand the interaction between the PAF receptor and hawanoids with different skeletons.

Ring-restricted N-nitrosated rhodamine as a green-light triggered,orange-emission calibrated and fast-releasing nitric oxide donor

Nitric oxide（NO） donors are versatile tools for nitric oxide biology. The biological response of NO is dependent on the transient concentration and the sustained duration. N-Nitrosated rhodamines are photo-triggered and photo-calibrated NO donors. We recently discovered that suppression of the dihedral angle between the N-nitroso fragment with the rhodamine scaffold facilitates NO release.Inspired by this discovery, we developed a fast-releasing NO donor （NOD575） suitable for biological applications, e.g., the pulmonary arterial smooth muscle cells（PASMCs）.