Anti-platelet pentacyclic triterpenoids from leaves of Campsis grandiflora.

Five pentacyclic triterpenoids, oleanolic acid (1), hederagenin (2), ursolic acid (3), tormentic acid (4) and myrianthic acid (5), were isolated from the methanol extract of the leaves of Campsis grandiflora, and structures of the compounds were established by the spectroscopic methods. Compounds 2, 3, 4, and 5 were isolated for the first time from the genus Campsis. All of the compounds (IC50: 45.3, 32.8, 82.6, 42.9 and 46.2 microM respectively) were as equivalently inhibitive as acetylsalicylic acid (IC50: 57.0 microM) on epinephrine induced platelet aggregation.

The effect of dissolved oxygen on the 1,4-dioxane degradation with TiO2 and Au-TiO2 photocatalysts.

In order to enhance the photocatalytic activity of TiO(2), the recombination of photogenerated electron-hole pairs needs to be suppressed. Noble metals, e.g. Au nanoparticles, have been incorporated with TiO(2) to efficiently separate charge carriers created in/on TiO(2). On the other hand, dissolved oxygen (DO) in an aqueous solution was also known to scavenge the electrons, which avoid the recombination of electrons and holes. In this study, we investigated the combined system of Au nanoparticles incorporated with TiO(2) and DO to gain insight into the relationship between them using a photocatalytic degradation of 1,4-dioxane. The rate constants of 1,4-dioxane photodegradation with respect to TiO(2) catalysts with three different Au loadings, as well as DO levels, indicated the DO dependency is disproportional to the Au loading amount, implying that there is an overlapping function in capturing electrons between Au nanoparticles and DO.

Reduced GPIIb/IIIa expression in platelets hyposensitive to catecholamines when activated with TRAP.

INTRODUCTION: A previous report assigned 35 healthy Koreans into five groups (groups A to E) based on their platelet responsiveness to catecholamines (CA). The present work aimed to elucidate the possible mechanism of heterogeneous responsiveness to CA in normal subjects. MATERIALS AND METHODS: The degrees of aggregation in platelet rich plasma (PRP) were measured with a turbidimetric method. The expression of platelet glycoprotein and activation maker was analyzed with flow cytometric method in whole blood. RESULTS AND CONCLUSIONS: The degrees of aggregation in response to other aggregation inducing agents (AA, ADP, and U46619) were significantly lower in platelets hyporesponsive to CA. The flow cytometric analysis showed that GPIIb, GPIIIa and GPIIb/IIIa expressions were 20.1%, 25.7%, and 38.2%, respectively, higher in the CA-responsive group than in the CA-hyporesponsive group when the groups were in a TRAP activated state, while no differences were observed between the two groups when in a resting state.

Two new non-glycosidic iridoids from the leaves of Campsis grandiflora.

Two new non-glycosidic iridoids, which were named cachinol (1) and 1-O-methyl cachinol (2), were isolated from the methanol extract of the leaves of Campsis grandiflora together with a known iridoid cachineside I (3). The structures of compounds 1 and 2 were determined on the basis of spectroscopic methods including two dimensional NMR and high resolution mass spectrometry. All of the isolated compounds showed mild inhibitory activities on rat platelet aggregation. Compounds 1 and 3 (IC50 : 246 and 219 microM, respectively) showed about 2-fold higher inhibitory effects than acetylsalicylic acid (ASA, IC50: 412 microM) on collagen-induced aggregation. Compounds 1 and 2 (IC50: 43.2 and 38.4 microM, respectively) were about 2-fold more inhibitory than ASA (IC50: 75.2 microM), and about 4-fold more effective than their glycoside 3 (IC50: 189 microM) on AA-induced aggregation.

Platelet anti-aggregating triterpenoids from the leaves of Acanthopanax senticosus and the fruits of A. sessiliflorus.

Six triterpenoids, chiisanogenin, chiisanoside, ursolic acid, oleanolic acid, beta-sitosterol and daucosterol, were isolated as the platelet anti-aggregating components from the leaves of Acanthopanax senticosus and the fruits of A. sessiliflorus. Chiisanogenin showed about 50-fold higher potency than acetylsalicylic acid (ASA) on U46619-induced platelet aggregation (IC50o:6.21 microM) and 10-20-fold higher effects than ASA on epinephrine- and arachidonic acid (AA)-induced aggregation (IC50:2.50 and 4.81 microM, respectively).