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.

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).

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.

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