Chemical Constituents from Licania cruegeriana and Their Cardiovascular and Antiplatelet Effects

Three new lupane-type triterpenoids: 6 beta,30-dihydroxybetulinic acid glucopyranosyl ester (4), 6 beta,30-dihydroxybetulinic acid (5) and 6 beta-hydroxybetulinic acid (6), were isolated from Licania cruegeriana Urb. along with six known compounds. Their structures were elucidated on the basis of spectroscopic methods, including IR, ESIMS, 1D- and 2D-NMR experiments, as well as by comparison of their spectral data with those of related compounds. All compounds were evaluated in vivo for their effects on the mean arterial blood pressure (MABP) and heart rate (HR) of spontaneously hypertensive rats (SHR) and also in vitro for their capacity to inhibit the human platelet aggregation. None of the isolated flavonoids 1-3 showed cardiovascular effects on SHR and among the isolated triterpenoids 4-9 only 5 and 6 produced a significant reduction in MABP (60.1% and 17.2%, respectively) and an elevation in HR (11.0% and 41.2%, respectively). Compounds 3, 4, 5 and 6 were able to inhibit human platelet aggregation induced by ADP, collagen and arachidonic acid with different selectivity profiles.