Bioactive 12-oleanene triterpene and secotriterpene acids from Maytenus undata

The aerial parts of Maytenus undata yielded four new 12-oleanene and 3,4-se co-12-oleanene triterpene acids, namely, 3-oxo-11 alpha-methoxyolean-12-ene -30-oic acid (I), 3-oxo-lla-hydroxyolean-12-ene-30-oic acid (2), 3-oxo-olea n-9(11),12-diene-30-oic acid (3), and 3,4-seco-olean-4(23),12-diene-3,29-di oic acid (20-epi-koetjapic acid) (5), together with the known 3,11-dioxoole an-12-ene-30-oic acid (3-oxo-18 beta-glycyrrhetinic acid) (4), koetjapic ac id (6), and the 12-oleanene artifact 3-oxo-11 alpha-ethoxyolean-12-ene-30-o ic acid (7). Koetjapic acid (6) inhibited the growth of Staphylococcus aure us, methicillin-resistant S. aureus, and Pseudomonas aeruginosa, with an MI C range of 3.125-6.25 mu g/mL. The new 3,4-secotriterpene acid 20-epi-koetj apic acid (5) potently inhibited rat neonatal brain microglia phorbol ester -stimulated thromboxane B-2 (IC50 = 0.5 mu M) and superoxide anion (IC50 = 1.9 mu M) generation.