Triterpenoid Saponins from Stem Bark of Pentaclethra macroloba

Six new triterpenoid saponins from the root and stem bark of Cephalanthus occidentalis.

From the root and stem bark of Cephalanthus occidentalis L., a common American wetland species, six new triterpenoid saponins (1 - 6), together with 29 known compounds were isolated and identified. On the basis of spectroscopic analysis and chemical degradation, the structures of new compounds were elucidated as 3-O-beta-glucopyranosylcincholic acid (1), cincholic acid 28-O-beta-glucopyranosyl ...

The impact of Pentaclethra macroloba on soil microbial nitrogen fixing communities and nutrients within developing secondary forests in the Northern Zone of Costa Rica

In the current study, we showed that Pentaclethra macroloba appears to influence the microbial communities within the soil of secondary forests in the Northern Zone of Costa Rica. The soil closest to the Pentaclethra macroloba trees (“tree soil”) had a lower abundance of the N-fixing bacteria Frankia, but greater amounts of both nifH gene and Rhizobium than soils furthest away (“forest soils”)....

The Effects of the N-Fixing Tree Pentaclethra macroloba on the Above and Below Ground Communities Within a Primary Forest in the Northern Zone of Costa Rica

Seed Success of Pentaclethra Macroloba across Soil Types and Seed Densities

Seed dispersal and germination are critical to the fitness of all tree species. Moreover, among most trees the percentage of seeds that become seedlings, or “seedling success”, is very low. We examined seed success of a dominant lowland rainforest species, Pentaclethra macroloba, across a soil moisture gradient. Previous studies have established that P. macroloba has reduced seed germination ra...

Costs of Defense and a Test of the Carbon-Nutrient Balance and Growth-Differentiation Balance Hypotheses for Two Co-Occurring Classes of Plant Defense

One of the goals of chemical ecology is to assess costs of plant defenses. Intraspecific trade-offs between growth and defense are traditionally viewed in the context of the carbon-nutrient balance hypothesis (CNBH) and the growth-differentiation balance hypothesis (GDBH). Broadly, these hypotheses suggest that growth is limited by deficiencies in carbon or nitrogen while rates of photosynthesi...