Late Quaternary hydroclimate and vegetation changes in an upland lake in southeastern Amazonia.

An integrated approach considering facies, isotopic, and palynological analyses of lake sediments from the Serra Norte de Carajás, southeastern Amazonia, is presented in this work to refine paleoclimate and paleohydrological changes based on upland lake sediments during the late Quaternary. The sediments have a fining-upward deposition cycle typical of upland swamps/lakes. The origin of organic matter is autochthonous mainly related to C3 terrestrial plants, macrophytes and algae.

Essential oils composition of croton species from the Amazon.

The essential oils of leaves and twigs from the Euphorbiaceous Croton draconoides, C. urucurana and Julocroton triqueter were obtained and analyzed by GC and GC-MS. In total, 101 volatile constituents were identified, comprising an average of 90% of the oil, mostly made up of mono- and sesquiterpenes.

Antioxidant capacity and larvicidal and antifungal activities of essential oils and extracts from Piper krukoffii.

The leaves and twigs of Piper krukoffii, collected in the Carajás National Forest, north Brazil, yielded essential oils (2.0% and 0.8%), the main constituents of which were myristicin (40.

Essential oil composition and antioxidant capacity of Lippia schomburgkiana.

The leaves and fine stems of Lippia schomburgkiana recorded an essential yield of 1.8%, the main constituents of which were 1,8-cineole (64.1%) and alpha-terpineol (12.