Essential oil chemical variability of Piper obliquum Ruiz & Pavan colected at the Cuniã Ecological Station, Porto Velho-Rondônia

Abstract

Seasonality is one of the factors that influence the secondary metabolism of plants, affecting the composition of essential oils. The Piperaceae family is ecologically and economically important, with Piper obliquum Ruiz & Pav. representative of that family. This species is called by the Yanomani Indians of Papiu as xama-hanaki. The plant was collected at the Cuniã Ecological Station, Porto Velho, Rondônia, in five periods of the year, covering the months of October, November 2011 and February, May and August 2012. The extraction of essential oil was carried out through hydrodistillation and material analysis was through gas chromatography associated with mass spectrometry. The components determined in were mostly from the terpene class, where the highest content was α-pinene, camphene and β-pinene. The hierarchical cluster analysis resulted in the formation of distinct groups for the samples in the months of October, November and August for the periods of February and May. Through Multiple Correspondence Analysis (MCA) and Principal Component Analysis (PCA) it was verified that some constituents did not show significant variations, but many substances showed a positive correlation concerning the period collected. Most compounds showed low composition regardless of the period collected. The chemical variation observed in the specimens obtained in different months corroborates the influence of the environment on the variation of the components of the secondary metabolism of plants.