39 Chemical Diversity of Essential Oils of 15 Piper Species from Guatemala S.M. Cruz, A. Cáceres and L.E. Álvarez M.A. Apel and A.T. Henriques Facultad de CCQQ y Farmacia Universidad de San Carlos Guetemala Guatemala Facultade de Farmácia Universidad Federal Rio Grande do Sul Porto Alegre Brasil Keywords: aromatic plants, biodiversity, chemical composition, gas chromatography, potential aroma Abstract Piper is a genus of high botanical, chemical, and pharmacological complexity. In this study, 15 species were collected and identified from two areas of the country, eight from the northern region (P. donnell-smithii, P. fallens, P. geniculatum, P. phytolaccifolium, P. psilorhachis, P. schippianum, P. sempervirens and P. variabile), and seven from the southern region (Piper amalago, P. jaquemontianum, P. oradendron, P. patulum, P. retalhuleuense, P. hispidum and P. umbellatum). From the sample, 10 species are native to Mesoamerica and the others are common to most of Latin America. Essential oils (EO) were obtained by hydrodistillation and analyzed by gas chromatography. Very high chemical diversity was demonstrated among the 15 EOs. The number of detected peaks varied from 58 (P. oradendron) to 11 (P. retahuleuense). -caryophyllene was common to 15 oils (16.8-0.2%), -pinene to 13 (20.5-0.2%), α-pinene to 12 (9.3-0.2%), germacrene D to 11 (18.4-0.7%), and 10 to caryophyllene oxide (27.0-1.2%), α-copaene (2.7-0.5%), -elemene (8.0-0.2%) and -cadinene (8.5-0.1%). In some instances, the EO contained an abundant metabolite, being the only one with this component, such as P. jacquemontianum (linalool 70.8%), P. amalago (nerolidol, 48.7%), P. patulum (1,3,5-trimethoxy-2- propenylbenzene, 33.7%, methyl eugenol, 24.6%), P. variabile (camphor, 29.7%), P. sempervirens (bicyclogermacrene, 28.5%), P. retalhuleuense (nerolidol, 28.2%), and P. schippianum (dihydroaromadendrene, 22.1%). The high diversity of EO composition from genus Piper was confirmed, as well as the possibility for agronomical development of some of the species due to the commercial potential of some of their components, such as linalool and nerolidol. INTRODUCTION The genus Piper belongs to the Piperaceae family and has over 700 species distributed in both hemispheres. Piper species are represented by herbs, shrubs and trees and are widely distributed in the tropical and subtropical regions of the world. Some Piper species are used in folk medicine to treat various diseases (Cronquist, 1981; Parmar et al., 1997; Takhtajan, 1997). People throughout the tropics use Piper for many purposes, such as food, ornamentals, spices, perfumes, oils, fish bait, fish poison, insecticides, hallucinogens, and many medicinal uses (Barrett, 1994; Joly, 1993; Schultes and Raffauf, 1990). The Piper species have many commercial, economical, and medicinal uses; economically, the Piperaceae is important for pepper in the worldwide spice markets and for the wide biological activity found within the family (Ahmad et al., 2012). Several chemical and biological investigations have been done to research the medicinal interest of plants in this family (Mundina et al., 1998). Many Piper species are aromatic and consequently the chemical composition of the EOs of several of them has been the subject of various studies. These studies have revealed a diverse range of volatile components, including monoterpenes, sesquiterpenes, arylpropanoids, aldehydes, ketones, and long chain alcohols (Cysne et al., 2005). Despite the commercial and medicinal importance of Piper, the genus has received only limited scientific attention. This genus has primarily been investigated in Asia, the Indian species have been particularly well analyzed (such as P. nigrum, Proc. IS on Medicinal and Aromatic Plants – IMAPS 2010 and “History of Mayan Ethnopharmacology” – IMAPS 2011 Eds.: J. Ghaemghami et al. Acta Hort. 964, ISHS 2012