Resumen Dahlia es un género de plantas floríferas que consta de 35 a 40 especies, distribuidas principalmente en Mesoamérica. El objetivo de este trabajo fue determinar la composición química de los aceites esenciales de hojuelas e inflorescencias de D. imperialis creciendo silvestre en Costa Rica. La extracción del aceite se efectuó por hidrodestilación con un equipo Clevenger modificado. La composición química del aceite se analizó mediante las técnicas de cromatografía gaseoso-líquida con detector de ionización de llama (GC-FID) y de cromatografía gaseoso-líquida acoplada a un detector selectivo de masas (GC-MS). Se utilizaron índices de retención obtenidos en una columna capilar tipo DB-5 y se compararon con los patrones de fragmentación de masas. Se identificaron en total 131 compuestos, correspondientes a 96.5-99.3 % de los constituyentes totales. Los componentes mayoritarios del aceite de los foliolos fueron β-pineno (35.2 %), α-felandreno (21.9 %), α-pineno (18.0 %), p-cimeno (8.3 %), limoneno (4.3 %) y γ-muuroleno (3.9 %). Los componentes mayoritarios del aceite de los capítulos florales fueron β-pineno (27.7 %), α-felandreno (26.2 %), α-pineno (12.4 %), β-felandreno (6.6 %), limoneno (5.6 %), (E)-β-ocimeno (2.9 %) y germacreno D (2.2 %). Este es el primer informe acerca de la composición química de aceites esenciales de D. imperialis.

Abstract Dahlia is a genus of flowering plants of about 35 to 40 species, distributed mainly in Mesoamerica. The aim of this work was to study the chemical composition of the leaflet and capitulum essential oils of D. imperialis growing wild in Costa Rica. The essential oils were obtained by hydrodistillation in a modified Clevenger apparatus. The chemical composition of the oils was performed by capillary gas chromatography with a flame detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) using the retention indices on a DB-5 type capillary column in addition to mass spectral fragmentation patterns. A total of 131 compounds were identified, accounting for 96.5-99.3 % of the total amount of the oils. The major constituents in the leaflet oil were β-pinene (35.2 %), α-phellandrene (21.9 %), α-pinene (18.0 %), p-cymene (8.3 %), limonene (4.3 %) and γ-muurolene (3.9 %). The major constituents in the capitulum (flower head) oil were β-pinene (27.7 %), α-phellandrene (26.2 %), α-pinene (12.4 %), β-phellandrene (6.6 %), limonene (5.6 %), (E)-β-ocimene (2.9 %), and germacrene D (2.2 %). This is the first report about the chemical composition of essential oils from D. imperialis.

Resumen Baccharis (Asteraceae) es un género de plantas con flor que consta de 340 a 400 especies que habitan desde el sur de EE. UU. hasta Argentina y Chile, incluyendo América Central y varias islas del Caribe. Baccharis trinervis es un arbusto nativo de México, América Central y América del Sur. En Costa Rica, esta especie se conoce popularmente como alcotán y las hojas frescas se utilizan en forma de cataplasma para curar heridas y úlceras. El objetivo del presente estudio fue el de identificar los constituyentes químicos de los aceites esenciales obtenidos de diferentes partes morfológicas de B. trinervis en tres localidades de Costa Rica, obtenidos mediante el método de hidrodestilación. Se analizó la composición química de los aceites por cromatografía capilar de gases con detector de ionización de flama (GCFID) y cromatografía de gases acoplada a un detector de masas (GC-MS), utilizando los índices de retención en una columna tipo DB-5 y los patrones de fragmentación, lo cual permitió la identificación de 268 constituyentes. Los siete aceites están constituidos principalmente por terpenoides (92.3 a 97.8 %). Los compuestos mayoritarios de los aceites de las hojas se identificaron como óxido de cariofileno (0.1-22.5 %), viridiflorol (8.8-21.0 %), germacreno D (0.5-19.1 %), germacreno B (0.2-16.0 %), β-cariofileno (3.5-9.1 %), espatulenol (0.1-8.3 %), δ-3-careno (2.06.8 %), α-pineno (2.5-5.9 %), biciclogermacreno (0-4.4 %), δ-cadineno (0.8-3.4 %), β-elemeno (0.8-3.0 %), limoneno (0.9-2.9 %) y β-pineno (1.3-2.5 %). Los aceites de las flores contienen principalmente globulol (0-24 %), β-cariofileno (9.5-17.1 %), cis-muurola-4(14),5-dieno (t-13.7 %), germacreno D (4.3-9.9 %), biciclogermacreno (5.9-8.3 %), ar-curcumeno (0-8.0 %), espatulenol (4.3-4.8 %), óxido de cariofileno (3.1-4.7 %), viridiflorol (0.3-4.7 %), β-elemeno (2.5-4.3 %), germacreno B (1.8-4.3 %), γ-cadineno (0.32.5 %), δ-3-careno (0.9-2.2 %) y α-humuleno (1.8-2.2 %). Los constituyentes mayoritarios del aceite de las ramitas fueron: germacreno B (1.4-18.7 %), germacreno D (14.7-15.6 %), β-cariofileno (10.1-12.4 %), viridiflorol (0-11.5 %), globulol (0.6-11.3 %), δ-3-careno (4.1-8.1 %), β-felandreno (1.5-6.5 %), biciclogermacreno (3.6-4.9 %), δ-cadineno (3.5-4.3 %), β-copaeno (0.6-2.8 %), β-elemeno (1.3-2.7 %) y γ- muuroleno (1.6-2.6 %). Los aceites estudiados presentan una composición compleja y se diferencian de los aceites obtenidos de la misma especie que crece en Brasil por la ausencia de los compuestos isoméricos diacetilénicos dec-2-en-4,6-diinoato de metilo(Z y E). También se diferencian de los aceites de las plantas de Brasil y Venezuela por la presencia de sesquiterpenoides de la familia de los guayanos, en especial por cantidades apreciables de viridiflorol, globulol y espatulenol.

Abstract Baccharis is an Asteraceae genus of flowering plants, which has about 340 to 400 species, ranging from the Southern United States to the Southern extreme of Argentina and Chile through Central America and the Caribbean regions. The species Baccharis trinervis is a native shrub from Mexico, Central America and throughout South America. In Costa Rica, this species is commonly known as alcotán and the fresh leaves are used as a poultice on wounds and ulcers. The objective of the present research was to characterize the chemical composition of seven hydrodistilled essential oils of diverse morphological parts of B. trinervis. For this, samples were obtained from three locations in Costa Rica and standard laboratory analyses were followed. The essential oils were analyzed by capillary gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) using the retention indices on a 5 % phenyl/dimethylpolysiloxane fused silica column in addition to mass spectral fragmentation patterns, which allowed the identification of 268 compounds. The essential oils consisted mainly of terpenoids (92.3 to 97.8 %). The major constituents from the leaf oils were caryophyllene oxide (0.1-22.5 %), viridiflorol (8.8-21.0 %), germacrene D (0.5-19.1 %), germacrene B (0.2-16.0 %), β-caryophyllene (3.5-9.1 %), spathulenol (0.1-8.3 %), δ-3-carene (2.0-6.8 %), and α-pinene (2.5-5.9 %). The flower oil consisted mainly of globulol (0-24 %), β-caryophyllene (9.5-17.1 %), cismuurola-4(14), 5-diene (traces-13.7 %), germacrene D (4.3-9.9 %), bicyclogermacrene (5.9-8.3 %), ar-curcumene (0-8.0 %), spathulenol (4.3-4.8 %), caryophyllene oxide (3.1-4.7 %), and viridiflorol (0.3-4.7 %). The major components of the branch oil were germacrene B (1.4-18.7 %), germacrene D (14.7-15.6 %), β-caryophyllene (10.1-12.4 %), viridiflorol (0-11.5 %), globulol (0.6-11.3 %), δ-3-carene (4.1-8.1 %), β-phellandrene (1.5-6.5 %), and bicyclogermacrene (3.6-4.9 %). The essential oil composition differed markedly from that of previously studied oils of plants growing in Brazil, which contain two characteristic stereoisomeric methyl dec-2-en4,6-diynoate compounds not detected in this study. This is the first report about the chemical composition of the essential oils obtained from this species growing wild in Costa Rica.

Pimenta es un género de plantas perteneciente a la familia Myrtaceae que contiene cerca de 15 especies, la mayoría ubicadas en las regiones del Caribe del Continente Americano, donde es utilizado con propósitos culinarios y medicinales. Las especies comerciales mejor conocidas son “pimienta de Jamaica” (P. dioica o P. officinalis) y “bay-rum” (P. racemosa) y existe muy poca información científica acerca de la especie P. guatemalensis. Cuando las hojas y frutos son triturados, desprenden un aroma de composición desconocida. El objetivo del presente estudio fue identificar la composición química de los aceites esenciales de las hojas y frutos de P. guatemalensis. La extracción de los aceites esenciales de P. guatemalensis, una especie arbórea silvestre en Costa Rica, se efectuó mediante el método de hidrodestilación a presión atmosférica, empleando un aparato de vidrio de tipo Clevenger. Se analizó la composición química de los aceites esenciales mediante cromatografía de gases con detector de ionización de flama (GC/FID) y cromatografía de gases acoplada a un detector de masas (GC/MS) y, utilizando índices de retención en una columna cromatográfica capilar tipo DB-5. En los aceites de hojas se identificaron 103 y en los de frutos 63 compuestos, correspondiendo a 96.8% y 86.1%, respectivamente, de los constituyentes totales. El aceite de las hojas está constituido principalmente por compuestos de naturaleza fenilpropanoide (72.9%) y de hidrocarburos monoterpénicos y sesquiterpénicos (18.2%). Los componentes mayoritarios del aceite de las hojas se identificaron como eugenol (72.8%), β-cariofileno (8.2%) y terpinoleno (3.0%). El aceite de los frutos está constituido principalmente por eugenol (74.7%), monoterpenos y sesquiterpenos oxigenados (7.3%) principalmente óxido de cariofileno (3.3%). Este es el primer informe acerca de la composición química de aceites esenciales obtenidos a partir de esta especie vegetal.

Pimenta is a genus of flowering plants in the Myrtaceae family, which has about 15 species, mostly found in the Caribbean region of the Americas. Commonly used for culinary and medicinal purposes, the best known commercial species are allspice, P. dioica (P. officinalis) and bay rum, P. racemosa, but there is little information concerning P. guatemalensis. The aim of the present study was to identify the chemical composition of the leaf and fruit essential oils of P. guatemalensis. The extraction of essential oils of P. guatemalensis growing wild in Costa Rica was carried out by the hydrodistillation method at atmospheric pressure, using a modified Clevenger type apparatus. The chemical composition of the oils was analyzed by capillary gas chromatographyflame ionization detector (GC/FID) and gas chromatography-mass spectrometry (GC/MS) using the retention indices on DB-5 type capillary column. A total of 103 and 63 compounds were identified in the leaf and fruit oils, respectively, corresponding to 96.8% and 86.1% of the total amount of the oils. The leaf oil consisted mainly of eugenol (72.8%), and mono- and sesquiterpene hydrocarbons (18.2%). Among terpenes the major components were β-caryophyllene (8.2%) and terpinolene (3.0%). The fruit oil also consisted mainly of eugenol (74.7%) and minor amounts of oxygenated mono- and sesquiterpenes (7.3%), mainly caryophyllene oxide (3.3%). This is the first report of the chemical composition of the essential oils obtained from this plant species. Rev. Biol. Trop. 63 (1): 303-311. Epub 2015 March 01.

En este artículo se presentan algunas pinceladas acerca de la importancia de la química, la ciencia y la tecnología en la vida diaria y en el desarrollo de la sociedad actual. Desde el punto de vista histórico y, tomando en consideración que la química es la ciencia de la materia y su transformación, se describen algunas concepciones acerca de la naturaleza de la materia y sus cambios, que fueron desarrolladas principalmente en la época arcaica y a inicios de la época clásica de Grecia.

In this paper, we present some brushstrokes about the importance of chemistry, science, and technology, in everyday life, and in the development of modern society. From a historic point of view, we describe some ideas about the nature of matter and its changes that were developed primarily in the archaic period and early classical times of Greece.

A composição química dos óleos essenciais obtidos de folhas, cascas e troncos de Ocotea gomezii e O. morae de populações silvestres da Costa Rica, está sendo descrita pela primeira vez. Os óleos de O. gomezii são constituídos principalmente por sesquiterpenóides enquanto os de O. morae apresentaram mono- e sesquiterpenóides na mesma proporção. A análise da composição química por CG/EM e CG/DIC resultou na identificação de 166 componentes, correspondente a 89,4-98,1% dos óleos totais. Quando comparada a atividade de todos os óleos obtidos sobre linhagens de células CCF-STTG1, Hep3B, HepG2, H-460, AGS, N-87, SW-620, MCF-7 e VERO, observou-se que as células de astrocitoma foram as mais resistentes aos mesmos. Concluiu-se que os óleos essenciais de folhas, cascas e tronco de Ocotea gomezii e Ocotea morae podem conter alguns compostos tóxicos, mas o uso potencial dos mesmos contra as células tumorais foi muito baixo, pois são tóxicos na mesma extensão, para as linhagens de células tumorais e não-tumorais.

The chemical composition of the essential oils of the leaves, bark and wood of Ocotea gomezii and O. morae from Costa Rica, were analyzed by capillary GC-FID and GC-MS. The oils of O. gomezii were predominantly composed by sesquiterpenoids whereas the oils of O. morae had both monoterpenoids and sesquiterpenoids. Analysis by GC/MS and GC/FID resulted in the identification of 166 compounds, representing about 89.4"98.1% of the total oils. When we compared the effect of the oils on cell lines (CCF-STTG1, Hep3B, HepG2, H-460, AGS, N-87, SW-620 and MCF-7 and VERO), we found that astrocytoma cells were the most resistant ones. We conclude that the essential oils of Ocotea gomezii and Ocotea morae could have some toxic compounds, but the potential use of them against the tumor cells would be very low, since they could be toxic to tumor and non-tumor cells in the same extent.

The chemical composition of the volatiles of Nectandra salicina growing wild in Costa Rica was determined by capillary GC/FID and GC/MS. Thirty-seven and forty-two compounds were identified in the leaf and branch oils respectively corresponding to about 92.6 and 86.2% of the total amount of the oils. The major components of the leaf oil were: atractylone (14.6%), viridiflorene (10.1%), α-pinene (9.4%), β-caryophyllene (7.2%), α-humulene (7.0%), δ-cadinene (6.1%), β-pinene (6.0%) and germacrene D (5.8%). The major components of the branch oil were: atractylone (21.1%), germacrene D (10.7%), viridiflorene (7.9%) and 7-epi-α-selinene (5.0%). When the oils were tested on different cell lines, all the LD50 values were higher than 150 µg/mL, with values very similar for the leaf and branch oils. Low toxicity could be explained by antagonistic effects among the main compounds present in the oils.

The composition of the leaf, bark and wood oils of Povedadaphne quadriporata W. Burger from Costa Rica were analyzed by capillary GC/FID and GC/MS. One hundred and sixty-three compounds were identified. The major components from the leaf oil were a-pinene (21.2%), germacrene D (18.1%), b-pinene (14.8%), a-phellandrene (7.8%), a-copaene (6.6%), b-caryophyllene (6.1%) and d-cadinene (3.5%). From bark oil, the main constituents were a-pinene (27.7%), p-cymene (7.8%), b-pinene (7.4%), camphene (3.6%), a-copaene (3.5%) and limonene (3.3%). From wood oil, 1,10-di-epi-cubenol (8.0%), a-eudesmol (3.4%), cadalene (3.4%) and d-cadinene (3.0%) were the major compounds identified. This paper describes for the first time the composition of essential oils in this unique species and genus.

Se determinó la composición química de los aceites esenciales obtenidos de las hojas y de la madera del árbol Ocotea brenesii Standl., perteneciente a la familia Lauraceae, que crece en forma silvestre en Costa Rica. Para el estudio se utilizaron técnicas de cromatografía de gases capilar con detector de ionización de flama (GC/FID) y cromatografía de gases capilar acoplada a un detector de espectrometría de masas (GC/MS). Del aceite volátil de las hojas fueron identificados 64 constituyentes, que correspondieron a un 85.9% del aceite. Del aceite de la madera se identificaron 57 compuestos que correspondieron a un 69.0% del aceite. Los constituyentes mayoritarios que se identificaron en el aceite de las hojas fueron α -copaeno (21.1%), δ -cadineno (9.2%), espatulenol (7.3%), globulol (5.6%) y β -cariofileno (5.2%). Los constituyentes mayoritarios del aceite de la madera fueron α -copaeno (6.6%), σxido de cariofileno (6.3%), β -cariofileno (6.1%) y el epσxido del humuleno (4.6%). La composiciσn de los aceites es de naturaleza terpιnica y no presentaron compuestos del tipo fenilpropanoide o bencenoide que son constituyentes característicos de la mayoría de los aceites de plantas del género Ocotea investigados anteriormente.

The chemical composition of the essential oils from leaves and wood of Ocotea brenesii Standl. growing wild in Costa Rica was determined by capillary GC/FID and GC/MS. From the leaves, 4 compounds were identified, corresponding to 85.9% of the oil, and from the wood 57 compounds were identified corresponding to 69.0% of the oil. The major constituents identified in the leaf oil were α -copaene (21.1%), δ -cadinene (9.2%), spathulenol (7.3%), globulol (5.6%) and β -caryophyllene (5.2%). The major constituents of the wood oil were α -copaene (6.6%), caryophyllene oxide (6.3%), β -caryophyllene (6.1%) and humulene epoxide (4.6%). Rev. Biol. Trop. 53(3-4): 431-436. Epub 2005 Oct 3.

Los aceites esenciales extraídos de las partes aéreas de la planta Tagetes lucida Cav.cultivada en Costa Rica y utilizada como condimento,fue estudiado mediante la técnica de GC/MS en combinación con los índices de retención.Se identificaron treinta compuestos.El componente mayoritario resultó ser metil chavicol (estragol)en un 95-97%.En el aceite de las flores se detectaron e identificaron dos compuestos minoritarios que resultaron ser bitienilos no informados anteriormente como constituyentes de esta planta.

The plant Tagetes lucida Cav.(syn.T.florida Sweet,T.schiedeana Less.)is an aromatic herb distributed naturally from Mexico to Honduras,at elevations between 1 000 and 2 000 m.It is used as a spice,for medicine,as insecticide and as ornamental plant.It is cultivated commercially in Costa Rica as a spice herb;it contains an oil having an anise-like odor,and the fresh aerial parts of this plant are sold in the supermarket as a substitute of tarragon (Artemisia dracunculus L.).The essential oils isolated from aerial parts bought,at May and October,in a supermarket in San José (Costa Rica).Fresh flowering aerial parts,flowers and leaves plus stems, were subjected to hydrodistillation for 3 hr using a modified Clevenger-type apparatus.The distilled oils were collected and dried over anhydrous sodium sulphate and stored in a freezer (0-10 °C).The light yellow green oil yield was about 0.07%(v/w).GC/MS analyses were performed using a Shimadzu GCMS-QP5050 apparatus and CLASS 5000 software with Wiley 139 computer database.Identification of the components of the oil was performed using the retention indices,which were calculated in relation to a homologous series of hydrocarbons, and by comparison of their mass spectra with those published in the literature or those of our own database. Thirty compounds were identified,of which methyl chavicol (95-97%)was the major constituent.From flower oil,two bithienyls were detected as minor constituents. Rev. Biol. Trop. 52(4):853-857.Epub 2005 Jun 24.

Se estudiaron el extracto acuoso y el aceite esencial de Satureja viminea . Los efectos fisiológicos generales se comprobaron por medio del ensayo hipocrático o tamizaje farmacológico en ratas Sprague Dawley. En ratones albinos se midieron la actividad exploratoria y la curiosidad por medio del ensayo de la placa perforada. Se utilizó el ensayo de la chimenea de Boissier para evaluar la coordinación motora y la fuerza muscular se comprobó con el ensayo del alambre. La actividad analgésica se exploró en ratas Sprague Dawley por medio del ensayo de calor sobre la cola (tail flick) descrito por D’Amour y Smith (1941) y modificado por CYTED. La actividad sobre la motilidad intestinal se investigó con el ensayo del tránsito intestinal sobre ratones albinos. También se determinó la dosis letal 50 (DL 50) con el método de Spearman- Karber. Se observó una disminución de la actividad motora espontánea la cual fue relacionada a la dosis. La actividad exploratoria y la curiosidad disminuyeron. La fuerza muscular de los ratones disminuyó. Se observó un claro y significativo efecto analgésico con la administración oral del aceite esencial de S. viminea (1000 mg/kg) comparado al observado con indometacina. El aceite esencial inhibió el tránsito intestinal y el vaciamiento gástrico. La DL 50 del aceite esencial de S. viminea es de 556.8 mg /kg.

The aqueous extract and the essential oil of Satureja viminea (Lamiaceae) were tested. General physiologic effects were assessed through the Hippocratic screening test. Non fasted female Sprague Dawley rats were utilized and 250, 500, 750 and 1000 mg/kg doses were used. Two animals were used for each dosage level and for the vehicle alone. Exploratory behavior and curiosity were measured using a hole board apparatus and placing non-trained mice on the board and recording the number of holes explored in a 5 minute period. The Boissier chimney test was used to evaluate motor coordination. Muscle strength was assessed through a grasping test where mice were hung by their fore-limbs 40 cm above the base on a horizontal metal stainless bar. In all these tests, 3 groups of 6 albino mice, were treated with 1000 mg/kg of each the essential oil of S. viminea, the vehicle and diazepan (1 mg/kg) as a positive control. Analgesic activity was explored in Sprague-Dawley rats. The tail flick method described by D`Amour and Smith (1941) modified by CYTED was implemented on three groups (6 rats each) of animals treated with, each the essential oil of S. viminea (1000 mg/kg), the vehicle and indomethacine. The test was carried out just before and 30, 60 and 120 min after oral treatment. Peristaltic activity was measured in albino mice, three groups of 6 animals each, treated orally with each the essential oil of S. viminea (1000 mg/kg), the aqueous extract (1000 mg/kg), and the vehicle. The marker used was activated carbon. Animals were sacrificed 30 min after the marker was given and the percent of total small intestine traversed by it was calculated. Also a lethal dose 50 (LD 50) was determined with the Spearman-Karber method. A dose-related spontaneous motor activity reduction was observed. Exploratory behavior and curiosity were diminished. The grasping strength of mice was reduced. A very clear and significant analgesic effect was observed with the oral administration of the essential oil of S. viminea (1000 mg/kg). This effect is compared to that of indomethacine. Intestinal transit and gastric emptying were inhibited by the essential oil. The LD50 of the essential oil of S. viminea is 556.8 mg/kg.

La composición química del aceite esencial de las hojas de Siparuna thecaphora (Poepp. et Endl.) A. DC., recolectada en Turrialba, Costa Rica, se estudió mediante la técnica de cromatografía capilar gaseoso-líquida, acoplada a un espectrómetro de masas (GC/MS). Se identificaron 76 compuestos que correspondieron a cerca del 95% del aceite. Los componentes mayoritarios fueron germacreno D (32.7%) α -pineno (16.3%), β -pineno (13.8%) y β -cariofileno (4.1%). Dentro de los compuestos minoritarios, treinta y uno se describen por primera vez como constituyentes de este género de plantas.

The composition of the essential oil from leaves of Siparuna thecaphora (Poepp. et Endl.) A. DC. collected in Turrialba, Costa Rica, was determined by capillary GC/MS. Seventy-six compounds were identified corresponding to ca. 95% of the oil. The major components were germacrene D (32.7%), α-pinene (16.3%), β - pinene (13.8%) and β -caryophyllene (4.1%). Thirty-one minor compounds were identified for the first time in this genus of plants.

Se estudiaron los constituyentes del aceite esencial de las partes aéreas de Lepechinia schiedeana (Lamiaceae) mediante el uso de cromatografía de gases (GC) y cromatografía de gases acoplada a espectrometría de masas (GC-MS). Se caracterizaron 51 compuestos (que representan ca. del 93% del aceite). El aceite se caracteriza por la presencia de gran cantidad de hidrocarburos monoterpénicos (45.9%) y de monoterpenos oxigenados (39.7%). Los componentes mayoritarios fueron <IMG SRC="http:/img/fbpe/rbt/v47n3/beta_pña.JPG" WIDTH=9 HEIGHT=16>-pineno (26.6%), cis -pinocanfona (25.1%), <IMG SRC="http:/img/fbpe/rbt/v47n3/de.JPG" WIDTH=9 HEIGHT=14>-3-careno (6.1%), trans -pinocanfona (4.0%), alcanfor (3.8%) y <IMG SRC="http:/img/fbpe/rbt/v47n3/beta_pña.JPG" WIDTH=9 HEIGHT=16>-cariofileno (3.7%).

The composition of the essential oil isolated by steam distillation from aerial parts of the Costa Rican herb Lepechinia schiedeana (Schlecht) Vatke (Lamiaceae) collected in El Empalme, Costa Rica, was determined by capillary gas chromatography (GC) and coupled gas chromatography-mass spectrometry (GC-MS) analyses. Fifty-one components were identified corresponding ca. 93% of the oil. The major components were <IMG SRC="http:/img/fbpe/rbt/v47n3/http:/img/fbpe/rbt/v47n3/beta_pña.JPG" WIDTH=9 HEIGHT=16>-pinene (26.6%), cis -pinocamphone (25.1%), <IMG SRC="http:/img/fbpe/rbt/v47n3/http:/img/fbpe/rbt/v47n3/de.JPG" WIDTH=9 HEIGHT=14>-3-carene (6.1%), trans -pinocamphone (4.0%), camphor (3.8%) and <IMG SRC="http:/img/fbpe/rbt/v47n3/http:/img/fbpe/rbt/v47n3/beta_pña.JPG" WIDTH=9 HEIGHT=16>-caryophyllene (3.7%).

Se investigaron los constituyentes del aceite esencial obtenido por hidrodestilación de la parte aérea de la planta Cunila polyantha (Lamiaceae), mediante las técnicas de cromatografía de gases y espectrometría de masas (GC-MS). Se encontró que los constituyentes mayoritarios del aceite fueron los monoterpenoides mentona (63%) y pulegona (14%), el sesquiterpeno <IMG SRC="http:/img/fbpe/rbt/v47n3/beta_pña.JPG" WIDTH=9 HEIGHT=16>-cariofileno (4.5%) y el acetato de 3-octanilo (3%).

The constituents of the volatile oil of Cunila polyantha from Dota, Costa Rica, were investigated using coupled gas chromatography-mass spectrometry (GC-MS) analyses. Menthone (63%), pulegone (14%), <IMG SRC="http:/img/fbpe/rbt/v47n3/http:/img/fbpe/rbt/v47n3/beta_pña.JPG" WIDTH=9 HEIGHT=16>-caryophyllene (4.5%) and 3-octanyl acetate (3%) were found to be the major constituents of the volatile oil.