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The essential oil of Ageratum conyzoides from S. Tomé and Príncipe was investigated for the first time. The oil was obtained by hydrodistillation of the aerial parts, and subsequently analyzed by GC, GC/MS and 13C-NMR. The oil was characterized by the presence of high percentages of precocene I (34.4%) and β-caryophyllene (24.6%), as well as small amounts of precocene II. Using the disk diffusion method, the oil of A. conyzoides showed weak activity against Staphylococcus aureus, S. epidermidis, Streptococcus faecalis, Proteus vulgaris and Cladosporium cladosporioides, and was inactive against Escherichia coli, Candida albicans, Cryptococcus neoformans, Aspergillus niger and A. fumigatus. [ABSTRACT FROM AUTHOR]

The morphology and distribution of the glandular trichomes of Teucrium capitatum L., as well as the chemical composition of the essential oils, were studied. Important differences were found with regard to the major constituents of the essential oils of five populations of T. capitatum grown in Portugal. The oil isolated from one population was characterized by a high content of oxygenated monoterpenes (33.0%), isomenthone (7.7%) being the major constituent. Another oil from a population collected from the same region was dominated by monoterpene and sesquiterpene hydrocarbons (43.9% and 23.2%, respectively), α-pinene (7.7%), sabinene (11.2%) and β-pinene (10.3%) being the main compounds. The oils from the other three populations were characterized by a high content of both sesquiterpene hydrocarbons (23.0%, 32.2% and 33.2%) and oxygenated sesquiterpenes (39.7%, 23.4% and 20.4%). T-cadinol (24.1%) and α-cadinol (9.8%) were the major compounds in the oil from one population, whereas δ-cadinene (7.5% and 9.8%) and E-caryophyllene (5.4%) or α-muurolol (6.0%) were the major constituents in the other samples. The indumentum of the vegetative and reproductive ograns from the five populations of T. capitatum, observed under scanning electron microscopy, showed the same type and distribution of glandular and non-glandular trichomes. Since the ecological and edaphic features of the collecting sites were quite similar, the chemical polymorphism observed seems to be due to genetic factors. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The composition and the antimicrobial activity of the essential oil of Luma chequen from Peru were investigated. Essential oil was analyzed by GC and GC/MS. The oil was characterized by the presence of small amounts of sesquiterpenes (3.1%), and large amounts of monoterpenes (90.1%), of which α-pinene (57.1%), 1,8-cineole (12.1%) and linalool (5.5%) were the major compounds. The oil showed significant antimicrobial activity against Proteus vulgaris, Cryptococcus neoformans and Cladosporium cladosporioides, with MIC values ranging from 0.45 to 1.67 µL/mL. [ABSTRACT FROM AUTHOR]

The essential oil of Cedrela odorata L. bark from S. Tomé and Príncipe, where this plant is used in traditional medicine mainly for the treatment of malaria as well as a febrifuge and against diabetes, was investigated for the first time. The oil was obtained by hydrodistillation of the bark, and subsequently analyzed by GC, GC/MS and 13 C-NMR. Thirty-seven constituents were identified in the oil that was characterized by high and similar amounts of sesquiterpene hydrocarbons and oxygenated sesquiterpenes (43.9 and 42.4%, respectively). Major compounds were a -copaene (14.4%), a -cadinol (11.2%), β -eudesmol (9.4%) and d -cadinene (9.2%). The oil from S. Tomé is different from those reported in samples of other origins in which a -cadinol (11.2%) was not detected. [ABSTRACT FROM AUTHOR]