Florência Venâncio

Evaluation of the Essential Oils of Rosemary (Rosmarinus officinalis L.) from Different Zones of “Alentejo” (Portugal)

Abstract Rosemary oil was isolated from plants collected from five zones in the south of Portugal. The oil yields in fresh material ranged between 0.3–0.7% (v/w). The oils were analyzed by GC and GC/MS and were found to be rich in myrcene (16.6–29.5%), 1,8-cineole (8.3–14.5%) and camphor (14.3–23.1%). Statistical analysis of the results showed that on comparison of the 10 major constituents significant differences were found in the oils obtained from the five different zones.

COMPOSITION AND BIOLOGICAL ACTIVITY OF THE ESSENTIAL OIL OF PERUVIAN LANTANA CAMARA

The composition of the essential oil from Lantana camara L. (Verbenaceae) obtained by hydrodistillation of the aerial parts was examined by GC, GC/ MS, and 13C-NMR. The GC analysis showed that carvone is the most abundant monoterpene 75.9%, together with limonene 16.9%, accounting for 92.8% of the oil. The major components were also tested by 13C-NMR analysis of the essential oil. The L. camara oil was assayed against several microorganisms, showing moderate antibacterial activity against the human pathogen Staphylococcus aureus (MIC 200 µg/ml). High antioxidant activity evaluated by the Trolox equivalent antioxidant capacity assay (TEAC) was found (29.0 mmol Trolox/kg) and relative low anti-inflammatory activity due to its weak ability for inhibiting lipoxygenase (IC 50 = 81.5 µg/ml).

Main Components of the Essential Oils from Wild Portuguese Thymus mastichina (L.) L. ssp. mastichina in Different Developmental Stages or Under Culture Conditions

Abstract The aerial parts of wild Thymus mastichina (L.) L. ssp. mastichina were collected during the flowering (May) and vegetative phases (October) at Sesimbra (southwest Portugal). The aerial parts of cultivated plants of T. mastichina maintained in two different substrates, obtained from those plants growing wild at Sesimbra, were collected during the flowering phase (May) at Algarve (southern Portugal). The oils were isolated by hydrodistillation and analyzed by GC and GC/MS. In the wild plants, it was found that harvesting time had a significant effect on the oil yield, but did not greatly affect the composition. The highest oil yield isolated from the wild plants was found to be at the time of full flowering (2.1%, v/w). The oils were comprised mainly of oxygenated monoterpenes, among which linalool (58.7–69.0%) was the most abundant. In the wild plants, α-pinene, (E)-β-ocimene, γ-cadinene and elemol were the compounds that showed the most important variations, according to the harvesting month. The effect of nutritive elements (NPK) on the yield and on the oil composition was investigated in cultivated plants in two different substrates: a non-fertilized substrate (without N:P:K supply) and a fertilized substrate (with N:P:K, 1:1:1 supply). This study was carried out only in May. In the cultivated plants the highest oil yield (2.7%, v/w) was registered in the plants maintained in the non-fertilized substrate. Although the qualitative composition of the wild and cultivated oil plants was similar, the results showed quantitative variability among the components. The fertilized substrate proved to be the best to obtain a higher concentration of linalool (69.0%), while the non-fertilized substrate provided the lowest percentage (58.7%). The non-fertilized substrate induced a higher accumulation of (E)-β-ocimene, γ-terpinene, sesquiterpene hydrocarbons and oxygenated sesquiterpenes than the fertilized substrate, while this latter supported higher p-cymene and linalool content formation. The wild plant oils were found to be richer in α-pinene, camphene, β-pinene, 1,8-cineole and camphor and poorer in p-cymene, γ-terpinene, and in sesquiterpene hydrocarbons and oxygenated sesquiterpenes, than the cultivated plant oils. Nevertheless, such quantitative differences can be also explained by the different maturity stage of the wild and cultivated plants though both were in the same developmental stage.

Comparison of the Main Components of the Essential Oils from Flowers and Leaves of Thymus mastichina (L.) L. ssp. mastichina Collected at Different Regions of Portugal

Abstract The chemical composition of the essential oils from the leaves and the flowers of Thymus mastichina collected at different regions of Portugal were analyzed by GC and GC/MS. It revealed that fresh flowers produce larger amounts of oils than the leaves. The highest oil yields were obtained from the flowers collected at Arrábida (3.5%, v/w) and Mértola (3.0%, v/w). Two types of oils were differentiated according to their main components. Oils rich in 1,8-cineole whose concentrations ranged from 39.4% (in the flower oils collected at Mértola) to 69.2% (in the leaf oils from Arrábida), and an oil rich in linalool (73.5%) that was only detected in a sole plant group from Sesimbra. Camphor, borneol, terpinen-4-ol and α-terpineol appeared in relative high levels in the oils of the plants from Mértola and S. Brás de Alportel. In spite of the samples collected at Arrábida belonging to the 1,8-cineole type, camphene, (E)-β-ocimene, camphor and borneol were the compounds detected in the smallest amounts in contrast to the two remaining oils. Besides the linalool contents determining the chemotype of the plants collected at Sesimbra, other compounds appeared in different concentrations to the remaining samples making it worthy to differentiate between them. Thus, those samples had the lowest concentrations of many monoterpenes and the highest levels of T-cadinol.

Essential oils of Portuguese Thymus mastichina (L.) L. subsp. mastichina grown on different substrates and harvested on different dates

Summary The effects of harvesting date and different substrates on the yield and chemical composition of the essential oils of Portuguese Thymus mastichina (L.) L. subsp. mastichina were compared with samples grown in pots. The best oil yields were obtained in June (3.2, 3.6 and 4.9% in the local sandy soil, in non-fertilized peat, and in fertilized peat, respectively). The essential oils were dominated by 1,8-cineole, the highest concentration of which was detected in June (58.6%) in samples kept in non-fertilized peat, and the lowest values were from plants growing in fertilized peat during April and June (45.1%). The remaining samples always reached the highest percentages in October (around 54% in both oil samples), although the concentration profile over time was similar in every sample. Concerning the monoterpene hydrocarbons, ケ-pinene, camphene, sabinene and ゲ-pinene were the most significant components. While the amounts of ケ-pinene tended to decrease from April to June, for ゲ-pinene such tendency was observed from October to January, independently of the growing material used. Amounts of camphene, being similar to those of ケ-pinene, decreased successively from October to April. Elemol and intermedeol were the most representative sesquiterpene components, although the concentrations never exceeded 2.2% and 1.3%, respectively. The results obtained in this work suggest that the harvesting dates of Portuguese T. mastichina influence oil yields and their chemical compositions much more than the different growing media used, although a higher oil yield was obtained with the fertilized growing material.

The Essential Oil of Ocimum basilicum L. from Portugal

ABSTRACT The essential oil obtained from Ocimum basilicum L. grown in Portugal was analyzed by gas chromatography. It was found that the major components were linalool (32.2%) and methyl chavicol (16.42%).

Composition and Antimicrobial Screening of the Essential Oil of Acantholippia deserticola (Phil.ex F. Phil.) Moldenke

Abstract The composition of the essential oil from Acantholippia deserticola (Phil. ex F. Phil.) Moldenke (Verbenaceae) obtained by hydrodistillation of the aerial parts was examined by GC, GC/MS and NMR. Twenty-two compounds were identifed representing 98.9% of the total oil. α- and β-Thujone were characterized as the main constituents, 10.5% and 77.9%, respectively. Furthermore, the oil was tested for its antimicrobial activity using a micro-dilution assay exhibiting no inhibition on human pathogenic bacteria and yeast.

Variation in the Main Components of the Essential Oils from the Leaves and Flowers of Portuguese Thymus albicans Over a Single Season

Abstract The comparison of the chemical composition of the leaf and the flower oils isolated from Thymus albicans Hoffm. et Link belonging to the 1,8-cineole chemotype, collected at Gambelas, Algarve, during the flowering phase (June to September) was carried out. The oils isolated from both the fresh leaves and the fresh flowers by hydrodistillation were analyzed and compared by GC and GC/MS. The oil yields from the fresh leaves ranged from 3.1% in June, to 6.7% in July (full bloom), while the oil yields from the fresh flowers ranged from 4.8% in July, to 7.0% in September. Independent of the harvesting period, the oils isolated were characterized by their richness in 1,8-cineole either from the leaves (59.7–66.0%) or from the flowers (57.0–66.7%). The flower oils contained the highest concentration of α-pinene, β-pinene and linalool, while the leaf oils were richest in camphor, citronellol, bornyl acetate and geranyl propionate. Quantitative differences were also found in some oxygenated sesquiterpenes according to the developmental flowering stage being one of the most interesting those registered for viridiflorol, ledol and intermedeol. The highest amounts of these components in both the leaf and the flower oils were observed in July, starting then to decrease until September just as the behavior already found for 1,8-cineole in the flower oils.

Composition of the Essential Oils from Portuguese Thymus albicans Collected at Different Regions of Ria Formosa (Algarve)

Abstract The chemical composition of the essential oils from the leaves and the flowers of Thymus albicans Hoffm. et Link collected at three regions of Algarve, south of Portugal, was analyzed by GC and GC/MS. The oils isolated from the flowers and the leaves were obtained in similar yields, 4.3% (v/w) and 4.2% (v/w), in the samples from Quinta do Lago, and 3.5% and 3.6%, in the samples from Ancão, respectively. In contrast, the oil yields from Gambelas ranged from 5.7%, in the leaf oils, to 9.2%, in the flower oils. The oils isolated from all samples of leaves and flowers were dominated by the oxygenated monoterpene 1,8-cineole (42.1–67.9%). In the samples collected at Quinta do Lago, high levels of linalool were also found (30.3–36.9%). The major monoterpene hydrocarbons in all samples were α-pinene (1.7–4.3%), sabinene (1.6–3.4%) and (β-pinene (2.6–4.9%). The concentrations of α-pinene (1.7–1.8%), camphene (0.2%) and (β-pinene (2.6–2.9%) in the samples from Quinta do Lago were in lower amounts than in the remaining samples. The most representative sesquiterpene hydrocarbons were (β-elemene (0.2–0.7%), (β-caryophyllene (0.1–0.8%) and γ-cadinene (0.2–0.5%). The oxygenated sesquiterpene that was always present in higher amounts in the leaf oils than in the respective flower oils was viridiflorol (0.4–1.0%), the most important compound belonging to this fraction. The previous separation of the leaves and the flowers from this species evidenced the existence of quantitative differences in some components according to the plant part used. Still, for the same chemotype there were quantitative differences in some components, showing the existence of some variability demanding a more careful study to explain it.