[Show abstract][Hide abstract] ABSTRACT: Six-year-old Levisticum officinale (lovage) hairy root cultures were used to study the effect of eight different NH(4) (+):NO(3) (-) ratios on their growth and volatile components. All cultures were kept at 24 degrees C on orbital shakers at 80 rpm, in darkness or in a 16 h light/8 h dark photoperiod. Growth was evaluated by dry and fresh weight determination. The volatiles were isolated by distillation-extraction and analysed by GC and GC-MS. Greater growth was attained in darkness with 10:90 (control, SH medium), 50:50 and 25:75 NH(4) (+):NO(3) (-) ratios, and also with SH control medium under the photoperiod condition, with a 10, 14, 12.5 and 12.5 fold increase of biomass in terms of dry weight, respectively, at the end of 42 days of growth. UPGMA cluster analysis of the mixtures of volatiles isolated from the hairy roots grown with different NH(4) (+):NO(3) (-) ratios confirmed their chemical variability. Although no particular grouping was detected in relation to the NH(4) (+):NO(3) (-) ratios or light conditions studied, most of the mixtures of volatiles isolated from the hairy roots were either dominated by n-octanal, (Z)-falcarinol or both components in about the same relative amounts.
[Show abstract][Hide abstract] ABSTRACT: The essential oil obtained from Heteropyxis natalensis by steam distillation was tested for antimicrobial properties. Twenty five bacterial and four fungal species were used as test organisms in this study. These included animal and plant pathogens, food poisoning bacteria and mycotoxigenic fungal strains. The essential oil exhibited considerable inhibitory activities against all the test organisms. GC–MS analysis indicated the essential oil contained 1,8-cineole, limonene, β-myrcene, -phellandrene and -pinene.
Journal of the Science of Food and Agriculture 09/2006; 63(3):361 - 364. · 1.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rosemary and sage samples, both of dried herbs and essential oil, were obtained from various dealers and suppliers of the British market. Both species were also cultivated in Scotland for comparison of the oil characteristics. Dried samples were hydrodistilled, and all samples were analysed using GC. Herbal material was also examined under the light microscope for purity and cleanliness. There were considerable variations between the samples and the resulting problems are discussed. Scottish-grown material was of very good quality compared with the imported samples. The antioxidative properties of the various rosemary and sage samples were determined and found to be variable based on geographical location and type of processing. There is a real need for natural antioxidants at a time when the synthetic moieties currently in use are receiving considerable attention with respect to their safety and acceptability.
[Show abstract][Hide abstract] ABSTRACT: The essential oil from clove Syzygium aromaticum (L.) Merr. & Perry exhibited significant antimicrobial activity against a collection of 25 different genera of test bacteria and 20 different isolates of Listeria monocytogenes. The oil was also tested against three fungal strains: a plant pathogen, a spoilage type and a mycotoxigenic strain. This resulted in high levels of growth inhibition at both concentrations of 1 and 10 μl ml−1 growth medium. The essential oil was fed to mice in order to assess the antioxidant capacity, with particular reference to the protection of polyunsaturated fatty acids, in the liver and retina during ageing.
[Show abstract][Hide abstract] ABSTRACT: Steam-distilled volatile (essential) oil from Heteromorpha trifoliata (Wendl.) Eckl. & Zeyh. (Apiaceae) was tested for antimicrobial activities. Twenty-five bacterial and four fungal species were used in this study as test organisms. These included animal and plant pathogens, food poisoning and spoilage bacteria and mycotoxigenic fungal strains. The volatile oil exhibited considerable inhibitory activities against all the test organisms.
[Show abstract][Hide abstract] ABSTRACT: Essential oil samples of Mentha x piperita L. (peppermint) were analysed by GC–MS and assayed for their antibacterial, antifungal and antioxidant activities. The steam-distilled oil samples were obtained from autumn and spring planted crops which were treated with nitrogen and phosphorus fertilizers at different rates. The oil samples from spring planted crops had a significantly higher menthol and lower terpinen-4-ol concentrations than those from autumn planted crops. Mineral fertilization seemed to increase the content of menthol in the oil, and decreased that of menthone and β-caryophyllene. The oil samples showed a different degree of inhibition against the twenty-five microorganisms tested. Some differences were found between the oil samples from autumn and spring planted crops, the former being more active against some microorganisms, and the oil samples from fertilized peppermint seemed to be, on the whole, slightly more effective. Peppermint oil exhibited a marked antifungal activity against Aspergillus niger.
[Show abstract][Hide abstract] ABSTRACT: Steam distilled volatile oil from marjoram (Origanum majorana L.) was evaluated for its antibacterial and antifungal activities. A range of 25 bacterial and five fungal species was used in this study, and included animal and plant pathogens, food poisoning bacteria and mycotoxigenic fungi. The oil exerted considerable inhibitory powers against several of the bacteria, with the food-poisoning bacterium Staphylococcus aureus being least affected. The most susceptible organisms were Beneckea natriegens, Erwinia carotovora and Moraxella sp. Of the fungi tested, Aspergillus niger proved the most susceptible to marjoram oil.
[Show abstract][Hide abstract] ABSTRACT: The composition of the essential oils isolated from 24 populations of Thymus caespititius collected on Corvo, Flores, São Miguel and Terceira (Azores) and on Madeira were studied by GC and GC–MS. All the oil samples analysed were dominated by their monoterpene fraction (66–89%). In the Azorean populations, the proportion of the oxygenated monoterpenes (51–79%) was higher than that of the monoterpene hydrocarbons (8–27%). In contrast, the monoterpene hydrocarbons and the oxygenated monoterpenes represented 35–44 and 42–43%, respectively, of the total oils from the populations grown on Madeira. Cluster analysis of the identified components with a concentration ≥1% grouped the oils into three main clusters that corresponded with their main components: carvacrol (41–65%), thymol (35–51%) and α-terpineol (33–37%). Although the populations collected on Madeira were grouped in the same cluster, the chiral analysis of sabinene, terpinen-4-ol and α-terpineol showed that there was a clear chemical polymorphism. Actually, in the oils from two populations (−)-sabinene, (−)-terpinen-4-ol and (+)-α-terpineol were the predominant enantiomers while in that from the third population an opposite ratio was found. The chemical polymorphism of the essential oils from T. caespititius may result either from the genetic variability of the populations or from the influence of edaphic factors.
[Show abstract][Hide abstract] ABSTRACT: Transformed root cultures of Levisticum officinale (lovage) were established by inoculation of aseptically grown seedlings with Agrobacterium rhizogenes strain A4 carrying plasmid pRiA4::70GUS. Hairy roots growth in four different types of liquid culture media was determined by the dissimilation method and by measuring the fresh and dry weight of the roots. The composition of the essential oils from the hairy roots and from lovage plant roots was analysed by GC and GC-MS. The main components of the oil samples from the hairy roots were falcarinol, (Z)-ligustilide, (Z)-3-butylidenephthalide, trans-beta-farnesene, beta-phellandrene, n-octanal, gamma-elemene and n-heptanal, in varying amounts depending on the culture media tested. The hairy roots essential oil yields ranged from 0.006 to 0.018% (v/fr. wt.). The main components of the oil from the lovage plant roots were (Z)-ligustilide, beta-pinene, pentylcyclohexadiene and alpha-pinene. The yield of the oil front the lovage plant roots was 0.16% (v/fr. wt.). (c) 2004 Elsevier Ireland Ltd. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Oils obtained by hydrodistillation from the aerial parts of Monarda citriodora var. citriodora, Myristica fragrans, Origanum vulgare ssp. hirtum, Pelargonium sp. and Thymus zygis were screened for antioxidative properties in a lipid-rich matrix as quantified by spectrophotometry using iron (II) sulphate and 2,2′-azobis(2-amidinopropane) dihydrochloride as sources of primordial free radicals. Furthermore, the antimicrobial properties of M. fragrans, O. vulgare, Pelargonium sp. and T. zygis were screened against 25 different genera of bacteria selected for their agricultural, economic and health significance. The oils demonstrated a range of bioactive properties, with the oils rich in phenolic monoterpenes (M. citriodora and T. zygis) being particularly active in both antioxidant and antibacterial test systems.
Journal of Essential Oil Research 03/2004; 16(2):145-150. · 0.82 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The compositions of the essential oils isolated from the aerial parts of 11 populations of Thymus caespititius collected during the flowering phase on Pico, Faial and Graciosa (Azores) were studied by GC and GC-MS. The monoterpene fraction was dominant in all the oils analysed (55-90%) and consisted mainly of oxygen-containing compounds (44-79%). Sesquiterpenes represented an important fraction of the oils from the populations grown on Graciosa (13-28%). In contrast, this fraction was rather small in the oils from the populations grown on Pico and Faial (6-11%). Despite this, oxygen-containing compounds (4-18%) were always dominant. Cluster analysis of all identified oil components grouped the oils into three main clusters that corresponded with their main components. The oils from the 11 populations studied showed a clear chemical polymorphism that, in some cases, was more evident among populations growing on the same island than among those from different islands.
[Show abstract][Hide abstract] ABSTRACT: Four samples, from two populations, of the liverwort Marchesinia mackaii were collected on Madeira and at the mainland of Portugal, at different collection times. The oil yields determined by hydrodistillation attained 0.5% (v/w). The essential oils isolated by distillation-extraction were analyzed by GC and GC/MS. The main components (>5%) were alpha-asarone (23-31%), 2,4,5-trimethoxyallylbenzene (10-23%), (E)-methyl isoeugenol (12-19%), asarone (11-13%) and beta caryophyllene (7-16%).
Journal of Essential Oil Research 11/2002; 14(6):439-442. · 0.82 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Antioxidants minimize the oxidation of lipid components in cell membranes by scavenging free radicals. However, imbalance between free radical production and removal tends to increase with age causing progressive damage. For the food industry it is of considerable interest to delay the autoxidation of food lipids, which cause the reduction in food quality, affecting color, taste, nutritive value, and functionality. A general orientation toward the use of natural compounds has stimulated research into the potential use of aromatic and medicinal plants as possible antioxidant replacements. This study characterized the antioxidant and pro-oxidant properties of thyme oil and a number of its components. The major components identified in thyme oil were found to inhibit ferric-ion-stimulated lipid peroxidation of rat brain homogenates, although none was as effective as the whole oil The order of antioxidant activity was; thyme oil > thymol > carvacrol > γ-terpinene > myrcene > linalool > p-cymene > limonene > 1,8-cineole > α-pinene. Both thyme oil and thymol were also found to inhibit tert-butyl-hydroperoxide-stimulated peroxidation and INT reduction by superoxide radicals generated by the xanthine-xanthine oxidase system. Of these compounds tested only p-cymene, 1,8-cineole and myrcene were found to exhibit pro-oxidant activity, albeit to a very small extent. Overall, the data suggest that thyme oil possesses useful antioxidant properties that may be utilized in the food industry and as a dietary supplement.
Journal of Essential Oil Research 05/2002; 14(3):210-215. · 0.82 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Transformed root cultures of Anethum graveolens were induced by inoculation of aseptically grown seedlings with Agrobacterium rhizogenes carrying plasmid pRi 1855. The main component of the essential oils from the fruits and from the roots of the parent plant was carvone, whereas -phellandrene and apiole were dominant in the oil from, respectively, the aerial parts and the hairy roots. The essential oils from the fruits, aerial parts and roots of the parent plant were at 2%, 0.3% and 0.06% (v/w), respectively, but only 0.02% (v/w) in the hairy root cultures. Growth of the hairy root cultures reached 600 mg dry wt/50 ml medium after 50 days. The essential oil composition did not change significantly during their growth.