Stanley G Deans

Publications (9)7.71 Total impact

• Article: Nitrogen stress induction on Levisticum officinale hairy roots grown in darkness and under photoperiod conditions: effect on growth and volatile components.

  Monya M Costa, A Cristina Figueiredo, José G Barroso, Luis G Pedro, Stanley G Deans, Johannes J C Scheffer
  [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.
  Biotechnology Letters 08/2008; 30(7):1265-70. · 1.68 Impact Factor
• Article: Chemical Composition, Antimicrobial and In Vitro Antioxidant Properties of Monarda citriodora var. citriodora, Myristica fragrans, Origanum vulgare ssp. hirtum, Pelargonium sp. and Thymus zygis Oils

  H. J. Damien Dorman, Stanley G. Deans
  Journal of Essential Oil Research 01/2004; 16(2):145-150. · 0.41 Impact Factor
• Source

  Available from: Jan Schripsema

  Article: Hairy root cultures of Anethum graveolens (dill): establishment, growth, time-course study of their essential oil and its comparison with parent plant oils

  Pedro A.G. Santos, A. Cristina Figueiredo, Pedro M.L. Lourenço, José G. Barroso, Luis G. Pedro, M. Margarida Oliveira, Jan Schripsema, Stanley G. Deans, Johannes J.C. Scheffer
  [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.
  Biotechnology Letters 01/2002; 24(12):1031-1036. · 1.68 Impact Factor
• Source

  Available from: Peter Surai

  Article: In Vitro Antioxidant Activity of a Number of Plant Essential Oils and Phytoconstituents

  H. J. Damien Dorman, Peter Surai, Stanley G. Deans
  Journal of Essential Oil Research 01/2000; 12(2):241-248. · 0.41 Impact Factor
• Article: Morphological stability of Pimpinella anisum hairy root cultures and time-course study of their essential oils

  Paula M. Santos, A Cristina Figueiredo, M. Margarida Oliveira, José G. Barroso, Luis G. Pedro, Stanley G. Deans, A.K.M. Younus, Johannes J.C. Scheffer
  [show abstract] [hide abstract]
  ABSTRACT: The morphological stability of hairy root cultures of Pimpinella anisum was studied using cultures grown in four different media, both in darkness and under photoperiod conditions of 16h light; they were first subcultured every eight days and then later on every three weeks. From the four media tested, the hairy root cultures grown in SH medium both in darkness and under photoperiod conditions showed a marked morphological stability with no de-differentiation or greening, when compared with the other culture systems. The time-course study of the essential oils, isolated by distillation-extraction and analysed by GC and GC-MS, showed only quantitative differences in the composition of the oils. A clear heterogeneity in the accumulation pattern was found with regard to the five dominant compounds (pregeijerene, geijerene, zingiberene, -bisabolene and trans-epoxypseudoisoeugenyl 2-methylbutyrate), i.e., those that appeared in a relative amount higher than 5% at least once during the time-course study of the oils from the eight culture systems.
  Biotechnology Letters 09/1999; 21(10):859-864. · 1.68 Impact Factor
• Article: The Antioxidant Effectiveness of Thyme Oil, α-Tocopherol and Ascorbyl Palmitate on Evening Primrose Oil Oxidation

  Kuresh A. Youdim, H. J. Damien Dorman, Stanley G. Deans
  Journal of Essential Oil Research 01/1999; 11(5):643-648. · 0.41 Impact Factor
• Article: Antimicrobial and antioxidant properties of some commercial essential oils

  M. Tiziana Baratta, H. J. Damien Dorman, Stanley G. Deans, A. Cristina Figueiredo, José G. Barroso, Giuseppe Ruberto
  [show abstract] [hide abstract]
  ABSTRACT: The essential oil composition of Cananga odorata, Boswellia thurifera, Cymbopogon citratus, Marjorana hortensis, Ocimum basilicum, Rosmarinus officinalis, Cinnamomum zeylanicum and Citrus limon was analysed by GC and GC–MS, and their antimicrobial and antioxidant activity tested. Twenty-five different genera of bacteria and one fungal species were used in this study as test organisms. These included animal and plant pathogens, food poisoning and spoilage bacteria and the spoilage fungus Aspergillus niger. The volatile oils exhibited considerable inhibitory effect against all the tested organisms. The oils also demonstrated antioxidant capacities, comparable with α-tocopherol and butylated hydroxytoluene (BHT). The method adopted in this study was the modified thiobarbituric acid reactive species (TBARS) assay. The antioxidant activity was carried out under different conditions by using egg yolk and rat liver in the absence and presence of the radical inducer 2,2′-azobis (2-amidinopropane) dihydrochloride (ABAP). © 1998 John Wiley & Sons, Ltd.
  Flavour and Fragrance Journal 06/1998; 13(4):235 - 244. · 1.42 Impact Factor
• Article: Chemical polymorphism of populations of Thymus caespititius grown on the islands Corvo, Flores, São Miguel and Terceira (Azores) and on Madeira, assessed by analysis of their essential oils

  Pedro A.G. Santos, José G. Barroso, A. Cristina Figueiredo, Luis G. Pedro, Lígia R. Salgueiro, Susana S. Fontinha, Stanley G. Deans, Johannes J.C. Scheffer
  [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.
  Plant Science.
• Article: Essential oils from Azorean Laurus azorica

  Luis G Pedro, Pedro A.G Santos, Jaime A da Silva, A.Cristina Figueiredo, José G Barroso, Stanley G Deans, Anja Looman, Johannes J.C Scheffer
  [show abstract] [hide abstract]
  ABSTRACT: The essential oils isolated from leaves of ten and from unripe berries of eight populations of Laurus azorica (Seub.) Franco, collected on five islands of the Azorean archipelago, were analysed by GC and GC–MS. All oil samples were dominated by their monoterpene fraction (60–94%), α-pinene (15–37%) and 1,8-cineole (12–31%) being the main components of the leaf oils, while trans-β-ocimene (27–45%) and α-pinene (12–22%) were the main components of the oils from the berries. The sesquiterpene fractions of the oils ranged from 3 to 17% and the main components were β-caryophyllene (traces — 8%) and β-elemene (traces—3%) both in the leaf and berry oils. Some phenylpropanoid components were also present, in total amounting to 17%, trans-cinnamyl acetate (215% of the leaf oils) being the main component of this fraction. Cluster analysis of the enantiomeric composition of α- and β-pinene in the oils from the leaves clearly showed two groups, one constituted by the two populations growing on the island S. Jorge, and the other constituted by the remaining populations.
  Phytochemistry.