کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6377344 1624860 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phenological changes to the chemical composition and biological activity of the essential oil from Moroccan endemic thyme (Thymus maroccanus Ball)
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
Phenological changes to the chemical composition and biological activity of the essential oil from Moroccan endemic thyme (Thymus maroccanus Ball)
چکیده انگلیسی


- Oil composition and biological activities of Thymus maroccanus at different growth stages were investigated.
- Oils from different growth stages showed in general the same chemical profile.
- Carvacrol is a predominant compound in T. maroccanus essential oils.
- Oil from flowering and vegetative stages showed higher biological activities.
- Flowering and vegetative stages are the optimal harvest times.

The chemical composition, antioxidant and antimicrobial activities of essential oils isolated by hydrodistillation from the aerial parts of wild endemic Moroccan Thymus maroccanus at different developmental stages (vegetative, flowering and post-flowering) were evaluated. The yield of essential oils (v/w%) based on dry weight at different stages were: vegetative (2.14%), flowering (leaves: 1.80%; flowers: 3.46%), and post-flowering (leaves: 0.98%; post-flowers: 2.46%). Analysis of the essential oils by GC/MS revealed the presence of 28 components represented mainly by monoterpenes, both oxygenated (59.4-79.4%) and hydrocarbons (14.3-34.2%). The ranges of major constituents were as follow: carvacrol (14.1-77.6%), p-cymene (3.5-7.9%), γ-terpinene (3.8-6.6%) and α-pinene (1.2-7.8%). Leaves at post-flowering stage also contained a significant amount of borneol (16.3%) and thymol (27.8%). Essential oils obtained from flowering stage showed the highest antioxidant activity as measured by DPPH free radical scavenging ability, reductive potential and β-carotene/linoleic acid assays with IC50 values ranging from 61.48 ± 1.58 μg/mL to 182.86 ± 2.84 μg/mL for leaves and from 63.81 ± 1.96 μg/mL to 129.93 ± 6.16 μg/mL for flowers. The essential oils were also screened for antimicrobial activity against seven bacteria of significant importance for food hygiene and four pathogenic fungal strains. The results indicated that Candida strains were the most sensitive among the microorganisms tested (MIC values of 0.12-0.25 mg/mL) followed by Gram positive and Gram negative bacterial strains, with the Gram-negative Pseudomonas aeruginosa being the most resistant strain. The maximum antimicrobial activity was observed with oils obtained from the vegetative and flowering stages, which therefore represent the optimal harvesting times of this plant for application in the pharmaceutical and food industries.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Industrial Crops and Products - Volume 49, August 2013, Pages 366-372
نویسندگان
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