Volume 17, Issue 4 (2-2024)
مرتع 2024, 17(4): 640-664 |
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Ahmadi H, Fatahi Moghadam M R, Zamani Z, Shorpoor M, Jahantab E, Morshedloo M. Characterization and Quantification of Predominant Active Substances in Different Phenological Stages of Two Thymus daenensis Chemotypes through LC-MS/MS and GC. مرتع 2024; 17 (4) :640-664
URL: http://rangelandsrm.ir/article-1-1226-en.html
URL: http://rangelandsrm.ir/article-1-1226-en.html
Hossein Ahmadi 
, Mohammad Reza Fatahi Moghadam , Zabihollah Zamani , Majid Shorpoor , Esfandyar Jahantab , Mohammadreza Morshedloo
, Mohammad Reza Fatahi Moghadam , Zabihollah Zamani , Majid Shorpoor , Esfandyar Jahantab , Mohammadreza Morshedloo
Department of Horticulture Science, Faculty of Agriculture and Natural Sciences, University of Tehran, Karaj
Abstract: (966 Views)
Background and objectives: Thymus daenensis, a thymol-rich thyme, is one of four endemic species of this genus in Iran, known for its pharmaceutical properties such as expectorant influence, antimicrobial, antifungal, and anti-inflammatory effects, primarily attributed to its metabolically active substances. This study aims to characterize and quantify the predominant active substances in different phenological stages of two Thymus daenensis chemotypes through LC-MS/MS and GC.
Methodology: Six genotypes from two phytochemically extreme Thymus daenensis Celak ecotypes (Zagheh and Malayer) were vegetatively propagated through stem cuttings (using 1000 ppm IBA hormone) in a greenhouse. Each clone consisted of at least eight individual plants. After well-rooted cuttings were transferred to eight-liter pots for further growth until cultivation in the farm. In the field, plants were adequately watered through drip irrigation and fertilized with 20:20:20 (N:K:P) fertilizer. Essential oil (EO) content, phenols, flavonoids, percentage of EO components, and antioxidant capacity of methanolic extracts were assessed in these clones at different phenological stages (vegetative, flower budding, early flowering, and full flowering) and in two organs (leaves and flowers). The data were analyzed using a two-factor full factorial experiment based on a completely randomized design (CRD).
Results: Malayer ecotype exhibited higher fresh weight, dry weight, vertical growth form, and significantly (65%) higher EO content than Zagheh ecotype. GC-MS analysis identified 24 constituents accounting for over 95% of essential oils, with thymol, carvacrol, carvacrol methyl ether, p-cymene, and γ-terpinene as the major components. Thymol content was 33% higher in Malayer ecotype (thymol chemotype) than Zagheh ecotype (thymol/carvacrol chemotype), while carvacrol content in Zagheh ecotype (~15%) was 13 times higher than Malayer ecotype. The highest amounts of thymol-carvacrol and p-cymene-γ-terpinene were observed in early flowering and vegetative stages, respectively. EO content and antioxidant properties peaked at the full flowering stage, with higher values in flower tissues than leaves. Regression analysis revealed negative and second-order relationships between p-cymene and thymol content, and between γ-terpinene and thymol content, as well as a significant linear relationship between p-cymene and γ-terpinene content. LC-MS/MS analysis identified 14 polyphenols and flavonoids, with rosmarinic acid and caffeic acid quantified through HPLC-PDA. Rosmarinic acid content was higher in Malayer samples, while Zagheh showed higher caffeic acid content, both peaking at early and full flowering stages.
Conclusion: Harvesting Thymus daenensis at the early flowering stage (~20% of flowers opened) is recommended for the highest biomass, EO, and thymol/carvacrol content. However, for higher antioxidant properties and phenols, harvesting at the full flowering stage (~90% of flowers opened) is advisable. Generally, the Malayer ecotype exhibited relative superiority in performance and essential oil production.
Methodology: Six genotypes from two phytochemically extreme Thymus daenensis Celak ecotypes (Zagheh and Malayer) were vegetatively propagated through stem cuttings (using 1000 ppm IBA hormone) in a greenhouse. Each clone consisted of at least eight individual plants. After well-rooted cuttings were transferred to eight-liter pots for further growth until cultivation in the farm. In the field, plants were adequately watered through drip irrigation and fertilized with 20:20:20 (N:K:P) fertilizer. Essential oil (EO) content, phenols, flavonoids, percentage of EO components, and antioxidant capacity of methanolic extracts were assessed in these clones at different phenological stages (vegetative, flower budding, early flowering, and full flowering) and in two organs (leaves and flowers). The data were analyzed using a two-factor full factorial experiment based on a completely randomized design (CRD).
Results: Malayer ecotype exhibited higher fresh weight, dry weight, vertical growth form, and significantly (65%) higher EO content than Zagheh ecotype. GC-MS analysis identified 24 constituents accounting for over 95% of essential oils, with thymol, carvacrol, carvacrol methyl ether, p-cymene, and γ-terpinene as the major components. Thymol content was 33% higher in Malayer ecotype (thymol chemotype) than Zagheh ecotype (thymol/carvacrol chemotype), while carvacrol content in Zagheh ecotype (~15%) was 13 times higher than Malayer ecotype. The highest amounts of thymol-carvacrol and p-cymene-γ-terpinene were observed in early flowering and vegetative stages, respectively. EO content and antioxidant properties peaked at the full flowering stage, with higher values in flower tissues than leaves. Regression analysis revealed negative and second-order relationships between p-cymene and thymol content, and between γ-terpinene and thymol content, as well as a significant linear relationship between p-cymene and γ-terpinene content. LC-MS/MS analysis identified 14 polyphenols and flavonoids, with rosmarinic acid and caffeic acid quantified through HPLC-PDA. Rosmarinic acid content was higher in Malayer samples, while Zagheh showed higher caffeic acid content, both peaking at early and full flowering stages.
Conclusion: Harvesting Thymus daenensis at the early flowering stage (~20% of flowers opened) is recommended for the highest biomass, EO, and thymol/carvacrol content. However, for higher antioxidant properties and phenols, harvesting at the full flowering stage (~90% of flowers opened) is advisable. Generally, the Malayer ecotype exhibited relative superiority in performance and essential oil production.
Type of Study: Research |
Subject:
Special
Received: 2023/10/2 | Accepted: 2024/01/30 | Published: 2024/02/29
Received: 2023/10/2 | Accepted: 2024/01/30 | Published: 2024/02/29
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