Activité antioxydante et composition chimique des huiles essentielles de quatre espèces de thym du Maroc

Abstract

Mots clés : huile essentielle -Thymus capitatus -Thymus ciliatus -Thymus bleicherianus -Thymus algeriensis -composition chimique -activité antioxydante.Abstract.-The chemical composition of four Thymus species essential oils (T. capitatus, T. ciliatus, T. bleicherianus and T. algeriensis) was determined by GCand GC/SM. The essential oil of T. capitatus is dominated by carvacrol (70.92%), that of T. ciliatus by thymol (44.2%), that of T. bleicherianus contains α-terpinene (42.23%) and thymol (23.95%) as major chemical constituents, while that of T. algeriensis is formed mainly by camphor (27.7%) and α-pinene (20.5%). The antioxidant activity was determined by the DPPH test. The essential oil of T. capitatus, T. ciliatus and T. bleicherianus show strong antioxidant activity with (IC 50 = 69,04 µg/ml, 74,025 µg/ml and 77,8 µg/ml) respectively, compared to the essence of T. algeriensis and other species of thyme in the literature.

Essential Oil of Thymus munbyanus subsp. coloratus from Algeria: Chemotypification and in vitro Biological Activities

“…This chemotype has never been reported for T. munbyanus before. In fact, previous studies conducted on plant samples collected in different areas of Algeria reported carvacrol (71.4 – 80.3%), carvacrol (35.2%) and thymol (18.5%), thymol (44.2%), thymol (37.7%) and p ‐cymene (14.7%), thymol (52.0 – 60.5%) and γ ‐terpinene (9.5 – 11.3%), thymol (44.2%), ( E )‐ β ‐ocimene (25.8%) and α ‐terpinene (12.3%), camphor (21.8 – 24.9%), camphene (13.5 – 17.3%) and 1,8‐cineole (11.9 – 15.7%), as the major essential oil constituents. Only in a few studies, the subspecies investigated (subsp.…”

“…However, in most cases only the subsp. ciliatus was analysed, while for the rest of the studies the subspecific level was not determined . In the above studies the most abundant volatile components reported were the phenols thymol and carvacrol, and their precursors p ‐cymene and γ ‐terpinene.…”

“…In the above studies the most abundant volatile components reported were the phenols thymol and carvacrol, and their precursors p ‐cymene and γ ‐terpinene. In some of the above studies the antioxidant and antimicrobial activities of the essential oil have been investigated as well …”

Chemical composition and in vitro antibacterial activity of the pure essential oils and essential oils extracted from their corresponding hydrolats from different w ild varieties of Moroccan thyme

“…The strong antibacterial activity of the pure essential oil of Thymbra capitata is rather due to its chemical profile rich in carvacrol (85.35%) which is known for its antibacterial power [55]. [56]. Similarly, the essential oil of Thymus vulgaris, comprises almost the same chemical composition as the studied Thymbra capitata [carvacrol (83.8%), terpinene (4.96%) and pcymene (8.15%)], showed great antibacterial effect [57].…”

Chemical Composition, Antimicrobial, and Antioxidant Activities of Two Moroccan Thymus Essential Oils

“…However, when compared to the pure reference antioxidant BHT (0.11±0.002 mg/ml), all the tested EOs showed a significantly lower antioxidant activity (p<0.05). T. bleherianus EOs showed the lowest activity than that founded by Amarti et al (IC 50 = 77.8 μg/ml) [48], and also lowest than T. serpyllum, Thymus algeriensis, and Thymus vulgaris with IC 50 = 0.96 μg/ml, IC 50 = 1.64 μg/ml, and IC 50 = 4.80 μg/ml, respectively, reported by Nikolić et al [49].…”