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Y.a. Muller - One of the best experts on this subject based on the ideXlab platform.
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expression crystallization and structure elucidation of γ Terpinene synthase from thymus vulgaris
Acta Crystallographica Section F-structural Biology and Crystallization Communications, 2016Co-Authors: K Rudolph, Wolfgang Kreis, Y.a. Muller, Christoph Parthier, Claudia Egerersieber, Daniel Geiger, Frieder MulleruriAbstract:The biosynthesis of γ-Terpinene, a precursor of the phenolic isomers thymol and carvacrol found in the essential oil from Thymus sp., is attributed to the activitiy of γ-Terpinene synthase (TPS). Purified γ-Terpinene synthase from T. vulgaris (TvTPS), the Thymus species that is the most widely spread and of the greatest economical importance, is able to catalyze the enzymatic conversion of geranyl diphosphate (GPP) to γ-Terpinene. The crystal structure of recombinantly expressed and purified TvTPS is reported at 1.65 A resolution, confirming the dimeric structure of the enzyme. The putative active site of TvTPS is deduced from its pronounced structural similarity to enzymes from other species of the Lamiaceae family involved in terpenoid biosynthesis: to (+)-bornyl diphosphate synthase and 1,8-cineole synthase from Salvia sp. and to (4S)-limonene synthase from Mentha spicata.
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γ-Terpinene synthase of Thymus vulgaris
Planta Medica, 2015Co-Authors: F Mueller-uri, C. Egerer-sieber, K Rudolph, Wolfgang Kreis, Y.a. MullerAbstract:Thyme is a plant genus comprising over 300 species within the Lamiaceae family. For medicine, especially for the treatment of respiratory diseases, the essential oil is the most important ingredient. It shows antibacterial and antiviral effects. Essential oils are complex mixtures composed of active and inactive compounds [1, 2]. In Thymus sepyllum (Ts) and six Thymus species the essential oils were isolated by hydrodestillation and analyzed by GC-MS. The γ-Terpinene was identified as a characteristic monoterpene in all essential oils, albeit in varying concentrations. It is a naturally occurring monoterpene and a major component in most essential oils of citrus fruits and many aromatic plants. γ-Terpinene is formed through cyclisation of geranyl diphosphate (GPP) by γ-Terpinene synthase which belong to the monoterpene cyclase family [3]. Traces of several other monoterpenoids were formed in addition to γ-Terpinene (product promiscuity). Using primers derived from Origanum vulgare, we here isolated and sequenced γ-Terpinene synthase cDNAs (TPS) from Thymus vulgaris (Tv), Thymus serpyllum (Ts), Thymus x citriodorus (Txc) and Thymus caespititius (Tc). Sequence data were used to study the chemical-taxonomic relationship between the four species. The bastard plant Txc showed a close relationship to Tv, whereas Tc γ-Terpinene synthase was closely related to that of Origanum vulgare [4]. The Tv γ-Terpinene synthase gene 1 (TvTPS1), which encoded for a protein of 596 amino acids was expressed as a recombinant protein in E. coli. We succeeded in overproduction, purification and crystallization of the TPS from Thymus vulgaris for the first time. References: [1] Lima AS et al. Planta 2013; 238: 191 – 204 [2] Crocoll C et al., Plant Mol Biol 2010; 73: 587 – 603 [3] Stahl-Biskup E, Saez F. Thyme – The genus Thymus, 2002 [4] Alonso WR, Croteau R. Arch Biochem Biophys 1990; 286: 511 – 517
F Mueller-uri - One of the best experts on this subject based on the ideXlab platform.
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γ-Terpinene synthase of Thymus vulgaris
Planta Medica, 2015Co-Authors: F Mueller-uri, C. Egerer-sieber, K Rudolph, Wolfgang Kreis, Y.a. MullerAbstract:Thyme is a plant genus comprising over 300 species within the Lamiaceae family. For medicine, especially for the treatment of respiratory diseases, the essential oil is the most important ingredient. It shows antibacterial and antiviral effects. Essential oils are complex mixtures composed of active and inactive compounds [1, 2]. In Thymus sepyllum (Ts) and six Thymus species the essential oils were isolated by hydrodestillation and analyzed by GC-MS. The γ-Terpinene was identified as a characteristic monoterpene in all essential oils, albeit in varying concentrations. It is a naturally occurring monoterpene and a major component in most essential oils of citrus fruits and many aromatic plants. γ-Terpinene is formed through cyclisation of geranyl diphosphate (GPP) by γ-Terpinene synthase which belong to the monoterpene cyclase family [3]. Traces of several other monoterpenoids were formed in addition to γ-Terpinene (product promiscuity). Using primers derived from Origanum vulgare, we here isolated and sequenced γ-Terpinene synthase cDNAs (TPS) from Thymus vulgaris (Tv), Thymus serpyllum (Ts), Thymus x citriodorus (Txc) and Thymus caespititius (Tc). Sequence data were used to study the chemical-taxonomic relationship between the four species. The bastard plant Txc showed a close relationship to Tv, whereas Tc γ-Terpinene synthase was closely related to that of Origanum vulgare [4]. The Tv γ-Terpinene synthase gene 1 (TvTPS1), which encoded for a protein of 596 amino acids was expressed as a recombinant protein in E. coli. We succeeded in overproduction, purification and crystallization of the TPS from Thymus vulgaris for the first time. References: [1] Lima AS et al. Planta 2013; 238: 191 – 204 [2] Crocoll C et al., Plant Mol Biol 2010; 73: 587 – 603 [3] Stahl-Biskup E, Saez F. Thyme – The genus Thymus, 2002 [4] Alonso WR, Croteau R. Arch Biochem Biophys 1990; 286: 511 – 517
K Rudolph - One of the best experts on this subject based on the ideXlab platform.
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expression crystallization and structure elucidation of γ Terpinene synthase from thymus vulgaris
Acta Crystallographica Section F-structural Biology and Crystallization Communications, 2016Co-Authors: K Rudolph, Wolfgang Kreis, Y.a. Muller, Christoph Parthier, Claudia Egerersieber, Daniel Geiger, Frieder MulleruriAbstract:The biosynthesis of γ-Terpinene, a precursor of the phenolic isomers thymol and carvacrol found in the essential oil from Thymus sp., is attributed to the activitiy of γ-Terpinene synthase (TPS). Purified γ-Terpinene synthase from T. vulgaris (TvTPS), the Thymus species that is the most widely spread and of the greatest economical importance, is able to catalyze the enzymatic conversion of geranyl diphosphate (GPP) to γ-Terpinene. The crystal structure of recombinantly expressed and purified TvTPS is reported at 1.65 A resolution, confirming the dimeric structure of the enzyme. The putative active site of TvTPS is deduced from its pronounced structural similarity to enzymes from other species of the Lamiaceae family involved in terpenoid biosynthesis: to (+)-bornyl diphosphate synthase and 1,8-cineole synthase from Salvia sp. and to (4S)-limonene synthase from Mentha spicata.
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γ-Terpinene synthase of Thymus vulgaris
Planta Medica, 2015Co-Authors: F Mueller-uri, C. Egerer-sieber, K Rudolph, Wolfgang Kreis, Y.a. MullerAbstract:Thyme is a plant genus comprising over 300 species within the Lamiaceae family. For medicine, especially for the treatment of respiratory diseases, the essential oil is the most important ingredient. It shows antibacterial and antiviral effects. Essential oils are complex mixtures composed of active and inactive compounds [1, 2]. In Thymus sepyllum (Ts) and six Thymus species the essential oils were isolated by hydrodestillation and analyzed by GC-MS. The γ-Terpinene was identified as a characteristic monoterpene in all essential oils, albeit in varying concentrations. It is a naturally occurring monoterpene and a major component in most essential oils of citrus fruits and many aromatic plants. γ-Terpinene is formed through cyclisation of geranyl diphosphate (GPP) by γ-Terpinene synthase which belong to the monoterpene cyclase family [3]. Traces of several other monoterpenoids were formed in addition to γ-Terpinene (product promiscuity). Using primers derived from Origanum vulgare, we here isolated and sequenced γ-Terpinene synthase cDNAs (TPS) from Thymus vulgaris (Tv), Thymus serpyllum (Ts), Thymus x citriodorus (Txc) and Thymus caespititius (Tc). Sequence data were used to study the chemical-taxonomic relationship between the four species. The bastard plant Txc showed a close relationship to Tv, whereas Tc γ-Terpinene synthase was closely related to that of Origanum vulgare [4]. The Tv γ-Terpinene synthase gene 1 (TvTPS1), which encoded for a protein of 596 amino acids was expressed as a recombinant protein in E. coli. We succeeded in overproduction, purification and crystallization of the TPS from Thymus vulgaris for the first time. References: [1] Lima AS et al. Planta 2013; 238: 191 – 204 [2] Crocoll C et al., Plant Mol Biol 2010; 73: 587 – 603 [3] Stahl-Biskup E, Saez F. Thyme – The genus Thymus, 2002 [4] Alonso WR, Croteau R. Arch Biochem Biophys 1990; 286: 511 – 517
Anntherese Karlberg - One of the best experts on this subject based on the ideXlab platform.
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α Terpinene an antioxidant in tea tree oil autoxidizes rapidly to skin allergens on air exposure
Chemical Research in Toxicology, 2012Co-Authors: Johanna Rudback, Moa Andresen Bergstrom, Anna Borje, Ulrika Nilsson, Anntherese KarlbergAbstract:The monoterpene α-Terpinene is used as a fragrance compound and is present in different essential oils. It is one of the components responsible for the antioxidant activity of tea tree oil. α-Terpinene is structurally similar to other monoterpenes, e.g., limonene, known to autoxidize on air exposure and form allergenic compounds. The aim of the present study was to investigate the possible autoxidation of α-Terpinene at room temperature. To investigate the sensitization potency of air-exposed α-Terpinene and the oxidation products formed, the murine local lymph node assay was used. Chemical analysis showed that α-Terpinene degrades rapidly, forming allylic epoxides and p-cymene as the major oxidation products and also hydrogen peroxide. Thus, the oxidation pathway differs compared to that of, e.g., limonene, which forms highly allergenic hydroperoxides as the primary oxidation products on autoxidation. The sensitization potency of α-Terpinene was increased after air-exposure. The allylic epoxides and a fraction, in which only an α,β-unsaturated aldehyde could be identified, were shown to be strong sensitizers in the local lymph node assay. Thus, we consider them to be the major contributors to the increased sensitization potency of the autoxidized mixture. We also investigated the presence of α-Terpinene and its oxidation products in four different tea tree oil samples of various ages. α-Terpinene and its oxidation products were identified in all of the tea tree oil samples. Thus, from a technical perspective, α-Terpinene is a true antioxidant since it autoxidizes rapidly compared with many other compounds, preventing these from degradation. However, as it easily autoxidizes to form allergens, its suitability can be questioned when used in products for topical applications, e.g., in tea tree oil but also in cosmetics and skin care products.
I A Khan - One of the best experts on this subject based on the ideXlab platform.
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quality evaluation of terpinen 4 ol type australian tea tree oils and commercial products an integrated approach using conventional and chiral gc ms combined with chemometrics
Journal of Agricultural and Food Chemistry, 2015Co-Authors: Mei Wang, Jianping Zhao, Bharathi Avula, Yanhong Wang, Amar G Chittiboyina, Jon F Parcher, I A KhanAbstract:GC/MS, chiral GC/MS, and chemometric techniques were used to evaluate a large set (n = 104) of tea tree oils (TTO) and commercial products purported to contain TTO. Twenty terpenoids were determined in each sample and compared with the standards specified by ISO-4730-2004. Several of the oil samples that were ISO compliant when distilled did not meet the ISO standards in this study primarily due to the presence of excessive p-cymene and/or depletion of Terpinenes. Forty-nine percent of the commercial products did not meet the ISO specifications. Four terpenes, viz., α-pinene, limonene, terpinen-4-ol, and α-terpineol, present in TTOs with the (+)-isomer predominant were measured by chiral GC/MS. The results clearly indicated that 28 commercial products contained excessive (+)-isomer or contained the (+)-isomer in concentrations below the norm. Of the 28 outliers, 7 met the ISO standards. There was a substantial subset of commercial products that met ISO standards but displayed unusual enantiomeric +/– rati...
