Health & Environmental Research Online (HERO)


tert-Amyl ethyl ether (TAEE)


7 References Were Found:

Journal Article
Journal Article

Pharmacological Properties and Molecular Mechanisms of Thymol: Prospects for Its Therapeutic Potential and Pharmaceutical Development

Authors: Nagoor Meeran, MF; Javed, H; Al Taee, H; Azimullah, S; Ojha, SK (2017) HERO ID: 4366728

[Less] Thymol, chemically known as 2-isopropyl-5-methylphenol is a colorless crystalline monoterpene phenol. . . . [More] Thymol, chemically known as 2-isopropyl-5-methylphenol is a colorless crystalline monoterpene phenol. It is one of the most important dietary constituents in thyme species. For centuries, it has been used in traditional medicine and has been shown to possess various pharmacological properties including antioxidant, free radical scavenging, anti-inflammatory, analgesic, antispasmodic, antibacterial, antifungal, antiseptic and antitumor activities. The present article presents a detailed review of the scientific literature which reveals the pharmacological properties of thymol and its multiple therapeutic actions against various cardiovascular, neurological, rheumatological, gastrointestinal, metabolic and malignant diseases at both biochemical and molecular levels. The noteworthy effects of thymol are largely attributed to its anti-inflammatory (via inhibiting recruitment of cytokines and chemokines), antioxidant (via scavenging of free radicals, enhancing the endogenous enzymatic and non-enzymatic antioxidants and chelation of metal ions), antihyperlipidemic (via increasing the levels of high density lipoprotein cholesterol and decreasing the levels of low density lipoprotein cholesterol and low density lipoprotein cholesterol in the circulation and membrane stabilization) (via maintaining ionic homeostasis) effects. This review presents an overview of the current in vitro and in vivo data supporting thymol's therapeutic activity and the challenges concerning its use for prevention and its therapeutic value as a dietary supplement or as a pharmacological agent or as an adjuvant along with current therapeutic agents for the treatment of various diseases. It is one of the potential candidates of natural origin that has shown promising therapeutic potential, pharmacological properties and molecular mechanisms as well as pharmacokinetic properties for the pharmaceutical development of thymol.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Cardioprotective Potentials of Plant-Derived Small Molecules against Doxorubicin Associated Cardiotoxicity

Authors: Ojha, S; Al Taee, H; Goyal, S; Mahajan, UB; Patil, CR; Arya, DS; Rajesh, M (2016) HERO ID: 4641562

[Less] Doxorubicin (DOX) is a potent and widely used anthracycline antibiotic for the treatment of several . . . [More] Doxorubicin (DOX) is a potent and widely used anthracycline antibiotic for the treatment of several malignancies. Unfortunately, the clinical utility of DOX is often restricted due to the elicitation of organ toxicity. Particularly, the increased risk for the development of dilated cardiomyopathy by DOX among the cancer survivors warrants major attention from the physicians as well as researchers to develop adjuvant agents to neutralize the noxious effects of DOX on the healthy myocardium. Despite these pitfalls, the use of traditional cytotoxic drugs continues to be the mainstay treatment for several types of cancer. Recently, phytochemicals have gained attention for their anticancer, chemopreventive, and cardioprotective activities. The ideal cardioprotective agents should not compromise the clinical efficacy of DOX and should be devoid of cumulative or irreversible toxicity on the naïve tissues. Furthermore, adjuvants possessing synergistic anticancer activity and quelling of chemoresistance would significantly enhance the clinical utility in combating DOX-induced cardiotoxicity. The present review renders an overview of cardioprotective effects of plant-derived small molecules and their purported mechanisms against DOX-induced cardiotoxicity. Phytochemicals serve as the reservoirs of pharmacophore which can be utilized as templates for developing safe and potential novel cardioprotective agents in combating DOX-induced cardiotoxicity.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Occupational trichloroethylene exposure as a cause of idiosyncratic generalized skin disorders and accompanying hepatitis similar to drug hypersensitivities

Authors: Kamijima, M; Hisanaga, N; Wang, H; Nakajima, T (2007) International Archives of Occupational and Environmental Health 80:357-370. [Review] HERO ID: 700355

[Less] Objectives: Workers exposed to trichloroethylene (TCE) rarely show severe generalized skin disorders . . . [More] Objectives: Workers exposed to trichloroethylene (TCE) rarely show severe generalized skin disorders and accompanying hepatitis which resemble drug hypersensitivities. The disorders are completely different from solvent-induced irritating contact dermatitis, and their serious consequences have become one of the critical occupational health issues recently in Asia. The present review sheds light on the analogous relationship between the reported patients' clinical manifestations and those of severe drug rash, and provides a comprehensive picture of the disorder occurrences among TCE-exposed workers to date.


Methods: All literature published in English and ad hoc publications in local languages were reviewed.


Results: The patients typically showed rash on the extremities, face, neck or trunk with/without fever 2 weeks to 2 months after commencement of occupational TCE exposure. Reported cutaneous manifestations were classified into two hypersensitivity categories, i.e. hypersensitivity syndrome and erythema multiforme/Stevens-Johnson syndrome/toxic epidermal necrolysis. Based on this categorization, 124 (52%) cases were classified as the former and 115 (48%) as the latter. According to the two spectra, the prevalence of each clinical finding of TCE-related skin disorders was close to that in drug hypersensitivities except for disease incidence and the prevalence of fever, hepatitis, and lymphadenopathy. Occurrences of the disorders have been reported from the USA, Japan, Spain, Singapore, China, Korea, Thailand, and the Philippines. The case reports from industrialized countries were mostly published up to 1990, whereas cases from Asian industrializing countries appeared thereafter.


Conlusions: The TCE-related generalized skin disorders are important not only in terms of the number of disease occurrences and severity but from the viewpoint of drug hypersensitivity. Systematic collection of clinical information is necessary in cases diagnosed by the same criteria as those used for drug hypersensitivities. Detailed exposure assessments are also required to establish preventive strategies in these countries.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Toxicokinetics of ethers used as fuel oxygenates

Authors: Dekant, W; Bernauer, U; Rosner, E; Amberg, A (2001) Toxicology Letters 124:37-45. [Review] HERO ID: 19269

[Less] The toxicokinetics and biotransformation of methyl-tert.butyl ether (MTBE), ethyl-tert.butyl ether (ETBE) . . . [More] The toxicokinetics and biotransformation of methyl-tert.butyl ether (MTBE), ethyl-tert.butyl ether (ETBE) and tert.amyl-methyl ether (TAME) in rats and humans are summarized. These ethers are used as gasoline additives in large amounts, and thus, a considerable potential for human exposure exists. After inhalation exposure MTBE, ETBE and TAME are rapidly taken up by both rats and humans; after termination of exposure, clearance by exhalation and biotransformation to urinary metabolites is rapid in rats. In humans, clearance by exhalation is slower in comparison to rats. Biotransformation of MTBE and ETBE is both qualitatively and quantitatively similar in humans and rats after inhalation exposure under identical conditions. The extent of biotransformation of TAME is also quantitatively similar in rats and humans; the metabolic pathways, however, are different. The results suggest that reactive and potentially toxic metabolites are not formed during biotransformation of these ethers and that toxic effects of these compounds initiated by covalent binding to cellular macromolecules are unlikely.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Microbial degradation and fate in the environment of methyl tert-butyl ether and related fuel oxygenates

Authors: Fayolle, F; Vandecasteele, JP; Monot, F (2001) Applied Microbiology and Biotechnology 56:339-349. [Review] HERO ID: 1071419

[Less] Oxygenates, mainly methyl tert-butyl ether (MTBE), are commonly added to gasoline to enhance octane . . . [More] Oxygenates, mainly methyl tert-butyl ether (MTBE), are commonly added to gasoline to enhance octane index and improve combustion efficiency. Other oxygenates used as gasoline additives are ethers such as ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and alcohols such as tert-butyl alcohol (TBA). As a result of its wide use, MTBE has been detected, mainly in the USA, in groundwater and surface waters, and is a cause of concern because of its possible health effects and other undesirable consequences. MTBE is a water-soluble and mobile compound that generates long pollution plumes in aquifers impacted by gasoline releases from leaking tanks. Field observations concur in estimating that, because of recalcitrance to biodegradation, natural attenuation is slow (half-life of at least 2 years). However, quite significant advances have been made in recent years concerning the microbiology of the degradation of MTBE and other oxygenated gasoline additives. The recalcitrance of these compounds results from the presence in their structure of an ether bond and of a tertiary carbon structure. For the most part, only aerobic microbial degradation systems have been reported so far. Consortia capable of mineralizing MTBE have been selected. Multiple instances of the cometabolism of MTBE with pure strains or with microflorae, growing on n-alkanes, isoalkanes, cyclohexane or ethers (diethyl ether, ETBE), have been described. MTBE was converted into TBA in all cases and was sometimes further degraded, but it was not used as a carbon source by the pure strains. However, mineralization of MTBE and TBA by several pure bacterial strains using these compounds as sole carbon and energy source has recently been reported. The pathways of metabolism of MTBE involve the initial attack by a monooxygenase. In several cases, the enzyme was characterized as a cytochrome P-450. After oxygenation, the release of a C -unit as formaldehyde or formate leads to the production of TBA, which can be converted to 2-hydroxyisobutyric acid and further metabolized. Developments in microbiology make biological treatment of water contaminated with MTBE and other oxygenates an attractive possibility. Work concerning ex situ treatment in biofilters by consortia and by pure strains, and involving or not cometabolism, is under way. Furthermore, the development of in situ treatment processes is a promisinggoal.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Toxicology and human health effects following exposure to oxygenated or reformulated gasoline

Author: Ahmed, FE (2001) Toxicology Letters 123:89-113. [Review] HERO ID: 87602

[Less] In order to replace antiknock leaded derivatives in gasoline, legislations were enacted in the United . . . [More] In order to replace antiknock leaded derivatives in gasoline, legislations were enacted in the United States and other countries to find safer additives and to reduce CO, O3, and volatile organic compounds (VOCs) in non-attainment areas. Oxygenates commonly used include various alcohols and aliphatic ethers. Methyl tert-butyl ether (MTBE) is the most widely used and studied ether oxygenate and is added to gasoline at concentrations up to 15% by volume. Inhalation of fumes while fueling automobiles is the main source of human exposure to MTBE. Humans are also exposed when drinking water contaminated with MTBE. Epidemiological, clinical, animal, metabolic and kinetic studies have been carried out to address human health risks resulting from exposure to MTBE. MTBE is an animal carcinogen, but its human carcinogenic potential remains unclear. Because MTBE functions as a non-traditional genotoxicant, several mechanisms were suggested to explain its mode of action, such as, functioning as a cytotoxic as opposed to a mitogenic agent; involvement of hormonal mechanisms; or operating as a promoter instead of being a complete carcinogen. Some studies suggested that carcinogenicity of MTBE might be due to its two main metabolites, formaldehyde or tributanol. A role for DNA repair in MTBE carcinogenesis was recently unveiled, which explains some, but not all effects. The totality of the evidence shows that, for the majority of the non-occupationally exposed human population, MTBE is unlikely to produce lasting adverse health effects, and may in some cases improve health by reducing the composition of emitted harmful VOCs and other substances. A small segment of the population (e.g. asthmatic children, the elderly, and those with immunodeficiency) may be at increased risk for toxicity. However, no studies have been conducted to investigate this hypothesis. Concern over ground and surface water contamination caused by persistent MTBE has lead the Environmental Protection Agency (EPA) to proposed reducing or eliminating its use as a gasoline additive. The major potential alternatives to MTBE are other forms of ethers such as ethyl tert-butyl ether (ETBE) or tert-amyl methyl ether (TAME), and alcohols such as ethanol. More definitive studies are needed to understand the mechanism(s) by which aliphatic ethers may pose health and environmental impacts. The switch from MTBE to ethanol is not without problems. Ethanol costs more to produce, poses challenges to the gasoline distribution system, extends the spread of hydrocarbons through ground water in gasoline plumes, and in the short-term is unlikely to be available in sufficient quantity. Moreover, its metabolite acetaldehyde is a possible carcinogen that undergoes a photochemical reaction in the atmosphere to produce the respiratory irritant peroxylacetate nitrate (PAN). Congress is addressing whether the Clean Air Act Amendments (CAA) provisions concerning reformulated gasoline (RFG) should be modified to allow refineries to discontinue or lessen the use of oxygenates.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Assessment of the health effects of trichloroethylene

Authors: Kaneko, T; Wang, P; Sato, A (1997) Industrial Health 35:301-324. [Review] HERO ID: 706347

[Less] The epidemiological studies performed thus far have presented only limited evidence for the carcinogenicity . . . [More] The epidemiological studies performed thus far have presented only limited evidence for the carcinogenicity of trichloroethylene (TRI) to humans. However, these studies had drawbacks such as insufficient size of cohort, short observation period, and inadequate TRI exposure assessment; therefore, no concrete conclusion has been reached concerning TRI carcinogenicity to humans. Despite the limited epidemiological evidence as to the carcinogenicity of TRI, the International Agency for Research on Cancer (IARC) has changed the carcinogenicity classification of TRI from Group 3 (not classifiable as to carcinogenicity to humans) to Group 2A (probably carcinogenic to humans). In regard to the new classification by the IARC, the committee for occupational exposure limits of the Japan Society for Occupational Health has made a proposal that it is too early to classify the carcinogenicity of TRI as Group 2A and that it is proper to promote exposure control with the carcinogenicity being classified as 2B for the moment. There are species differences in TRI carcinogenicity, particularly between rats and mice. Although experimental studies have found no evidence that TRI induces liver cancer in rats, there is ample evidence that TRI promotes the development of liver cancer in mice, particularly in B6C3F1 mice. The carcinogenicity of TRI in this strain of mice may be based on an epigenetic mechanism rather on a genotoxic mechanism and the liver cancer may be induced only after TRI has been inhaled for a long period of time at concentrations high enough to cause cytotoxicity. Conversely, with no reports showing TRI-induced renal tumors in mice, the possibility has been suggested that this chemical induces such tumors in male rats. The species differences are mainly accounted for by differences in the metabolism of TRI between rats and mice. From a general survey of the literature, it can be concluded that TRI itself is not mutagenic. However, the conjugation of TRI with glutathione (GSH), a minor pathway of TRI metabolism, results in mutagenic metabolites in the kidney of rats. The acute toxicity of TRI is neurotoxicity based on its anesthetic action. An exposure to extremely high levels of TRI may cause the liver and kidney disorders. Repeated exposures to high levels of TRI may result in neuro-, hepato-, and/or nephrotoxicity. The main symptoms appearing after chronic exposure at low levels are neurological changes represented by subjective symptoms relating to central and autonomic nervous systems, or by a lowered conduction velocity of the nerves or a prolonged latency of the nerve responses. For the present, it is reasonable to use the neurological findings for establishing the reference values of TRI for both work and general environments. A value of 25 ppm (135 mg/m3) is proposed as a reference value for work environments, and 25-50 ppb (135-270 micrograms/m3) for the general environment (1/1,000 of the value for work environment).