Nutr Cancer. ;62(1) doi: / Natural phenolic compounds from medicinal herbs and dietary plants: potential use for. Phenolic compounds, ubiquitous in plants are an essential part of the human diet , and are of considerable interest due to their antioxidant properties. In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group (—OH) bonded directly to an .
Hydroquinone is a reducing agent and is used extensively as a photographic developer, an antioxidant, and a stabilizer in paints, varnishes, motor fuels and oils. Many derivatives of hydroquinone have been used as bacteriostatic agents. Pyrogallic acid also serves as a developer in photography as well as a mordant for wool, a dyeing agent for furs and hair, an antioxidant in lubricating oils, and a reducing agent for gold, silver and mercury salts.
It is used for staining leather, preparing synthetic drugs, and for maintaining anaerobic conditions for bacterial growth. Its use is based primarily on its property of being easily oxidized in alkaline solutions even by atmospheric oxygen.
It acts as a solvent, disinfectant, germicide and sanitizer in commercial mixtures used in all hospital areas, instruments and equipment. It is used in the rubber and food-storage industries and serves as a dye-stuff carrier for polyester fibres and a disinfectant for cutting oils, timber and paper.
The cresols have wide applications in the phenolic resin, explosive, petroleum, photographic, paint and agricultural industries. They are ingredients of many household disinfecting solutions. Cresol is also an additive to lubricating oils and a component of degreasing compounds and paintbrush cleaners.
The chlorophenols are intermediates in the synthesis of dyes, pigments and phenolic resins. Certain chlorophenols are used directly as mould inhibitors, antiseptics, disinfectants and anti-gumming agents for gasoline.
Pentachlorophenol and its sodium salt are used to protect various industrial products from microbiological attack. These include wood and other cellulosic products, starches, adhesives, proteins, leather, finished yarn and cloth, photographic solutions, oils, paints, latex and rubber.
Pentachlorophenol is used in the construction of boats and buildings, for mould control in petroleum drilling and production, and as an antibacterial agent in disinfectants and cleaners. It is also useful in the treatment of cable coverings, canvas belting, nets, poles and cooling-tower water. Pentachlorophenol is equally important in controlling termites in wood and insulating board, powder post beetles and other wood-boring insects, and slime and algae.
It is also used in manufacturing herbicides, and as an agent to inhibit fermentation in various materials. Some chlorophenols are used as intermediates and preservatives in the paint, textile, cosmetics and leather industries.
The tetrachlorophenols and their sodium salts have been used as fungicides and wood preservatives. Phenol is readily absorbed through the skin and from the gastroenteric tract, while phenol vapours are readily absorbed into the pulmonary circulation. The toxic effects of phenol are related directly to the concentration of free phenol in the blood. In humans, acute phenol poisoning results in vasodilation, cardiac depression, hypothermia, coma and respiratiory arrest.
Ingested phenol causes intense abdominal pain, and mouth burning occurs. Acute renal failure may also result. In animals, the signs of an acute intoxication are very similar, regardless of the site or the mode of administration of this compound. The predominant effects are exerted upon the motor centres in the spinal cord, resulting in tremors and severe convulsions. Chronic phenol poisoning is reported comparatively infrequently today.
Severe cases are characterized by systemic disorders such as digestive disturbances, including vomiting, difficulty in swallowing, ptyalism, diarrhoea and anorexia; by nervous disorders, with headache, fainting, vertigo and mental disturbances; and possibly by ochronosis and an eruption on the skin.
The prognosis is grave when there is extensive damage to the liver and kidneys. Ingestion of a dose of 1 g of phenol has been lethal to humans. Approximately every second reported case of acute phenol poisoning has resulted in death. Generally speaking, the signs and symptoms of intoxication by di- and trihydroxy phenols resorcinol, hydroquinone, pyrogallol resemble that of phenol toxicity.
The antipyretic action of resorcinol is more marked than that of phenol. The approximate lethal dose of resorcinol, in aqueous solution, for rabbits is 0. Hydroquinone is more toxic than phenol. Lethal doses have been reported as 0. Skin breakdown and irritation has been reported with dermal application of pyrogallol. Eventually with repeated contact, skin sensitization can occur.
The symptoms observed in acute intoxications in humans resemble closely the signs displayed by experimental animals. These may include vomiting, hypothermia, fine tremors, weakness, muscular incoordination, diarrhoea, loss of reflexes, coma, asphyxia, and death by respiratory failure.
Estimated lethal doses of aqueous pyrogallol are 1. Pentachlorophenol and its sodium salt are capable of inducing discomfort and local or systemic effects.
A solution containing 0. The symptoms of severe systemic intoxication include loss of appetite, respiratory difficulties, anaesthesia, hyperpyrexia, sweating, dyspnoea and a rapidly progressive coma.
Fine dusts and sprays of pentachlorophenol or sodium pentachlorophenate will cause painful irritation to the eyes and upper respiratory tract, respiratory tract and the nose. Dermatoses in humans caused by tetrachlorophenol and its sodium salt have been reported; these included papulofollicular lesions, sebaceous cysts and marked hyperkeratosis.
Occupational exposure to chlorophenols increases the risk of soft-tissue sarcomas. Chlorophenoxy derivatives including 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, 2,4,5-trichlorophenoxypropionic acid, and 2,4-D salts and esters are discussed elsewhere in this chapter and Encyclopaedia. Signs of intoxication due to o -, m - and p -chlorophenol in rats include restlessness, increased rate of respiration, rapidly developing motor weakness, tremors, clonic convulsions, dyspnoea and coma.
It could be through conference attendance, group discussion or directed reading to name just a few examples. We provide a free online form to document your learning and a certificate for your records.
Already read this title? Exclusive web offer for individuals. Characterization and Analysis 1st Edition Leo M. Add to Wish List. Toggle navigation Additional Book Information. Description Table of Contents Editor s Bio.
Summary Phenolic compounds, one of the most widely distributed groups of secondary metabolites in plants, have received a lot of attention in the last few years since the consumption of vegetables and beverages with a high level of such compounds may reduce risks of the development of several diseases.
Villegas-Ochoa, and Gustavo A. Editor s Bio Leo M. Request an e-inspection copy. Phenolics in Food and Nutraceuticals. Found in coal tar and creosote. Butylated hydroxy anisole BHA or 2-tert-butylmethoxyphenol An antioxidant Catechol, or 1,2-benzenediol, or 2-hydroxyphenol, Present in skin irritants in poison ivy Resorcinol, An antiseptic and disinfectant which used in the treatment of psoriasis, eczema, and other skin conditions. Hydroquinone, or 1,4-benzenediol, or 4-hydroxyphenol, Used in photograph developing solutions 1-Napthol Used in organic synthetic chemistry 4-tert-Butylcalixarene or calixarenes capable of forming coordination complexes with a wide variety of metal ions.
Phenolic Compounds in Plants Back to Top. Calculate Compound Interest Formula. Compound Daily Interest Formula. Compound Interest Formula Monthly.
Jun 30, Phenolic compounds are a large class of plant secondary metabolites, showing a diversity of structures, from rather simple structures, e.g. Phenolic compounds including simple phenols and phenolic acids, hydroxycinnamic acid derivatives and flavonoids are bioactive substances occurring widely. The natural phenolic compounds have received increasing interest in the last years, since a great amount of them can be found in plants and consumption of.