Таниновая кислота химические свойства, назначение, производство
Описание
Tannic acid is a naturally occurring plant polyphenol and can
be found in practically all aerial plant tissues. Tannic acid was
historically used for the treatment of diarrhea, topically to dress
skin burns and rectally for treatment of unspecified rectal
disorders. Pharmaceutical use of tannic acid is discontinued
due to safer and better alternatives.
An unusually high incidence of esophageal cancer has been
noted in areas of South Africa, where a sorghum rich in tannins
is consumed. A positive relation has been observed between the
tannin content of the sorghum and the incidence of esophageal
cancer.
Химические свойства
Tannic acid, C14H10O9, also known as digallic acid, tannin, and gallotannin, is a yellowish powder that decomposes at 210°C (410°F). Tannic acid is derived from nutgalls. It is soluble in water and alcohol,and is insoluble in acetone and ether. Tannic acid is used in tanning,textiles, and as an alcohol denaturant. An amorphous form of tannic acid, also known as pentadigalloylglucose, exists with the formula C76H52O46. It is a yellowish to brownish powder that is very soluble in alcohol and ether.It also decomposes between 210 and 215°C (410 and 419 °F). This form is used to clarify wine or beer, as a reagent,and as a mordant in dyeing.
Вхождение
Reported found in Quercus oliver and related species; Tara (Caesalpinia spinosa); and various sumac species, including Rhus semialata, R. coriaria, R. glabra and R. typhia.
Использование
Tannic Acid is a sequestrant that refers to a mixture of hydrolyzable
tannins of a more complex structure than gallic acid. it is used in
clarifying beer and wine. see tannins.
Подготовка
Tannic acid is obtained by solvent extraction from the nutgalls or the excrescences that form on the young twigs of Quercus olivier and allied species of Quercus L.; from the seed pods of Tara (Caesalpinia spinosa); or from the nutgalls of various sumac species, including Rhus semialata, R. coriaria, R. glabra and R. typhia.
Определение
tannic acid: A yellowish complexorganic compound present in certainplants. It is used in dyeing as a mordant.
Общее описание
Light yellow to tan solid with a faint odor. Sinks and mixes with water.
Реакции воздуха и воды
Water soluble. Gradually darkens on exposure to air and/or light
Профиль реактивности
Glycerite decomposes at 210° to carbon dioxide and pyrogallol, which can form irritating vapors [USCG, 1999]. Incompatible with salts of heavy metals, alkaloids, gelatin, albumin, starch, oxidizing substances-e.g., permanganates, chlorates; lime water [Merck].
Опасность
Toxic by ingestion and inhalation. Questionable
carcinogen.
Угроза здоровью
Inhalation causes irritation of nose and throat, coughing, and sneezing. Ingestion may cause gastric disturbance. Contact with eyes causes irritation.
Пожароопасность
Special Hazards of Combustion Products: Decomposes at 210° to carbon dioxide and pyrogallol, which can form irritating vapors.
Промышленное использование
Quebracho is the most common tannic acid derivative widely used in flotation. The
main phenolic nuclei present in Quebracho are resorcinol/phloroglucinol and catechol/pyrogallol.
Quebracho is commercially available in the following three forms: (a) standard
Quebracho, a direct hot-water extract from the heart-wood with adjusted pH (Qu–O), (b)
sulfited Quebracho, in which sulfonic acid groups have been introduced (Qu–S) and (c)
aminated Quebracho (Qu–A), where amine groups are introduced to ordinary Quebracho,
rendering the polymer amphoteric (iso-electric point at pH 7). Each of these types of
Quebracho has a different depressing effect.
Профиль безопасности
Poison by intravenous
and intraperitoneal routes. Questionable
carcinogen with experimental tumorigenic
data. When heated to decomposition it
emits acrid smoke and irritating fumes.
Синтез
Tannic acid is synthesized by extraction from Nutgalls (Chinese or Turkish), Myrobalans (Terminalia SP.), Oakbark, etc. It is also synthesized by esterification of Glucose with meta-galloylgallic acid.
Экологическая судьба
Tannins and tannic acid occur naturally in plants. Essentially all
wood and plant tissue contain tannins. Therefore, biodegradation
is expected to be the major environmental fate process
for tannic acid.
Таниновая кислота препаратная продукция и сырье
сырьё
препарат