Crystal violet or gentian violet (also known as methyl violet 10B or hexamethyl pararosaniline chloride ) is a triarylmethane dye used as histological stains and in the Gram method classifies bacteria. Crystalline violets have antibacterial, antifungal, and anthelmintic properties and were once important as topical antiseptics. The use of medically dyes has been replaced by more modern medicines, although it is still listed by the World Health Organization.
The name "gentian violet" was originally used for a mixture of methyl pararosanilin dyes (methyl violet), but is now often considered synonymous for violet crystals. Its name refers to its color, like fiber flower petals; it is not made of gentians or of violet.
Video Crystal violet
Produksi
A number of possible routes can be used to prepare the violet crystal. The original procedure developed by the German chemists Kern and Caro involved the reaction of dimethylillin with phosgene to give benzophenone 4,4? -bis (dimethylamino) (keton Michler) as an intermediary. This is then reacted with additional dimethylineiline in the presence of phosphorous oxychloride and hydrochloric acid.
Dyes can also be prepared with condensate formaldehyde and dimethyilinine to provide leuco dye:
- CH 2 <3 < N
3 > 2 -> CH (C 6 H 4 N (CH 3 ) 2 ) < sub> 3 H 2 O
Secondly, this colorless compound is oxidized into a colorless cationic form: (Typical oxidizing agent is manganese dioxide).
- CH (C 6 H 4 N (CH 3 ) 2 ) 3 HCl 1 / 2 O 2 -> [C (C 6 2 3 Cl H 2 3 sub> O
Maps Crystal violet
Color dye
When dissolved in water, the dye has a blue-violet color with maximum absorbance at 590 nm and an extinction coefficient of 87,000 M -1 cm -1 . The color of the dye depends on the acidity of the solution. At pH 1.0, the dye is green with maximum absorption at 420 nm and 620 nm, whereas in a strong acid solution (pH -1.0), yellow dye with maximum absorption at 420 nm.
Different colors are the result of different molecular charge states of dye. In yellow form, the three nitrogen atoms carry a positive charge, in which two are protonated, while the green color corresponds to the dye form with two positively charged nitrogen atoms. At neutral pH, the two additional protons are lost to the solution, leaving only one nitrogen atom positively charged. P K a for the loss of two protons is about 1.15 and 1.8.
In an alkaline solution, a nucleophilic hydroxyl ion attacks the electrophilic central carbon to produce a triphenylmethanol form without color or carbinol from the dye. Some triphenylmethanol also form under very acidic conditions when a positive charge on a nitrogen atom leads to an increase in the electrophilic character of the central carbon, allowing nucleophilic attacks by water molecules. This effect produces a slight fade from the yellow color.
Apps
Nonmedical
Violet crystal is not used as a textile dye. Instead, it is used for coloring paper and as a component of blue and black inks for printing, ballpoint pens, and inkjet printers. It is also used for coloring various products such as fertilizer, antifreez, detergent, and leather.
Dyes are also used as histologic staining, especially Gram staining to classify bacteria.
When conducting gel-metal electrophoresis, violet crystals can be used as non-toxic DNA dyes as an alternative to fluorescent, intercalative dyes such as ethidium bromide. Used in this way, it may either be incorporated into agarose gel or applied after the electrophoresis process is complete. Used at concentrations of 0.001% and allowed to stain the gel after electrophoresis for 30 minutes, it can detect at least 16 ng of DNA. Through the use of methyl orange counterstain and more complex staining methods, the sensitivity can be increased further up to 8 ng DNA. When violet crystals are used as an alternative to fluorescent stains, there is no need to use ultraviolet illumination; this has made the popular purple crystals as a means of avoiding UV-induced DNA damage when conducting in vitro DNA cloning .
In biomedical research, violet crystals can be used to color the cell nucleus that is adherent. In this application, violet crystals work as an intercalation dye and allow quantification of DNA that is proportional to the number of cells.
In forensics, gentian violet is used to develop fingerprints. Violet crystals are also used as tissue stains in the preparation of light microscopy parts. In the laboratory, a solution containing violet crystals and formalin is often used to repair and stabilize cells that grow in tissue culture to preserve it and make it visible, since most cells are colorless. Sometimes it is also used as a cheap way to put identification marks on laboratory mice; because many strains of lab rats are albino, purple color remains in their fur for several weeks.
In body piercing, gentian violet is usually used to mark the location for placing piercings, including surface piercings.
Medical
Gentian violet has antibacterial, antifungal, antihelminthic, antitrypanosomal, antiangiogenic, and antitumor properties.
It is used medically for these properties, especially for dentistry, and is also known as "pyoctanin" (or "pyoctanine"). Usually used for:
- Marks the skin for preparation of surgery and allergy testing;
- Treating Candida albicans and associated fungal infections, such as thrush, yeast infections, various types of tinea (ringworm, athlete's foot, itchy athlete);
- Treating impetigo; it is used primarily before the advent of antibiotics, but is still useful for people who may be allergic to isiline pens.
In resource-limited settings, gentian violet is used to manage burns, inflammation of the umbilical cord (omphalitis) in the neonatal period, oral candidiasis in HIV-infected patients and oral ulcers in children with measles.
Veterinary
Due to its antimicrobial activity, Gentian violet can be used for the treatment of skin and eye infections in farm animals, and fish ich in fish. However, it is not acceptable for use in cultivation in most developed countries.
History
Synthesis
The violet crystal is one of the methyl violet components, the first dye synthesized by Charles Lauth in 1861. From 1866, methyl violet was produced by the Saint-Denis-based firm of Poirrier et Chappat and marketed under the name "Violet de Paris". It is a mixture of pararosaniline tetra-, penta- and hexamethylated.
Crystal violet itself was first synthesized in 1883 by Alfred Kern (1850-1893) who worked in Basel at firms Bindschedler and Busch. To optimize the difficult synthesis of using toxic gases of phosgene (carbonyl chloride), Kern co-operates with the German chemist Heinrich Caro at BASF. Kern also found that by starting with diethyililin rather than dimethylillin, he was able to synthesize a closely related purple dye now known as C.I. 42600 or C.I. Basic purple 4.
Gentian violet
The name "gentian violet" (or Gentianaviolett in German) is considered to have been introduced by German pharmacist Georg GrÃÆ'¼bler, who in 1880 started a company in Leipzig specializing in the sale of staining reagents for histology.. Gentian violet stains marketed by GrÃÆ'¼bler may contain a mixture of methylosaniline dye that is methylated. This stain proved popular and in 1884 was used by Hans Christian Gram to tarnish the bacteria. He praised Paul Ehrlich for anilin-gentian violet blend. The purple gentian GrÃÆ'¼bler may be very similar, if not identical, to the purple meth marine, which has been used as a dye by Victor AndrÃÆ' © Cornil in 1875.
Although the name of gentian violet continues to be used for histologic stains, the name is not used in dye and textile industries. The dye composition is not specified and different suppliers use different mixtures. In 1922, the Commission on Biological Stain appointed a committee headed by Harold Conn to see the suitability of different commercial products. In his book Biological Stains , Conn explains gentian violet as "a poorly defined mix of violet pillars".
German eye doctor Jakob Stilling is credited with the discovery of gentian violet antiseptic properties. He published a monograph in 1890 about the bactericidal effect of a solution which he called "pyoktanin", which may be a mixture of aniline dyes similar to gentian violet. He established collaboration with E. Merck & amp; Co. to market "Pyoktanin caeruleum" as an antiseptic.
In 1902, Drigalski and Conradi found that although violet crystals inhibit the growth of many bacteria, it has little effect on Bacillus coli ( Escherichia coli ) and Bacillus typhi ( Salmonella typhi ), which is a Gram-negative bacterium. A much more detailed study of the gentian violet effect of GrÃÆ'¼bler on various bacterial strains was published by John Churchman in 1912. He found that most Gram-positive bacteria are sensitive to dyes, while most Gram-negative bacteria are not, and are observed. that dyes tend to act as bacteriostatic agents rather than bactericidal.
Precautions
One study in mice showed a dose-related carcinogenic potential in several different organ sites. The Food and Drug Administration in the US (FDA) has determined that gentian violet has not been demonstrated by sufficient scientific data to be safe for use in animal feed. The use of gentian violet in animal feed causes fodder to be forged and is a violation of the Federal Food, Drug and Cosmetic Act in the US. On June 28, 2007, the FDA issued "import alerts" on farms that lift seafood from China because unapproved antimicrobials, including gentian violet, have been consistently found in the product. The FDA report states:
"Like MG [malachite green], CV [crystal violet] is readily absorbed into fish tissue from water exposure and reduced metabolically by fish to leuco moiety, leucocrystal violet (LCV).Several studies by the National Toxicology Program report that carcinogenic and mutagenic effects crystal violet in rodents, leuco form induces kidney, liver and lung tumors in mice. "
Common side effects of gentian violet are skin and cloth dyeing, but can be easily cleared from the skin with bleach and water solutions. However, if used on ulcers or open sores, it can cause tattoos. Generally considered safe for use in children and lactating mothers. This has even been applied to the mouths and lips of premature babies, and has a long history of safe use. Jack Newman recommends the use of gentian violet as a point in his "Candida Protocol", although it limits the amount of time suggested for use by breastfeeding mothers. La Leche League recommends gentian violet for canker sores on the nipple. However, in large numbers, gentian violet can cause ulceration of the mouth and throat of the baby and is associated with oral cancer and has been linked to cancer in the digestive tract of other animals.
In popular culture
In Catch-22 , medical officers are depicted using gentian violet on the feet and gums as a panacea. This may be because in World War I American soldiers returned after the leave was irrigated with gentian violet to prevent sexually transmitted diseases.
In Picnic at Batu Gantung , the orphan's father told how he had been punished by an orphanage guard, who 'painted my head with violet fibers'.
Engineering students in Canada use gentian violet to color their skin and jackets, a tradition begun to honor World War 2 Naval Engineers whose purple armbands will leave their skin dyed after countless days spent in the boiler room.
See also
References
Further reading
- "Methylrosanilinium chloride (gentian violet)", WHO model prescribes information: drugs used in skin diseases , Geneva: World Health Organization, 1997, p.Ã, 70, ISBNÃ, 92-4-140106-0 .
External links
- Drug Information Portal: Crystal violet , National US Medical Library, National Institutes of Health .
Source of the article : Wikipedia
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