Usnic acid

344.32

344.32

231-456-0

8517|5890|5889

DTXSID0040123

... yellowish /colored/ pigment.|Yellow orthorombic prisms from acetone|Crystalline yellow solid

2932999099

118

1.4

1.5±0.1 g/cm3

204 °C

605.4°C at 760 mmHg

219.1±23.6 °C

1.643

Solubility at 25 deg C (g/100 ml): water, <0.01

2-8ºC

3E-15mmHg at 25°C

D16 +509.4° (c = 0.697 in chloroform)

Pale yellow silky needles; slightly soluble in water /Sodium salt dihydrate/|Occurs in nature in both the d- and l-forms as well as a racemic mixture.

25-50/53

22-24/25-61-60-45

HP5270000

T,N

P264, P270, P273, P301+P310, P301+P312, P321, P330, P391, P405, P501

H301

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

|Danger|H301 (87.39%): Toxic if swallowed [Danger Acute toxicity, oral]|P264, P270, P273, P301+P310, P301+P312, P321, P330, P391, P405, and P501|Aggregated GHS information provided by 222 companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Several cases of clinically apparent acute liver injury have been attributed to commercial dietary supplements that contain usnic acid. “LipoKinetix” was one such supplement advertised as a weight loss and body building supplement. Each tablet contained sodium usniate (100 mg), norephedrine (25 mg), diiodothyronine (100 mg), yohimbine (3 mg) and caffeine (100 mg). The product has been linked to multiple instances of acute liver injury. The time to onset was 2 to 12 weeks and the clinical presentation resembled acute viral hepatitis with onset of fatigue and nausea, followed by jaundice. The pattern of serum enzyme elevations was hepatocellular, with marked elevations in serum ALT and minimal increases in alkaline phosphatase levels. Liver biopsy demonstrated acute hepatocellular necrosis and inflammation. Immunoallergic features (fever, rash and eosinophilia) were not common and autoantibodies were usually not present. Recovery was rapid with stopping the dietary supplement, but some cases were severe and led to acute liver failure and either death or need for emergency liver transplantation. Instances of acute hepatitis have also been reported with other multi-ingredient dietary supplements that contain usnic acid, but much more rarely than with LipoKinetix which was withdrawn from distribution after a FDA warning letter. Rare instances of hepatotoxicity have also been reported with use of lichen based teas known as Kombucha tea, but whether these were due to usnic acid or another contaminant of the tea was not shown.

LD50 Dog iv 40 mg/kg|LD50 Rabbit iv 30 mg/kg|LD50 Rat iv 30 mg/kg|LD50 Rabbit oral 500 mg/kg|For more Non-Human Toxicity Values (Complete) data for USNIC ACID (6 total), please visit the HSDB record page.

Usnic acid is one of the most common and abundant lichen metabolites.|Usnic acid is widely distributed in species of Cladonia (Cladoniaceae),Usnea (Usneaceae), Lecanora (Lecanoraceae), Ramalina (Ramalinaceae), Evernia, Parmelia (Parmeliaceae) and other lichen species.

Usnic acid is a furandione found uniquely in lichen that is used widely in cosmetics, deodorants, toothpaste and medicinal creams as well as some herbal products. Taken orally, usnic acid can be toxic and has been linked to instances of clinically apparent, acute liver injury.

Herbal and Dietary Supplements

Recent studies in which the anti-inflammatory activity of (+)-usnic acid was compared to that of ibuprofen using the rat paw edema assay (acute effects) and the cotton pellet assay (chronic effects) showed (+)-usnic acid to be significantly effective in both assays at an oral dose of 100 mg/kg adn comparable to ibuprofen at the same dose.|/EXPL THER: / Commercially obtained (+)-usnic acid was shown to inhibit cytopathic effects of Herpes simplex type 1 and polio type 1 viruses when administered on filter paper discs which were placed on virus-infected African green monkey kidney (BS-C-1) cells.|/EXPL THER:/ Oral administration of usnic acid at 30 and 100 mg/kg resulted in significant analgesic effects as determined by the acetic acid-induced writhing- and tail pressure tests. Usnic acid administered orally at doses of 100 and 300 mg/kg exhibited significant antipyretic activity as evaluated through lipopolysaccharide-induced hyperthermia.|/Usnic acid/ inhibits the growth of multi-resistant strains of Staphylococcus aureus, enterococci and mycobacteria.|For more Therapeutic Uses (Complete) data for USNIC ACID (8 total), please visit the HSDB record page.

Substances that destroy fungi by suppressing their ability to grow or reproduce. They differ from FUNGICIDES, INDUSTRIAL because they defend against fungi present in human or animal tissues. (See all compounds classified as Antifungal Agents.)|Agents used to treat trichomonas infections. (See all compounds classified as Antitrichomonal Agents.)|Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection. (See all compounds classified as Anti-Infective Agents.)

The physiological effects of usnic acid /was investigated/ in two cultured species of the lichen alga Trebouxia. Exposing Trebouxia to the sodium salt of usnic acid resulted in the inhibition of growth and photosynthesis, an incr in membrane permeability and immobilization of zoospore. /Usnic acid, sodium salt/|The mechanism of action expressed by usnic acid remains speculative. (+)-Usnic acid has been shown to be an uncoupler of oxidative phosphorylation in mouse-liver mitochondria at levels of 1 uM.|The accumulation of usnic acid can be stimulated by the inhibition of photosynthesis, suggesting a possible role of glucose in regulating enzymes of phenol synthesis.|Experiments show that usnic acid is an allelopathic agent, inhibiting moss spore germination and that its effectiveness is pH dependent.|In vitro, usnic acid has a slight inhibitory action against leukotriene biosynthesis in bovine polymorphonuclear leukocytes by a specific enzyme interaction rather than acting as an antioxidant against the peroxidation process, or as a scavenger, or even as a source of free radicals.

/SRP:/ Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poison A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poison A and B/

/HUMAN EXPOSURE STUDIES/ ... Usnic acid gave negative patch test reactions in subjects found to be allergic to lichen substances. ... Positive test reactions against usnic acid in 0.35% of tested patients.|/HUMAN EXPOSURE STUDIES/ Two forest workers affected with allergic contact dermatitis, which occurred only during work in forest areas, showed positive patch test reactions to lichens containing usnic acid and to isolated usnic acid. Lichens are plants composed of fungi living in symbiosis with algae. Usnic acid, one of the lichenic acids which accumulates in lichenized fungi, is a monobasic acid with dibenzofuran structure and antibiotic properties. Dibenzofuran is chemically related to furocoumarans. Lichens are plentiful in temperate zone forests and allergy to usnic acid represents some part of the "cedar-poisoning" problem in British Columbia. Geographical distribution of lichens containing usnic acid suggests that allergy to usnic acid will be found to be more common than presently recognized.|/SIGNS AND SYMPTOMS/ The only reported adverse effects /concerning usnic acid toxicity in humans/ are local irritation and allergic contact dermatitis, sometimes accompanied by conjunctivitis.|/SPECIAL STUDIES/ In vitro challenges were /conducted/ on primary and continuously cultured cells /to determine/ the cytotoxic action of usnic acid alone or as a component of oral care formulations. The cell strains KB human epidermoid and gingival keratinocytes and fibroblasts (taken from human biopsies), usnic acid alone or as part of a formulation did not /result/ in any sign of cytotoxicity. ...|For more Human Toxicity Excerpts (Complete) data for USNIC ACID (6 total), please visit the HSDB record page.

2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzofurandione

1,3(2H,9bH)-Dibenzofurandione, 2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-: ACTIVE|Antibacterial substance found in lichens. Isolation from varieties of Usnea barbata.

Cosmetics -> Antimicrobial