Usnea Usnic acid

Usnea diffracta Dill, ex Adans. U. longissima Acharius Lao Jium Xiu Song Lo (whole plant) Barbaric acid, usnic acid, diffractaic acid, ramalic acid, lichenin.54 Treat throat discharges, malaria, headache, cough, a detoxicant. 

C-Methylation also features in the biosynthesis of usnic acid (Figure 3.41), an antibacterial metabolite found in many lichens, e.g. Usnea and Clado-nia species, which are symbiotic combinations of alga and fungus. However, the principal structural modification encountered involves phenolic oxidative coupling (see page 28). Two molecules of methylphloracetophenone are incorporated, and these are known to derive from a pre-aromatization methylation reaction and not by... 

Dibenzofurans (Phe furan Phe) include various fungal infection-induced plant antifungal compounds (phytoalexins) such as the Rosaceae-derived cotonefuran (from Cotoneaster lactea) and a-pyrofurans (from Pyrus communis). Usnic acid from lichens (notably Usnea species) is anti-mycobacterial, anti-mitotic, an uncoupler and a potent inhibitor of plant protoporphyrinogen synthetase and 4-hydroxphenylpyruvate dioxygenase. 

Usnic acid Usnea articulata (lichen) Uncoupler (< 1)... 

Usnic acid (7.53)—a highly biologically active dibenzofuran—is a phenol oxidation product of an acylphlorogludnol. It is produced by numerous lichens, including several Usnea species. Apart from its antibiotic and anti-leukemic activity, it has insect anti-feedant activity. Its presence may account for the observation that many lichens are resistant to serious insect attack. 

Usnic Acid. 2I6 Diacetyl 7t9-dihydraxy 8i9b-di-methyl-It3(2H,9bH)-dibenzofurandione usninic acid usnein Usniacin. C H,407 mol wt 344.31. C 62.79%. H 4.68%, O 32.53%. Antibacterial substance found in lichens. Isolation from varieties of Usnea barbota (L.) Wigg., Usneaceae Rochleder, Heidi> Ann. 48, If (1843) Widman Ann. 310, 230 (1900) 324, 139 (1902). Isoin from Ramalina reticulata Marshak, Public Health Reports 62, 3 (1947) Stark et of., J. Am. Chem. Soc. 72, 1819 (1950). Occurs in nature in both the d- and /-forms as well as a racemic mixture. Structure Curd, Robertson, J. Chem. Soc. 1937, 894 Schopf, Ross, Ann. 546, (1941) Barton, Brunn, /. Chem. Soc. 1953, 603. Resolution of ( )-usnic acid Dean et ai, ibid. 1250. Synthesis Barton et a/., ibid. 1956, 530. Biosynthesis in vitro Penttila, FaJes, Chem. Commun 1966, 656. Abs config of (+)-fomv S. Huneck et aL, Tetrahedron Letters 22, 351 (1981). 

Though animal testing has shown that excessively large amounts of usnic acid, one of the components of usnea, is toxic to animals, no toxicity has been noted in human use. Usnea also readily absorbs heavy metals in potentially toxic amounts. This is particularly problematic in far northern latitudes. Generally, the amount of usnea taken internally will... 

Most safety concerns reported for usnea are based on studies of the compound usnic acid, which is present at a concentration of 1 to 3% (Cansaran et al. 2006,2008 Cocchietto et al. 2002). Data regarding this isolated compound may not apply directly to products or extracts made from usnea. 

Cansaran, D., D. Kahya, E. Yurdakulol, and O. Atakol. 2006. Identification and quantitation of usnic acid from the lichen Usnea species of Anatolia and antimicrobial activity. Z. Naturfor. 61(11/12) 773. 

Foti, R.S., L.J. Dickmann, J.A. Davis, et al. 2008. Metabolism and related human risk factors for hepatic damage by usnic acid containing nutritional supplements. Xenobiotica 38(3) 264-280. Guo, L., Q. Shi, J.L. Fang, et al. 2008. Review of usnic acid and Usnea barbata toxicity. /. Environ. Sci. Health C Environ. Carcinog. Ecotoxicol. Rev. 26(4) 317-338. 

Pramyothin, R, W. Janthasoot, N. Pongnimitprasert, S. Phrukudom, and N. Ruangrungsi. 2004. Hepatotoxic effect of (+) usnic acid from Usnea siamensis Wainio in rats, isolated rat hepatocytes and isolated rat liver mitochondria. /. Ethnopharmacol. 90(2-3) 381-387. 

USG Paper Fiiier 1. See Calcium sulfate Usnea barbata Usnea barbata extract. See Lichen (Usnea barbata) extract Usnein. See Usnic acid Usnic acid... 

Usnic acid is found in oak moss and used in perfumes. Usnea barbata is a lichen species that occurs in oak moss. Cross-reactions between structurally related lichen compounds are unclear, but must be considered (Mitchell 1965 Hausen et al. 1993). Contact dermatitis in vaginal ovules and contact allergy in deodorant spray has been reported (Hein and Tarnick 1987 Rafanelli et al. 1995). The patch-test concentration is 0.1% pet. Allergic reactions are rare or uncommon. 

Usnea diffracta Usnic acid Usnic acid Yamamoto (1990)... 

Usnea flexilis Usnic acid Protocetraric acid Salazinic acid Protocetraric acid Salazinic acid Yoshimura et al. (1989)... 

C, pressure 350bar, time 6h, flow rate 20kg CO2 per h for the extraction of usnic acid from Usnea barbata. For microscale extraction, acetone is recommended, as most lichen substances are soluble in this solvent. The use of the microextractor shown in the monograph of Asahina and Shibata (1954) cannot be recommended because of the risk of inflammation of the solvent. A simple and safe device is shown in Fig. 4. 

Nishitoba Y, Nishimura H, Nishiyama T, Mizutani J (1987) Lichen acids, plant growth inhibitors from Usnea longissitna. Phytochemistry 26 3181-3185 Nolan TJ, Murphy D (1940) The chlorination of derivatives of orsellinic acid. Sci Proc R Dublin Soc 22 315-319 Norrestam R, Glehn M von, Wachtmeister CA (1974) Three-dimensional structure of usnic acid. Acta Chem ScandB 28 1149-1152... 

Wright J, Drtina GJ, Roberts RA, Paquette LA (1988) A cohvergent synthesis of triquinane sesterterpenes. Enantioselective synthesis of (-)-retigeranic acid A. J Am Chem Soc 110 5806-5817 Yamamoto Y (1985) Tissue cultures of Usnea rubescens and Ramalina yasudae and production of usnic acid in their cultures. Agric Biol Chem 49 3347-3348... 

It was first isolated by German scientist W. Knop in 1844 and first synthesised between 1933 and 1937 by Curd and Robertson. Usnic acid was identified in many genera of lichens including Usnea, Cladonia, Lecanora, Ramalina, Evernia, Parmelia and Alectoria. 

Okuyama E, Umeyama K, Yamazaki M et al (1995) Usnic acid and diflractaic acid as analgesic and antipyretic cmnpmients of Usnea diffracla. Planta Med 61 113—115... 

Marcano V, Rodriguez-Alcocer V, Morales Mendez A (1999) Occurrence of usnic acid in Usnea laevis Nylander (lichenized ascomycetes) from the Venezuelan Andes. J Ethnopharmacol 66 343-346... 

Rankovic B, Kosanic M, Stanojkovic T et al (2012) Biological activities of Toninia Candida and Usnea barbata together with their norstictic acid and usnic acid constituents. Int J Mol Sci 13 ... 

Odabasoglu et al. (2006) investigated gastroprotective effect of usnic acid isolated from Usnea longissima in the indomethacin-induced gastric ulcers in... 

In the study described by Rankovic et al. (2012), lichen compounds, norstictic acid isolated from Toninia Candida and usnic acid from Usnea barbata, exhibited high antioxidant potential in vitro, but it should be noted that the norstictic acid had a larger antioxidant capacity. 

Behera BC, Verma N, Sonone A et al (2006) Determination of antioxidative potential of lichen Usnea ghattensis in vitro. LWT Eood Sci Technol 39 80-85 Cabrera C (1996) Materia Medica—Usnea spp. Eur J Herbal Med 2 11-13 Cardarelli M, Serino G, Campanella L et al (1997) Antimitotic effects of usnic acid on different biological systems. Cell Mol Life Sci 53(8) 667-672 Clare G (2012) The in vitro mammalian chromosome aberration test. Methods Mol Biol 817 69-91... 

Usnea complanata Psoromic acid Usnic acid Depsidones Dibenzofuranes APP APP Antioxidant activity Antimicrobial activity Cardiovascular protective activity Mahadiketal. (2011) Behera et al. (2012)... 

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