Extraction of antibiotic usnic acid - from lichen wax residues remaining after extraction of perfume components

摘要

(+) Usnic acid (I) is extracted from the residues after alcohol extn. of lichen waces obtd. from Oak mosses or tree mosses, (I) being extracted by benzene, hexane, acetone, or a chlorinated solvent such as chloroform or trichloroethylene. The lichens are extracted with benzene or hexane, the solns. evaporated and the residual wax extracted with alcohol to obtain perfume components. The residue after this stage is then extractd, pref. with 6 litres boiling benzene per kilo of wax. Cooling the benzene soln. gives (I), 20-25% by weight (I) being obtd. when the original extn. was made with benzene, and 35-40% when the original extraction was with hexane, these percentages being calculated on weight of wax residues. (I) is antibiotic and intermediate for antibiotics. The residues from which (I) is extracted are waste prods. from the perfumery industry.