Reference

Extraction of (+) usnic acid

Extraction of (+) usnic acid. (Robertet, P., et Cie., Fr.). Fr. Demande FR 2347361 4 Nov 1977, 6 pp. (French). (France). CODEN: FRXXBL. CLASS: IC: C07D307-91. APPLICATION: FR 76-11964 9 Apr 1976. DOCUMENT TYPE: Patent CA Section: 63 (Pharmaceuticals) (+)-Usnic acid (I) [7562-61-0] is extd. from the waxy residue left from lichen abs. extns. using solvents such as benzene, hexane, acetone, CHCl3, or Cl2C:CHCl. The soln. is boiled, filtered, and cooled, after which I ppts. I yields are 20-25% and 35-40% with benzene and hexane, resp. For example, waxy residue from 1 kg of oak moss from Yugoslavia or Morocco was dissolved in benzene 6L. The hot soln. was filtered and cooled using a Buchner funnel. The alc. soln. left from the abs. extn. was also filtered after being evapd. to half its original vol. A 20-25% yield of I was obtained.

Adaptive significance of O-methylated lichen depsides and depsidones

Adaptive significance of O-methylated lichen depsides and depsidones. Lawrey, J. D. (Dep. Bot., Ohio State Univ., Columbus, Ohio, USA). Lichenologist, 9(2), 137-42 (English) 1977. CODEN: LCHNB8. DOCUMENT TYPE: Journal CA Section: 3 (Biochemical Interactions) The O-methylated squamatic acid [569-36-8] and evernic acid [537-09-7] inhibited spore germination of Funaria hygrometrica, Ceratodon purpureus, and Mnium cuspidatum, whereas hydroxylated norstictic acid [571-67-5] and the cumarone derivs. l-usnic acid [7562-61-0] and d-usnic acid [6159-66-6] showed no inhibition of moss spore germination. O-methylated lichen depsides and depsidones are thought to be produced by morphol. advanced groups of lichens. The adaptive advantage that prodn. of O-methylated compds. confers upon lichens is possibly due to the inhibitory activity of these compds. on moss spore germination inasmuch as niche overlap between cryptogams is often considerable.