Notes on the chemistry of some lichens, including four species of ...

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44 John. A. Elix and Tor Tønsberg GRAPHIS SCRIPTA 16 (2004) previous accounts of the chemical constituents of this species (Leuckert et al. 1995), up to four dibenzofurans are listed. Specimen examined: Norway. Rogaland: Sauda, 2003, Tønsberg 31824 (BG). Lepraria multiacida Aptroot Contains: atranorin (major), stictic acid (minor), constictic acid (minor), salazinic acid (trace), cryptostictic acid (trace), norstictic acid (trace), 3,7-di-O-methylstrepsilin (minor), strepsilin (trace),7-O-methylstrepsilin (trace), together with traces of a number of other dibenzofurans. Note. 3,7-di-O-methylstrepsilin and 7-Omethylstrepsilin have not previously been reported as occurring in nature. Strepsilin and related compounds are new to Lepraria (see also below under L. xerophila). Specimen examined: Brazil. Minas Gerais: Catas Altas, 1997, Aptroot 40640 a40 (ABL isotype). Lepraria vouauxii (Hue) R.C.Harris Contains: pannaric acid 6-methyl ester (major), 4-oxypannaric acid 6-methyl ester (minor), 4oxypannaric acid 2-methyl ester (trace), pannaric acid (trace), pannaric acid 2-methyl ester (trace to minor), methyl porphyrilate (trace to minor), ± porphyrilic acid (trace), ± atranorin (trace.) Note. The two accessory substances were present in Nash 3872. In a previous account of the chemical constituents of this species (Leuckert et al. 1995), three dibenzofurans are listed. Specimens examined: USA. Arizona: Cochise Co., 1972, Nash 3872 (ASU); Santa Cruz Co., 1997, Biringer 53 (ASU). Lepraria xerophila Tønsberg (ined.) Chemotype I Contains: pannaric acid 6-methyl ester (major), atranorin (minor), methyl porphyrilate (trace to minor), ± porphyrilic acid (trace), ± pannaric acid (trace), ± unknown dibenzofuran (trace). Specimens examined: Mexico. Baja California: 1995, Nash 38224 (ASU). USA. California: Santa Barbara Co., San Miguel Island, 1998, Tønsberg 25399 (BG). Chemotype II Contains: norascomatic acid (major), strepsilin (minor), isostrepsilic acid (minor), atranorin (minor) and chloroatranorin (minor). Specimens examined: USA. California: Santa Barbara Co., Santa Rosa Island, 1994, Nash 32904 (3 samples tested: all identical chemically; ASU). Note. To our knowledge this is the first report of the dibenzofuran isostrepsilic acid from a lichen. It has previously been demonstrated only from the mycobiont of Usnea orientalis Motyka grown under culture conditions (Kon et al. 1997). The new species, L. xerophila, is widely distributed in the westernmost part of the Greater Sonoran Region. Pyrrhospora quernea (Dicks.) Körb. Chemotype I Contains: thiophanic acid (major), isoarthothelin (submajor), 2,4,7-trichloronorlichexanthone (minor), 2,5-dichloronorlichexanthone (minor), 2,7-dichloronorlichexanthone (trace), arthothelin (trace). Note. Unfortunately 7-chloroemodin occurs very close to isoarthothelin on HPLC, so if it were present it would be swamped by the latter.
GRAPHIS SCRIPTA 16 (2004) <strong>Notes</strong> on lichen chemistry including Lepraria 45 Specimen examined: Denmark. Sønderjylland: 1989, Jacobsen 6106 (BG). Chemotype II Contains: 6-O-methylarthothelin (major), arthothelin (major), thiophanic acid (minor), thiophaninic acid (minor), 2,4-dichloronorlichexanthone (minor), 7-chloroemodin (minor = orange pigment), atranorin (trace) and 4,5dichloronorlichexanthone (trace). Specimen examined: USA. Washington: San Juan Co., Lopez Island, 1998, Tønsberg 26950 (BG). Chemotype III Contains: thuringione (major), arthothelin (major), thiophanic acid (minor), 2,4-dichloro- 3-O-methylnorlichexanthone acid (minor), 2,4dichloronorlichexanthone (minor), 7-chloroemodin (minor = orange pigment), atranorin (trace), 4,5-dichloro-3-O-methylnorlichexanthone (trace) and 4,5-dichloronorlichexanthone (trace). Note. 2,4-dichloro-3-O-methylnorlichexanthone acid has not previously been reported as occurring in nature. Specimen examined: USA. California: San Luis Obispo Co., 1992, Tønsberg 18442 (BG). Rhizocarpon leptolepis Anzi Contains: friesiic acid (major). Note. The depsido-depsone friesiic acid was recently reported as a new substance from the lichen Hypocenomyce friesii (Elix et al. 2004) where it is the diagnostic substance (Timdal 1984; as friesii unknown). According to Timdal (1984) this substance is also the diagnostic substance in H. caradocensis. Although we tested only one specimen of Rhizocarpon leptolepis, this substance may also prove to be a diagnostic constituent in this species. Specimen examined: Norway. Buskerud: Sigdal, 1987, Timdal 4929 (O). References Elix, J. A. & Tønsberg, T. 1999. <strong>Notes</strong> on the chemistry of some lichens from Norway. Graphis Scripta 10: 4-6. Elix, J. A., Tønsberg, T. & Wardlaw, J. H. 2004. The structure of friesiic acid. Bibliotheca Lichenologica 88: 103-109. Kon, Y., Iwashina, T., Kashiwadani, H., Wardlaw, J. H. & Elix, J. A. 1997. A new dibenzofuran, isostrepsilic acid, produced by cultured mycobiont of the lichenized ascomycete Usnea orientalis. Journal of Japanese Botany 72: 67-71. Laundon, J. R. 1981. The species of Chrysothrix. Lichenologist 13: 101-121. Leuckert, C., Kümmerling, H. & Wirth, V. 1995. Chemotaxonomy of Lepraria Ach. and Leproloma Nyl. ex Crombie, with particular reference to Central Europe. Bibliotheca Lichenologica 58: 245-259. Timdal, E. 1984. The genus Hypocenomyce (Lecanorales, Lecideaceae), with special emphasis on the Norwegian and Swedish species. Nordic Journal of Botany 4: 83- 108. Tønsberg, T. 1992. The sorediate and isidiate, corticolous, crustose lichens in Norway. Sommerfeltia 14: 1-331. Tønsberg, T. 1994. Chrysothrix flavovirens sp. nov. - the sorediate counterpart of C. chrysophthalma. Graphis Scripta 6: 31-33.
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