Artificial Re-Establishment of Lichens IV. Comparison between Natural and Synthetic Thalli of Usnea Strigosa

1985 ◽  
Vol 17 (2) ◽  
pp. 149-165 ◽  
Author(s):  
V. Ahmadjian ◽  
J. B. Jacobs
Keyword(s):  
Functional Role ◽  
Usnic Acid ◽  
Secondary Compounds ◽  
Outer Cortex ◽  
Alcohol Dehydration ◽  
Lichen Thallus ◽  
The Common ◽  
Fibril Morphology ◽  
Related Compounds ◽  
Natural And Synthetic

AbstractSynthetic thalli of Usnea strigosa produced the same fibril morphology and secondary compounds as natural thalli. The outer cortex of synthetic lichens was covered with crystals of usnic acid and compounds related to norstictic acids. The common presence on the fibrils of lichen acids suggests that these compounds have a functional role in the symbiosis. During alcohol dehydration, crystals of usnic acid dissolved and left impressions in the mucilage around the symbionts. The impressions were valuable indicators of the position of crystals in the lichen thallus. Crystal impressions of usnic acid were common on the cortical hyphae and were seen also on the surface of algal cells. The crystal impressions were larger in the synthetic lichen than in natural thalli. Impressions of norstictic acid and related compounds were not seen.

The gastropod Arion fuscus prefers cyanobacterial to green algal parts of the tripartite lichen Nephroma arcticum due to low chemical defence

2009 ◽  
Vol 42 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Johan ASPLUND ◽  
Yngvar GAUSLAA
Keyword(s):  
Usnic Acid ◽  
Chemical Defence ◽  
Secondary Compounds ◽  
Distribution Limit ◽  
Green Algal ◽  
Defensive Role ◽  
N Starvation ◽  
And Control ◽  
Terricolous Lichen ◽  
Acetone Rinsing

AbstractAlthough the tripartite terricolous lichen Nephroma arcticum is easily accessible to lichen-feeding gastropods, grazing marks are mainly restricted to localized cephalodia with N-fixing Nostoc. We tested if this gastropod preference for cephalodia can be explained by differences in carbon based secondary compounds (CBSCs) in cyanobacterial versus green-algal tissues. CBSCs were non-destructively removed from air-dry thalli by 100% acetone. Compound deficient and control thallus parts were offered to the slug Arion fuscus and grazing preferences were quantified by area measurements in ArcGIS™. The concentrations of CBSCs (phenarctin, usnic acid, nephroarctin and methyl gyrophorate) in thallus parts with and without cephalodia were quantified with HPLC. Compared to purely green-algal parts, cephalodial parts with adjoining fungal tissues contained less defensive compounds, and were preferred by A. fuscus. The cephalodia themselves do not contain any CBSCs. After acetone rinsing, A. fuscus did not discriminate between green-algal and cyanobacterial parts. The results were consistent with the hypothesis that CBSCs in green-algal parts of N. arcticum play a herbivore-defensive role. It is further hypothesized that grazing of cephalodia may lead to N-starvation and reduced growth of N. arcticum thalli in southern portions of its range where lichenivorous gastropods are more abundant. This may play a role in shaping the southern distribution limit of this arctic-boreal lichen species.

Lichen Products of Cladonia Stellaris and C. Rangiferina Maintained Under Artificial Conditions

1981 ◽  
Vol 13 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Dianne Fahselt
Keyword(s):  
Light Intensity ◽  
Light Availability ◽  
Usnic Acid ◽  
Dry Weight ◽  
Lichen Thallus

AbstractLichen thallus fragments were maintained in a growth cabinet under four differing conditions of light intensity. Levels of usnic acid and atranorin did not differ significantly from the control under any of the treatments. However, perlatolic acid and fumarprotocetraric acid per unit dry weight of thallus were dependent upon light availability.

scholarly journals Usnic acid and Triacylglycerides Production by the Cultured Lichen Mycobiont of Ramalina celastri

2014 ◽  
Vol 9 (2) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Alejandra T. Fazio ◽  
Mónica T. Adler ◽  
Marta S. Maier
Keyword(s):  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Usnic Acid ◽  
Culture Conditions ◽  
High Yield ◽  
Acid Methyl ◽  
Solid Media ◽  
Lichen Thallus ◽  
The Impact ◽  
Very High

A strain of the lichen mycobiont of Ramalina celastri, isolated from ascospores, was cultured axenically on two solid media containing high amounts of the carbon source: sucrose in MY10 and mannitol in BMRM. Usnic acid, the major cortical lichen metabolite, was produced by the colonies grown on MY10, with a very high yield (7.9%) in comparison with that in the lichen thallus. Mycelia grown on BMRM did not produce the lichen secondary metabolite and rendered triacylglycerides (8.5%) instead. Analysis by GC-MS of the fatty acid methyl esters revealed the presence of oleic, palmitic and stearic acids as the main triacylglyceride constituents. The present results highlight the impact of the culture conditions on the lichen mycobiont secondary metabolism and confirm that MY10 is a useful medium to obtain usnic acid from mycobionts in the laboratory.

Secondary Compounds Following Northsouth Transplantation of Three Lichen Species

1981 ◽  
Vol 13 (3) ◽  
pp. 253-258 ◽  
Author(s):  
Dianne Fahselt
Keyword(s):  
Usnic Acid ◽  
Secondary Compounds ◽  
Lichen Species ◽  
Quantitative Variation

AbstractWide north-south transplants were made with three lichen species, Parmelia cumberlandia, Cladonia turgida and Stereocaulon saxarile. The objective was to determine whether thallus chemistry would be altered due to wide geographic displacement of thallus segments from the control locations. Significant quantitative variation in microchemistry was observed among thalli of P. cumberlandia and among those of C. turgida, but there were no qualitative or quantitative effects on the lichen products, usnic acid, atranorin, constictic, stictic, norstictic, fumarprotocetraric and lobaric acids, due to transplantation.

Carbamylphosphonates and Related Compounds—Nuclear-Magnetic-Resonance and Infrared Spectra

1967 ◽  
Vol 21 (1) ◽  
pp. 9-15 ◽  
Author(s):  
T. H. Siddall ◽  
C. A. Prohaska
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Infrared Spectra ◽  
Proton Magnetic Resonance ◽  
Structural Features ◽  
Slow Rotation ◽  
The Common ◽  
Related Compounds ◽  
Great Evidence ◽  
Nitrogen Bond

Proton magnetic resonance and infrared spectra were obtained for 44 carbamylphosphonates and related compounds, the common structural features being the grouping As with ordinary amides, slow rotation is observed around the carbonyl-to-nitrogen bond, but the chemical shift between nitrogen substituents is three to five times as great. Evidence is presented for long range coupling of phosphorus to protons in N-substituents. Correlations are observed between the carbonyl and phosphoryl stretching frequencies and substituents both on nitrogen and on phosphorus.

Mass spectral fragmentation studies in usnic acid and related compounds

1974 ◽  
Vol 8 (1) ◽  
pp. 129-146 ◽  
Author(s):  
James P. Kutney ◽  
Ignacio H. Sanchez ◽  
Trevor H. Yee
Keyword(s):  
Usnic Acid ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Related Compounds

Difference in secondary compounds and chlorophylls between fibrils and main stems in the lichen Usnea longissima suggests different functional roles

2007 ◽  
Vol 39 (5) ◽  
pp. 491-494 ◽  
Author(s):  
Line Nybakken ◽  
Yngvar Gauslaa
Keyword(s):  
Quantitative Data ◽  
Usnic Acid ◽  
Secondary Compounds ◽  
Forest Canopies ◽  
Functional Roles ◽  
Wide Range ◽  
Usnea Longissima ◽  
Lichen Compounds ◽  
Fungal Genus

Usnea is a species-rich and widespread lichenized fungal genus of well-lit parts of forest canopies (Motyka 1936, 1947; Clerc 1998). The bright greenish colour of these beard lichens reflects the presence of usnic acid in the cortex, which forms a thin, but dense sleeve around the trebouxioid photobiont in the outermost parts of the medulla. Usnic acid, a widely distributed dibenzofuran derivative produced by various mycobiont genera, strongly absorbs UV-B, but also the shortest PAR wavelengths (e.g. McEvoy et al. 2006, M. McEvoy, K. A. Solhaug and Y Gauslaa unpublished). Depending on species (Halonen et al. 1998), Usnea also contains a wide range of UV-B absorbing depsidones and depsides, though these are usually assumed to be confined to the medulla. Quantitative data on lichen compounds are rare in Usnea species, particularly with respect to the intrathalline variation.

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