scholarly journals Antibacterial activities and chemical characteristics of usnic acid and other secondary metabolites extracted from Flavoparmelia caperata lichen species using methanol as a solvent (LB293)

2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Ida Bixho ◽  
Elizabeth Scott ◽  
Michael Berger
2016 ◽  
Vol 75 (2) ◽  
pp. 186-193 ◽  
Author(s):  
Ana Maslać ◽  
Maja Maslać ◽  
Mirta Tkalec

Abstract Lichens are one of the most common air quality bioindicators. Airborne heavy metal pollution causes various physiological changes in lichens, but sensitivity to metal pollution is species specific. In this research, three lichen species (Parmelia sulcata, Flavoparmelia caperata and Evernia prunastri) were exposed to cadmium (50 mg L−1) in laboratory conditions. Photosynthetic efficiency of photosystem II and content of secondary metabolites were determined after one, three and eight days of exposure. In all investigated species treatment of lichen thalli with cadmium significantly changed Fv/Fm and RFd only after eight days of exposure. Quantification of metabolites showed a decreased content of the medullary depsidones salazinic acid (in P. sulcata) and protocetraric acid (in F. caperata) but increased content of cortical depside atranorin (in P. sulcata) and dibenzofurane usnic acid (in F. caperata) after cadmium exposure. However, no changes in secondary metabolites were found in E. prunastri. Results show that investigated species are relatively resistant to short-term cadmium-exposure and that secondary metabolites could have an important role in the protection of primary metabolism from negative cadmium impacts, at least in some species.


Botany ◽  
2018 ◽  
Vol 96 (4) ◽  
pp. 267-279 ◽  
Author(s):  
Mohanad Zraik ◽  
Tom Booth ◽  
Michele D. Piercey-Normore

Many lichen secondary metabolites have functions related to the environmental conditions of lichen habitats but few studies have compared soil characteristics with lichen species composition or their secondary products. The goal of this study was to investigate the relationship between soil characteristics with lichen species composition and secondary metabolites. Five locations were chosen in Manitoba, each with five sites (transects), and each transect with five quadrats (1 m × 1 m). All species were collected from each of the quadrats, presence of secondary metabolites was determined by thin layer chromatography, and soil characteristics were examined. The results revealed that rounded sand grains were significantly higher in southeastern Manitoba than in other locations, corresponding to a distinct species composition. Angular grains were significantly higher in northern locations, corresponding to a different group of species. Some of the significant relationships between soil characteristics and secondary metabolites include correlations of atranorin with pH, organic matter, and sand content; fumarprotocetraric acid with organic matter and sand content; and usnic acid with pH and organic matter. A better understanding of the role of lichens with respect to soil characteristics will be important for improving soil stabilization in land reclamation.


2015 ◽  
Vol 62 (4) ◽  
pp. 216-228 ◽  
Author(s):  
Carlos L. Céspedes ◽  
Julio E. Alarcon ◽  
Pedro Aqueveque ◽  
David S. Seigler ◽  
Isao Kubo

Secondary metabolites are involved in diverse functions in plants, including defense and protective processes. Information concerning the biosynthesis of secondary metabolites in plants points at a constitutive or induced chemical defense, generated for protection against a variety of phytopathogenic attacks. Our phytochemical studies are aimed at finding biopesticides of botanical origin. Some plant taxa of American distribution are toxic to selected insects, fungi and bacterial strains, and their effect has been associated with the presence of phenolics, phenylpropanoids and terpenes. We have isolated some diterpenes, triterpenes, sesquiterpene lactones, flavonoids, and phenylpropanoids from members of the plant families Araucariaceae, Asteraceae, Calceolariaceae, Celastraceae, and Rhamnaceae. In addition, we have identified a number of chemical derivatives of these compound classes from the plants. A major finding indicates that compounds or their derivatives that possess antioxidant, antifungal, insect growth regulator or insecticidal activity and enzymatic inhibitors are natural compounds. Insecticidal activities were assayed against strains of lepidopteran, dipteran, and coleopteran insect pests that affect many crops. Antifungal and antibacterial activities were assayed against phytopathogenic species of filamentous fungi and bacterial strains that are pests on many crops. Our results indicate that the plant-derived compounds obtained from the abovementioned plants have excellent insect growth regulatory activity and a good potency as antifungal agents. However, little is known about the effects of these natural compounds and their derivatives on insect pests. The natural compounds that we have isolated represent a valuable resource for future studies of plant chemical defense and the role of these substances in chemical ecology.


2009 ◽  
Vol 4 (7) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Daniel A. Dias ◽  
Sylvia Urban

Phytochemical investigation of the Australian lichen, Ramalina glaucescens resulted in the isolation of a new halogenated depside, 5-chlorosekikaic acid 5, together with (+)-usnic acid 1, sekikaic acid 2, atranorin 6 and parietin 7, the latter of which was isolated from the associated (co-occurring) lichen, X. parietina. Compound 5 is suspected to be an artifact of the isolation procedure. All structures were assigned using spectroscopic methods and mass spectrometry. In addition to the full characterization of 5, this report represents the first application of 2D NMR spectroscopy to complete the unequivocal chemical shift assignment for compounds 2 and 7. Compounds 1-2 and 5-7 all displayed varying degrees of antitumor activity (ranging from an IC50 of 15 μM to >44 μM) with compounds 1, 2 and 5 also displaying antibacterial properties. Of these, (+)-usnic acid 1 displayed the most significant antitumor and antibacterial activities.


Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 186 ◽  
Author(s):  
Xiuli Xu ◽  
Jiahui Han ◽  
Rui Lin ◽  
Steven Polyak ◽  
Fuhang Song

Two new piperazine-triones lansai E and F (1, 2), together with four known secondary metabolites lansai D (3), 1-N-methyl-(E,Z)-albonoursin (4), imidazo[4,5-e]-1,2,4-triazine (5), and streptonigrin (6) were isolated from a deep-sea-derived Streptomycetes sp. strain SMS636. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compound 4 exhibited moderate antibacterial activities against Staphylococcus aureus and methicillin resistant S. aureus (MRSA) with Minimum Inhibitory Concentration (MIC) values of 12.5 and 25 μg/mL, respectively. Compound 6 displayed significant antibacterial activities against S. aureus, MRSA and Bacillus Calmette-Guérin (BCG) with MIC values of 0.78, 0.78 and 1.25 μg/mL, respectively.


1976 ◽  
Vol 24 (5) ◽  
pp. 663 ◽  
Author(s):  
JA Elix

Parmelia (subgen. Xanthoparmelia) barbatica, Parmelia (subgen. Xanthoparmelia) burmeisterii and Parmelia (subgen. Xanthoparmelia) pseudohypoleia are described as new from the Australian Capital Territory and New South Wales. The former two species are the first representatives of this subgenus to be described in which usnic acid, barbatic acid and 4-O-demethylbarbatic acid are the major secondary metabolites.


2009 ◽  
Vol 55 (No. 4) ◽  
pp. 154-158 ◽  
Author(s):  
A.U. Akpinar ◽  
S. Ozturk ◽  
M. Sinirtas

This paper is aimed to investigate the effects of some terricolous lichens on soil bacteria’s growth in natural conditions. It is focused on species of bacteria and also on numbers of colony of soil specimens that were taken from substrates of three different terricolous lichen species. <I>Peltigera rufescens</I> (Weiss) Humb., which has not secondary metabolites, did not show an inhibition effect on soil bacteria. However, <I>Peltigera neckerii</I> Hepp ex Müll. Arg., which has secondary metabolites, has a negative effect on soil bacteria’s growth. Besides, it was observed that<I> Cladonia rangiformis</I> Hoffm., which has many kinds of secondary metabolites, has the highest inhibition effect among the studied species. For this reason, we think that in the next researches, it is convenient to investigate elaborately by soil analysis the effect of lichen’s secondary metabolites that have an effect on soil mineralization, on soil bacteria’s growth.


1981 ◽  
Vol 13 (3) ◽  
pp. 253-258 ◽  
Author(s):  
Dianne Fahselt

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.


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