Especial compounds of lichens

Shibata, Shoji

doi:10.1007/978-3-662-26784-4_16

Cited by 6 publications

(5 citation statements)

References 253 publications

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“…Psoromic acid (PA) is a β-orcinol depsidone widely scattered throughout the lichen species; however, it is predominantly present in three genera: Usnea , Psoroma, and Alectoria . Although PA was first isolated in the year 1880, its structure was resolved in 1958 [ 20 ]. Of late, a mounting body of research evidence has shown diverse pharmaceutical properties of PA, including anti-tumour, antigenotoxic, antibacterial, antiplasmodial, cytotoxic, antioxidant, and osteoporosis-inducing characteristics, as well as cardiovascular effects [ 18 , 21 , 22 , 23 , 24 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

Antimycobacterial, Enzyme Inhibition, and Molecular Interaction Studies of Psoromic Acid in Mycobacterium tuberculosis: Efficacy and Safety Investigations

Hassan

Šudomová²,

Berchová‐Bímová

et al. 2018

JCM

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The current study explores the antimycobacterial efficacy of lichen-derived psoromic acid (PA) against clinical strains of Mycobacterium tuberculosis (M.tb). Additionally, the inhibitory efficacy of PA against two critical enzymes associated with M.tb, namely, UDP-galactopyranose mutase (UGM) and arylamine-N-acetyltransferase (TBNAT), as drug targets for antituberculosis therapy were determined. PA showed a profound inhibitory effect towards all the M.tb strains tested, with minimum inhibitory concentrations (MICs) ranging between 3.2 and 4.1 µM, and selectivity indices (SIs) ranging between 18.3 and 23.4. On the other hand, the standard drug isoniazid (INH) displayed comparably high MIC values (varying from 5.4 to 5.8 µM) as well as low SI values (13.0–13.9). Interestingly, PA did not exhibit any cytotoxic effects on a human liver hepatocellular carcinoma cell line even at the highest concentration tested (75 µM). PA demonstrated remarkable suppressing propensity against UGM compared to standard uridine-5'-diphosphate (UDP), with 85.8 and 99.3% of inhibition, respectively. In addition, PA also exerted phenomenal inhibitory efficacy (half maximal inhibitory concentration (IC50) value = 8.7 µM, and 77.4% inhibition) against TBNAT compared with standard INH (IC50 value = 6.2 µM and 96.3% inhibition). Furthermore, in silico analysis validated the outcomes of in vitro assays, as the molecular interactions of PA with the active sites of UGM and TBNAT were unveiled using molecular docking and structure–activity relationship studies. Concomitantly, our findings present PA as an effective and safe natural drug plausible for use in controlling tuberculosis infections.

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Section: Introductionmentioning

confidence: 99%

Antimycobacterial, Enzyme Inhibition, and Molecular Interaction Studies of Psoromic Acid in Mycobacterium tuberculosis: Efficacy and Safety Investigations

Hassan

Šudomová²,

Berchová‐Bímová

et al. 2018

JCM

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“…A further milestone in lichen chemistry is attributable to the works of Japanese researchers Yasuhiko Asahina and Shoii Shibata, who-together with their co-authors-elucidated the chemical structures of numerous compounds, described their synthesis and introduced the identification of lichen substances by micro-recrystallization (e.g. Asahina, 1936;Shibata, 1958Shibata, , 2000; and citations therein). In the second half of the 20th century, thinlayer chromatography became a routine technology, and was broadly applied to study the presence of compounds in diverse lichens.…”

Section: Introductionmentioning

confidence: 99%

Lichens—a promising source of bioactive secondary metabolites

Boustié

Grube

2005

Plant Genet. Resour.

308

192

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Lichen-forming fungi are unique organisms, producing biologically active metabolites with a great variety of effects, including antibiotic, antimycobacterial, antiviral, anti-inflammatory, analgesic, antipyretic, antiproliferative and cytotoxic activities. However, only very limited numbers of lichen substances have been screened for their biological activities and their therapeutic potential in medicine. This is certainly due to the difficulties encountered in identification of the species, collection of bulk quantities, and the isolation of pure substances for structure determination and testing activity. Recently, possibilities for bypassing some of these former difficulties have arisen by the introduction of new techniques. This includes axenic cultivation for production of the genuine compounds or new ones, extraction of focused compounds, or synthesis of natural products or their derivatives for testing. Utilizing these new opportunities, the discovery of novel active metabolites, which could serve as lead compounds, is significantly facilitated. At the same time, the evolution of secondary metabolite patterns is studied using phylogenetic approaches. Yet, the genetic background of the complex chemical patterns is poorly understood. The scattered occurrence of some compounds suggests that their production evolved either in parallel or that ancient biosynthetic pathways are abandoned in many lineages. At least, studies on polyketide synthase genes from different lichen groups suggest a high level of gene paralogy. In this context, clades of orthologous polyketide synthase genes, which are often shared with distantly related non-lichenized fungi, can roughly be identified by their sequence similarity and their similar patterns of substitution rates. The functional assignment of paralogs is nevertheless difficult and reasonable only in a few cases. A global approach of the lichen metabolomic features appears to be essential in developing new and viable biotechnological processes which could afford suitable amounts of unique lichen compounds.

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“…The organic compounds which occur in lichens have been studied by chemists interested in chemical structures and biosynthesis (Asahina and Shibata, 1954;Shibata, 1958). These compounds are usual1 referred to as lichen acids, although not all of them are in fact acids.…”

Section: Introductionmentioning

confidence: 99%

Metal‐complex Formation by Lichen Compounds

Iskandar

Syers

1972

Journal of Soil Science

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The formation of soluble complexes, frequently coloured, when solid lichen compounds were shaken with water suspensions of biotite, granite, and basalt indicated that chemical weathering had occurred. The formation of colourless complexes and the adsorption of the dissolved lichen compound or complex by the silicate phase complicate the interpretation of the spectrophotometric analysis data. Lichen compounds invariably released greater amounts of Ca than of Mg, Fe, and A1 from the silicates and, for each lichen compound, the release of Ca was usually greater from biotite than from granite or basalt. Release of cations from the silicate materials resulted largely from metal-complex formation rather than from reactions directly involving hydrogen ions. Citric, salicylic, and p-hydroxybenzoic acids and EDTA, used as control organic acids, usually released considerably greater amounts of cations from the silicates than did the lichen compounds, consistent with the higher water solubility of the control organic acids. Similar amounts of Fe, All Ca, and Mg were released from the silicates by solutions of the lichen compounds and by solid lichen compounds. Lichen compounds are sufficiently soluble in water to form soluble metal complexes and to effect chemical weathering of minerals and rocks.

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Especial compounds of lichens

Cited by 6 publications

References 253 publications

Antimycobacterial, Enzyme Inhibition, and Molecular Interaction Studies of Psoromic Acid in Mycobacterium tuberculosis: Efficacy and Safety Investigations

Antimycobacterial, Enzyme Inhibition, and Molecular Interaction Studies of Psoromic Acid in Mycobacterium tuberculosis: Efficacy and Safety Investigations

Lichens—a promising source of bioactive secondary metabolites

Metal‐complex Formation by Lichen Compounds

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