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16
result(s) for
"Sangvichien, Ek"
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Eumitrins I–K: three new xanthone dimers from the lichen Usnea baileyi
by
Phan-Si-Nguyen Dong
,
Ek Sangvichien
,
Hioki Yusuke
in
Absolute configuration
,
Antibacterial activity
,
antibacterial properties
2023
In the continuing discovery and structure elucidation of natural xanthone dimers, which are still rarely reported in absolute configuration, three new xanthone dimers, eumitrins I–K (
1
–
3
) were isolated from the lichen
Usnea baileyi
, a rich source of natural xanthone dimers. Their structures were elucidated unambiguously by spectroscopic analyses, including high-resolution electrospray ionization mass spectrometry (HRESIMS), 1D and 2D nuclear magnetic resonance spectroscopy (1D and 2D NMR). The absolute configuration of all three compounds was established through DP4 probability and ECD calculation. All compounds revealed weak activity for their enzymatic inhibition against α-glucosidase and tyrosinase, as well as antibacterial activity.
Graphical abstract
Journal Article
Exploring the Xylariaceae and its relatives
by
Thamvithayakorn, Pisit
,
Ruchikachorn, Nutthaporn
,
McCloskey, Sirirath
in
Agricultural production
,
Biodiversity
,
Biological activity
2023
The Xylariaceae and its relatives rank as one of the best-known members of the Ascomycota. They are now well recognized for their diversity, global distribution, ecological activities and their outstanding novel metabolites with wide ranging bioactivity.
Journal Article
Should we hail the Red King? Evolutionary consequences of a mutualistic lifestyle in genomes of lichenized ascomycetes
2022
The Red Queen dynamic is often brought into play for antagonistic relationships. However, the coevolutionary effects of mutualistic interactions, which predict slower evolution for interacting organisms (Red King), have been investigated to a lesser extent. Lichens are a stable, mutualistic relationship of fungi and cyanobacteria and/or algae, which originated several times independently during the evolution of fungi. Therefore, they represent a suitable system to investigate the coevolutionary effect of mutualism on the fungal genome. We measured substitution rates and selective pressure of about 2000 protein‐coding genes (plus the rDNA region) in two different classes of Ascomycota, each consisting of closely related lineages of lichenized and non‐lichenized fungi. Our results show that independent lichenized clades are characterized by significantly slower rates for both synonymous and non‐synonymous substitutions. We hypothesize that this evolutionary pattern is connected to the lichen life cycle (longer generation time of lichenized fungi) rather than a result of different selection strengths, which is described as the main driver for the Red Kind dynamic. This first empirical evidence of slower evolution in lichens provides an important insight on how biotic cooperative interactions are able to shape the evolution of symbiotic organisms. Lichens are a stable, mutualistic relationship of fungi and cyanobacteria and/or algae, which originated several times independently during the evolution of fungi. Our results show that independent lichenized clades are characterized by significantly slower rates for both synonymous and non‐synonymous substitutions, as predicted by the Red King dynamic for mutualistic relationships. We hypothesize that this evolutionary pattern is connected to the lichen life cycle (longer generation time of lichenized fungi) rather than a result of different selection strengths on specific genes in lichenized fungal taxa.
Journal Article
A molecular phylogeny of Pilocarpaceae Zahlbr., including a new species of Tapellaria Müll. Arg. and new records of foliicolous lichenized fungi from Thailand
by
Wei, Jiang-Chun
,
Wei, Tie-Zheng
,
Sangvichien, Ek
in
Aqueous solutions
,
Ascospores
,
Bayesian analysis
2020
The phylogeny of foliicolous taxa in Pilocarpaceae was reconstructed using Bayesian and maximum likelihood analyses of concatenated ITS and mtSSU sequences. Sixty-six new partial sequences representing 36 taxa were generated and 29 sequences were downloaded from GenBank. Our results indicate that Lasioloma R. Sant. is nested within a paraphyletic Calopadia Vězda, whereas Fellhanera Vězda is polyphyletic and the phylogenetic relationships of Eugeniella Lücking et al. and Sporopodium Mont. with Fellhanera require further investigation. In addition, Tapellaria parvimuriformis W. C. Wang & J. C. Wei is described as a new species from Khao Yai National Park, Thailand, and is characterized by its small muriform ascospores, grey campylidia with a pale base, and short conidia. Eight new records of foliicolous lichens for Thailand are also listed.
Journal Article
A molecular study of the lichen genus Byssoloma Trevisan (Pilocarpaceae) with descriptions of three new species from China
by
Wei, Jiang-Chun
,
Sangvichien, Ek
,
van den Boom, Pieter
in
Apothecia
,
Aqueous solutions
,
Ascospores
2020
A molecular phylogeny of the genus Byssoloma is inferred from mtSSU sequences using Bayesian and maximum likelihood phylogenetic analyses. Byssoloma subdiscordans is resolved as sister to B. citricola rather than to the B. leucoblepharum clade, the B. subundulatum group (species with a compact apothecial margin) is shown to be a monophyletic group, and three species belonging to this group are described as new to science from Hainan Province in China: B. brunneodiscum W. C. Wang & J. C. Wei, with dark brown apothecia, crystals in the excipulum and the presence of 2,5,7-trichloro-3-O-methylnorlichexanthone; B. rubrofuscum W. C. Wang & J. C. Wei, with red-brown apothecia, 3–6-septate ascospores and the presence of 5,7-dichloro-3-O-methylnorlichexanthone; B. melanodiscocarpum W. C. Wang & J. C. Wei, with pure black apothecia, a K+ olive-black hypothecium and the presence of thiophanic acid.
Journal Article
Comparative Study on the Antimicrobial Activities and Metabolic Profiles of Five Usnea Species from the Philippines
by
Notarte, Kin Israel R.
,
Sangvichien, Ek
,
Santiago, Krystle Angelique A.
in
Acids
,
Antibiotics
,
Antimicrobial agents
2023
The rapid emergence of resistant bacteria is occurring worldwide, endangering the efficacy of antibiotics. Hence, there is a need to search for new sources of antibiotics that either exhibit novel structures or express a new mechanism of action. The lichen Usnea, with its wide range of unique, biologically potent secondary metabolites, may solve this problem. In this study, Usnea species were collected in the Northern Philippines, identified through combined morphological and biochemical characterization, and tested for antimicrobial activities against the multidrug-resistant ESKAPE pathogens, i.e., Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae, two standard antibiotic-sensitive test bacteria, and a yeast. A total of 46 lichen specimens were collected and later identified as Usnea baileyi (10), U. diffracta (10), U. glabrata (12), U. longissima (4), and U. rubicunda (10). The results show that the crude extracts of the Usnea species exhibited promising in vitro inhibitory activities against standard antibiotic-sensitive (E. faecalis ATCC 29212) and multidrug-resistant (methicillin-resistant S. aureus and E. faecalis) Gram-positive bacteria. Additionally, lichen compounds of representative specimens per species were identified and profiled using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The detection of lichen acids (LA) via HPLC showed the presence of 24 peaks of lichen acids. TLC-bioautography identified the bioactive lichen acids as alectronic acid, connorstictic acid, consalazinic acid, diffractaic acid, echinocarpic acid, erythrin acid, galbinic acid, hypoconstictic acid, hyposalazinic acid, hypostictic acid, lobaric acid, menegazzaic acid, micareic acid, pannarin, salazinic acid, stictic acid, and usnic acid. Our study highlighted the wide spectrum of opportunities for using lichens for the discovery of potential antimicrobial agents.
Journal Article
A preliminary study of Badimia Vězda (Ramalinaceae) in East Asia
2021
The tropical areas of eastern Asia contain a high diversity of foliicolous lichens, including various species of the genus Badimia. Badimia xanthocampylidia W. C. Wang & J. C. Wei is described from tropical rainforests in southern China and Thailand based on morphology, chemistry, and combined mtSSU, ITS and nrLSU sequences. It is characterized by a pale green thallus with yellow verrucae and bright yellow campylidia and the presence of isousnic acid. Three other species, B. multiseptata Papong & Lücking, B. pallidula (Kremp.) Vězda and B. polillensis (Vain.) Vězda, are discussed and the genus Badimia is newly reported from China. A worldwide key to currently known species in the genus is presented.
Journal Article
Architrypethelium murisporum (Ascomycota, Trypetheliaceae), a remarkable new lichen species from Thailand challenging ascospore septation as an indicator of phylogenetic relationships
by
Luangsuphabool, Theerapat
,
Piapukiew, Jittra
,
Lumbsch, H. Thorsten
in
Ascomycota
,
Ascospores
,
Coniferous forests
2018
Architrypetheliummurisporum Luangsuphabool, Lumbsch & Sangvichien is described for a crustose lichen occurring in dry evergreen forest in Thailand. It is characterised by a green to yellow-green corticated thallus, perithecia fused in black pseudostromata with white rim surrounding the ostiole and small, hyaline and muriform ascospores. Currently, all species in the genus Architrypethelium have transversely septate ascospores, hence the discovery of this new species indicates that ascospore septation is variable within the genus, similar to numerous other groups of lichen-forming ascomycetes. Phylogenetic analyses of two loci (mtSSU and nuLSU) supported the position of the new species within Architrypethelium . This is the first report of the genus in Southeast Asia.
Journal Article
A new checklist of lichenized fungi occurring in Thailand
by
Vongshewarat, Kajohnsak
,
Aptroot, André
,
Saipunkaew, Wanaruk
in
Biodiversity
,
classification
,
Fungi
2017
A new revised checklist of lichenized fungi in Thailand is presented, including 1, 292 species. Recent work on the taxonomy of these organisms in Thailand resulted in an enormous increase in our knowledge of the lichen biota of the country – the current checklist includes more than twice as many species as the previous catalogue published 15 years ago – and phylogenetic studies resulted in numerous changes in the generic classification of lichenized fungi. Hence, a new checklist is here presented summarizing the current knowledge of lichens in Thailand. Six new records are reported, viz. Acanthothecis salazinica , Bactrospora metabola , Buellia parastata , Diploschistes cinereocaesius , Rolfidium coccocarpioides , and Trapelia placodioides . Five previously recorded species, namely Lecanora carpinea , Platismatia glauca , P. lacunosa , P. tuckermanii and Roccella phycopsis are shown to be based on misidentifications and are excluded from the checklist. Three new combinations of species previously placed in Pertusaria to Lepra are proposed: L. bulolensis (A.W.Archer, Elix & Streimann) Schmitt & Lumbsch, L. patellifera (A.W.Archer) Schmitt & Lumbsch, and L. subventosa (Malme) Schmitt & Lumbsch. Asia, biodiversity, lichens, new records, taxonomy
Journal Article
Architrypethelium murisporum (Ascomycota, Trypetheliaceae), a remarkable new lichen species from Thailand challenging ascospore septation as an indicator of phylogenetic relationships
by
Luangsuphabool, Theerapat
,
Piapukiew, Jittra
,
Lumbsch, H. Thorsten
in
ascospores
,
evergreen forests
,
lichens
2018
Architrypetheliummurisporum Luangsuphabool, Lumbsch & Sangvichien is described for a crustose lichen occurring in dry evergreen forest in Thailand. It is characterised by a green to yellow-green corticated thallus, perithecia fused in black pseudostromata with white rim surrounding the ostiole and small, hyaline and muriform ascospores. Currently, all species in the genus Architrypethelium have transversely septate ascospores, hence the discovery of this new species indicates that ascospore septation is variable within the genus, similar to numerous other groups of lichen-forming ascomycetes. Phylogenetic analyses of two loci (mtSSU and nuLSU) supported the position of the new species within Architrypethelium . This is the first report of the genus in Southeast Asia.
Journal Article