Search results for: John A. Elix

Items from 1 to 20 out of 31 results

article

Evolution of complex symbiotic relationships in a morphologically derived family of lichen‐forming fungi

Pradeep K. Divakar, Ana Crespo, Mats Wedin, Steven D. Leavitt, more

We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen‐forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six‐locus data set including nuclear, mitochondrial and low‐copy protein‐coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle...

article

Erratum: A molecular phylogeny of the Lecanora varia group, including a new species from western North America

Sergio Pérez-Ortega, Toby Spribille, Zdeněk Palice, John A. Elix, more

Mycological Progress > 2011 > 10 > 1 > 129-130

The online version of the original article can be found at http://dx.doi.org/10.1007/s11557-010-0660-y .

article

The identity of Buellia sequax

Mireia Giralt, Frank Bungartz, John A. Elix

Mycological Progress > 2011 > 10 > 1 > 115-119

The study of the type specimens of Buellia sequax revealed that the current concept of this species is erroneous and instead corresponds to B. abstracta. By contrast, B. sequax s. str. is characterized by the same diagnostic characters as presently accepted for B. excelsa. Consequently, they represent one and the same taxon. Since B. sequax is the older name, B. excelsa is reduced to synonymy. Buellia lepidastroidea...

article

Endohyalina, the genus in the Physciaceae to accommodate the species of the Rinodina ericina-group

Mireia Giralt, Pieter P. G. Boom, John A. Elix

Mycological Progress > 2010 > 9 > 1 > 37-48

The genus Endohyalina is characterized by crustose, autonomous, or obligately lichenicolous thalli, lecideine apothecia with a hymenium often more or less inspersed with oil droplets and a brown hypothecium, Bacidia-type asci, small Dirinaria-type ascospores developing with type B ontogeny, bacilliform conidia and containing diploicin as the major secondary metabolite. The genus is based on four species...

article

A molecular phylogeny of the Lecanora varia group, including a new species from western North America

Sergio Pérez-Ortega, Toby Spribille, Zdeněk Palice, John A. Elix, more

Mycological Progress > 2010 > 9 > 4 > 523-535

The phylogeny of the Lecanora varia group is inferred from ITS sequences using Bayesian and ML phylogenetic analysis methods. According to our data, usnic acid-containing, corticolous Lecanora species do not form a monophyletic group but occur in three major clades together with other groups of Lecanora and Protoparmeliopsis. The new combination Lecanora filamentosa (Stirt.) Elix & Palice is proposed...

article

Intraspecific chemical variation within the crustose lichen genus Haematomma: anthraquinone production in selected cultured mycobionts as a response to stress and nutrient supply

Elfie Stocker-Wörgötter, Armin Hager, John A. Elix

Phytochemistry Reviews > 2009 > 8 > 3 > 561-569

The mycobionts isolated from selected species of Haematomma (Haematomma africanum, Haematomma fenzlianum, Haematomma flourescens, Haematomma persoonii, Haematomma stevensiae) have been successfully cultured. The chemical profile of the mycobionts could be effectively influenced and modulated by varying the composition of the nutrient medium using alternative carbohydrates (glucose, sucrose, and polyols)...

article

Cloning and sequence characterization of a non-reducing polyketide synthase gene from the lichen Xanthoparmelia semiviridis

Yit-Heng Chooi, David M. Stalker, Meryl A. Davis, Isao Fujii, more

Mycological Research > 2008 > 112 > 2 > 147-161

Lichens produce a diverse array of secondary metabolites that have shown various biological activities. Of particular interest are the coupled phenolics that originate from polyketide pathways, such as depsides, depsidones and usnic acids, which are produced almost solely by lichens. Based on the presumed catalytic domains required for the synthesis of the key intermediates β-orsellinic acid and methylphloroacetophenone,...

article

Does secondary chemistry enable lichens to grow on iron-rich substrates?

Markus Hauck, Siegfried Huneck, John A. Elix, Alexander Paul

Flora > 2007 > 202 > 6 > 471-478

Lichen substances are shown to increase or to inhibit the adsorption of Fe at cation exchange sites. The influence on the adsorption strongly differs between individual lichen substances and is different for Fe ²⁺ and Fe ³⁺ . These results add a new biological role to the known functions of lichen secondary metabolites. In an experiment with cellulose filters, which were soaked with...

article

Stictic Acid Derivatives from the Lichen Usnea articulata and Their Antioxidant Activities

Françoise Lohézic-Le Dévéhat, Sophie Tomasi, John A. Elix, Aurélie Bernard, more

Journal of Natural Products > 2007 > 70 > 7 > 1218 - 1220

article

Concise Formal Total Synthesis of Hybocarpone and Related Naturally Occurring Naphthazarins

Christina L. L. Chai, John A. Elix, Felicity K. E. Moore

The Journal of Organic Chemistry > 2006 > 71 > 3 > 992 - 1001

article

The synthetic versatility of alkoxycarbonyl- and hydroxymethyl-piperazine-2,5-diones

Christina L.L. Chai, John A. Elix, Paul B. Huleatt

Tetrahedron > 2005 > 61 > 36 > 8722-8739

Alkoxycarbonylpiperazine-2,5-diones are versatile precursors for the α-functionalisation of piperazine-2,5-diones. The alkoxycarbonyl group activates the α-carbon position to alkylation reactions and this provides a mild and selective method for the extension of the carbon framework of piperazine-2,5-diones. In addition, the alkoxycarbonyl group can be converted to the carboxy group, which in turn...

article

Chemical variation in the lichen genus Letrouitia (Ascomycota, Letrouitiaceae)

Sanne Johansson, Ulrik Søchting, John A. Elix, Judith H. Wardlaw

Mycological Progress > 2005 > 4 > 2 > 139-148

Secondary metabolites from 193 specimens belonging to 15 species of Letrouitia were analyzed by HPLC. Significant quantities of the anthraquinones parietin and fragilin were found in most species and occasionally minor quantities of emodin, 5-chloroemodin, 7-chloroemodin, 7-chloroteloschistin, 7-chlorofallacinal and 7-chloroparietinic acid were present. Eight previously unknown lichen substances were...

article

Scabrosin esters and derivatives: chemical derivatization studies and biological evaluation

Christina L.L. Chai, John A. Elix, Paul B. Huleatt, Paul Waring

Bioorganic & Medicinal Chemistry > 2004 > 12 > 22 > 5991-5995

Several derivatives of the natural scabrosin esters were synthesized in order to elucidate the structural features present, which are responsible for the biological activities. The studies demonstrate that full anti-proliferative activities of the scabrosin esters, both the carboskeleton core as well as the ability to form the dithiol and/or the disulfide linkage of the epidithiopiperazine-2,5-dione...

article

Phenolic and steroidal constituents of the lichen Usnea longissima

U.V. Mallavadhani, A.V.S. Sudhakar, Anita Mahapatra, K. Narasimhan, more

Biochemical Systematics and Ecology > 2004 > 32 > 1 > 95-97

article

The lichen genus Neofuscelia (Ascomycota, Parmeliaceae) in Italy

Paolo Giordani, Renato Benesperi, Ivano Rellini, Luisa Frati, more

The Lichenologist > 2003 > 35 > 5-6 > 377-385

Seven Neofuscelia species have been identified from Italy. A key to the species is provided and the distinguishing morphological and chemical characters, distribution, ecology, substratum preference and interrelationships of each are discussed. Neofuscelia perrugata is new to Italy. N. pyrenaica is new to Greece and Cyprus. New data on the distribution and ecology of N. perrugata, N. delisei and N...

article

New species and new records of Xanthoparmelia (lichenized Ascomycota, Parmeliaceae) from Western Australia

John A. Elix

The Lichenologist > 2003 > 35 > 4 > 291-299

The following new species of Xanthoparmelia (Parmeliaceae) are described from Western Australia: X. cranfieldii Elix, X. elevata Elix, X. kimberleyensis Elix, X. monadnockensis Elix,X. nanoides Elix, X. nortegeta Elix, X. sleei Elix and X. toolbrunupensis Elix. In addition, X. luminosa (Elix) Hale and X. victoriana Elix & J. Johnst. are reported from Western Australia for the first time.

article

A tribute to William Louis Culberson

John A. Elix, Thomas H. Nash

The Lichenologist > 2003 > 35 > 2 > 93-95

article

Multi-purpose functionality for the structural elaboration of the piperazine-2,5-dione motif

Christina L. L. Chai, John A. Elix, Paul B. Huleatt

Tetrahedron Letters > 2003 > 44 > 2 > 263 - 265

Mild methods for controlled C- and N-alkylation of 3-benzyloxycarbonylpiperazine-2,5-diones are reported. The benzyloxylcarbonyl substituent can also serve as latent functionality for N-acyliminium ion formation and subsequent trapping enables installation of new carbon and/or heteroatom substituents.

article

The Parmeliaceae (lichenized Ascomycota) of New Caledonia

Simone H. J. J. Louwhoff, John A. Elix

The Lichenologist > 2002 > 34 > 5 > 373-394

A key to forty-one species in ten parmelioid genera [Bulbothrix (4 spp.),Canoparmelia (1 sp.), Hypotrachyna (7 spp.), Myelochroa (1 sp.), Parmelina (2 spp.),Parmelinopsis (1 sp.), Parmotrema (18 spp.), Relicina (2 spp.), Rimelia (3 spp.) andXanthoparmelia (2 spp.)] from New Caledonia is provided, in addition to brief taxonomic descriptions as well as notes on distribution. Five of the forty-one species...

article

Secondary chemistry of cultured mycobionts: formation of a complete chemosyndrome by the lichen fungus of Lobaria spathulata

Elfie Stocker-Wörgötter, John A. Elix

The Lichenologist > 2002 > 34 > 4 > 351-359

Abstract:The study aimed to optimize culture conditions and nutrient requirements for the production of secondary metabolites by the cultured mycobiont Lobaria spathulata. This species proved to be an excellent model system for such studies, as the complete chemosyndrome found in the natural lichen thallus was repeatedly formed in the cultured mycobiont with differentiated, aerial mycelia. Nutrient...

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Keywords

PARMELIACEAE (4)
NATURAL PRODUCTS (3)
ALKYLATIONS (2)
AMINO ACIDS AND DERIVATIVES (2)
CHEMOTAXONOMY (2)
N-ACYLIMINIUM IONS (2)
NEW SPECIES (2)
PHYLOGENY (2)
QUINONES (2)
TRAPPING REACTIONS (2)
LECANORA VARIA GROUP (1)
(+)-USNIC ACID (1)
(-)-PLACODIOLIC ACID (1)
ACAROSPORETUM SINOPICAE (1)
AFRICA, LICHENIZED, ASCOMYCOTIA, NEW SPECIES, PARMELIACEAE, XANTHOPARMELIA (1)
ANCESTRAL CHARACTER RECONSTRUCTION (1)
ANTHRAQUINONS (1)
ANTI-PROLIFERATIVE AGENTS (1)
ANTI-TUMOUR COMPOUNDS (1)
ASCOMYCOTA (1)
AUSTRALIA (1)
AXENIC CULTURE, CULTURED MYCOBIONTS, GYROPHORIC ACID CHEMOSYNDROME, LOBARIA SPATHULATA (1)
BARBATIC ACID (1)
CATION ADSORPTION (1)
CHEMISTRY (1)
CHEMOSYNDROMES (1)
CHONDROPSIS (1)
DEPSIDONES (1)
DIBENZOFURANS (1)
DISTRIBUTION (1)
DISTRIBUTION, ITALY, PARMELIACEAE, XANTHOPARMELIA (1)
ERGOSTEROL-5Β-8Β-PEROXIDEΒ (1)
GENERIC RECIRCUMSCRIPTION (1)
HAEMATOMMONE (1)
HEAVY METAL TOLERANCE (1)
HPLC (1)
ITALY (1)
ITS (1)
LECANORACEAE (1)
LECANORETUM EPANORAE (1)
LECANOROMYCETES (1)
LETROUITIA (1)
LICHEN (1)
LICHEN SUBSTANCES (1)
LICHENICOLOUS FUNGI (1)
LICHENICOLOUS SPECIES (1)
LICHENIZED ASCOMYCETES (1)
LICHENIZED ASCOMYCOTA (1)
LICHENS (1)
LITHIATION (1)
MORPHOLOGY (1)
MUTUALISM (1)
MYCOBIONT CULTURES (1)
NAPHTHALENES (1)
NEOFUSCELIA (1)
NEW COMBINATIONS (1)
PACIFIC, DISTRIBUTION, BIOGEOGRAPHY, GONDWANA, LICHENOLOGICAL EXPLORATION (1)
PHYSCIACEAE (1)
POLYCYCLIC HETEROCYCLIC COMPOUNDS (1)
POLYKETIDES (1)
RAESAENENIA (1)
RUSSULONE (1)
SECONDARY CHEMISTRY (1)
SECONDARY METABOLITES (1)
SPECIES RECIRCUMSCRIPTION (1)
TAXONOMY (1)
USNEA LONGISSIMA (1)
USNIC ACID (1)
XANTHOPARMELIA (1)
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Elsevier (22)
Springer (6)
ACS (2)
Wiley (1)

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Search results for: John A. Elix

Evolution of complex symbiotic relationships in a morphologically derived family of lichen‐forming fungi

Erratum: A molecular phylogeny of the Lecanora varia group, including a new species from western North America

The identity of Buellia sequax

Endohyalina, the genus in the Physciaceae to accommodate the species of the Rinodina ericina-group

A molecular phylogeny of the Lecanora varia group, including a new species from western North America

Intraspecific chemical variation within the crustose lichen genus Haematomma: anthraquinone production in selected cultured mycobionts as a response to stress and nutrient supply

Cloning and sequence characterization of a non-reducing polyketide synthase gene from the lichen Xanthoparmelia semiviridis

Does secondary chemistry enable lichens to grow on iron-rich substrates?

Stictic Acid Derivatives from the Lichen Usnea articulata and Their Antioxidant Activities

Concise Formal Total Synthesis of Hybocarpone and Related Naturally Occurring Naphthazarins

The synthetic versatility of alkoxycarbonyl- and hydroxymethyl-piperazine-2,5-diones

Chemical variation in the lichen genus Letrouitia (Ascomycota, Letrouitiaceae)

Scabrosin esters and derivatives: chemical derivatization studies and biological evaluation

Phenolic and steroidal constituents of the lichen Usnea longissima

The lichen genus Neofuscelia (Ascomycota, Parmeliaceae) in Italy

New species and new records of Xanthoparmelia (lichenized Ascomycota, Parmeliaceae) from Western Australia

A tribute to William Louis Culberson

Multi-purpose functionality for the structural elaboration of the piperazine-2,5-dione motif

The Parmeliaceae (lichenized Ascomycota) of New Caledonia

Secondary chemistry of cultured mycobionts: formation of a complete chemosyndrome by the lichen fungus of Lobaria spathulata

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