Isolation of a fluorone pigment from the Indian paint fungus Echinodontium tinctorium and Pyrofomes albomarginatus

Yang, Yong; Josten, Ingrid; Arnold, Norbert; Steffan, Bert; Steglich, Wölfgang

doi:10.1016/0040-4020(96)00204-9

Cited by 10 publications

(7 citation statements)

References 6 publications

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“…The physical and spectroscopic properties of synthetic 3 were identical with those of the natural product. 1 The low yield in the last step of the biomimetic approach caused us to develop a more efficient synthesis of echinotinctone (3) by a stepwise procedure (Scheme 3). Benzylation of 7 under standard conditions yielded the tribenzyl ether 8 that was converted to benzophenone 10 in 66% yield by trifluoroacetic anhydride-mediated acylation with O,O-dibenzylorsellinic acid (9).…”

Section: Methodsmentioning

confidence: 99%

“…The biomimetic approach commences with aldehyde 6, which was obtained in 77% yield by O-benzylation 5 of orcinol (4) and Vilsmeier formylation of the resulting dibenzyl ether 5 (Scheme 2). Treatment of aldehyde 6 with 30% H 2 O 2 under acidic conditions 6 afforded phenol 7 in 92% yield which was deprotected by catalytic hydrogenation to give the air sensitive 1,2,4-trihydroxy-6-methylbenzene (1) in 67% overall yield. This sequence is superior to a literature procedure 7 in which orcylaldehyde (2) is directly oxidized with H 2 O 2 .…”

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Synthesis of Echinotinctone, A Fungal Fluorone Pigment

Rüth¹,

Steglich²

2000

Synthesis

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Echinotinctone (3) is formed by acid-catalyzed condensation of 1,2,4-trihydroxytoluene (1) with orcylaldehyde (2), a reaction mimicking the probable biosynthesis. A more efficient stepwise synthesis proceeds via the benzophenone intermediate 11, which can be converted to 2,6-dihydroxy-1,8-dimethyl-3H-xanthen-3-one (3) by LiAlH 4 reduction and subsequent acid-catalyzed ring closure.Echinotinctone (3) is a rust-red pigment from fruit bodies of the wood-rotting Indian Paint Fungus, Echinodontium tinctorium, and Pyrofomes albomarginatus. 1 It represents the first natural product with a simple fluorone chromophore. 2 Structurally closely related are the more complex natural quinone methides trametin 3 and santalin A 4 and the artificial xanthene dyes fluorescein and eosin. We reasoned that echinotinctone (3) might be derived biosynthetically from 1,2,4-trihydroxytoluene (1) and orcylaldehyde (2) by C-C-bond formation followed by the elimination of two molecules of water (Scheme 1). Scheme 1In this publication we report that this reaction can be mimicked in vitro, albeit in low yield, and that echinotinctone (3) can be prepared more efficiently by a stepwise version of this procedure.The biomimetic approach commences with aldehyde 6, which was obtained in 77% yield by O-benzylation 5 of orcinol (4) and Vilsmeier formylation of the resulting dibenzyl ether 5 (Scheme 2). Treatment of aldehyde 6 with 30% H 2 O 2 under acidic conditions 6 afforded phenol 7 in 92% yield which was deprotected by catalytic hydrogenation to give the air sensitive 1,2,4-trihydroxy-6-methylbenzene (1) in 67% overall yield. This sequence is superior to a literature procedure 7 in which orcylaldehyde (2) is directly oxidized with H 2 O 2 . Scheme 2The condensation of 2 with aldehyde 1 8,9 in acetic anhydride/sulfuric acid 10 (cf. Scheme 1) afforded a complex reaction mixture from which echinotinctone (3) was isolated in 11% yield. The physical and spectroscopic properties of synthetic 3 were identical with those of the natural product. 1The low yield in the last step of the biomimetic approach caused us to develop a more efficient synthesis of echinotinctone (3) by a stepwise procedure (Scheme 3). Benzylation of 7 under standard conditions yielded the tribenzyl ether 8 that was converted to benzophenone 10 in 66% yield by trifluoroacetic anhydride-mediated acylation with O,O-dibenzylorsellinic acid (9). 11 Benzophenone 10 was deprotected by catalytic hydrogenation to give the polyphenolic intermediate 11, which after reduction with an excess of LiAlH 4 and acidic workup afforded echinotinctone (3) in 80% yield.The ease of this cyclization can be explained by the formation of carbinol 12, which on treatment with acid undergoes water elimination, ring closure and formation of 3 by a second dehydration step as illustrated in Scheme 4.Since several attempts to close the xanthone ring from the o,o'-dihydroxybenzophenone 11 by literature procedures Downloaded by: University of Arizona Library. Copyrighted material.

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Section: Methodsmentioning

confidence: 99%

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Synthesis of Echinotinctone, A Fungal Fluorone Pigment

Rüth¹,

Steglich²

2000

Synthesis

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“…Ryv. [5]. The latter species related to P. demidoffii occurring widespread in the tropics from Japan to Zaire.…”

Section: Introductionmentioning

confidence: 98%

Pyrofomins A-D, polyoxygenated sesquiterpenoids from Pyrofomes demidoffii

et al. 2016

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“…It produces a woody, large hydnaceous basidiocarp or conk [4,5] that typically grows beneath dead branch stubs on live tree trunks [6]. Most studies pertaining to E. tinctorium relate to its taxonomy, disease cycle, and management [4,5,7,8,9], but this conk also has a history of use as an anti-bacterial agent by Indigenous peoples [10].…”

Section: Introductionmentioning

confidence: 99%

Anti-Inflammatory Activity of the Wild Mushroom, Echinodontium tinctorium, in RAW264.7 Macrophage Cells and Mouse Microcirculation

Javed

Zeb

et al. 2019

Molecules

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The aim of this study was to investigate the anti-inflammatory activity of a previously un-studied wild mushroom, Echinodontium tinctorium, collected from the forests of north-central British Columbia. The lipopolysaccharide (LPS)-induced RAW264.7 macrophage model was used to study the in vitro anti-inflammatory activity. The crude alkaline extract demonstrated potent anti-inflammatory activity, and was further purified using a “bio-activity-guided-purification” approach. The size-exclusion and ion-exchange chromatography yielded a water-soluble anti-inflammatory polysaccharide (AIPetinc). AIPetinc has an average molecular weight of 5 kDa, and is a heteroglucan composed of mainly glucose (88.6%) with a small amount of galactose (4.0%), mannose (4.4%), fucose (0.7%), and xylose (2.3%). In in vivo settings, AIPetinc restored the histamine-induced inflammatory event in mouse gluteus maximus muscle, thus confirming its anti-inflammatory activity in an animal model. This study constitutes the first report on the bioactivity of Echinodontium tinctorium, and highlights the potential medicinal benefits of fungi from the wild forests of northern British Columbia. Furthermore, it also reiterates the need to explore natural resources for alternative treatment to modern world diseases.

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Isolation of a fluorone pigment from the Indian paint fungus Echinodontium tinctorium and Pyrofomes albomarginatus

Cited by 10 publications

References 6 publications

Synthesis of Echinotinctone, A Fungal Fluorone Pigment

Synthesis of Echinotinctone, A Fungal Fluorone Pigment

Pyrofomins A-D, polyoxygenated sesquiterpenoids from Pyrofomes demidoffii

Anti-Inflammatory Activity of the Wild Mushroom, Echinodontium tinctorium, in RAW264.7 Macrophage Cells and Mouse Microcirculation

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