Studies in the biochemistry of micro-organisms

Birkinshaw, J. H.; Chambers, Angus Ross; Raistrick, Harold

doi:10.1042/bj0360242

Cited by 66 publications

(29 citation statements)

References 5 publications

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“…After reduction with zinc and acetic acid, however, anhydrosepedonin gave a copious precipitate with Brady's reagent indicating a masked ketonic function as is the case with the tropolonoid stipitatic acid (2). The infrared absorption spectra of sepedonin and its derivatives show intense maxima in the 1 500 -1 605 cm-I region with weaker maxima a t 1 625 -1 650 cm-I.…”

mentioning

confidence: 95%

Studies in the Biochemistry of Microorganisms: Part 117. Sepedonin, a Tropolone Metabolite of Sepedonium Chrysospermum Fries

Divekar¹,

Raistrick²,

Dobson³

et al. 1965

Can. J. Chem.

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Two yellow substances were isolated from culture filtrates of the fungus Sepedoniuna chrysospermunz Fries. One of these, named sepedonin, predominates in growing cultures and is believed t o be the direct product of metabolism. The second, an anhydro derivative of sepedonin, was probably formed spontaneously in the culture filtrate, and during the isolation process, by chemical dehydration. Sepedonin, C1lH1205 with one C-methyl group, gave two dimethyl ethers with diazomethane and has the spectral characteristics of a substituted tropolone. Dehydration under mild conditions afforded anhydrosepedonin, from which a monomethyl ether and two dimethyl ethers were prepared. One of the latter was unstable and rearranged slowly to a third dimethyl ether. By fusion with alkali, anhydrosepedonin was converted to a mixture from which two substituted benzoic acids and a product formulated as 6-hydroxy-4-methyltropolone were separated. The bathochromic displacement of the peaks in the ultraviolet spectrum of anhydrosepedonin compared with those in sepedonin indicated a n unsaturated group conjugated to the tropolone ring, confirmed by catalytic reduction to a dihydro derivative. By careful oxidation of one of the dimethyl ethers of anhydrosepedonin with permanganate a substance believed to be a tropolone containing ester and carboxyl substituents was obtained, together with a second product formulated as the 3,4-cyclic anhydride. From these results and supporting n.m.r. and spectral evidence anhydrosepedonin is considered to be a 6-hydroxytropolone with a 2'-methylpyran ring fused a t the 4,5,4',5'-positions. Sepedonin differs only by having a 2'-hydroxy-2'-methyldihydropyran ring as the heterocyclic moiety.Sepedoniz~m chrysospermz~m (Bull.) Fr., the iinperfect stage of Hypomyces chrysospermus (Bull.) Tul., has been isolated froin soils in Europe and the Ainerican continent and is a coxnnlon parasite of the fleshy fungi. The strain used in the present work was isolated from Boletz~s luridus. Cultures of this hypholnycete developed a yellow color in the broth and the surface inyceliuin showed patches of orange-yellow color after approxiinately 10 days undisturbed growth on Raulin-Thom or Czapek-Dox media. The color of the culture fluid later deepened and, in addition, gave an increasingly strong greenish-brown reaction with ferric chloride. Spectrophotoilletric exaxnination of the solution showed that these changes corresponded with the appearance of a strong absorption peak a t 250-275 n~p and weaker absorption in the region between 300 and 360 n~p . The wavelengths a t which the lnaxixna appeared varied with the pH of the culture filtrate. The

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confidence: 95%

Studies in the Biochemistry of Microorganisms: Part 117. Sepedonin, a Tropolone Metabolite of Sepedonium Chrysospermum Fries

Divekar¹,

Raistrick²,

Dobson³

et al. 1965

Can. J. Chem.

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“…Erste Befütterungsversuche in verschiedenen Organismen ließen erkennen, dass die Biosynthesevorstufen der Tropolone aus Polyketid‐, Terpen‐, Alkaloid‐ oder Shikimisäure‐Zwischenstufen stammen könnten und die Ringerweiterung eines alkylierten Sechsrings zum Tropolon der gemeinsame Schritt in allen vermuteten Biosynthesewegen ist (Abbildung ). Ein typisches Beispiel für Tropolone ist der aus dem Pilz Talaromyces stipitatus isolierte Metabolit Stipitatsäure ( 282 ) . Als Vorstufe wurde das aromatische Polyketid 3‐Methylorcinaldehyd ( 281 ) anhand einer Radiotracer‐Untersuchung identifiziert .…”

Section: Umlagerungenunclassified

Die Enzymologie organischer Umwandlungen: Namensreaktionen in biologischen Systemen

2017

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Chemische Reaktionen, die zu Ehren ihrer wahren oder zumindest wahrgenommenen Entdecker benannt sind, werden als “Namensreaktionen” bezeichnet. Dieser Aufsatz ist eine Zusammenstellung von biologischen Beispielen für benannte chemische Reaktionen. Der Schwerpunkt liegt dabei auf Reaktionsarten und Katalysemechanismen, die die chemische Diversität in der Biosynthese von Naturstoffen wie auch Parallelen zur organischen Synthesechemie veranschaulichen. Enzymatische Katalysemechanismen werden soweit möglich im Kontext mit den entsprechenden Mechanismen in der Synthese beschrieben, und für derzeit noch untersuchte Reaktionen werden mechanistische Hypothesen diskutiert. Der Aufsatz ist nach Reaktionsarten gegliedert, z. B. Kondensation, Reduktion und Oxidation, Substitution, Carboxylierung, Radikal‐vermittelte Reaktionen und Umlagerungen, und diese sind anhand der Namensreaktionen weiter unterteilt.

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“…Puberulic acid ( 1 ) 7 , stipitatic acid ( 2 ) 8 and viticolins A and B ( 3 , 4 ) as novel natural products have been isolated from a culture broth of Penicillium viticola 9 FKI-4410 through our screening system and found to have promising antimalarial activity (Fig. 1 ) 10 , 11 .…”

Section: Introductionmentioning

confidence: 99%

Antimalarial troponoids, puberulic acid and viticolins; divergent synthesis and structure-activity relationship studies

Sennari

Saito

Hirose

et al. 2017

Sci Rep

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Divergent synthesis of antimalarial troponoids, including naturally occurring compounds, some of which were identified and isolated by our group, has been achieved utilizing the total synthetic route of puberulic acid. Structure-activity relationships of natural products and simple troponoids inspired us to explore more detailed properties of this class of compounds. Access to new derivatives was facilitated through intermediate compounds generated during the total synthesis of puberulic acid by a stepwise oxidation-aromatization sequence to provide 7-hydroxytropolones and bromination for conversion of the carboxylic acid moiety. The first total synthesis of viticolin A, as well as the synthesis of different methyl-substituted derivatives, has also been achieved. In vitro antimalarial activity and cytotoxicity of novel derivatives were evaluated and fundamental information to facilitate the discovery of more promising antimalarials was obtained.

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Studies in the biochemistry of micro-organisms

Cited by 66 publications

References 5 publications

Studies in the Biochemistry of Microorganisms: Part 117. Sepedonin, a Tropolone Metabolite of Sepedonium Chrysospermum Fries

Studies in the Biochemistry of Microorganisms: Part 117. Sepedonin, a Tropolone Metabolite of Sepedonium Chrysospermum Fries

Die Enzymologie organischer Umwandlungen: Namensreaktionen in biologischen Systemen

Antimalarial troponoids, puberulic acid and viticolins; divergent synthesis and structure-activity relationship studies

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