Biotransformation of solidagenone by Alternaria alternata, Aspergillus niger and Curvularia lunata cultures

Schmeda-Hirschmann, Guillermo; Astudillo, Luís; Palenzuela, J. Antonio

doi:10.1023/b:wibi.0000013317.60257.33

Cited by 11 publications

(5 citation statements)

References 28 publications

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“…[α] 25 D −148.2 ( c 0.2 CHCl 3 ) [lit . [α] D −168 ( c 1.0 CHCl 3 )]; 1 H and 13 C NMR spectra were very similar to those reported in the literature; HRESIMS (+) m / z 239.0918 [M + H] + (calcd for C 12 H 15 O 5 239.0920).…”

Section: Methodssupporting

confidence: 60%

Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris)

et al. 2017

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Buffelgrass (Pennisetum ciliare or Cenchrus ciliaris) is a perennial grass that has become highly invasive in the Sonoran Desert of southern Arizona. In the search for novel control strategies against this weed, strains of the foliar fungal pathogen Cochliobolus australiensis from buffelgrass have been screened for their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides in an integrated pest management strategy. A new phytotoxin, named cochliotoxin, was isolated from liquid culture of this fungus together with radicinin, radicinol, and their 3-epimers. Cochliotoxin was characterized, essentially by spectroscopic methods, as 3-hydroxy-2-methyl-7-(3-methyloxiranyl)-2,3-dihydropyrano[4,3-b]pyran-4,5-dione. Its relative stereochemistry was assigned by H NMR techniques, while the absolute configuration (2S,3S) was determined applying the advanced Mosher's method by esterification of its hydroxy group at C-3. When bioassayed in a buffelgrass coleoptile elongation test and by leaf puncture bioassay against the host weed and two nontarget grasses, cochliotoxin showed strong phytotoxicity. In the same tests, radicinin and 3-epi-radicinin also showed phytotoxic activity, while radicinol and 3-epi-radicinol were largely inactive. All five compounds were more active in leaf puncture bioassays on buffelgrass than on the nontarget grass tanglehead (Heteropogon contortus), while the nontarget grass Arizona cottontop (Digitaria californica) was more sensitive to radicinin and 3-epi-radicinin. Cochliotoxin at low concentration was significantly more active on buffelgrass than on either native grass, but the difference was small.

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Section: Methodssupporting

confidence: 60%

Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris)

et al. 2017

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“…Derivatives 4, 5, 7, 9 and 10 were prepared according to previous work (Anthonsen et al, 1970;Razmilic and Schmeda-Hirschmann, 2000;SchmedaHirschmann et al, 2002). Compounds 2 and 6 were obtained by microbial transformation of solidagenone with Aspergillus niger (Schmeda-Hirschmann et al, 2004). Compound 3 was prepared by acetylation of 2.…”

Section: Compoundsmentioning

confidence: 99%

Gastroprotective and ulcer-healing effect of new solidagenone derivatives in human cell cultures

Rodrı́guez¹,

Theoduloz²,

Sánchez³

et al. 2005

Life Sciences

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“…The NMR spectral data of compound 2 are summarized in the Table 1. Among the several recently reported diterpene biotransformations by A. niger [9,11,12], only in the bioconversion of isoesteviol, in which the 1α,7α-dihydroxy derivative is obtained, was the 1α position hydroxylated [13]. Related compounds with an additional OH function include 3,15-dihydroxy-8(17)-labden-19-oic acid from Juniperus thurifera [14,15], the 6,15-dihydroxyderivative from Viburnum suspensum [16] and 7α-hydroxy-8(17)labdene-15,18-dioic acid from Haplopappus pulchellus [17].…”

Section: Resultsmentioning

confidence: 99%

Biotransformations of Imbricatolic Acid by Aspergillus niger and Rhizopus nigricans Cultures

et al. 2007

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Microbial transformation of imbricatolic acid (1) by Aspergillus niger afforded 1α-hydroxyimbricatolic acid (2), while transformation with Rhizopus nigricans yielded 15-hydroxy-8,17-epoxylabdan-19-oic acid (3). When the diterpene 1 was added to a Cunninghamella echinulata culture, the main products were the microbial metabolites mycophenolic acid (4) and its 3-hydroxy derivative 5. All the structures were elucidated by spectroscopic methods. The cytotoxicity of these compounds towards human lung fibroblasts and AGS cells was assessed. While 4 and 5 showed low cytotoxicity, with IC 50 values > 1000 µM against AGS cells and fibroblasts, 1α-hydroxyimbricatolic acid (2) presented moderate toxicity towards these targets, with IC 50 values of 307 and 631 µM, respectively. The structure of 2 is presented for the first time.

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Biotransformation of solidagenone by Alternaria alternata, Aspergillus niger and Curvularia lunata cultures

Cited by 11 publications

References 28 publications

Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris)

Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris)

Gastroprotective and ulcer-healing effect of new solidagenone derivatives in human cell cultures

Biotransformations of Imbricatolic Acid by Aspergillus niger and Rhizopus nigricans Cultures

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