Dimers of Altersolanol A from Alternaria solani

Lazarovits, George; William, Ray D.; Stoessl, A.

doi:10.1515/znc-1988-11-1204

Cited by 12 publications

(13 citation statements)

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“…The maximum chemical shift difference between these molecules was 0.04 ppm (in both CD 3 OD and THF-d 8 ). Our analyses led us to conclude that these compounds have identical structures with alterporriols D and E which had been reported by Stoessl and coworkers 6 in 1988 or Suemitsu et al 7 in 1989. However, Stoessl reported that the difference of the d values for C7-OCH 3 between the isomers was 0.12 ppm in methanol-d 4 , which is much larger than what we observed.…”

Section: Axial Stereochemistries Of Alterporriols D (2) and E (3)supporting

confidence: 84%

“…and its relatives by several groups. [1][2][3][4][5] Dimers 2 and 3 were also reported by Stoessl and coworkers 6 and Suemitsu et al 7 independently, and the names alterporriols D and E (2 and 3) were given by Suemitsu et al 7 We also isolated these compounds from Pleospora herbarum, a close relative of the aforementioned fungus. Although our NMR spectral analyses of the dimers suggested the same structures with those of alterporriols D and E, their 1 H NMR data showed considerable difference to those of Suemitsu (max Dd was 0.6 ppm in THF-d 8 ).…”

Section: Introductionsupporting

confidence: 74%

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Absolute stereochemistry of altersolanol a and alterporriols

et al. 2011

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The absolute stereochemistry of altersolanol A (1) was established by observing a positive exciton couplet in the circular dichroism (CD) spectrum of the C3,C4-O-bis(2-naphthoyl) derivative 10 and by chemical correlations with known compound 8. Before the discussion, the relative stereochemistry of 1 was confirmed by X-ray crystallographic analysis. The shielding effect at C7'-OMe group by C1-O-benzoylation established the relative stereochemical relationship between the C8-C8' axial bonding and the C1-C4/C1'-C4' polyol moieties of alterporriols E (3), an atropisomer of the C8-C8' dimer of 1. As 3 could be obtained by dimerization of 1 in vitro, the absolute configuration of its central chirality elements (C1-C4) must be identical to those of 1. Spectral comparison between the experimental and theoretical CD spectra supported the above conclusion. Axial stereochemistry of novel C4-O-deoxy dimeric derivatives, alterporriols F (4) and G (5), were also revealed by comparison of their CD spectra to those of 2 and 3.

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Section: Axial Stereochemistries Of Alterporriols D (2) and E (3)supporting

confidence: 84%

Section: Introductionsupporting

confidence: 74%

Absolute stereochemistry of altersolanol a and alterporriols

et al. 2011

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“…[5, 23,24,37] However, their axial chirality has not yet been assigned. Regarding their biaryl chromophoric system, 6 and 7 show close similarity to 2, which also has a 5 monomeric unit but the other monomer is fully conjugated.…”

Section: Resultsmentioning

confidence: 99%

New Anthracene Derivatives – Structure Elucidation and Antimicrobial Activity

et al. 2012

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Three new anthracene derivatives, which include tetrahydroanthraquinone 1 and two tetrahydroanthraquinone heterodimers 2 and 3, were isolated from Stemphylium globuliferum, together with four known metabolites 4-7. Detailed analysis of the spectroscopic data allowed the unambiguous determination of the structures of 1 and 2 and a revision of the structure of alterporriol C and its atropisomer. Furthermore, alterporriol G, previously obtained as part of a mixture, was isolated in its pure form for the first time and its structure was also revised. The absolute configurations of 1, 2 and 3 were assigned by calculation of their CD spectra, which also allowed the configurational assignment of altersolanol A and the determination of the axial chirality of alterporriols D and E. All isolated compounds were analysed for their antimicrobial and cytotoxic activities. Compounds 1 and 5 inhibited the growth of most pathogenic microorganisms tested, whereas 2, 6 and 7 showed selective inhibition of bacteria but were inactive against fungi. Three new anthracene derivatives and four known metabolites were isolated from the extract of the endophytic Stemphylium globuliferum. The structures were determined by comprehensive NMR spectroscopy and MS, and the absolute configurations by TDDFT and ZINDO methods. All isolated compounds were tested for their cytotoxic and antimicrobial activities

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“…On the basis of their NMR and mass spectroscopic data and by comparison with the literature data, the remaining compounds were identified as altersolanol A (5), [29][30][31] altersolanol B (6), [30,31] altersolanol C (7), [32] alterporriol D (8), [33][34][35] alterporriol E (9), [32][33][34][35] macrosporin (10), [30] and 6-O-methylalaternin (11). [26] Compounds 1-11 were examined for their effects on the growth of the murine lymphoma L5178Y cell line through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays (Table 3).…”

Section: Resultsmentioning

confidence: 99%

“…The fungal extract caused a significant growth inhibition of the murine lymphoma cell line L5178Y, which prompted us to investigate the compounds produced by this endophyte. [26,[29][30][31][32][33][34][35] The structure elucidation of the new compounds as well as results of cytotoxic and antibacterial bioassays are reported. produce a broad spectrum of polyketide secondary metabolites with different bioactivities, such as the antimicrobial stemphyltoxin I-IV, [22] the phytotoxic chromone glucosides stemphyloxin I and II, [23,24] the cytotoxic altersolanol A, B, and C, [25,26] as well as the protein kinase inhibitors alterporriol G and H. [25][26][27] In our previous study, the first naturally occurring trimeric anthraquinone derivatives, stemphylanthranol A and B, were isolated from S. globuliferum.…”

Section: Introductionmentioning

confidence: 99%

Tetrahydroanthraquinone Derivatives from the Endophytic FungusStemphylium globuliferum

et al. 2015

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Four new tetrahydroanthraquinone derivatives, namely, dihydroaltersolanol B (1), dihydroaltersolanol C (2), and the atropisomers acetylalterporriol D (3) and acetylalterporriol E (4), were obtained from the endophytic fungus Stemphylium globuliferum, which was isolated from Juncus acutus growing in Egypt. The structures of the new compounds were unambiguously elucidated on the basis of one-and two-dimensional NMR spectroscopy, as well as by high-resolution mass spectrometry and electronic circular dichroism (ECD) spectroscopy. In addition, seven known anthraquinone deriva-

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Dimers of Altersolanol A from Alternaria solani

Abstract: Weakly phytotoxic, water-soluble pigments from culture filtrates of the potato early blight organism Alternaria solani have been identified by 1H NMR, UV, mass spectrometric, and acetylation studies as the pair of rotamers represented by structure 1a.

Cited by 12 publications

References 0 publications

Absolute stereochemistry of altersolanol a and alterporriols

Absolute stereochemistry of altersolanol a and alterporriols

New Anthracene Derivatives – Structure Elucidation and Antimicrobial Activity

Tetrahydroanthraquinone Derivatives from the Endophytic FungusStemphylium globuliferum

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