The chemistry of fungi. Part LXV. The structures of ergochrysin A, isoergochrysin A, and ergoxanthin, and of secalonic acids A, B, C, and D

Hooper, J. W.; Marlow, W.; Whalley, W. B.; Borthwick, Alan D.; Bowden, R.

doi:10.1039/j39710003580

Cited by 59 publications

(48 citation statements)

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“…A comparison with the images of the four lowest redshift objects in our sample (MS 07546+3928, IRAS 07598+6508, IRAS 13218+0552 and PKS 0312-77) shows clearly that the quality of the morphological information that can be derived from WFPC imaging of quasars falls dramatically beyond z Ӎ 0:3. A comparison of our results and those of Bahcall and his co-workers with those of Hooper et al (1997)…”

Section: O N C L U S I O N Ssupporting

confidence: 60%

“…Clearly the probability of the observed number of apparent companions in our sample being a chance realization of the background is similarly small. Hooper, Impey & Foltz (1997) presented the results of PC imaging of a sample of quasars in the redshift range 0:4 < z < 0:5. They found host galaxy magnitudes similar to or brighter than L ૺ , consistent with the results of Bahcall et al and our work.…”

Section: Comparison With Other Hst Quasar Imagingmentioning

confidence: 99%

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HST Planetary Camera images of quasar host galaxies

Boyce

Disney

Blades

et al. 1998

Monthly Notices of the Royal Astronomical Society

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We present Hubble Space Telescope (HST) images of seven low‐redshift quasars (six taken with the Planetary Camera, one with the Wide Field Camera). These complete the sample of 14 quasars observed by the Faint Object Camera Investigation Definition Team (FOC IDT). Following subtraction of the quasar nuclear light, host galaxies can be seen in all seven cases. A combination of the optical morphology and luminosity profiles of the residual host galaxies and the results of 2D cross‐correlation model fitting implies that five of the objects have elliptical host galaxies and two have disc host galaxies. The luminosities vary from slightly fainter than L* to about 1.3 mag brighter than L*. We discuss the properties of the complete sample of 14 quasars. Nine of the objects appear to have elliptical host galaxies (all six of the radio‐loud quasars in the sample as well as three radio‐quiet quasars). Two further radio‐quiet quasars appear to lie in disc galaxies. The other three objects (radio‐quiet, ultraluminous infrared quasars) all lie in violently interacting systems. The sample as a whole has an average luminosity about 0.8 mag brighter than L*, although the radio‐loud objects have hosts on average 0.7 mag brighter than the radio‐quiet objects. We compare our results with those from HST imaging of quasars by other authors. Taken together, our observations are in broad agreement with those of Bahcall et al. Radio‐loud quasars appear to lie in luminous elliptical galaxies whereas radio‐quiet quasars are found to lie in either elliptical or spiral hosts. Host galaxy luminosities (of radio‐quiet and radio‐loud quasars) are much brighter than would be expected if they followed a Schechter luminosity function.

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Section: O N C L U S I O N Ssupporting

confidence: 60%

Section: Comparison With Other Hst Quasar Imagingmentioning

confidence: 99%

HST Planetary Camera images of quasar host galaxies

Boyce

Disney

Blades

et al. 1998

Monthly Notices of the Royal Astronomical Society

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“…The chemical principles are surprisingly simple and some of the features are aromatic versus hydrogenated xanthones, ring extension, rearrangements, different placement of the methyl group(s), reduction of the ester group, and, very importantly, creation of stereoisomers. In addition, the dimerization of these different monomers (even heterodimers of linear (e.g., 16) and rearranged (e.g., 18) xanthones are known) [26,76] further extends the chemical diversity of hydrogenated xanthones and creates metabolites of potentiated bioactivity relative to the monomers.…”

Section: Resultsmentioning

confidence: 98%

Xanthones and Oxepino[2, 3‐b]chromones from Three Endophytic Fungi

Krohn

Kouam

Kuigoua

et al. 2009

Chemistry A European J

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Three new metabolites, microsphaeropsones A-C (1-3) with a unique oxepino[2,3-b]chromen-6-one (ring-enlarged xanthone) skeleton, were isolated from the endophytic fungus Microsphaeropsis species, co-occurring with their putative biogenetic anthraquinoide precursors citreorosein (4) and emodin (5). From another Microsphaeropsis species, large amounts of fusidienol A (8 a), smaller amounts of emodin (5), the known aromatic xanthones 9 a and 9 b, the new 3,4-dihydrofusidienol A (8 b), and the new aromatic xanthone 9 c were isolated. The endophyte Seimatosporium species produced a new aromatic xanthone, seimatoxanthone A (10), and 3,4-dihydroglobosuxanthone A (12), closely related to alpha-diversolonic ester (13) from Microdiplodia sp.. The structures were determined mainly by extensive 1D and 2D NMR experiments and supported by X-ray single-crystal analysis of 1 and the oxidation product 7. The absolute configurations of the microsphaeropsones A-C (1-3) were established by comparison of the electronic and vibrational circular dichroism (ECD and VCD) spectra of 1 with time-dependent DFT (TDDFT) and DFT calculations by using either the solid-state structures or DFT-optimized geometries as inputs. Preliminary studies indicated that 1, 2, and enone 7 showed antibacterial, fungicidal, and algicidal properties.

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“…Secalonic acid D (3) was obtained as a yellow solid, a dixanthone compound, which has been reported before from Penicillium oxalicum 5, 6 and Aspergillus aculeatus, 7 and Gliocladium sp. T31.…”

Section: Spectral Assignments and Reference Datamentioning

confidence: 99%

¹H and ¹³C NMR signal assignments of Paecilin A and B, two new chromone derivatives from mangrove endophytic fungus Paecilomyces sp. (tree 1–7)

Guo

She

Shao

et al. 2007

Magnetic Reson in Chemistry

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Two new natural products, named paecilin A (1) and B (2), together with two known compounds secalonic acid D (3) and (11)-cytochalasa-6(12),13-diene-1,21-dione-16,18-dimethyl-7-hydroxy-10-phenyl-(7S*,13E,16S*,18S*) (4), were isolated from the mangrove endophytic fungus, Paecilomyces sp. (tree 1-7) from the South China Sea. 1D and 2D NMR experiments including COSY, HMQC, and HMBC were used for the determination of their structures. In our cytotoxicity assays, secalonic D (3) showed cytotoxicity toward KB cells with IC(50) < 1 microg ml(-1) and inhibiting human topoisomerase I with IC(50) at 0.16 micromol ml(-1). 1, 2, and 4 showed no activity to KB cells.

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The chemistry of fungi. Part LXV. The structures of ergochrysin A, isoergochrysin A, and ergoxanthin, and of secalonic acids A, B, C, and D

Cited by 59 publications

References 0 publications

HST Planetary Camera images of quasar host galaxies

HST Planetary Camera images of quasar host galaxies

Xanthones and Oxepino[2, 3‐b]chromones from Three Endophytic Fungi

¹H and ¹³C NMR signal assignments of Paecilin A and B, two new chromone derivatives from mangrove endophytic fungus Paecilomyces sp. (tree 1–7)

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The chemistry of fungi. Part LXV. The structures of ergochrysin A, isoergochrysin A, and ergoxanthin, and of secalonic acids A, B, C, and D

Cited by 59 publications

References 0 publications

HST Planetary Camera images of quasar host galaxies

HST Planetary Camera images of quasar host galaxies

Xanthones and Oxepino[2, 3‐b]chromones from Three Endophytic Fungi

1H and 13C NMR signal assignments of Paecilin A and B, two new chromone derivatives from mangrove endophytic fungus Paecilomyces sp. (tree 1–7)

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¹H and ¹³C NMR signal assignments of Paecilin A and B, two new chromone derivatives from mangrove endophytic fungus Paecilomyces sp. (tree 1–7)