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Dal 1222 al 1509
No full textSaggi storici introduttivi ad una scelta antologica di fonti storiche relative all'Ateneo di Padova (1222-1509) presentate nel testo originale ed in traduzione italian
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Missouri Pacific (MP) 1509 (neg)
No full textA photograph negative showing Missouri and Pacific (MoPac) 1509, 2-8-2, Kansas City, MO
Isolation and Identification of Novel Antioxidant Polyketides from an Endophytic Fungus Ophiobolus cirsii LZU-1509
No full textSixteen
new polyketides, ophicirsins A–P (1–16),
including four novel carbon skeletons (5–9, 14, 15, and 16), were isolated
from the extract of an endophytic fungus Ophiobolus
cirsii LZU-1509. The unique frameworks of ophicirsin
N (14) and O (15) feature a different cyclic
ether connected with an aromatic ring system. Ophicirsin P (16) is characterized by the unprecedented heterozygote of
a polyketide and an alkaloid. The absolute stereochemistries of those
polyketides were characterized via single-crystal X-ray diffraction
analysis and the experimental and computational electric circular
dichroism spectra comparison. Theoretical reaction pathways in the
fermentation to generate different novel skeletons starting from acetyl
CoA and malonyl CoA helped to assign their structures. Compounds 1–16 appear almost nontoxic in HepG2 and HT-1080 tumor
cells. Their antioxidant effects were further evaluated, and 15 exhibits an excellent protection activity in hydrogen peroxide-stimulated
oxidative damage in neuron-like PC12 cells via screening all compounds.
Moreover, 15 displays a greater ability to scavenge the
2,2-diphenyl-1-picrylhydrazyl free radicals than resveratrol. Taken
together, these findings suggest that the novel polyketides could
serve as potential antioxidant agents for neuroprotection
Isolation and Identification of Novel Antioxidant Polyketides from an Endophytic Fungus Ophiobolus cirsii LZU-1509
No full textSixteen
new polyketides, ophicirsins A–P (1–16),
including four novel carbon skeletons (5–9, 14, 15, and 16), were isolated
from the extract of an endophytic fungus Ophiobolus
cirsii LZU-1509. The unique frameworks of ophicirsin
N (14) and O (15) feature a different cyclic
ether connected with an aromatic ring system. Ophicirsin P (16) is characterized by the unprecedented heterozygote of
a polyketide and an alkaloid. The absolute stereochemistries of those
polyketides were characterized via single-crystal X-ray diffraction
analysis and the experimental and computational electric circular
dichroism spectra comparison. Theoretical reaction pathways in the
fermentation to generate different novel skeletons starting from acetyl
CoA and malonyl CoA helped to assign their structures. Compounds 1–16 appear almost nontoxic in HepG2 and HT-1080 tumor
cells. Their antioxidant effects were further evaluated, and 15 exhibits an excellent protection activity in hydrogen peroxide-stimulated
oxidative damage in neuron-like PC12 cells via screening all compounds.
Moreover, 15 displays a greater ability to scavenge the
2,2-diphenyl-1-picrylhydrazyl free radicals than resveratrol. Taken
together, these findings suggest that the novel polyketides could
serve as potential antioxidant agents for neuroprotection
Isolation and Identification of Novel Antioxidant Polyketides from an Endophytic Fungus Ophiobolus cirsii LZU-1509
No full textSixteen
new polyketides, ophicirsins A–P (1–16),
including four novel carbon skeletons (5–9, 14, 15, and 16), were isolated
from the extract of an endophytic fungus Ophiobolus
cirsii LZU-1509. The unique frameworks of ophicirsin
N (14) and O (15) feature a different cyclic
ether connected with an aromatic ring system. Ophicirsin P (16) is characterized by the unprecedented heterozygote of
a polyketide and an alkaloid. The absolute stereochemistries of those
polyketides were characterized via single-crystal X-ray diffraction
analysis and the experimental and computational electric circular
dichroism spectra comparison. Theoretical reaction pathways in the
fermentation to generate different novel skeletons starting from acetyl
CoA and malonyl CoA helped to assign their structures. Compounds 1–16 appear almost nontoxic in HepG2 and HT-1080 tumor
cells. Their antioxidant effects were further evaluated, and 15 exhibits an excellent protection activity in hydrogen peroxide-stimulated
oxidative damage in neuron-like PC12 cells via screening all compounds.
Moreover, 15 displays a greater ability to scavenge the
2,2-diphenyl-1-picrylhydrazyl free radicals than resveratrol. Taken
together, these findings suggest that the novel polyketides could
serve as potential antioxidant agents for neuroprotection
Isolation and Identification of Novel Antioxidant Polyketides from an Endophytic Fungus Ophiobolus cirsii LZU-1509
No full textSixteen
new polyketides, ophicirsins A–P (1–16),
including four novel carbon skeletons (5–9, 14, 15, and 16), were isolated
from the extract of an endophytic fungus Ophiobolus
cirsii LZU-1509. The unique frameworks of ophicirsin
N (14) and O (15) feature a different cyclic
ether connected with an aromatic ring system. Ophicirsin P (16) is characterized by the unprecedented heterozygote of
a polyketide and an alkaloid. The absolute stereochemistries of those
polyketides were characterized via single-crystal X-ray diffraction
analysis and the experimental and computational electric circular
dichroism spectra comparison. Theoretical reaction pathways in the
fermentation to generate different novel skeletons starting from acetyl
CoA and malonyl CoA helped to assign their structures. Compounds 1–16 appear almost nontoxic in HepG2 and HT-1080 tumor
cells. Their antioxidant effects were further evaluated, and 15 exhibits an excellent protection activity in hydrogen peroxide-stimulated
oxidative damage in neuron-like PC12 cells via screening all compounds.
Moreover, 15 displays a greater ability to scavenge the
2,2-diphenyl-1-picrylhydrazyl free radicals than resveratrol. Taken
together, these findings suggest that the novel polyketides could
serve as potential antioxidant agents for neuroprotection
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