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1. |
Sesquiterpenes fromMaytenus magellanica(Celastraceae) |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 163-170
AntonioG. Gonzalez,
MercedesP. Nuñez,
IsabelL. Bazzocchi,
AngelG. Ravelo,
IgnacioA. Jimenez,
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摘要:
Five dihydro-β-agarofuran [5,11-epoxy-5β,10α-eudesm-4(14)-ene] sesquiterpenes, three of which have a novel substitution pattern were isolated fromMaytenus magellanicaand their structures were elucidated by means of1H and13C NMR spectroscopic studies, including1H-13C heteronuclear correlation (HETCOR), long range correlation spectra with inversal detection (HMBC) and NOE experiments. Their absolute configurations were determined by application of the CD exciton chirality method while hydrolysis and preparation of derivatives provides additional information. Two of the sesquiterpenes exhibited significant antifeedant activity againstSpodoptera littoralis.
ISSN:1057-5634
DOI:10.1080/10575639308043803
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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2. |
Phytochemical Evolution: The Redox Theory |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 171-176
OttoR. Gottlieb,
Maria AuxiliadoraC. Kaplan,
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摘要:
Evolution of secondary metabolites in angiosperms is postulated to imply superposition of 1. stepwise abandonment of the intermediates of the shikimate pathway and their replacement by the intermediates of the acetate routes as biosynthetic precursors, and 2. gradual replacement of polyphenols by intermediate metabolites within binary antioxidant systems for the regulation of the oxidation level.
ISSN:1057-5634
DOI:10.1080/10575639308043804
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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3. |
Studies on a Population ofCalliblepharis jubata. (Normandy France). II- Seasonal Aspects and Physical Properties of Carrageenan |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 177-182
Zinoun Mustapha,
Joel Cosson,
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摘要:
The phycocolloids ofC. jubataharvested in Cap Lévy (Normandy, France) are a mixture of iota-carrageenan type, with its precursor nu-carrageenan. Throughout the yearC. jubataproduces only an iota-carrageenan, with seasonal fluctuation in physicochemical properties.
ISSN:1057-5634
DOI:10.1080/10575639308043805
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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4. |
Iterative and Stereoselective One-Carbon Homologation of 1,2-O-Cyclohexylidene-D-Glyceraldehyde to Aldose Derivatives by Employing 2-Lithio-1,3-Dithiane as a Formyl Anion Equivalent |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 183-190
Hidenori Chikashita,
Toshiki Nikaya,
Kazuyoshi Itoh,
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摘要:
1,2-Polyol synthesis based on the iterative and diastereofacially selective carbonyl addition of 2-lithio-1,3-dithiane to chiral α-alkoxy aldehydes by starting from 1,2-O-cyclohexylidene-D-glyceraldehyde was studied in synthesizing aldose derivatives.
ISSN:1057-5634
DOI:10.1080/10575639308043806
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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5. |
Structure and Stereochemistry of a New Neoflavonoid fromCalophyllum Inophylloide(Guttiferae) |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 191-195
S.H. Goh,
I. Jantan,
Chen Wei,
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摘要:
NMR spectral data and single crystal X-ray diffraction analysis on a new neoflavonoid, isolated from the heartwood ofCalophyllum inophylloide, have established its structure as (+)-(2R,3S,16S)-2,3-dimethyl-5-hydroxy-6-(3-methyl-but-2-enyl)-7-methoxy-8-(2-carboxyl-1-phenylethyl)-2,3-dihydrobenzopyran.
ISSN:1057-5634
DOI:10.1080/10575639308043807
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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6. |
The Absolute Configuration of the Poppy Alkaloid Nudaurine |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 197-201
Jürgen Gollwitzer,
Hermann Lotter,
Werner Döpke,
MeinhartH. Zenk,
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摘要:
The poppy alkaloid, nudaurine, was shown by X-ray crystallography to have an (S)-configuration at C-7 opposite to the configuration previously assigned by oxidative degradation.
ISSN:1057-5634
DOI:10.1080/10575639308043808
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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7. |
Mabioside B, A Novel Saponin fromColubrina Elliptica |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 203-207
Ali Oulad-ali,
Dominique Guillaume,
Yulin Jiang,
Bernard Weniger,
Robert Anton,
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摘要:
One novel saponin, mabioside B (1), containing asecoring D dammarane triterpenoid aglycone has been isolated from the bark ofColubrina elliptica. The structure was established by spectroscopic methods.
ISSN:1057-5634
DOI:10.1080/10575639308043809
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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8. |
Structural Anlysis of the Phycocolloid Extracted fromSchizymenia dubyi(Gigartinales, Rhodophyceae) |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 209-213
E. Deslandes,
M. Zinoun,
P. Potin,
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摘要:
The polysaccharide extracted fromSchizymenia dubyiwas studied with several methodes; multiple analysis demonstrate that the carrageenan is similar to lambda type.
ISSN:1057-5634
DOI:10.1080/10575639308043810
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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9. |
Synthesis and Mass Spectral Confirmation of the Identity of Two New Tricyclic Terpanes Found in Chinese Bituminous Sandstones |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 215-220
TeodoroS. Kaufman,
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摘要:
The syntheses of the 4α,4β,8β,10β-tetramethyl perhydrophenanthrene3and the 13α-ethyl (4) and 14β-ethyl (5) derivatives are described. GC-MS analyses demonstrated identity between the first two synthetic tricyclanes and the novel C18and C20terpanes found in Chinese oils.
ISSN:1057-5634
DOI:10.1080/10575639308043811
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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10. |
New Aliphatic d-Lactones, Metabolites ofCeratocystis piceae |
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Natural Product Letters,
Volume 2,
Issue 3,
1993,
Page 221-226
Hiroshi Yada,
Hiroji Sato,
Shigeru Kaneko,
Akitami Ichihara,
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摘要:
The structures of the metabolites ofCeratocystis piceaewere revealed to be (3R,5R)-(+)-3-hydroxytetradecan-5-olide (1), (5R)-(-)-2-tetradecen-5-olide (2), (3R,5R,12R)-(+)-3,12-dihydroxytetradecan-5-olide (3), and (3R,5R,11R)-(+)-3,11-dihydroxytetradecan-5-olide (4). The absolute configurations of novel compounds (1), (3), and (4) were determined via chemical correlation and spectral data. (1) inhibited the growth of red pine seedlings at 10 ppm.
ISSN:1057-5634
DOI:10.1080/10575639308043812
出版商:Taylor & Francis Group
年代:1993
数据来源: Taylor
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