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1. |
Synthesis of Two New Maytansinoid Model Compounds from Carbohydrate Precursors |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 323-339
ThomasE. Goodwin,
KimberleyR. Cousins,
HeidiM. Crane,
PhyllisO. Eason,
TimothyE. Freyaldenhoven,
CharlesC. Harmon,
BrockK. King,
ChristineD. LaRocca,
RobertL. Lile,
ShariG. Orlicek,
RonaldW. Pelton,
OmerL. Shedd,
JohnS. Swanson,
JosephW. Thompson,
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摘要:
Maytansine (1) is a macrocyclic natural product with significant anti-cancer activity. A derivative (4) of D-glucal is converted to a model compound (10) for the lower periphery of the maytansinoid ring via alkylation at C-6 using an allylic sulfide anion, followed by oxidation to the sulfoxide and [2,3]-sigmatropic rearrangement to the sulfenate ester. In addition, a method is disclosed for conversion of D-arabinose to a chiron (18) for a portion of the upper periphery of the maytansinoids.
ISSN:0732-8303
DOI:10.1080/07328309808002895
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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2. |
Synthesis of Some Analogs of the Methyl α-Glycoside of the Presumed Antigenic Determinant of the O-Specific Polysaccharide ofVibrio choleraeO:1, Serotype Ogawa |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 341-357
Jian Zhang,
Pavol Kováč,
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摘要:
The following analogs of the title determinant, methyl 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido)-2-O-methyl-α-D-mannopyranoside, have been prepared: methyl 3,4,6-trideoxy-4-(3-deoxy-L-glycero-tetronamido)-2-O-methyl-α-D-mannopyranoside, methyl 4,6-dideoxy-4-(4-hy droxybutyramido)-2-O-methyl-α-D-mannopyranoside, methyl 4,6-dideoxy-4-(3,4-dideoxy-L-glycero-tetronamido)-2-O-methyl-1-a-D-mannopyranoside, methyl 4,6-dideoxy-4-(3-deoxy-D-glycero-tetronamido)-2-O-methyl-α-D- mannopyranoside, methyl 4,6-dideoxy-4-(2-deoxy-L-glycero-tetronamido)-2-O-methyl-α-D- mannopyranoside, methyl 4-acetamido-4,6-dideoxy-2-O-methyl-α-D-mannopyranoside, methyl 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido)-2-O-ethyl-α-D-mannopyranoside, and methyl 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido)-2-O-propyl-α-D- mannopyranoside.
ISSN:0732-8303
DOI:10.1080/07328309808002896
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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3. |
HPLC Analysis of the Product Distribution in the Iodine-Catalyzed Methyl Glycosidation of Pentoses and 6-Deoxyhexoses |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 359-368
Gyöngyi Gyémánt,
András Lipták,
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摘要:
The product distribution of the iodine-catalyzed methyl glycosidation of four pentoses (D-ribose, D-arabinose, D-xylose, and D-lyxose) and two 6-deoxyhexoses (L-rhamnose, and D-fucose) was studied by HPLC using an APS column (dihydrogen sulphate form) with different acetonitrile-water mobile phases. In agreement with earlier results, a temperature dependent on-column isomerization was observed for all the investigated aldoses, except for ribose. The first-eluted furanosides were followed by pyranosides, and the free sugars were eluted last with the highest retention volumes.
ISSN:0732-8303
DOI:10.1080/07328309808002897
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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4. |
Syntheses of All Regioisomers ofMyo-Inositol Bisphosphate |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 369-384
Sung-Kee Chung,
Young-Tae Chang,
Yong-Uk Kwon,
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摘要:
All possible nine regioisomers ofmyo-inositol bisphosphate were synthesized using various isopropylidene and benzoyl inositol derivatives as intermediates. These intermediates were successfully phosphorylated with diethyl chlorophosphite followed by oxidation. Selective diphosphorylations on several IBz3intermediates were also examined as possible routes to IP2S. All of the protecting groups were easily removed in a one-pot procedure to give the sodium salts of the title compounds, IP2regioisomers.
ISSN:0732-8303
DOI:10.1080/07328309808002898
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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5. |
Syntheses of D-Myo-Inositol-1,2,6-Trisphosphate and -2,6-bisphosphate |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 385-390
Sung-Kee Chung,
Seok-Ho Yu,
Young-Tae Chang,
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摘要:
A D-myo-inositol derivative (3), obtained from methyl α-D-glucopyranoside by Ferrier rearrangement, was efficiently transformed to D-myo-inositol 1,2,6-trisphosphate (1, α-trinositol) and D-myo-inositol 2,6-bisphosphate (2).
ISSN:0732-8303
DOI:10.1080/07328309808002899
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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6. |
Photochemical Reactions of Imidazole-1-Sulfonates (Imidazylates) |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 391-396
Shaoming Duan,
RogerW. Binkley,
EdithR. Binkley,
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摘要:
Imidazylates1-3were irradiated in methanol in the presence and in the absence of the electron donortriethylamine. In each case photochemical deprotection occurred in excellent yield to form the partially protected sugar from which the imidazylate was synthesized. Reactions in the presence of triethylamine required much shorter irradiation times.
ISSN:0732-8303
DOI:10.1080/07328309808002900
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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7. |
Preparation and Antioxidant Activities of Phenolic Esters and Ethers of L-Ascorbic Acid |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 397-404
Lixian Gan,
PaulA. Seib,
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摘要:
Esterification of L-ascorbic acid in concentrated sulfuric acid with 0.33 moles of gallic acid gave a 90% yield of a 2:5 mixture of L-ascorbyl 5- and 6-gallate esters. The 6-gallate ester (1) was purified from the 5-gallate ester (2) by fractional crystallization in 40% yield. Three other aromatic derivatives of L-ascorbic acid also were prepared. The order of antioxidant activities of the L-ascorbyl derivatives determined by thiobarbituric acid number in methyl linolenate at 37 °C was as follows: 6-gallate (1) > 6-(3′,4′ -dihydroxy)benzoate (3) = 6-(4′ -hydroxy)phenyl ether (4) >6-(4′ methoxy)phenyl ether (5).
ISSN:0732-8303
DOI:10.1080/07328309808002901
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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8. |
Synthesis of Novel α,ω-Type 1-Glucosamide and 1-Galactosamide Bolaamphiphiles |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 405-416
Mitsutoshi Masuda,
Toshimi Shimizu,
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摘要:
A new family of bolaamphiphiles in which two glucosylamine or galactosylamine moieties are linked via a β-N-glycosidic bond to an α,ω-dicarboxylic acid has been described. The 1-D-glucosamide and 1-D-galactosamide bolaamphiphiles were obtained in good yield by the condensation of the dicarboxylic acid dichloride with the corresponding 1-aldopyranosylamine.
ISSN:0732-8303
DOI:10.1080/07328309808002902
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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9. |
Synthesis and Semisynthesis of Some Structural Elements of Oligo-Mannose Type N-Glycoproteins |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 417-437
Zoltán Szurmai,
Lóránt Jánossy,
Zoltán Szilágyi,
Károly Vékey,
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摘要:
For the construction of N-glycoprotein glycan chains, valuable potential glycosyl donors,O-α-D-mannopyranosyl-(1→2)-α-D-mannopyranose octaacetate (19) andO-α-D-mannopyranosyl-(1→2)-O-α-D-mannopyranosyl-(1→2)-α-D-mannopyranose undeca-acetate (20) were obtained in gram-scale by the acetylation and subsequent partial acetolysis of baker's yeast, without the isolation of mannan. The acetolytic products were investigated by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Octaacetates of mannobiose (1→3) (11) and (1→6) (17) were chemically synthesized.
ISSN:0732-8303
DOI:10.1080/07328309808002903
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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10. |
Chemical Synthesis of (4,6-Pyr)-Gal β1→4GlcNAcβ1→3Fucβ1→OMe: A Pyruvated Trisaccharide Related to the Cell Aggregation of the SpongeMicrociona Prolifera |
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Journal of Carbohydrate Chemistry,
Volume 17,
Issue 3,
1998,
Page 439-452
Shaojiang Deng,
Biao Yu,
Zhongwu Guo,
Yongzheng Hui,
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摘要:
4,6-O-[(R)-1-carboxylethylidene]Galβ1 →4GlcNAcβ1 →3Fucβ1 →OMe, a pyruvated trisaccharide unit involved in the aggregation factor of the marine spongeMicrociona prolifera, was synthesized stereospecifically and unambiguously employing thioglycosides as glycosyl donors to construct glycosidic bonds.
ISSN:0732-8303
DOI:10.1080/07328309808002904
出版商:Taylor & Francis Group
年代:1998
数据来源: Taylor
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