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1.
Lauryl glycoside of β-D-Glcp-(1→3)-[β-D-Glcp-(1→6)-]α-D-Glcp-(1→3)-β-D-Glcp-(1→3)-[β-D-Glcp-(1→6)-]α-D-Glcp-(1→3)-β-D-Glcp-(1→3)-[β-D-Glcp-(1→6)-]β-D-Glcp was synthesized through 3 3 3 strategy. 3-O-Allyl-2,4,6-tri-O-benzoyl-β-D-glucopyranosyl-(1→3)- -[2, 3, 4, 6-tetra-O-benzoyl-β-D-glucopyranosyl-(1→6)-] 1,2-O-isopropylidene-α-D-glucofuranose was used as the key intermediate which was converted to the corresponding trisaccharide donor and acceptor readily. 相似文献
2.
具有β-(1→6)-半乳吡喃糖骨架和α-L-(1→3)-阿拉伯呋喃糖侧链的阿拉伯半乳寡糖的简易合成 总被引:1,自引:0,他引:1
4-Methoxyphenyl glycoside of β-D-Galp-(1→6)-[α-L-Araf-(1→3)-]β-D-Galp-(1→6)-β-D-Galp-(1→6)-{β-D-Galp-(1→6)-[α-L-Araf-(1→3)-]β-D-Galp-(1→6)-β-D-Galp-(1→6)-}2β-D-Galp-(1→6)-[α-L-Araf-(1→)3)-]β-D-Galp-(1→)6)-β-D-Galp was synthesized with 2,3,4,6-tetra-O-benzoyl-α-D-galactopyranosyl trichloroacetimidate (1), 6-O-acetyl-2,3,4-tri-O-benzoyl-α-D-galactopyranosyl trichloroacetimidate (11), 4-methoxyphenyl 3-O-allyl-2,4-tri-O-benzoyl-β-D-galactopyranoside (2),isopropyl 3-O-allyl-2,4-tri-O-benzoyl--thio-β-D-galactopyranoside (12),4-methoxyphenyl 2,3,4-tri-O-benzoyl-β-D-galactopyranoside (5), and 2,3,5-tri-O-benzoyl-α-L-arabinofuranosyl trichloroacetimidate (8) as the key synthons. 相似文献
3.
The phytoalexin elicitor β-(1→3)-branched β-( 1→6)-linked glucohexatose has been regio- and stereospecifically synthesized by coupling of the 3, 6-branched gluco-trisaccharide Schmidt reagent 10 with a mixture of multiol 3,6-branched gluco-trisaccharides 13 which consists of free 5,6‘-OH trisaccharide, free 5,2‘ ,6‘-OH trisaccharide, free 5,3‘ ,6‘-OH trisaccharide and so on. The compounds 10 and 13 were prepared from 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose , 2, 3, 4, 6-tetra-O-ben-zoyi-a-D-glucopyranosyl trichioroacetimldate, and 2,3,4, 6-tetra-O-acetyl-α-D-glucopyranosyl trichloreacetimidate through regio- and stereoselective manners. 相似文献
4.
Jian Jun Zhang~a Guang Hui Zong~a Xiao Mei Liang~a Yun Qi Li~a Dao Quan Wang~ 《中国化学快报》2008,19(4):415-418
An efficient synthesis ofα-D-GlcpNAc-(1→2)-[α-D-ManpNAc-(1→3)-]α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-L-Rhap(1), the repeating unit of the O10 antigen from Acinetobacter baumannii was achieved via sequential assembly of the building blocks,p- methoxylphenyl 2,4-di-O-benzoyl-α-L-rhamnopyranoside(2);2-O-allyloxycarbonyl-3,4-di-O-bcnzoyl-α-L-rhamnopyranosyl tri- chloroacetimidate(3);4-methoxylphenyl 3-O-allyloxycarbonyl-4-O-benzoyl-α-L-rhanmopyranoside(4);2-azido-3-O-benzoyl-2- deoxy-4,6-O-isopropylidene-α-D-mannopyranosyl trichloroacetirnidatc(5);2-azido-3,4,6-tri-O-benzoyl-2-deoxy-α,β-D-glucopyr- ano syl trichloroacetimidatc(6).The total yield of 1 from 4 was 4.7%. 相似文献
5.
A β-(1→)6)-branched β-(1→)3)-linked glucohexaose (1) and its lauryl glycoside (2), present in many biologically active polysaccharides from traditional herbal medicines such as Ganoderma lucidum, Schizophyllum commune and Lentinus edodes, were highly efficiently synthesized. Coupling of 2,3,4,6-tetra-O-benzoyl-β-D-glucopyranosyl- (1--)3)-2-O-benzoyl-4,6-O-benzylidene-a-D-glucopyranosyl trichloroacetimidate (7) with 3,6-branched acceptors 8 and 12 gave β-(1→)3)-linked pentasaccharides (9) and (13), then via simple chemical transformation 4',6'-OH pentasaccharide acceptors 10 and 14 were obtained. Regio- and stereoselective coupling of 3 with 10 and 14 gave β-(1→)3)-linked hexasaccharides (11) and (15) as the major products. Deprotection of 11 and 15 provided the target sugar 1 and 2. Thus, a new method for the preparation of this kind of compounds was developed. 相似文献
6.
ShouJunGUO XingHuaZHAO DongLiangCHENG 《中国化学快报》2004,15(12):1451-1453
A new diterpenoid trisaccharide, smithoside A, was isolated from Aster smithianus. Its structure was identified as pimar- 15 (16)-β-en-3β, 8β, 11α-triol-3-O-β-D-glucopyranosyl ( 1→3)- [β-glucopyranosyl (1→2)]-β-D-glucopyranoside on the basis of the spectral and chemical methods. 相似文献
7.
Flavonoid triglycosides from the seeds of Camellia oleifera Abel 总被引:1,自引:0,他引:1
Two flavonoid triglycosides, kaempferol 3-O-{ β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→ 6)]-β-D-glucopyranoside} (1) and kaempferol 3-O-{ β-D-xylopyranosyl-(1 → 2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside } (2), were isolated from the seed of Camellia oleifera Abel. The absolute configuration of compound 1 was established on the basis of its X-ray analysis. Their cytotoxic activities and anti-HIV-RT activities were evaluated. 相似文献
8.
Propyl O-(α-L-rhamncpyranosyl)-(1→3)-[2,4-di-O-(2s-methylbutyryl)-α-L-rham-nopyranosyl]-(1→2)-(3-O-acetyl-β-D-glucopyranosyl)-(1→2)-β-D-fucopyranoside (1), the tetrasac-charide moiety of Tricolorin A, was synthesized in total 23 steps with a longest linear sequence of 10 steps, and overall yield of 3.7% from D-Glucose. The isomerization of the dioxolane-type berzyli-dene in the presence of NIS/AgOTf was observed. Tetrasaccharide 1 exhibited no activity against the cultured P388 cell as Tricolorin A did. 相似文献
9.
An antimetastatic tetrasaccharide T1,β-D-Gal-(1→4)-β-D-GlcpNAc-(1→6)-α-D-Manp-(1→6)-β-D-Manp-OMe,was synthesized with two approaches.The first approach was a conventional method employing thioglycoside and Koenigs-Knorr glycosylation reaction in 24%overall yield.The second one was a novel route through the azidoiodo-glycosylation strategy by using 2-iodo-2-deoxylactosyl azide as the donor in 36%overall yield. 相似文献
10.
Two new spirostanol glycosides named agamenoside A and B, ere isolated from the fermented leaves of Agave americana. Their structures were elucidated as (23S,25R)-5α-spirostan-3β,6α,23-triol 3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside(1) and (25R)-5α-spiro-stan-3β,6α-diol 3-O-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyra-nosyl-(1→4)-β-D-galactopyranoside(2) by a combination of chemical and spectral methods. 相似文献
11.
Two symmetrical trehalose glycosyl ‘acceptors’ 4 and 6 were prepared and three of the unsymmetrical type, 8 , 10 , and 11 . Glucosylation of symmetrical ‘acceptor’ 4 gave a higher yield of trisaccharide (44%) than protect ve-group manipulation, namely via selective debenzylidenation 2 → 9 or monoacetylation 2 → 5 which proceeded in moderate yields (33–34%). A comparison of catalysts in the cis-glucosylation of trehalose ‘acceptor’ 10 with tetra-O-benzyl-β-D -glucopyranosyl fluoride 13 profiled triflic anhydride ((Tf)2O) as a new reactive promoter yielding 92% of trisaccharide 14 , deblocking gave the target saccharide α-D -glucopyranosyI-( 1 → 4 )-α,α-D -trehalose. 1H-NMR spectra of most compounds were analyzed extensively. The use of the ID TOCSY technique is advocated for its time efficiency, if needed supplemented by ROESY experiments. 相似文献
12.
First Total Synthesis of Trehalose‐Containing Branched Oligosaccharide OSE‐1 of Mycobacterium gordonae (Strain 990)
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Manishkumar A. Chaube Prof. Dr. Suvarn S. Kulkarni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(39):13544-13548
The first total synthesis of the branched oligosaccharide OSE‐1 of Mycobacterium gordonae (strain 990) is reported. An intramolecular aglycon delivery approach was used for constructing the desymmetrized 1,1′‐α,α‐linked trehalose moiety. A [3+2] glycosylation of the trisaccharide donor and trehalose acceptor furnished the right hand side pentasaccharide. Regioselective O3 glycosylation of L ‐rhamnosyl 2,3‐diol allowed expedient synthesis of the left hand side tetrasaccharide. The nonasaccharide was assembled in a highly convergent fashion through a [4+5] glycosylation. 相似文献
13.
Luigi Lay Francesco Nicotra Luigi Panza Giovanni Russo Elena Adobati 《Helvetica chimica acta》1994,77(2):509-514
The synthesis of the trisaccharide α-L -Fucp-(1 → 2)-β-D -Galp-(1 → 3)-β-D -GalpNAc-1-OPr ( 2 ) is described. The N-acetylgalactosamine 6 was obtained from 4 by an intramolecular displacement of a (trifluoromethyl)sulfonyloxy by a pivaloyloxy group with its concomitant migration from position 3 to position 4 (Scheme 1). The galactosyl donor 9 was obtained from 7 via 8 by regioselective opening of the orthoester function with AcOH/pyridine followed by treatment with CCl3CN and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (Scheme 2). Glycosylation of 6 with 9 in the presence of BF3 · OEt2 gave the disaccharide 10 . Selective deprotection of 10 at O? C(2′) followed by glycosylation with 12 and by standard deprotection afforded the title trisaccharide 2 (Scheme 3). Preliminary biological testing showed that 2 is able to inhibit the binding of the monoclonal antibody MBrl to the target tumor cells MCF7 in a dose-dependent manner. 相似文献
14.
Isolation and Structure Elucidation of Neapolitanose (O-β-D -Glucopyranosyl-(1→2)-O-[β-D -glucopyranosyl-(1→6)]-D -glucose), New Trisaccharide from the Stigmas of Garden Crocusses (Crocus neapolitanus var.) From the stigmas of Crocus neapolitanus var. ‘Blue Bird’ two new crocetin glycosyl esters were isolated. They contained a hitherto unknown trisaccharide. For the structure elucidation a homonuclear 2D-1H-NMR-shift-correlation experiment was carried out with the peracetate of the isolated trisaccharide. This experiment revealed that the carbohydrate is O-β-D -glucopyranosyl-(1→2)-O-[β-D -glucopyranosyl-(1→6))]-D -glucose, for which we suggest the name ‘neapolitanose’. The two new C20-carotenoids from Crocus neapolitanus are crocetin (β-gentiobiosyl) (β-neapolitanosyl) ester ( 4 ) and crocetin di(β-neapolitanosyl) ester ( 5 ). 相似文献
15.
The reaction of 2‐(2‐methylaziridin‐1‐yl)‐3‐ureidopyridines 12 with triphenylphosphine, carbon tetra‐chloride, and triethylamine (Appel's conditions) led to the corresponding carbodiimides 13 , which underwent intramolecular cycloaddition reaction with aziridine under the reaction conditions to give the pyridine‐fused heterocycles, 2,3‐dihydro‐1H‐imidazo[2′,3′:2,3]imidazo[4,5‐b]pyridines 16 and 12,13‐dihydro‐5H‐1,3 ‐benzodiazepino [2′,3′:2,3] imidazo[4,5‐b]pyridines 17 . 相似文献
16.
Lucija Juki Sorak Gorazd Sorak Renata Toplak David Bevk Jurij Svete Branko Stanovnik 《Journal of heterocyclic chemistry》2006,43(5):1205-1215
17.
John N. Low Justo Cobo Rodrigo Abonia Jairo Quiroga Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o194-o195
Molecules of the title compound, C13H16N4O2, are linked by one N—H⋯O hydrogen bond [H⋯O = 2.47 Å, N⋯O = 3.326 (2) Å and N—H⋯O = 166°] and one N—H⋯N hydrogen bond [H⋯N = 2.19 Å, N⋯N = 3.063 (2) Å and N—H⋯N = 173°] into sheets containing alternating (20) and (32) rings, both types of which are centrosymmetric. 相似文献
18.
Georgii Bogdanov John P. Tillotson Victor N. Khrustalev Sergei Rigin Tatiana V. Timofeeva 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(8):1175-1181
The synthesis, crystal structure studies and solvatochromic behavior of 2‐{(2E,4E)‐5‐[4‐(dimethylamino)phenyl]penta‐2,4‐dien‐1‐ylidene}malononitrile, C16H15N3 (DCV[3]), and 2‐{(2E,4E,6E)‐7‐[4‐(dimethylamino)phenyl]hepta‐2,4,6‐trien‐1‐ylidene}malononitrile, C18H17N3 (DCV[4]), are reported and discussed in comparison with their homologs having a shorter length of the π‐conjugated bridge. The compounds of this series have potential use as nonlinear materials with second‐order effects due to their donor–acceptor structures. However, DCV[3] and DCV[4] crystallized in the centrosymmetric space group P21/c which excludes their application as nonlinear optical materials in the crystalline state. They both crystallize with two independent molecules having the same molecular conformation in the asymmetric unit. The series DCV[1]–DCV[4] demonstrated reversed solvatochromic behavior in toluene, chloroform, and acetonitrile. 相似文献
19.
Anton V. Dolzhenko Wai‐Keung Chui Anna V. Dolzhenko 《Journal of heterocyclic chemistry》2006,43(6):1513-1521