共查询到20条相似文献,搜索用时 46 毫秒
1.
Michaela Freiler Gottfried Reznicek Johann Jurenitsch Wolfgang Kubelka Wolfram Schmidt Manfred Schubert-Zsilavecz Ernst Haslinger Josef Reiner 《Helvetica chimica acta》1996,79(2):385-390
Three new saponins 1–3 were isolated from Herniaria glabra by means of prep. HPLC and TLC. The structures were established mainly by a combination of 2D-NMR techniques (COSY, TOCSY, ROESY, HMQC, and HMBC) as O-α-L -rhamnopyranosyl-(1→4)-O-β-D -glucopyranosyl-(1-→6)-O-[β-D -glucopyranosyl-(1→2)]-β-D -glucopyranosyl medicagen-28-ate (herniaria saponin 4; 1 ), O-β-D -glucopyranosyl-(1→3)-O-α-L -rhamnopyranosyl-(1→2)-O-[β-(3R)-D -apiofuranosyl-(1→3)]-β-D -4-O-acetylfucopyranosyl 3-O-(β-D -glucuronopyranosyl)-16α-hydroxymedicagen-28-ate (herniaria saponin 5; 2 ), and O-α-L -rhamnopyranosyl-(1→4)-O-β-D -glucopyranosyl-(1→6)-O-[β-D -6-O-acetylglucopyra nosyl-(1→2)]-β-D -glucopyranosyl medicagen-28-ate (herniaria saponin 6; 3 ). 相似文献
2.
Two new saponins, β-D -glucopyranosyl 3-O[O-βD -xylopyranosyl-(1→3)-O-(β-D -glucopyranosyluronic acid)]oleanolate ( 1 ) and 3-O-[O-β-D -xylopyranosyl-(1→3)-O-(β-D-glucopyranosyluronic acid)]oleanolic acid ( 2 ), have been isolated from the tubers of Talinum tenuissimum. The structures have been established mainly by 13C-NMR and FAB-MS. The monodesmosidic saponin 2 exhibits very strong molluscicidal activity against the schistosomiasis-transmitting snail Biomphalaria glabrata. 相似文献
3.
Ihsan ali Ayen Yürüker Heinz Rüegger Anthony D. Wright Otto Sticher 《Helvetica chimica acta》1993,76(1):416-424
Five new acyclic monoterpene glycosides 1 – 5 were isolated from the leaves of Viburnum orientale (Caprifoliaceae). Anatolioside ( 1 ) is a monoterpene diglycoside and its structure was elucidated as linalo-6-yl 2′-O-(α-L -rhamnopyranosyl)β-D -glucopyranoside (arbitrary numbering of linalool moiety). Compounds 2 – 5 are all derivatives of 1 , containing additional monoterpene and sugar units, connected by ester and glycoside bonds. Their structures were established as linalo-6-yl O-[(2E,6R)-6-hydroxy-2, 6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″? → 2″″)-β-D -glucopyranoside ( = anatolioside A; 2 ), linalo-6-yl O-β-D -glucopyranosyl-(1? → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″ → 2′)–β-D -glucopyranoside ( = anatolioside B; 3 ), linalo-6-yl O-β-D ribo-hexopyranos-3-ulosyl-(1′? → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″ → 2′)-β-D -glucopyranoside ( = anatolioside C; 4 ) and linalo-6-yl O-[(2E, 6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1″? → 2″″)-O-β-D -glucopyranosly-(1″″ → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl(1″ → 2′)-β-D -glucopyranoside ( = anatolioside D ; 5 ). The structure determinations were based on spectroscopic and chemical methods (acid and alkaline hydrolysis, acetylation and methylation). 相似文献
4.
From the aerial parts of Lagotis stolonifera (Scrophulariaccae), a new phenylpropanoid glycoside, lagotoside ( 8 ), and the three known glycosides ehrenoside ( 5 ), verbascoside (= acteoside; 6 ), and plantamajoside ( 7 ) were isolated, together with the four known iridoid glucosides aucubin ( 1 ), catalpol( 2 ), globularin ( 4 ), and lythantosalin ( 3 ). The structure of the new compound 8 was elucidated on the basis of chemical and spectral data as 2-(3-hy-droxy-4-methoxyphenyl)ethyl O-[α-L -arabinopyranosyl-(1 → 2)]-O-[α-L -rhamnopyranosyl-(1 → 3)]-4-O-feruloyl-β-D -glucopyranoside. 相似文献
5.
hsan ali Murat Zor A. Ahmet Baaran Athony D. Wright Otto Sticher 《Helvetica chimica acta》1993,76(3):1352-1360
From the aerial parts of Scrophularia ilwensis, four new triterpene saponins, ilwensisaponins A–D ( 1 – 4 ) were isolated. The structures of the compounds were elucidated using chemical and spectral data as 13β, 28-epoxy-3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}-oxy} olean-11-en-23-ol ( 1 ), 3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}oxy}olena-11, 13(18)-diene-23, 28-diol ( 2 ), 3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D glucopyranosyl-(1→3)]-β-D fucopyranosyl}oxy}-11α-methoxyolean- 12-ene-23, 28-diol (3) , and 3-β-{{[β-D -glucopyransoyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}oxy}olean-12-ene-11α,23,28-triol (4) . 相似文献
6.
Kenichi Takeo Masaki Kawaguchi Shinichi Kitamura 《Journal of carbohydrate chemistry》2013,32(8):1043-1056
Abstract The allyl β-glycosides of a trisaccharide O-β-D-Glcp-(1→3)-O-[β-D-Glcp-(1→6)]-β-D-Glcp and of a tetrasaccharide O-β-D-Glqp-(1→3)-O-[β-D-Glqp-(1→6)]-O-β-D-Glcp-(1→3)-β-D-Glcp, corresponding to the branching point or the repeating unit of antitumor (1→6)-branched-(1→3)-β-D-glucans, have been synthesized starting from ethyl 2-O-benzoyl-4,6-O-benzylidene-l-thio-α-D-glucopyranoside and copolymerized in a radical reaction with acrylamide to obtain polyacrylamide copolymers containing the tri-and tetra-saccharides for immunochemical studies of schizophyllan. 相似文献
7.
Olivier Placide Noté Line Made Simo Joséphine Ngo Mbing Dominique Guillaume Christian Dominique Muller Dieudonné Emmanuel Pegnyemb 《Natural product research》2019,33(2):180-188
As a continuation of our interest in the study of triterpenoid saponins from Albizia zygia, phytochemical investigation of its stem barks led to the isolation of two new oleanane-type saponins, named zygiaosides C–D (1–2). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (1H-, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as, 3-O-[ β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (1) and 3- O-[β-d-glucopyranosyl-(1→2) -[ β-d-fucopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (2). 相似文献
8.
K. Eklind R. Gustafsson A. K. Tidén T. Norberg P. M. ?berg 《Journal of carbohydrate chemistry》2013,32(9):1161-1178
ABSTRACT The 2-aminoethyl glycoside of O-α-L-fucopyranosyl-(1→2)-O-β-D-galactopyranosyl-(1→3)-[O-α-L-fucopyranosyl-(1→4)]-2-acetamido-2-deoxy-β-D-glucopyranose (Lewis B tetrasaccharide) was synthesized on a large scale and acryloylated with acryloyl chloride. The obtained oligosaccharide 2-acrylamidoethyl glycoside was then copolymerized with acrylamide to form a water-soluble, high molecular weight polymer, suitable for use in adhesion inhibition studies with Helicobacter pylori. Also synthesized were the corresponding derivatives of O-α-L-fucopyranosyl-(1→2)-O-β-D-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-β-D-glucopyranose and O-β-L-fucopyranosyl-(1→2)-β-D-galactopyranose. 相似文献
9.
《Tetrahedron: Asymmetry》2005,16(3):733-738
α-d-Galactopyranosyl-(1→6)-[β-d-galactofuranosyl-(1→5)]-β-d-galactofuranosyl-(1→6)-β-d-galactofuranosyl-(1→5)-[α-d-galactopyranosyl-(1→6)]-β-d-galactofuranose, the dimer of the trisaccharide repeating unit of the cell-wall galactans of Bifidobacterium catenulatum YIT 4016, has been synthesized as its dodecyl glycoside 2 by coupling of 2,3,4,6-tetra-O-benzyl-α-d-galactopyranosyl-(1→6)-[6-O-acetyl-2,3,5-tri-O-benzoyl-β-d-galactofuranosyl-(1→5)]-2-O-acetyl-3-O-benzyl-β-d-galactofuranosyl trichloroacetimidate 14 with dodecyl 2,3,4,6-tetra-O-benzyl-α-d-galactopyranosyl-(1→6)-[2,3,5-tri-O-benzoyl-β-d-galactofuranosyl-(1→5)]-2-O-acetyl-3-O-benzyl-β-d-galactofuranoside 16. The trisaccharide trichloroacetimidate donor 14 and trisaccharide acceptor 16 were regiospecifically prepared by employing 3-O-benzyl-1,2-O-isopropylidene-α-d-galactofuranose 4 as the glycosyl acceptor, and isopropyl 2,3,4,6-tetra-O-benzyl-1-thio-β-d-galactopyranoside 5 and 6-O-acetyl-2,3,5-tri-O-benzoyl-β-d-galactofuranosyl trichloroacetimidate 9 as glycosyl donors. 相似文献
10.
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
11.
FAN Gao-Jun HE Zhi-ShengShanghai Institute of Materia Medica Chinese Academy of Sciences Shanghai ChinaWU Hou-Ming XU Jing-FeiState Key Laboratory of Bioorganic Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai China 《中国化学》1997,15(5):431-437
Four new triterpenoid saponins were isolated from the roots of Adina rubella Hance. They were characterized as adinaic acid 3β-O-[α-L-rhamnopyranosyl(l→2)-β-D-glucopyranosyl(l→2)-β-D-glucurono-pyranoside-6-O-methyl ester]-28-O-β-D)-glucopyranoside, adinaic acid 3β-O-[α-L-rham-nopyranosyl(l→2)-β-D-glucopyranosyl(l→2)-β-D-glucuronopyranoside-6-O-butyl ester]-28-O-β-D-glu-copyranoside, adinaic acid 3β-O-[β-D-glucopyranosyl(l→2)-β-D-glucopyranosyl]-(28→1)-β-D-gluco-pyranosyl(l→6)-β-D-glucopyranosyl ester, 27-hydroxyursolic acid 3β-O-[α-L-rhamnopyranosyl (l→2)-β-O-glucopyranosyl(l→2)-β-D)-glucuronopyranoside-6-O-methyl ester]-28-O-β-D)-glucopyranoside. Their structures were elucidated by spectral methods, especially with the aid of 2D NMR techniques. Their complete assignments of the 1H and 13C NMR signals were carried out. 相似文献
12.
Two new oleanane-type triterpenoid glycosides, 3-O-β-D-xylopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→3)-[β-D-glucuronopyranosyl-(1→2)]-β-D-glucuronopyranosyl-22α-angeloyloxyolean-12-ene-15α,16α,28-triol(1) and 3-O-β-D-xylopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→3)-[β-D-glucuronopyranosyl-(1→2)]-β-D-glucuronopyranosyl-21β-acetyl-22α-angeloyloxyolean-12-ene-16α,28-diol (2) were isolated from the stems of Camellia oleifera Abel. Their structures were elucidated by means of spectroscopic methods and chemical evidence. The cytotoxic activities of compounds 1–2 were evaluated against five human tumour cell lines (HCT-8, BGC-823, A5049, and A2780). Compounds 1–2 showed cytotoxic activity against five human cancer cell lines, with IC50 values ranging from 3.15 to 7.32 μM. 相似文献
13.
Ihsan ali Ayen Yürüker Heinz Rüegger Anthony D. Wright Otto Sticher 《Helvetica chimica acta》1993,76(7):2563-2569
A new open-chain monoterpene glycoside, anatolioside E ( 1 ), was isolated from the leaves of Viburnum orientale in addition to three known acyclic monoterpene glycosides, betulalbusides A ( 2 ) and B ( 3 ), and 2(E)-2,6-dimethyl-2,7-octadien-1,6-diol-6-O-β-D -glucopyranoside( 4 ). The structure of anatolioside E ( 1 ) was elucidated on the basis of chemical and spectral data as 6-O-[β-D -glucopyransoyl-(1?? → 6?″)-2-(E), 6(R), 2,6-dimethyl-6-hydroxy-2,7-octadienoyl-(1?″ → 2″″)-β-D -glucopyranosyl-(1″″ → 6?)-2-(E), 6(R), 2,6-dimethyl-6-hydroxy-2,7-octadienoyl-(1? → 4″)-α-L -rhamnopyranosyl-(1″″ → 2′)-β-D -glucopyranosyl]linalool. 相似文献
14.
Olivier Placide Noté Joséphine Ngo Mbing Marie-Claude Kilhoffer Dieudonné Emmanuel Pegnyemb Annelise Lobstein 《Natural product research》2019,33(16):2292-2299
One new acacic acid-type saponin, named lebbeckoside C (1), was isolated from the stem barks of Albizia lebbeck. Its structure was established on the basis of extensive analysis of 1D and 2D NMR (1H, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as 3-O-[β-d-xylopyranosyl-(l→2)-β-d-fucopyranosyl-(1→6)-[β-d-glucopyranosyl(1→2)]-β-d-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-β-d-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28 O-[β-d-quinovopyranosyl-(l→3)-[α-l-arabinofuranosyl-(l→4)]-α-l-rhamnopyranosyl-(l→2)-β-d-glucopyranosyl] ester. The isolated saponin (1) displayed significant cytotoxic activity against the human glioblastoma cell line U-87 MG and TG1 stem-like glioma cells isolated from a patient tumor with IC50 values of 1.69 and 1.44 μM, respectively. 相似文献
15.
Tan Pei Jean Khozirah Shaari Christian Paetz Intan Safinar Ismail Faridah Abas Nordin H. Lajis Viqar Uddin Ahmad 《Helvetica chimica acta》2009,92(10):1973-1982
Three new oleanane‐type triterpenoid saponins, 3‐O‐(α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐fucopyranosyl)‐28‐O‐{[α‐L ‐rhamnopyranosyl(1→2)] [β‐D ‐fucopyranosyl(1→6)]‐β‐D ‐glucopyranosyl} oleanolic acid ( 1 ), 3‐O‐[α‐L ‐rhamnopyranosyl(1→3)‐β‐D ‐fucopyranosyl]‐28‐O‐[α‐L ‐rhamnopyranosyl(1→4)‐β‐D ‐glucopyranosyl] oleanolic acid ( 2 ), and 3‐O‐{α‐L ‐rhamnopyranosyl(1→2)‐[3′,4′‐diacetoxy‐β‐D ‐fucopyranosyl]}‐28‐O‐[α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐glucopyranosyl] oleanolic acid ( 3 ) have been isolated from the stems of Xerospermum noronhianum. The structures of the saponins were determined as a series of bidesmosidic oleanane saponins based on spectral evidence. The anticholinesterase activity of the saponins 1 – 3 was also evaluated. 相似文献
16.
Debabrata Acharya Anne‐Claire Mitaine‐Offer Nutan Kaushik Tomofumi Miyamoto Thomas Paululat Marie‐Aleth Lacaille‐Dubois 《Helvetica chimica acta》2008,91(12):2262-2269
Four new furostanol steroid saponins, borivilianosides A–D ( 1 – 4 , resp.), corresponding to (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐hydroxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 1 ), (3β,5α,22R,25R)‐ 26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 2 ), (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 3 ), and (3β,5α,25R)‐26‐(β‐D ‐glucopyranosyloxy)furost‐20(22)‐en‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 4 ), together with the known tribuluside A and (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside were isolated from the dried roots of Chlorophytum borivilianum Sant and Fern . Their structures were elucidated by 2D ‐NMR analyses (COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry. 相似文献
17.
Methyl palmitate (I), methyl stearate (II), stigmasterol (III), β-sitosterol (IV), (O -acyl)-β-D -glucopyranosyl-(1→3)-stigmasterol (V), (O -acyl)-β-D -glucopyranosyl-(1→3)-β-sitosterol (VI), β-D -glucopyranosyl-(1→3)-stigmasterol (VII), β-D -glucopyranosyl-(1→3)-β-sitosterol (VIII), β-D -ecdysone (IX), diosgenin-3-α-L -rhamopyranosyl-(1→2)-[α-L -arabinofuranosyl-(1→4)]-β-D -glucopyranoside (X), diosgenin-3-O -β-chacotrioside (dioscin) (XI), and diosgenin-3-O -α-L -rhamnopyranosyl-(1→4)-α-L -rhamnopyranosyl-(1→4)-[α-L -rhamnopyranosyl-(1→2)]-β-D -glucopyranoside (XII) were isolated and characterized from the stems of Paris formosana Hayata (Liliaceae). 相似文献
18.
Mohamed Elbandy Tomofumi Miyamoto Clment Delaude Marie‐Aleth Lacaille‐Dubois 《Helvetica chimica acta》2002,85(9):2721-2728
Five new triterpene saponins 1 – 5 were isolated from the roots of Muraltia ononidifolia E. Mey along with the two known saponins 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester and 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester (medicagenic acid=(4α,2β,3β)‐2,3‐dihydroxyolean‐12‐ene‐23,28‐dioic acid). Their structures were elucidated mainly by spectroscopic experiments, including 2D‐NMR techniques, as 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[O‐β‐ D ‐apiofuranosyl‐(1→3)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 1 ), 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐{[O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 2 ), 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐{O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 3 ), 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 4 ), and 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid ( 5 ). 相似文献
19.
《Journal of carbohydrate chemistry》2013,32(1-2):99-111
An efficient synthesis of NeuAcα-(2→3)-Galβ-(1→3)-[NeuAcα-(2→6)]-GalNAcα1- O-(Z)-Serine (N-protected MUC II oligosaccharide–serine, 14) by a chemoenzymatic strategy is described. The enzymatic reaction of GalNAcα1- O-(Z)-Ser- OAll 7 with pNP-β-Gal in the presence of recombinant β1,3-galactosidase from Bacillus circulans gave Galβ-(1→3)-GalNAcα1- O-(Z)-Ser- OAll 3 in 68%. The introduction of two sialic acids into 3 was accomplished by a stepwise method. The branched Galβ-(1→3)-[NeuAcα-(2→6)]-GalNAcα1- O-(Z)-Ser- OAll 11 was constructed by a chemical method. Sialylation at the C-3 position of the terminal Gal residue on Galβ-(1→3)-[NeuAcα-(2→6)]-GalNAcα1- O-(Z)-Serine 2 using α2,3-(O)-sialyltransferase from rat liver gave a target compound 14 in a practical yield. 相似文献
20.
Two dammarane‐type saponins with a novel aglycone derived from the parent 16,22‐epoxy‐24‐methylidenedammarane and lotoside A, a new lotogenin derivative, were isolated from the MeOH extract of the stem bark of the Brazilian medicinal plant Zizyphus joazeiro, in addition to the known saponin 3β‐{{O‐[O‐[α‐L ‐arabinofuranosyl‐(1→2)]‐O‐[β‐D ‐glucopyranosyl‐(1→3)]]‐α‐L ‐arabinopyranosyl}oxy}jujubogenin ( 1 ). The structures of the new compounds were determined as 16,22‐epoxy‐3β‐[(β‐D ‐glucopyranosyl)oxy]‐24‐methylidenedammarane‐15α,16α,20β‐triol ( 2 ), 16,22‐epoxy‐3β‐{{O‐[O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐[β‐D ‐apiofuranosyl‐(1→3)]]‐β‐D ‐glucopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl}oxy}‐24‐methylidenedammarane‐15α,16α,20β‐triol ( 3 ), and 3β‐{{O‐[O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐[β‐D ‐apiofuranosyl‐(1→3)]]‐β‐D ‐glucopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl}oxy}lotogenin ( 4 ) by means of 1D‐ and 2D‐NMR spectroscopy, as well as FAB mass spectrometry. For the novel aglycone, we propose the name joazeirogenin and, for the new saponins, joazeiroside A ( 2 ) and B ( 3 ). Joazeirogenin was found to be 16,22‐epoxy‐24‐methylidenedammarane‐3β,15α,16α,20β‐tetrol. 相似文献