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1.
元胡多糖YhPS-1的理化性质、结构分析及抗肿瘤活性研究 总被引:2,自引:0,他引:2
A polysaccharide named YhPS- 1 was isolated from the root of Cordalis yanhusuo Wang and purified by means of gel-permeation chromatography and ionexchange chromatography. Its physicochemical properties, including monosaccharide composition, carbohydrate content, molecular weight and elemental composition, were determined. The structure of YhPS-1 was elucidated by chemical methods along with ^1H and ^13C NMR spectroscopy ways, such as including two-dimensional HMQC and HMBC experiments. These results show that YhPS-1 possesses a backbone consisting of terminal α-Glcp-(1→, a-Glcp-(1→6), a-Glcp-(1→4) and a-Glcp-(1→4,6). The bioactive assay showed that it could inhibit the growth of Sarcoma 180 and Lewis pulmonary carcinoma implanted in mice. 相似文献
2.
Ulrika Olsson Dr. Elin Säwén Roland Stenutz Docent Göran Widmalm Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(35):8886-8894
The conformational flexibility and dynamics of two (1→6)‐linked disaccharides that are related to the action of the glycosyl transferase GnT‐V have been investigated. NMR NOE and T‐ROE spectroscopy experiments, conformation‐dependent coupling constants and molecular dynamics (MD) simulations were used in the analyses. To facilitate these studies, the compounds were synthesised as α‐d‐ [6‐13C]‐Manp‐OMe derivatives, which reduced the 1H NMR spectral overlap and facilitated the determination of two‐ and three‐bond 1H,1H, 1H,13C and 13C,13C‐coupling constants. The population distribution for the glycosidic ω torsion angle in α‐d‐ Manp‐(1→6)‐α‐d‐ Manp‐OMe for gt/gg/tg was equal to 45:50:5, whereas in α‐d‐ Manp‐OMe it was determined to be 56:36:8. The dynamic model that was generated for β‐d‐ GlcpNAc‐(1→6)‐α‐d‐ Manp‐OMe by MD simulations employing the PARM22/SU01 CHARMM‐based force field was in very good agreement with experimental observations. β‐d‐ GlcpNAc‐(1→6)‐α‐d‐ Manp‐OMe is described by an equilibrium of populated states in which the ? torsion angle has the exo‐anomeric conformation, the ψ torsion angle an extended antiperiplanar conformation and the ω torsion angle a distribution of populations predominantly between the gauche–trans and the gauche–gauche conformational states (i.e., gt/gg/tg) is equal to 60:35:5, respectively. The use of site‐specific 13C labelling in these disaccharides leads to increased spectral dispersion, thereby making NMR spectroscopy based conformational analysis possible that otherwise might be difficult to attain. 相似文献
3.
Guangzong Tian Jing Hu Chunjun Qin Lingxin Li Xiaopeng Zou Juntao Cai Peter H. Seeberger Jian Yin 《Angewandte Chemie (International ed. in English)》2020,59(32):13362-13370
The development of glycoconjugate vaccines against Helicobacter pylori is challenging. An exact epitope of the H. pylori lipo‐polysaccharide (LPS) O‐antigens that contain Lewis determinant oligosaccharides and unique dd ‐heptoglycans has not yet been identified. Reported here is the first total synthesis of H. pylori serotype O6 tridecasaccharide O‐antigen containing a terminal Ley tetrasaccharide, a unique α‐(1→3)‐, α‐(1→6)‐, and α‐(1→2)‐linked heptoglycan, and a β‐d ‐galactose connector, by an [(2×1)+(3+8)] assembly sequence. Seven oligosaccharides covering different portions of the entire O‐antigen were prepared for immunological investigations with a particular focus on elucidation of the roles of the dd ‐heptoglycan and Ley tetrasaccharide. Glycan microarray analysis of sera from rabbits immunized with isolated serotype O6 LPS revealed a humoral immune response to the α‐(1→3)‐linked heptoglycan, a key motif for designing glycoconjugate vaccines for H. pylori serotype O6. 相似文献
4.
《Magnetic resonance in chemistry : MRC》2002,40(9):603-608
Four new ursane‐type saponins, monepalosides C–F, together with a known saponin, mazusaponin II, were isolated from Morina nepalensis var. alba Hand.‐Mazz. Their structures were determined to be 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside C, 1 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside D, 2 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[beta;‐D ‐glucopyranosy‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside E, 3 ) and 3‐O‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranoside (monepaloside F, 4 ) on the basis of chemical and spectroscopic evidence. 2D NMR techniques, including 1H–1H COSY, HMQC, 2D HMQC‐TOCSY, HMBC and ROESY, and selective excitation experiments, including SELTOCSY and SELNOESY, were utilized in the structure elucidation and complete assignments of 1H and 13C NMR spectra. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
5.
《Magnetic resonance in chemistry : MRC》2002,40(9):609-613
Two new triterpenoid saponins, gledistside A ( 1 ) and gledistside B ( 2 ), isolated from the fruits of Gledistsia dolavayi Franch., were characterized as the 3,28‐O‐bisdesmoside of echinocystic acid acylated with monoterpene carboxylic acids. On the basis of spectroscopic and chemical evidence, their structures were elucidated as 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2,6‐dimethyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 1 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2‐hydroxymethyl‐6‐methyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 2 ). The complete 1H and 13C assignments of saponins 1 and 2 were achieved on the basis of 2D NMR spectra including HMQC‐TOCSY, TOCSY, 1H–1H COSY, HMBC, ROESY and HMQC spectra. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
6.
The effect of using different solvothermal approaches, involving heat‐up and hot‐injection routes, on the phase, morphology and optical properties of tin sulfide nanoparticles using novel dibutyltin(IV) p‐methylphenyl dithiocarbamate as single source precursor compound have been studied. Dibutyltin(IV) p‐methylphenyldithiocarbamate was synthesized and characterized using various spectroscopic techniques (FT‐IR, 1H, 13C and 119Sn), and elemental analysis. TG analysis, studied under nitrogen, revealed tin sulfide of the rare mixed‐valence binary phase (Sn2S3) as the final residue at the end of the decomposition process. The samples presented as SnS1 and SnS2 obtained by the heat‐up and hot injection routes respectively, at 220 °C and in the presence of oleylamine as surfactant, revealed the α‐cubic phase of SnS with Herzenbergite structure. The X‐ray diffraction analysis of the nanoparticles also revealed patterns which showed preferred growth along (111) orientation; hence, favoring anisotropic shapes which were more distinct at higher magnification images of the TEM as a pseudo spherical morphology tending toward the formation of short rods. The optical property of the nanoparticles exhibited a blue shift in the bandgap energy with respect to the bulk, which is an evidence of quantum confinement effect. 相似文献
7.
Ying Guo De‐Qiang Dou Ting‐Guo Kang Shi‐Cheng Wang Hai‐Xue Kuang 《Magnetic resonance in chemistry : MRC》2009,47(11):982-988
Two new saponins were isolated from husks of Xanthoceras sorbifolia Bunge and their structures were elucidated as 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21‐O‐(3,4‐diangeloyl)‐α‐L‐rhamnose‐3β, 16α, 21β, 22α, 28β‐pentahydroxyl‐22‐acetoxy‐olean‐12‐ene(1) and 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21,22‐O‐diangeloyl‐3β,15α,16α,21β,22α,28β‐hexahydroxyl‐olean‐12‐ene(2) on the basis of 1D and 2D NMR (including 1H, 13C‐NMR, 1H? 1H COSY, HSQC, HMBC and DEPT), ESI‐MS spectrometry and chemical methods. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
8.
《Magnetic resonance in chemistry : MRC》2002,40(6):415-420
From the whole plant of Morina nepalensis var. alba Hand.‐Mazz., two new acylated flavonoid glycosides ( 1 and 2 ), together with four known flavonoid glycosides ( 3–6 ), were isolated. Their structures were determined to be quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (monepalin A, 1 ), quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranoside (monepalin B, 2 ), quercetin 3‐O‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (rumarin, 3 ), quercetin 3‐O‐β‐D ‐galactopyranoside ( 4 ), quercetin 3‐O‐β‐D ‐glucopyranoside ( 5 ) and apigenin 4′‐O‐β‐D ‐glucopyranoside ( 6 ). Their structures were determined on the basis of chemical and spectroscopic evidence. Complete assignments of the 1H and 13C NMR spectra of all compounds were achieved from the 2D NMR spectra, including H–H COSY, HMQC, HMBC and 2D HMQC‐TOCSY spectra. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
9.
Andrei V. Afonin Dmitry V. Pavlov Igor A. Ushakov Natalia A. Keiko 《Magnetic resonance in chemistry : MRC》2012,50(7):502-510
In the 13C NMR spectra of methylglyoxal bisdimethylhydrazone, the 13C‐5 signal is shifted to higher frequencies, while the 13C‐6 signal is shifted to lower frequencies on going from the EE to ZE isomer following the trend found previously. Surprisingly, the 1H‐6 chemical shift and 1J(C‐6,H‐6) coupling constant are noticeably larger in the ZE isomer than in the EE isomer, although the configuration around the –CH═N– bond does not change. This paradox can be rationalized by the C–H?N intramolecular hydrogen bond in the ZE isomer, which is found from the quantum‐chemical calculations including Bader's quantum theory of atoms in molecules analysis. This hydrogen bond results in the increase of δ(1H‐6) and 1J(C‐6,H‐6) parameters. The effect of the C–H?N hydrogen bond on the 1H shielding and one‐bond 13C–1H coupling complicates the configurational assignment of the considered compound because of these spectral parameters. The 1H, 13C and 15N chemical shifts of the 2‐ and 8‐(CH3)2N groups attached to the –C(CH3)═N– and –CH═N– moieties, respectively, reveal pronounced difference. The ab initio calculations show that the 8‐(CH3)2N group conjugate effectively with the π‐framework, and the 2‐(CH3)2N group twisted out from the plane of the backbone and loses conjugation. As a result, the degree of charge transfer from the N‐2– and N‐8– nitrogen lone pairs to the π‐framework varies, which affects the 1H, 13C and 15N shieldings. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
10.
《Magnetic resonance in chemistry : MRC》2003,41(9):735-738
Extensive 1D (1H NMR, HBBD‐13C NMR, DEPT‐13C NMR) and 2D (COSY, TOCSY, NOESY, HMQC and HMBC) NMR analysis was used to characterize the structure of a new bisdesmoside saponin isolated from the methanol extract of stems of Cordia piauhiensis Fresen as 3β‐O‐[α‐L ‐rhamnopyranosyl‐(1 → 2)‐β‐D ‐glucopyranosyl]ursolic acid 28‐O‐[β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranosyl] ester. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
11.
《Magnetic resonance in chemistry : MRC》2002,40(11):752-754
An NMR study of five highly functionalized and rearranged abietane diterpenoids is described. In addition to 1D NMR methods, including 1D NOESY spectra, 2D shift‐correlated experiments [1H, 13C‐gHSQC‐1J (C,H) and 1H, 13C‐gHMBC‐nJ (C,H) (n = 2 and 3)] were used for the complete and unambiguous 1H and 13C chemical shift assignments of these substances. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
12.
The focus of this work is the synthesis of an ursolic acid saponin with an N-acetylglucosamine-containingtrisaccharide residue.Therefore,ursolic acid 3-yl α-L-arabinopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→6)-2-acetamido-2-deoxy-β-D-glucopyranoside(1)was concisely synthesized in convergent synthesis with 48.0% overallyield.The structure of saponin 1 was confirmed by ~1H NMR,~(13)C NMR and mass spectra. 相似文献
13.
Separation of α‐amylase inhibitors from Abelmoschus esculentus (L).Moench by on‐line two‐dimensional high‐speed counter‐current chromatography target‐guided by ultrafiltration‐HPLC
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Hualiang Zeng Qi Liu Jingang Yu Meiling Wang Miao Chen Ranhao Wang Xi He Menghuan Gao Xiaoqing Chen 《Journal of separation science》2015,38(22):3897-3904
In this study, an on‐line two‐dimensional high‐speed counter‐current chromatography system based on a six‐port valve was developed. Target‐guided by ultrafiltration with high‐performance liquid chromatography, the one‐step isolation of three potential α‐amylase inhibitors from Abelmoschus esculentus (L).Moench was achieved by employing the developed orthogonal system and extrusion elution mode. The purities of three potential α‐amylase inhibitors were all over 95% as determined by high‐performance liquid chromatography. Furthermore, UV, mass spectrometry and 1H NMR spectroscopy were applied to the structural identification of the isolated three target compounds, their structures were assigned as quercetin‐3‐O‐sophoroside (i), 5,7,3′,4′‐tetrahydroxy flavonol‐3‐O‐[β‐d ‐rhamnopyranosil‐(1→2)]‐β‐d ‐glucopyranoside (ii ) and isoquercitrin (iii), respectively. The Results demonstrated that the proposed method was highly efficient to screen and isolate enzyme inhibitors from complex natural products extracts, and on‐line two‐dimensional high‐speed counter‐current chromatography can effectively increase the peak resolution of target compounds. 相似文献
14.
Toshiaki Taira Yuji Suzaki Dr. Kohtaro Osakada Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(22):6518-6529
Mixtures of N‐alkyl pyridinium compounds [py‐N‐(CH2)nOC6H3‐3,5‐(OMe)2]+(X?) ( 1b Cl: n=10, X=Cl; 1c Br: n=12, X=Br) and α‐cyclodextrin (α‐CD) form supramolecular hydrogels in aqueous media. The concentrations of the two components influences the sol–gel transition temperature, which ranges from 7 to 67 °C. Washing the hydrogel with acetone or evaporation of water left the xerogel, and 13C CP/MAS NMR measurements, powder X‐ray diffraction (XRD), and scanning electron microscopy (SEM) revealed that the xerogel of 1b Cl (or 1c Br) and α‐CD was composed of pseudorotaxanes with high crystallinity. 13C{1H} and 1H NMR spectra of the gel revealed the detailed composition of the components. The gel from 1b Cl and α‐CD contains the corresponding [2]‐ and [3]pseudorotaxanes, [ 1b? (α‐CD)]Br and [ 1b? (α‐CD)2]Br, while that from 1c Br and α‐CD consists mainly of [3]pseudorotaxane [ 1c? (α‐CD)2]Br. 2D ROESY 1H NMR measurements suggested intermolecular contact of 3,5‐dimethoxyphenyl and pyridyl end groups of the axle component. The presence of the [3]pseudorotaxane is indispensable for gel formation. Thus, intermolecular interaction between the end groups of the axle component and that between α‐CDs of the [3]pseudorotaxane contribute to formation of the network. The supramolecular gels were transformed into sols by adding denaturing agents such as urea, C6H3‐1,3,5‐(OH)3, and [py‐N‐nBu]+(Cl?). 相似文献
15.
Regina Janciene Zita Stumbreviciute Daiva Podeniene Benedikta D. Puodziunaite Steve Black Stephen M. Husbands 《Journal of heterocyclic chemistry》2006,43(4):979-984
16.
Nury Pérez‐Hernández Celina Álvarez‐Cisneros Carlos M. Cerda‐García‐Rojas Martha S. Morales‐Ríos Pedro Joseph‐Nathan 《Magnetic resonance in chemistry : MRC》2013,51(3):136-142
1,2,3,4,6‐Penta‐O‐acetyl‐α‐d ‐glucopyranose and the corresponding [1‐2H], [2‐2H], [3‐2H], [4‐2H], [5‐2H], and [6,6‐2H2]‐labeled compounds were prepared for measuring deuterium/hydrogen‐induced effects on 13C chemical shift nΔ (DHIECS) values. A conformational analysis of the nondeuterated compound was achieved using density functional theory (DFT) molecular models that allowed calculation of several structural properties as well as Boltzmann‐averaged 13C NMR chemical shifts by using the gauge‐including atomic orbital method. It was found that the DFT‐calculated C–H bond lengths correlate with 1Δ DHIECS. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
17.
Leszek Pazderski Jaromír Toušek Jerzy Sitkowski Kateřina Maliňáková Lech Kozerski Edward Szłyk 《Magnetic resonance in chemistry : MRC》2009,47(3):228-238
1H, 13C and 15N NMR studies of gold(III), palladium(II) and platinum(II) chloride complexes with picolines, [Au(PIC)Cl3], trans‐[Pd(PIC)2Cl2], trans/cis‐[Pt(PIC)2Cl2] and [Pt(PIC)4]Cl2, were performed. After complexation, the 1H and 13C signals were shifted to higher frequency, whereas the 15N ones to lower (by ca 80–110 ppm), with respect to the free ligands. The 15N shielding phenomenon was enhanced in the series [Au(PIC)Cl3] < trans‐[Pd(PIC)2Cl2] < cis‐[Pt(PIC)2Cl2] < trans‐[Pt(PIC)2Cl2]; it increased following the Pd(II) → Pt(II) replacement, but decreased upon the trans → cis‐transition. Experimental 1H, 13C and 15N NMR chemical shifts were compared to those quantum‐chemically calculated by B3LYP/LanL2DZ + 6‐31G**//B3LYP/LanL2DZ + 6‐31G*. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
18.
Andrei V. Afonin Igor A. Ushakov Alexander V. Vashchenko Dmitry E. Simonenko Andrei V. Ivanov Alexander M. Vasil'tsov Al'bina I. Mikhaleva Boris A. Trofimov 《Magnetic resonance in chemistry : MRC》2009,47(2):105-112
According to the 1H, 13C and 15N NMR spectroscopic data and DFT calculations, the E‐isomer of 1‐vinylpyrrole‐2‐carbaldehyde adopts preferable conformation with the anti‐orientation of the vinyl group relative to the carbaldehyde oxime group and with the syn‐arrangement of the carbaldehyde oxime group with reference to the pyrrole ring. This conformation is stabilized by the C? H···N intramolecular hydrogen bond between the α‐hydrogen of the vinyl group and the oxime group nitrogen, which causes a pronounced high‐frequency shift of the α‐hydrogen signal in 1H NMR (~0.5 ppm) and an increase in the corresponding one‐bond 13C–1H coupling constant (ca 4 Hz). In the Z‐isomer, the carbaldehyde oxime group turns to the anti‐position with respect to the pyrrole ring. The C? H···O intramolecular hydrogen bond between the H‐3 hydrogen of the pyrrole ring and the oxime group oxygen is realized in this case. Due to such hydrogen bonding, the H‐3 hydrogen resonance is shifted to a higher frequency by about 1 ppm and the one‐bond 13C–1H coupling constant for this proton increases by ~5 Hz. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
19.
Enantiopure α‐amino acids were converted to 4‐substituted 2‐aryl‐ and 2‐alkyl‐5(4H)‐oxazolones under partial racemization. These nonracemic mixtures were dissolved in CDCl3, an equimolar amount of the chiral dirhodium complex [(R)? (+)? MTPA]4 (MTPA‐H = Mosher's acid) was added, and the 1H NMR spectra of the resulting samples were recorded (dirhodium method). The relative intensities of 1H signals dispersed by the formation of diastereomeric adducts allow to determine the absolute configuration (AC) of the starting α‐amino acids. Binding atoms in the adducts were identified by comparing the 1H and 13C chemical shifts of the oxazolones in the absence and presence of [(R)? (+)? MTPA]4. Thereby, information about the scope and limits of this method can be extracted. A protocol how to use this method is presented. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
20.
《Magnetic resonance in chemistry : MRC》2002,40(8):541-544
Two novel oligosaccharides, mono‐ and difructosyllactosucrose {[O‐β‐D ‐fructofuranosyl‐(2 → 1)]n‐β‐D ‐fructofuranosyl‐O‐[β‐D ‐galactopyranosyl‐(1 → 4)]‐α‐D ‐glucopyranoside, n = 1 and 2} were synthesized using 1F‐fructosyltransferase purified form roots of asparagus (Asparagus officinalis L.). Their 1H and 13C NMR spectra were assigned using several NMR techniques. The spectral analysis was started from two anomeric methines of aldose units, galactose and glucose, since they showed separate characteristic signals in their 1H and 13C NMR spectra. After assignments of all the 1H and 13C signals of two units of aldose, they were discriminated as galactose and glucose using proton–proton coupling constants. The HMBC spectrum revealed the galactose residue attached to C‐4 of glucose, fructose residue attached to the C‐1 of glucose, and further fructosyl fructose linkage extended from the glucosyl fructose residues. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献