菟丝子多糖H3的研究

目的　研究从中药菟丝子(Cuscuta chinensis Lam.)种子中提取分离所得的酸性纯多糖H3的结构特征。方法　利用化学方法(糖组分分析、甲基化分析、糖醛酸还原和部分酸水解等)和光谱分析方法(¹HNMR谱、¹³CNMR谱、IR谱等)对其结构进行了研究。结果H3的分子量大于1.0×10⁶,糖组分分析显示其是由阿拉伯糖、鼠李糖、半乳糖和半乳糖醛酸组成的,甲基化分析,部分酸水解和NMR光谱分析进一步揭示H3分子中各糖残基的连接方式及次序。结论　H3为一多分枝的结构复杂的杂多糖,为首次从该植物中分得。     

人参果胶的纯化与鉴定

人参果胶经分离、纯化获两种(SA、SB)酸性杂多糖。经醋酸纤维薄膜电泳、玻璃纤维纸电泳分别呈章一色斑。SA的组成以中性糖为主,其中半乳糖、阿拉伯糖、鼠李糖间摩尔比为4.7:2.6:1,半乳糖醛酸含量为26%。将SA先经部分酸水解,再经Smtch降解得到β-(1→3)-D-聚半乳糖。SB的组成以酸性糖为主,半乳糖醛酸含量为76%,半乳糖、阿拉伯糖、鼠李糖间的摩尔比为3.3:1.8:1。用部分酸水解方法,可从SB获得分子量小于2万的α-(1→4)-D-聚半乳糖醛酸。     

徐长卿多糖CPB54的结构及其活性的研究

目的　研究从常用中药徐长卿中获得的一种分子量为6.0×10⁵的杂多糖CPB54的化学结构及其药理活性。 方法　运用糖组成分析、甲基化分析、部分酸水解及NMR等方法确定该多糖的结构并测定其药理活性。结果 该多糖由阿拉伯糖、鼠李糖和半乳糖以0.8∶0.5∶1.0摩尔比组成,其主链由1,4连接的半乳糖残基和1,2连接的鼠李糖残基组成,阿拉伯糖作为侧链主要位于鼠李糖残基的O-4位上,体内实验表明,其具有较强的促脾细胞和淋巴细胞增殖作用。结论　该多糖为一新结构多糖,具较强的促脾细胞和淋巴细胞增殖作用。     

山药多糖RDPS-I的结构分析及抗肿瘤活性

目的研究山药多糖的化学结构和抗肿瘤活性。方法用水提取山药块茎粗多糖,经Sevag反复脱蛋白8次,透析后经DEAE-cellulose及Sephadex G-100柱色谱纯化得山药多糖RDPS-I。经完全酸水解、部分酸水解,用PC,GC,IR,高碘酸氧化,Smith降解,甲基化分析,¹HNMR及¹³CNMR等研究山药多糖的化学结构。并用小鼠移植性实体瘤研究了RDPS-I的体内抗肿瘤作用。结果RDPS-I的分子量为41 000,比旋光度为［α］²⁰_D=+188.4°(c 0.80,H₂O),特性粘度为［η］=16.48×10^-3(g·mL^-1)。RDPS-I是由葡萄糖、甘露糖和半乳糖以1∶0.4∶0.1的摩尔比组成,以α-D-(1→3)-Glcp为主链,在6-O位有α-D-(1→2)-Manp-β-D-1)-Galp支链的杂多糖。RDPS-I对移植性黑色素B16和Lewis肺癌有很强的抑制作用。结论RDPS-I是由葡萄糖、甘露糖和半乳糖构成的杂多糖,有很强的体内抗肿瘤活性。     

麦冬多糖MDG-1的分离纯化和结构分析

目的分离纯化麦冬多糖抗心肌缺血的活性部位，得到相对分子质量均一的组分MDG-1，并进行结构分析。方法水提醇沉得麦冬粗多糖，超滤后经DEAE Sepharose FF柱和Sephadex G25柱色谱纯化后得MDG-1。经完全酸水解、高碘酸氧化、Smith降解、甲基化分析、¹H NMR及¹³C NMR等研究分析MDG-1的化学结构。结果和结论 MDG-1为β-D-果聚糖，易溶于水，数均分子量(M_n)为3 400，重均分子量(M_w)为4 800，峰尖分子量(M_p)为5 000，以2→1连接的呋喃型果糖为主，平均每2.8个主链残基上有一个Fruf(2→6)Fruf(2→分支)。该多糖还含有微量葡萄糖(果糖∶葡萄糖=35∶1)，可能连接在多糖的还原端。     

白木通多糖的研究

用碱液从白木通(Akebia trifoliate)茎中提取所得的粗多糖ATB经DEAE-Celulose及SephadexG-200柱层析后得到一多糖纯品ATBB 2,其分子量为2.3×10⁵。糖组分分析ATBB-2中各糖残基的摩尔比为Rha∶Ara∶Xyl∶Gal∶Glc∶GalA=1.22∶1.00∶1.10∶0.85∶0.24∶0.82。经甲基化,高碘酸氧化,Smith降解,部分酸水解,¹H和¹³CNMR谱的分析揭示ATBB-2是一个结构复杂的杂多糖。     

云芝子实体多糖化学结构的研究

目的　研究云芝子实体中多糖的化学结构。方法　应用柱色谱方法进行分离、纯化得一均一多糖组份B-1-3。通过完全水解、甲基化、一维和二维¹H和¹³CNMR阐明B-1-3的化学结构。结果　经完全水解证实B-1-3主要由Glc单糖残基组成,用HPLC方法测得其分子量为3.16×10⁵,通过对甲基化反应数据和¹H和¹³CNMR分析发现B-1-3为由β-D-1,4-Glc和β-D-1,3-Glc残基构成主链的葡聚糖,同时在β-D-1,3,6-Glc及β-D-1,4,6-Glc残基处产生分枝。经¹H和¹³CNMR分析表明B-1-3分子中存在β-D-Glc-1→3-β-D-Glc-β-D-Glc-1→4-β-D-Glc及β-D-Glc-1→4-β-D-Glc-β-D-Glc-1→4-β-D-Glc片段。结论　云芝子实体多糖B-1-3为由β-D-1,4-Glc,β-D-1,3-Glc和β-D-1,6-Glc残基构成主链的葡聚糖。     

赤芝多糖肽GL-PP-3A的分离纯化和结构研究

分离纯化赤芝多糖肽，得到具有活性部位GL-PP-3A，对其进行结构分析。水提醇沉透析得赤芝多糖肽，经分级沉淀，Bio-Gel P-10柱色谱纯化得GL-PP-3A。经HPGPC、糖基组成、甲基化分析、 ¹H NMR和 ¹³C NMR等方法研究分析GL-PP-3A的结构。GL-PP-3A是以葡萄糖为主的杂多糖，含Rha、Xyl、Man、Gal、Glc糖残基和17种氨基酸。其M_w为1.7×10⁴；M_n为1.1×10⁴；M_w/M_n为1.49。M_p为1.3×10⁴。该多糖主链由1,6-或1,3-连接的β-D-Glcp构成，二者的比例约为2∶1，在部分1,6-连接的主链葡萄糖的2或3位有分支，分支的非还原末端均主要为β-D-Glcp,少量为鼠李糖，分支内部含有1～3个1,6-连接的β-D-Galp或1,3-连接的α-D-Manp。     

人参果胶的结构研究

人参果胶是一酸性杂多糖混合物,经分离纯化获均一的S_A-1,它含半乳糖、半乳糖醛酸、阿拉伯糖、鼠李糖基摩尔比为3.7:1.7:1.8:1。S_A-1的结构分析用高碘酸氧化、Smith降解、甲基化等方法,在S_A-1中的羧基用Taylor与Conrad方法较原·来自S_A-1甲基化与乙酰化水解物的乙酰化衍生物用G.C.与G.C.—MS联用鉴定。结果表明S_A-1为多分支结构,分子主干由β(1-3)D-半乳糖基组成,部分半乳糖基C₆位有支链,尚有部分半乳糖基以(1-6)键连接。分子的支链由半乳糖醛酸基(1-4),鼠李糖基(1-3或1-2,4),阿拉伯糖基(1-5或1-3,5)组成。     

甘草葡聚糖的分离纯化与化学结构

从甘草(Glycyrrhiza uralensis Fisch)的稀碱提取液中得到的甘草葡聚糖GBW,是经脱蛋白、透析和沉淀、再经Cellex-D和Sephadex G-100相继柱层析得到的均一组分.它是由单一葡萄糖残基组成,分子量4000,[α]_D²⁸+120°(c0.1,H₂O)。全水解,甲基化反应,过碘酸氧化,Smith降解,部分酸水解,KI—I₂反应,和IR,¹³CNMR揭示了其化学结构为直链的α-D-(1→4)葡聚糖(6)。     

Structural features of an immunostimulating and antioxidant acidic polysaccharide from the seeds of Cuscuta chinensis

Three crude polysaccharide fractions, named CS-A, CS-B and CS-C, were prepared from the seeds of Cuscuta chinensis by hot water extraction and diluted alkali extraction subsequently, then EtOH precipitation, and tested for lymphocyte proliferation activity. CS-A showed a stimulating effect on concanavalin A or lipopolysaccharide induced mitogenic activity of lymphocytes. An acidic polysaccharide (CS-A-3beta) was purified from CS-A by anion exchange and gel filtration chromatography. The polysaccharide showed potent stimulating effects on lymphocyte proliferation and antibody production, but did not significantly influence the serum IgG level. Its structural features were elucidated by methylation analysis, partial acid hydrolysis, 1D and 2D NMR and ESI-mass spectroscopy. The data obtained indicated that CS-A-3beta had a backbone consisting of alpha-D-1,4-linked GalpA residues and beta-L-1,2-linked Rhap residues with branches at C-4 of Rhap residues and C-3 of GalpA residues, composed of arabinogalactan and glucobiose. This structure is typical for a pectic polysaccharide of the rhamnogalacturonan type. In addition, the effect of CS-A, CS-B, CS-C and CS-A-3beta on hydrogen peroxide induced cell lesion in rat pheochromocytoma line PC 12 was investigated. The results indicated that, besides its immunostimulating activity, CS-A-3beta had a protective effect against free radical-induced cell toxicity.     

石见穿酸性多糖SC4的结构特征和生物活性

目的:研究从石见穿(Salvia chinensis)中得到的酸性多糖SC4的化学结构和生物活性.方法:利用化学和光谱方法分析了SC4的结构特征,并观察了SC4对淋巴细胞增殖的影响以及增强PC12细胞对抗H_2O_2造成的损伤的作用.结果:SC4的分子量为4.5×10~5,由Rha,Xyl,Ser,Gal和GalA组成,摩尔比为1.0:7.0:5.3:1.2:4.2.甲基化和~(13) C NMR进一步确定了SC4中各糖残基的连接方式.SC4能显著促进B淋巴细胞的增殖,增加小鼠脾重,增强PC12细胞对抗H_2O_2造成的氧化损伤的能力.结论:SC4为一多分枝的酸性多糖,其免疫活性的靶细胞为B淋巴细胞,并显著增强PC12细胞对抗H_2O_2造成的损伤的能力.     

果胶多糖可控性降解及果胶寡糖的制备

目的建立一套果胶多糖可控性降解和果胶寡糖分离分析的完整方法。方法采用酸水解和生物酶法等不同降解方法对柑橘果胶多糖进行可控性降解,以所得果胶寡糖的聚合度范围及相对含量为指标,确定最优降解条件,对降解所得的果胶寡糖进行分离分析。结果以果胶酸为底物,用果胶酶40℃反应1h,可得聚合度范围1~5的寡聚半乳糖醛酸混合物;经强阴离子交换树脂Dowex-1×4分离、薄层色谱和电喷雾电离质谱检测,得到聚合度范围1~5的单一聚合度的半乳糖醛酸寡糖。结论建立的果胶多糖可控性降解和果胶寡糖分离的分析方法为果胶多糖的系统研究提供了参考。     

Structure elucidation of glycan of glycoconjugate LbGp3 isolated from the fruit of Lycium barbarum L

The structure of the repeat unit of the glycan of glycoconjugate LbGp3 with pronounced immuno-activity, isolated from the fruit of Lycium barbarum L. was elucidated based on methylation analysis, partial acid hydrolysis and ¹H, ¹³C NMR spectroscopy of the original glycan and products of its partial hydrolysis.     

Structural features of a pectic polysaccharide from mulberry leaves

A pectic polysaccharide SDA was obtained from the boiling water extract of mulberry leaves. It consisted of rhamnose, arabinose, xylose, glucose, galactose, and galacturonic acid units in the molar ratio of 5:4:1:2:6:38. Its molecular weight was determined to be 1.5 x 10(4) by high-performance gel filtration chromatography. A combination of linkage analysis, partial acid hydrolysis, ESIMS, (1)H-NMR, and (13)C-NMR spectral analyses revealed its structural features. It was found that SDA possessed an alpha-(1 --> 4)-galacturonan backbone with some insertions of (1 --> 2) Rha residues, with the side chains attached to the O-3 or O-2 position of GalA residues, or the O-4 position of 1,2-linked Rha residues. The side chains contained branched (1 --> 5) linked arabinan, branched (1 --> 3) linked rhamman, linear (1 --> 4) linked xylan, linear (1 --> 4) linked glucan, and linear (1 --> 2) linked galactan. SDA was a new acidic polysaccharide isolated from mulberry leaves for the first time.     

Isolation and characterization of alpha-(1-->6)-glucans from Cistanche deserticola

Three unique polysaccharides (1-3) have been obtained from the 0.5 M NaOH extract of the stem of Cistanche deserticola Y. C. Ma. The results of methylation analysis, partial acid hydrolysis, 13C, 1H NMR, 1H-1H COSY, HMQC and HMBC spectroscopic analyses indicate that they are all composed of glucose, having a backbone of alpha-(1 --> 6)-glucan, and have different molecular weights. Their structures differ from that of linear starch.