RP-HPLC法测定罗汉果中罗汉果皂苷V的含量

目的:建立 RP—HPLC 测定罗汉果药材中罗汉果皂苷 V 含量的方法。方法:采用 Alltima—C_(18)(4.6 mm×250 mm,5μm)色谱柱,乙腈-水(23:77)为流动相,流速1.0 mL·min~(-1),检测波长203 nm,柱温32℃。结果:罗汉果皂苷 V 线性范围为0.17～4.2μg,平均回收率为99.05%(RSD=0.78%,n=9)。结论:所建立的方法结果稳定,回收率良好,可用于测定罗汉果药材中罗汉果皂苷 V 的含量。     

市售制剂中罗汉果总皂苷的含量测定

目的 测定市售制剂中罗汉果总皂苷含量.方法 运用水提正丁醇萃取后,过D101大孔树脂的方法提取制剂中罗汉果总皂苷,香草醛-高氯酸显色的方法进行显色,在589 nm处测定吸光度,计算罗汉果总皂苷的含量.结果 测得不同罗汉果制剂及提取物中总皂苷含量从0.6%～48%.结论 该方法稳定,重复性良好,可为含罗汉果的食品、保健食品及药物制剂的质量控制提供依据.     

市售制剂中罗汉果总皂苷的含量测定

目的测定市售制剂中罗汉果总皂苷含量。方法运用水提正丁醇萃取后,过D101大孔树脂的方法提取制剂中罗汉果总皂苷,香草醛-高氯酸显色的方法进行显色,在589 nm处测定吸光度,计算罗汉果总皂苷的含量。结果测得不同罗汉果制剂及提取物中总皂苷含量从0.6%~48%。结论该方法稳定,重复性良好,可为含罗汉果的食品、保健食品及药物制剂的质量控制提供依据。     

HPLC-ELSD测定复方罗汉果止咳冲剂中罗汉果皂苷Ⅴ的含量

目的 建立HPLC-ELSD测定止咳冲剂中的罗汉果皂苷复方罗汉果V的含量的方法。方法 色谱条件是AlltimaTM-C18色谱柱（4.6 mm×250 mm,5μm）;流动相乙腈-水（23∶77）,柱温30℃,ELSD检测条件,漂移管温度为105℃,气流流量为2.0 L.min 1。结果 罗汉果皂苷Ⅴ进样量在1.608--9.648μg内时,进样量的对数与峰面积的对数呈良好的线性关系,回归方程为Y=1.634 3X＋12.591（r=0.999 7）,平均回收率为101.36%,RSD为1.29%。结论 该方法准确、专属性强,可用于测定复方罗汉果止咳冲剂中罗汉果皂苷Ⅴ的含量。     

辽东楤木芽中的一个新三萜皂苷

目的对从辽东木芽中提取的总皂苷进行化学成分的研究。方法通过硅胶柱色谱和制备HPLC等手段分离,利用理化性质和光谱方法鉴定。结果得到化合物1,鉴定为3O[βDglu-copyranosyl(1→3)βDglucopyranosyl]caulophyllogenin。结论该化合物为未见文献报道的新化合物,命名为木芽皂苷Ⅰ(congmuyanosideⅠ)。     

辽东楤木芽中的两个新三萜皂苷

通过硅胶柱色谱和制备HPLC等方法从辽东楤木的芽中分离得到2个化合物,利用理化性质和光谱方法分别鉴定为3-O-[β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl]caulophyllogenin(1)和3-O-[β-D-glucopyranosyl-(1→2)]-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl echinocystic acid(2).2个化合物均为未见文献报道的新化合物,分别命名为congmuyanoside A和congmuyanoside B.     

快速溶剂萃取-超高效液相色谱法测定罗汉果中罗汉果皂苷V含量

目的 建立测定罗汉果中罗汉果皂苷V含量的超高效液相色谱法.方法 快速溶剂萃取条件,萃取剂为甲醇,萃取温度为100℃,静态萃取5 min;色谱条件,色谱柱为Thermo Syncronis C18柱(100 mm×3.0 mm,3μm),流动相为乙腈-水(23:77,V/V),流速为0.5 mL/min,检测波长为203...     

辽东楤木芽中的一个新三萜皂苷

目的对从辽东木芽中提取的总皂苷进行化学成分的研究。方法通过硅胶柱色谱和制备HPLC等手段分离 ,利用理化性质和光谱方法鉴定。结果得到化合物 (1) ,鉴定为 3 O β D glu copyranosyl (1→ 4 ) β D glucopyranosylechinocysticacid。 结论该化合物为未见文献报道的新化合物 ,命名为木芽皂苷C (congmuyanosideC)。     

地榆中三萜及其皂苷类成分的化学结构和核磁波谱特征

结合国内外文献,综述了地榆中三萜及其皂苷类成分的化学结构和核磁波谱特征,为今后此类化合物的结构鉴定和波谱数据归属提供了参考。     

罗汉果皂苷提取物对糖尿病小鼠血糖、血脂及抗氧化作用的影响

目的探讨罗汉果皂苷提取物对四氧嘧啶糖尿病小鼠血糖的调节作用及其作用机制。方法分别以50,100,300,500 mg.kg-1bw剂量的罗汉果皂苷提取物连续30 d灌胃四氧嘧啶糖尿病小鼠,末次给药后眼眶取血测定血糖、血脂指标;分离肝组织测定抗氧化指标。结果①100,300和500 mg.kg-1bw剂量组可降低四氧嘧啶糖尿病小鼠的血糖(P<0.01),且以中剂量100 mg.kg-1bw的降糖作用最佳。②罗汉果皂苷提取物可降低四氧嘧啶糖尿病小鼠的TC、TG含量,提高HDL-C含量,有利于糖尿病小鼠血脂水平的恢复(P<0.01或P<0.05)。③罗汉果皂苷提取物可降低四氧嘧啶糖尿病小鼠肝脏的MDA含量,提高SOD、GSH-Px含量,表明罗汉果皂苷提取物可改善糖尿病小鼠的氧化应激水平(P<0.01或P<0.05)。④在其最佳剂量(100 mg.kg-1bw),罗汉果皂苷提取物的降血糖,降血脂及其抗氧化效果同消渴丸相当(P>0.01)。结论罗汉果皂苷提取物对糖尿病小鼠有明显的治疗作用,其降糖机制可能与提高糖尿病小鼠抗氧化能力及改善血脂水平有关。     

Assignments of ^1H and ^13C NMR Signals of Mogroside IVa

Aim To investigate the structure of mogroside IVa isolated from traditional Chinese medicine fructus momordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] and summarize the NMR characteristics of the structure. Methods Cormnon extraction, separafion and purification methods were used. Various NMR techniques including ^1H NMR,^13C NMR, DEPT, ^1H-^1H COSY, HSQC, HMBC, NOESY and molecular model simulated by comtmter were used to elucidate the structure. Results ^1H and ^13C NMR signals of mogroside IVa were assigned, and spectroscopic basis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniques including ^1H-^1H COSY, HSQC, HMBC, NOESY spectra are powerful tools for structure analysis. The structure determined by NMR methods is identical with energy minimized conformation simulated by computer.     

莫沙必利的核磁共振氢谱与碳谱指定

用一维和二维核磁共振技术(gCOSY，gNOESY，gHMQC，gHMBC)，对莫沙必利的核磁共振氢谱与碳谱进行了指定。计算机模拟的结果证明了我们对吗啉环优势构象的推测。     

氨氯地平和利培酮的1H和13C核磁共振信号归属

目的对氨氯地平和利培酮两种药物分子进行核磁共振研究.方法应用一维和二维核磁共振技术,如gCOSY, gHSQC和gHMBC.结果对两种药物分子核磁共振氢谱和碳谱进行了归属,氟碳间的耦合常数对碳谱的解析提供了有利的证据.结论通过核磁共振化学位移和耦合常数的分析,确证了氨氯地平和利培酮两种药物分子的化学结构.     

Substituted Xanthones as Antimycobacterial Agents,Part 1: Synthesis and Assignment of 1H/13C NMR Chemical Shifts

A series of substituted xanthones was synthesized in order to prove the hypothesis that electron-withdrawing substituents enhance the antimycobacterial activity of these compounds, which is described by means of a QSAR equation with ¹³C NMR chemical shifts as independent parameters. The key step of the synthesis is the formation of substituted 2-phenoxybenzoic acids by Ullmann reaction followed by intramolecular Friedel-Crafts acylation, leading to methyl-, carboxy-, nitro-, cyano-, and aminoxanthones as a test set for QSAR investigations. Spectroscopic data (¹H and ¹³C chemical shifts, IR, UV) of these xanthones are presented and analyzed. Specific shift increments for xanthones depending on the substituent position and on the position of the respective proton/carbon atom as well as additivity rules were developed.     

1H-NMR and 13C-NMR Spectral Assignments of Spiramycins I and III

Pharmaceutical Research -     

1H and 13C NMR assignments of the thiopeptide antibiotic nosiheptide

The 1H and 13C NMR spectra of nosiheptide have been assigned by use of 2D NMR techniques on unlabeled samples and biosynthetically multiple-labeled samples from stable isotope feeding experiments.     

1H and 13C NMR assignments and molecular modelling of a minor groove DNA-binding peptide from the HMG-I protein

The HMG-I subfamily of high mobility group (HMG) chromatin proteins consists of DNA-binding proteins that preferentially bind to stretches of A·T-rich sequence both in vitro and in vivo. Recently, members of the HMG-I family have been suggested to bind in vitro to the narrow minor groove of A·T-DNA by means of an 11 amino acid peptide binding domain (BD) which, because of its predicted structure, is called the‘A·T-hook motif [Reeves, R. & Nissen, M. (1990) J. Biol. Chem. 265 , 8573–8582], and would appear to be crescent-shaped. A BD peptide with 13 amino-acid residues was synthesized and examined by proton and carbon-13 nuclear magnetic resonance (NMR) spectroscopy. The peptide contains four proline residues, and on the basis of NOES and ¹³C chemical shifts was found to exist in an all-trans conformation. Molecular modelling based on this result provides evidence for a dynamic equilibrium between turn-like conformations in solution, the most populated of which is likely to be an S-shaped conformer, on the basis of amide exchange data. © Munksgaard 1995.     

Reexamination of the 1H and 13C NMR spectral assignments of thiostrepton

The use of 2D NMR techniques on unlabeled and biosynthetically multiple 13C-labeled samples enabled us to refine the 1H and 13C NMR spectral assignments for thiostrepton.     

Structural studies of two antiaggregant RGDW peptides by lH and 13C NMR

The structural features of Arg-Gly-Asp-related sequences have been investigated by ¹H and ¹³C NMR. Two linear peptides which inhibit platelet aggregation with a high efficiency have been studied: D-Arg-Gly-Asp-Trp and L-Arg-Gly-Asp-Trp. Analysis of pH titration effects, amide proton exchange rates and inter-proton distances obtained from ROESY spectra suggest that these small fragments predominantly adopt a type II′β-turn structure in solution. Folding features of a non-active cyclic peptide based on the same sequence (cyclo-[Arg-Gly-Asp-Trp]₂) have also been investigated. The biological relevance of these structures is discussed.