人参二醇类皂苷的生物转化动态及人参稀有皂苷C-K或F2的制备

为了低成本有效制备人参稀有皂苷C-K或F₂, 将A. niger g.848菌酶用于转化含有人参皂苷(质量分数)分别为49.6% Rb₁, 25.9% Rd, 19.3% Rc和5.23% Rb₂的西洋参二醇混合皂苷. 霉菌发酵时, 采用人参二醇皂苷诱导物比人参提取液诱导物的产酶总活力提高10%~15%. 所产的2种诱导酶均能水解人参二醇皂苷的3-O-和20-O-多种糖基, 均为人参皂苷酶Ⅰ型; 但是人参二醇皂苷诱导物所产酶几乎全部转化人参二醇皂苷为C-K, 而人参提取液诱导物所产酶则残留中间产物. 使用黑曲霉人参二醇皂苷诱导所产酶, 在转化西洋参二醇皂苷的动态研究中发现, 酶反应1.5~2.5 h, 主要为产物F₂; 酶反应12 h后, 主要产物为C-K皂苷. 基于此, 40 g人参二醇类皂苷在45 ℃粗酶反应24 h, 经处理得到含C-K质量分数为87%的23 g酶反应产物, C-K转化率达85%(摩尔分数). 用40 g西洋参二醇皂苷在45 ℃粗酶反应2.5 h, 经处理得到含有质量分数为58%的F₂和27%的C-K的26 g酶反应产物, F₂转化率为50.4%, C-K转化率为29.5%. 通过人参二醇皂苷诱导的黑曲霉粗酶转化人参二醇类皂苷动态研究, 建立了C-K转化率为85%, F₂转化率为50%的制备方法, 为大批量制备提供了基础依据.     

Antioxidant,Anti-Inflammatory and Antithrombotic Effects of Ginsenoside Compound K Enriched Extract Derived from Ginseng Sprouts

Partially purified ginsenoside extract (PGE) and compound K enriched extract (CKE) were prepared from ginseng sprouts, and their antioxidant, anti-inflammatory and antithrombotic effects were investigated. Compared to the 6-year-old ginseng roots, ginseng sprouts were found to have a higher content of phenolic compounds, saponin and protopanaxadiol-type ginsenoside by about 56%, 36% and 43%, respectively. PGE was prepared using a macroporous adsorption resin, and compound K(CK) was converted and enriched from the PGE by enzymatic hydrolysis with a conversion rate of 75%. PGE showed higher effects than CKE on radical scavenging activity in antioxidant assays. On the other hand, CKE reduced nitric oxide levels more effectively than PGE in RAW 264.7 cells. CKE also reduced pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β and IL-6 than PGE. Tail bleeding time and volume were investigated after administration of CKE at 70–150 mg/kg/day to mice. CKE administered group showed a significant increase or increased tendency in bleeding time than the control group. Bleeding volume in the CKE group increased than the control group, but not as much as in the aspirin group. In conclusion, ginseng sprouts could be an efficient source of ginsenoside, and CKE converted from the ginsenosides showed antioxidant, anti-inflammatory and antithrombotic effects. However, it was estimated that the CKE might play an essential role in anti-inflammatory effects rather than antioxidant effects.     

Two new triterpenoid saponins from notoginseng medicinal fungal substance

Two new triterpenoid saponins, named ginsenoside Rh₁₀ (1) and notoginsenoside ST-6 (2), were isolated from notoginseng medicinal fungal substance. Their structures were elucidated by a combination of 1D and 2D NMR, MS and chemical analysis.     

Silver (Ι)‐assisted enantiomeric analysis of ginsenosides using electrospray ionization tandem mass spectrometry

For identification of ginsenoside enantiomers, electrospray ionization mass spectrometry (ESI‐MS) was used to generate silver complexes of the type [ginsenoside + Ag]⁺. Collision induced dissociation of the silver‐ginsenoside complexes produced fragment ions by dehydration, allowing differentiation of ginsenoside enantiomers by the intensity of [M + Ag ? H₂O]⁺ ion. In the meanwhile, an approach based on the distinct profiles of enantiomer‐selective fragment ion intensity varied with collision energy was introduced to refine the identification and quantitation of ginsenoside enantiomers. Five pairs of enantiomeric ginsenosides were distinguished and quantified on the basis of the distribution of fragment ion [M + Ag ? H₂O]⁺. This method was also extended to the identification of other type of ginsenoside isomers such as ginsenoside Rb2 and Rb3. For demonstrating the practicability of this novel approach, it was utilized to analyze the molar ratio of 20‐(S) and 20‐(R) type enantiomeric ginsenosides in enantiomer mixture in red ginseng extract. The generation of characteristic fragment ion [M + Ag ? H₂O]⁺ likely results from the reduction of potential energy barrier of dehydration because of the catalysis of silver ion. The mechanism of enantiomer identification of ginsenosides was discussed from the aspects of computational modeling and internal energy. Copyright © 2012 John Wiley & Sons, Ltd.     

Ginsenoside Rb1 attenuates intestinal ischemia-reperfusion-induced liver injury by inhibiting NF-��B activation

Intestinal ischemia-reperfusion (I/R) is an important event in the pathogenesis of multiple organ dysfunction syndrome (MODS). The aim of this study is to determine the effects of ginsenoside Rb1 on liver injury induced by intestinal I/R in rats. Adult male Wistar rats were randomly divided into four groups: (1) a control, sham-operated group (sham group); (2) an intestinal I/R group subjected to 1 h intestinal ischemia and 2 h reperfusion (I/R group); (3) a group treated with 20 mg/kg ginsenoside Rb1 before reperfusion (Rb1-20 group); and (4) a group treated with 40 mg/kg ginsenoside Rb1 before reperfusion (Rb1-40 group). Liver and intestinal histology was observed. Aspartate aminotransferase (AST), alanine aminotransferase (ALT) level in serum and malondialdehyde (MDA) level in intestinal tissues were measured. Myeloperoxidase (MPO), TNF-α, MDA level and immunohistochemical expression of NF-κB and intracellular adhesion molecale-1 (ICAM-1) in liver tissues was assayed. In addition, a western blot analysis of liver NF-κB expression was performed. Results indicated intestinal I/R induced intestinal and liver injury, which was characterized by increase of AST and ALT in serum, MDA level in intestine, MPO, TNF-α and MDA level and ICAM-1 and NF-κB expression in the liver tissues. Ginsenoside Rb1 (20, 40 mg/kg) ameliorated liver injury, decreased MPO, TNF-α and MDA level, NF-κB and ICAM-1 expression in liver tissues. In conclusion, ginsenoside Rb1 ablated liver injury induced by intestinal I/R by inhibiting NF-κB activation.     

Two new acetylated ginsenosides from the roots of Panax quinquefolium

Two new acetylated ginsenosides, 20（S）-protopanaxatriol-6-O-α-L-rhamnopyranosyl （1 → 2）-β-D-6＇-O-acetylglucopyranoside （1） and 20（R）-protopanaxatrol-6-O-α-L-rhamnopyranosyl （1 → 2）-β-o-6＇-O-acetylglucopyranoside （2）, were isolated from the roots of Panax quinquefolium. The structures were elucidated on the basis of spectroscopic techniques and chemical means.     

Comparative study on chemical components and anti‐inflammatory effects of Panax notoginseng flower extracted by water and methanol

Methanol and water are commonly used solvents for chemical analysis and traditional decoction, respectively. In the present study, a high‐performance liquid chromatography with ultraviolet detection method was developed to quantify 11 saponins in Panax notoginseng flower extracted by aqueous solution and methanol, and chemical components and anti‐inflammatory effects of these two extracts were compared. The separation of 11 saponins, including notoginsenoside Fc and ginsenoside Rc, was well achieved on a Zorbax SB C18 column. This developed method provides an adequate linearity (r ² > 0.999), repeatability (RSD < 4.26%), inter‐ and intraday variations (RSD < 3.20%) with recovery (94.7–104.1%) of 11 saponins concerned. Our data indicated that ginsenoside biotransformation in PNF was found, when water was used as the extraction solvent, but not methanol. Specifically, the major components of Panax notoginseng flower, ginsenosides Rb1, Rc, Rb2, Rb3, and Rd, can be near completely transformed to the minor components, gypenoside XVII, notoginsenoside Fe, ginsenoside Rd2, notoginsenoside Fd, and ginsenoside F2, respectively. Total protein isolated from Panax notoginseng flower is responsible for this ginsenoside biotransformation. Additionally, methanol extract exerted the stronger anti‐inflammatory effects than water extract in lipopolysaccharide‐induced RAW264.7 cells. This difference in anti‐inflammatory action might be attributed to their chemical difference of saponins.     

Polymorphic Characterization,Pharmacokinetics, and Anti-Inflammatory Activity of Ginsenoside Compound K Polymorphs

Polymorphism exhibits different physicochemical properties, which can impact the bioavailability and bioactivity of solid drugs. This study focused on identifying the polymorphs of ginsenoside compound K (CK) and studying their different behaviors in pharmacokinetics (PK) and pharmacodynamics (PD). Four CK polymorphs (form I, II, III, and IV) from organic solvents were characterized by scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (PXRD). A feasible LC-MS/MS method was exploited to determine the PK parameters. Form II displayed the most exposure, followed by form I, III, and IV. Notably, all forms showed sex dimorphism, and the bioavailability in the female group was about two-fold higher than in the male group. The PD properties were investigated in carrageenan-induced acute paw inflammation, and form II at 20 mg/kg showed significant inhibition of edema by 42.7%. This study clarified the polymorphic, PK, and PD characters of four crystal forms of CK, and the data suggested that form II had the best efficacy for drug development.     

甲基化辅助实时直接分析电离的机理研究

实时直接分析电离源(DART)已经广泛应用于固体、液体和气体样品的快速检测. 在使用DART对低挥发性化合物进行分析时, 样品衍生化是十分重要的. 四甲基氢氧化铵(TMAH)是强的瞬时甲基化试剂, 常用于GC-MS的分析中. 以人参皂苷及人参寡糖为例, 研究了它们在TMAH的辅助下在DART中发生甲基化及电离的过程, 并从凝聚相和气相的角度对电离过程中的甲基化机理进行了研究. 人参皂苷主要发生不完全和全甲基化, 人参寡糖的甲基化则随着糖链的增长以及羟基的增多由全甲基化主导转变为过甲基化主导. 结果表明, 凝聚相和气相的共同作用是质谱检测到甲基化及过甲基化样品分子的根本原因.     

反相高效液相色谱法测定人参皂甙Compound-K的含量

人参皂甙compound-K(C-K)在人参中的含量极低,但它是其他含量较高的人参皂甙Rb1和Rb2等在人体肠道内的主要 降解产物和最终吸收形式,具有很高的生物活性。采用反相高效液相色谱法测定了人参总皂甙发酵液中C-K的含量。色谱 条件为:反相C18柱;乙腈-水(体积比为48∶52)溶液为流动相,流速1.0 mL/min;紫外检测波长203 nm;柱温35 ℃;外标法 定量。结果表明:C-K的质量浓度为0.05~0.8 g/L时,其峰面积与质量浓度具有良好的线性关系,相关系数为0.9998。方法 的检测限(S/N=3)为2.5 mg/L,峰面积测定值的相对标准偏差(n=6)为2.20%。测定栽培人参总皂甙及三七茎叶总皂甙微生 物发酵液中C-K的平均加标回收率(n=3)分别为98.6%和99.7%。该方法快速简便,准确可靠,可用于C-K的制备研究及药物 开发。