Studies on absorption, distribution, excretion and metabolism of ginseng saponins. VII. Comparison of the decomposition modes of ginsenoside-Rb1 and -Rb2 in the digestive tract of rats.

In order to clarify some similarities and differences of decomposition modes between 20(S)-protopanaxadiol (20(S)-ppd) saponins, represented by ginsenoside Rb1 (Rb1) and ginsenoside Rb2 (Rb2), the decompositions of Rb1 and Rb2 in the rat gastrointestinal tract, 0.1 N HCl and crude hesperidinase were investigated in detail. As in the case of Rb2 reported previously, Rb1 was hydrolyzed to 20(R,S)-ginsenoside Rg3 in 0.1 N HCl. On the other hand, hydroperoxidation of Rb1 occurred in rat stomach; the major hydroperoxide was separated and identified as the 25-hydroperoxy-23-ene derivative of Rb1 (VIII) by 1H- and 13C-nuclear magnetic resonance and fast atom bombardment mass spectrometry. The decomposition modes of 20(S)-ppd saponins (Rb1 and Rb2) differed from that of 20(S)-protopanaxatriol saponin (Rg1) in rat stomach. In rat large intestine, five decomposition products of Rb1 were observed by thin-layer chromatography, and these were identified as gypenoside XVII (G-XVII), ginsenoside Rd (Rd), ginsenoside F2 (F2), compound K (C-K) and VIII. The decomposition modes of Rb1 and Rb2, both 20(S)-ppd saponins, are considered to be different because of the hydrolysis rate in the terminal sugar moiety at the C-20 hydroxyl group in the rat large intestine. Using crude hesperidinase, Rb1 was decomposed to G-XVII, F2 and C-K, and Rb2 was decomposed to 3-O-beta-D-glucopyranosyl-20-O-[alpha-L-arabinopyranosyl(1----6)-b eta-D- glucopyranosyl]-20-(S)-ppd, F2 and C-K. Consequently, it appears that hydrolysis by beta-glucosidase, which is present in the rat large intestine, is distinct from that by crude hesperidinase.(ABSTRACT TRUNCATED AT 250 WORDS)     

高效液相色谱-飞行时间质谱联用法分析人参及人参皂苷与山楂配伍过程中的水解行为

利用高效液相色谱-飞行时间质谱联用的方法,分别对人参配伍山楂前后人参皂苷的变化进行分析,同时对人参皂苷Re、Rg1、Rb1、Rd与山楂配伍的水解规律进行系统研究,并与单独煎煮液、仿山楂配伍pH值煎煮液的水解产物进行比较,结果发现人参与山楂配伍后人参皂苷Rg1、Rb1含量明显减少,而人参皂苷Re、Rd、Rg2、Rg3、F2、Rh1含量明显增加,其中人参皂苷Re与山楂配伍后水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2,仿山楂配伍pH值水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2、Rg4、Rg6;人参皂苷Rg1与山楂配伍后水解产物为20(S)-Rh1、20(R)-Rh1,仿山楂pH值水解产物为20(S)-Rh1、20(R)-Rh1、Rh4、Rk3;人参皂苷Rb1与山楂配伍后水解产物为Rd、20(S)-Rg3,仿山楂pH值水解产物为F2、20(S)-Rg3;人参皂苷Rd与山楂配伍后水解产物为F2、20(S)-Rg3、20(R)-Rg3,仿山楂pH值水解产物为20(S)-Rg3、20(R)-Rg3。研究表明,不同人参皂苷和山楂配伍后与仿山楂pH值的水解产物并不相同,人参与山楂配伍改变了人参皂苷成分的种类及含量。本研究为临床方剂中人参与山楂配伍后成分的变化提供物质基础数据。     

Marked production of ginsenosides Rd, F2, Rg3, and compound K by enzymatic method

The hydrolysis of protopanaxadiol-type saponin mixture by various glycoside hydrolases was examined. Among these enzymes, crude preparations of lactase from Aspergillus oryzae, beta-galactosidase from A. oryzae, and cellulase from Trichoderma viride were found to produce ginsenoside F(2) [3-O-(beta-D-glucopyranosyl)-20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], compound K [20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], and ginsenoside Rd {3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol}, respectively, from protopanaxadiol-type saponin mixture in large quantities. Moreover, the crude preparation of lactase from Penicillium sp. having a high producing activity of ginsenoside Rh(1) (6-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol) from protopanaxatriol-type saponin mixture gave ginsenoside Rd as a main product, ginsenoside Rg(3) {3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol}, and compound K from protopanaxadiol-type saponin mixture. The hydrolytic pathways of ginsenosides Rb(1), Rb(2), and Rc to ginsenosides Rd, Rg(3), and F(2), and compound K by crude preparations of four glycoside hydrolases were also studied. This is the first report on the enzymatic preparation of an intestinal bacterial metabolite, ginsenoside F(2), in quantity, and a considerable amount of a minor saponin, ginsenoside Rg(3), from a protopanaxadiol-type saponin mixture.     

Ginsenoside Rg8, a new dammarane-type triterpenoid saponin from roots of Panax quinquefolium

A new dammarane-type triterpenoid saponin, ginsenoside Rg(8) (1), was isolated from the roots of Panax quinquefolium, along with five known saponins, (20E)-ginsenoside F(4) (2), ginsenosides Rh(1) (3), Rg(2) (4), F(1) (5), and (20R)-ginsenoside Rh(1) (6). The structure of ginsenoside Rg(8) (1) was determined to be (3beta,6alpha,12beta,20E)-24,25-epoxy-3,12,23-trihydroxydammar-20(22)-en-6-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranoside by various spectroscopic analyses. Among the known saponins, (20E)-ginsenoside F(4) (2) and ginsenoside F(1) (5) were first reported from the title plant.     

Major ginsenoside contents in rhizomes of Panax sokpayensis and Panax bipinnatifidus

This study compared eight major ginsenosides (Rg1, Rg2, Rf, Re, Rd, Rc, Rb1 and Rb2) between Panax sokpayensis and Panax bipinnatifidus collected from Sikkim Himalaya, India. High-performance liquid chromatographic analysis revealed that all major ginsenosides were present in the rhizomes of P. sokpayensis except ginsenoside Rc, whereas ginsenoside Rf, Rc and Rb2 were not detected in P. bipinnatifidus.     

Determination of ginsenoside content in Asian and North American ginseng raw materials and finished products by high-performance liquid chromatography: single-laboratory validation

A single-laboratory validation study was conducted for the quantification of Rg1, Re, Rb1, Rc, Rb2, and Rd in Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) raw materials and finished products by RP-HPLC. The extraction with aqueous methanol was optimized for whole root, powdered extract, and finished product (raw, tablet, and capsule matrixes) test articles. Root materials were treated with base to hydrolyze acidic malonyl ginsenosides to their neutral counterparts. Calibration curves for each ginsenoside were linear over the following ranges (microg/g): 5-394 for Rg1, 15-1188 for Re, 39-2981 for Rb1, 6-499 for Rc, 5-406 for Rb2, and 7-600 for Rd, all having a coefficient of determination (r2) of > or = 99.5%. The LOD for Rg1, Re, Rb1, Rc, Rb2, and Rd was determined to be 1.06, 1.25, 2.19, 1.24, 1.27, and 1.70 microg/mL, respectively. Quantitative determinations performed with eight test materials by two analysts over 3 days (n = 12) resulted in RSDr values that ranged from 1.11 to 7.61%.     

Determination of Seven Major Ginsenosides in Different Parts of Panax quinquefolius L.(American Ginseng) with Different Ages

Ginsenosides Rg1,Re,Rb1,Rc,Rb2,Rb3,and Rd in different parts of the American ginseng plant were investigated.The extraction process was a pressurized microwave-assisted extraction(PMAE).The seven ginsenosides were separated and determined by high-performance liquid chromatography(HPLC) with a ultraviolet(UV) detector,at 203 nm.The experiment results showed significant variations in the individual ginsenoside contents of the American ginseng in different parts and ages of the plant.The results demonstrated that the leaves,root hairs,and rhizomes of Panax quinquefolius L.contained higher ginsenoside contents,followed by the main roots and stems.The leaves contained dramatically higher levels of ginsenoside Rg1,Rb3,and Rd than the other four parts.Higher contents of Rb1 and Re were present in the main roots,root hairs,and rhizomes.The amount of ginsenoside content in the stems was the lowest.The total content of the seven ginsenosides in main roots,root hairs and rhizomes increased with the age of the plant.In contrast,the ginsenoside contents in the leaves and stems decreased with a year of growth.     

Purification and characterization of new special ginsenosidase hydrolyzing multi-glycisides of protopanaxadiol ginsenosides, ginsenosidase type I

In this paper, the new type ginsenosidase which hydrolyzing multi-glycosides of ginsenoside, named ginsenoside type I from Aspergillus sp.g48p strain was isolated, characterized and generally described. The enzyme molecular weight was about 80 kDa. Ginsenosidase type I can hydrolyze different glycoside of protopanaxadiol type ginsenosides (PPD); i.e., can hydrolyze the 3(carbon)-O-beta-glucoside of Rb1, Rb2, Rb3, Rc, Rd; can hydrolyze 20(carbon)-O-beta-glucoside of Rb1, 20-O-beta-xyloside of Rb3, 20-O-alpha-arabinoside(p) of Rb2 and 20-O-alpha-arabinoside(f) of Rc to produce mainly F2, compound-K (C-K) and small Rh2, but can not hydrolyze the glycosides of protopanaxatriol type ginsenoside (PPT) such as Re, Rf, Rg1. So, when the ginsenosidase type I hydrolyzed ginsenosides, the enzyme selected ginsenoside-aglycone type, can hydrolyze different glycosides of PPD type ginsenoside; however no selected glycoside type, can hydrolyze multi-glycosides of PPD type ginsenosides. These properties were novel properties, and differentiated with the other previously described glycosidases.     

液相色谱-质谱联用技术结合多探针底物法研究人参皂苷Rb1的体外代谢

以奥美拉唑、 苯妥英、 卡马西平和非那西丁为检测肝药酶细胞色素P450酶(CYP450)亚型的专属探针药物, 通过原型药物减少量测定法考察药物体外代谢的变化, 评价人参皂苷Rb1对CYP450不同亚型酶的作用. 结果表明, P2C9, P2C19和P3A4实验组与对照组差异不显著, P1A2实验组与对照组差异显著, 表明人参皂苷Rb1能诱导P1A2亚型酶的活性, 促进底物与酶反应, 加快底物的代谢, 而对P2C9, P2C19和P3A4三个亚型酶有弱的诱导或无诱导作用. 根据快速分离液相色谱-质谱联用(RRLC-MS/MS)检测结果推断, 人参皂苷Rb1在CYP450酶中的代谢产物可转化为人参皂苷Rb1氧化产物(Rb1+O)及人参皂苷Rd和F2.     

Studies on absorption, distribution, excretion and metabolism of ginseng saponins. VI. The decomposition products of ginsenoside Rb2 in the stomach of rats

The decomposition of ginsenoside Rb2 (Rb2) in rat stomach (in vivo) and in 0.1 N HCl solution (in vitro) was investigated in detail. By treating with 0.1 N HCl, the acidity of which is similar to that of gastric juice, a part of Rb2 was hydrolyzed to 20(R,S)-ginsenoside Rg3. On the other hand, Rb2 was little decomposed in rat stomach and a small quantity of an unidentified metabolite, which was different from the hydrolyzed products in 0.1 N HCl, was observed. The metabolite was separated into four compounds, which were identified by 1H- and 13C-nuclear magnetic resonance and fast atom bombardment mass spectrometry. These compounds were determined to be 25-hydroxy-23-ene (IV), 24-hydroxy-25-ene (V), 25-hydroperoxy-23-ene (VI) and 24-hydroperoxy-25-ene (VII) derivative of Rb2, respectively. In this study, it is suggested that 20(S)-protopanaxatriol saponins undergo hydrolysis of the C-20 glycosyl moiety and hydration of the side chain, on the other hand, 20(S)-protopanaxadiol saponins undergo oxygenation of the side chain.     

重组内切纤维素酶Fpendo5A转化三七总皂苷

从嗜热细菌基因组中克隆到1个新的纤维素酶基因,并在大肠杆菌中进行了高效可溶性表达,粗酶液经镍柱亲和层析进行分离纯化.利用快速分离液相色谱-四极杆飞行时间质谱联用仪(RRLC/Q-TOF-MS)对重组内切纤维素酶Fpendo5A转化三七总皂苷的产物结构进行了鉴定,并进一步阐明其转化机制.结果表明,该酶的最适反应温度和pH值分别为80℃和5.5.Fpendo5A能够催化三七总皂苷中的主要皂苷成分,即Ra_1,Rb_1,Rc,Rd和Rg_3的侧链糖基的水解反应,但对于不同的皂苷底物,Fpendo5A选择性催化的侧链糖基类型不同.经鉴定,Fpendo5A转化Ra_1,Rb_1,Rc,Rd和Rg_3的转化产物分别为Rb_2,GypⅩⅦ,CMC_1,F_2和Rh_2.由此可见,Fpendo5A通过水解Rb_1,Rc,Rd和Rg3的C3位的β-(1,2)糖苷键分别生成GypⅩⅦ,CMC1,F2和Rh2.在转化Ra_1时,Fpendo5A通过水解Ra_1的C20位的α-(1,4)木糖苷键生成Rb2.     

动态泡沫浮选法分离富集人参提取液中的二醇型人参皂苷

采用动态泡沫浮选法分离富集人参提取液中的二醇型人参皂苷, 用高效液相色谱法测定6种人参皂苷Rg₁, Re, Rb₁, Rc, Rb₂和Rd的含量. 考察了浮选液pH值、电解质NaCl浓度、载气流量、料液浓度及料液流速对人参皂苷浮选率的影响, 确定了动态泡沫浮选的最佳条件, 并与溶剂提取法、溶剂浮选法以及静态泡沫浮选法进行了比较. 结果表明, 动态泡沫浮选法对二醇型人参皂苷Rb₁, Rc, Rb₂和Rd具有高富集效率, 回收率分别为93.3%, 98.6%, 96.9%和98.3%, 而对三醇型人参皂苷Rg1和Re的富集效率却很低, 回收率分别为4.8%和4.2%. 该法是分离纯化二醇型人参皂苷的一种简便有效的方法.     

基于HPLC-HRMS/MS~n/QqQ技术的人参皂苷Rb_1化学转化产物的结构与途径分析

利用液相色谱-质谱联用技术分析了Keggin型12-磷钨酸化学转化人参皂苷Rb1产物的结构与转化途径.基于高效液相色谱对转化产物的快速分离,利用Q Exactive高分辨质谱的Full MS-AIF模式快速鉴定了产物结构,并利用多级串联质谱进行结构验证.进一步结合人参皂苷异构体在反向C18色谱柱上的相对保留时间,快速分析鉴定出Rb1的10种转化产物为20(S)-Rg3,20(R)-Rg3,20(S)-25-OH-Rg3,20(R)-25-OH-Rg3,25-OH-Rk1,25-OH-Rg5,Rg5,Rk1,(20S,25)-环氧-Rg3和(20R,25)-环氧-Rg3.根据转化产物的结构初步推断了人参皂苷的转化途径:在12-磷钨酸产生的酸性环境中,Rb1主要通过C20位去糖基化、差向异构化和烯烃链的水合、消除及环合反应转化为稀有皂苷.采用三重四极杆质谱的选择反应监测模式准确定量分析了Rb1的转化效率和稀有皂苷20(S)-Rg3,20(R)-Rg3,Rk1和Rg5的产率.定量分析结果显示,与生物转化相比,12-磷钨酸对Rb1有更高的转化效率,反应40 min后转化率达到100%.本文结果表明,HPLC-HRMS/MSn/Qq Q技术是人参皂苷等天然产物结构解析与定量分析的有效方法.     

Simultaneous determination of panax notoginsenoside R1, ginsenoside Rg1, Rd, Re and Rb1 in rat plasma by HPLC/ESI/MS: platform for the pharmacokinetic evaluation of total panax notoginsenoside, a typical kind of multiple constituent traditional Chinese medicine

A platform for the pharmacokinetic study of multiple constituent traditional Chinese medicine was developed and validated. An HPLC/ESI/MS method was employed for the simultaneous determination of panax notoginsenoside R1, ginsenoside Rg1, Rd, Re and Rb1 in rat plasma. After the addition of digoxin as an internal standard (IS), rat plasmas were extracted with n-butanol saturated with pure water and all analytes were separated on a reversed-phased C(18) column with a mobile phase of acetonitrile-water (0.5 mM ammonium chloride) and pumped at a flow rate of 0.2 mL/min. Analytes were determined in a single quadrupole mass spectrometer using an electrospray ionization source. HPLC/ESI/MS was performed in the selected-ion monitoring mode with the chlorinated adducts of molecular ions [M + Cl]( -) at m/z 967.75, 835.80, 981.80, 981.80, 1143.65 and 815.40 for R1, Rg1, Rd, Re, Rb1 and digoxin, respectively. The method showed excellent linearity over the concentration range 3.03-775.00 ng/mL (r(2) = 0.9994) for R1, 4.00-1025.00 ng/mL (r(2) = 0.9991, 0.9988, 0.9991) for Rg1, Rd and Re, respectively, and 2.77-710.00 ng/mL for Rb1 (r(2) = 0.9990). The low limit of quantification was 3.03, 4.00, 4.00, 4.00 and 2.77 ng/mL for R1, Rg1, Rd, Re and Rb1, respectively, with S/N > 10. The intra- and inter-day precisions were below 12.00% and the accuracy was between -2.31 and +4.43% for all analytes. The extract recoveries of analytes were from 67.47 to 94.18%. All analytes were stable in rat plasma after storage for 12 h at ambient temperature, at 4 degrees C for 12 h in the sample pool, at -20 degrees C for 4 weeks and at -20 degrees C for three thaw-freeze cycles. The HPLC/ESI/MS technique provided an excellent method for the simultaneous quantification of R1, Rg1, Rd, Re and Rb1 in rat plasma and was successfully applied to the pharmacokinetic study of a multiple-constituent traditional Chinese medicine, total panax notoginsenoside (Xuesaitong injection).     

Effect of gamma irradiation on the conversion of ginsenoside Rb1 to Rg3

Ginsenosides, the most important secondary metabolites in ginseng, have various biological activities. Many studies have focused on the conversion of one of the major ginsenosides, Rb1, to the more active minor ginsenoside, Rg3. This study was carried out to investigate the effect of gamma irradiation on the conversion of Rb1 to Rg3. Rb1 solutions were gamma-irradiated at doses of 10 and 30 kGy and analyzed by high performance liquid chromatography (HPLC). HPLC chromatograms showed a decreased content of Rb1 with increasing irradiation dose, but the content of Rg3 was increased. The highest content of Rg3 was present in the 30 kGy-irradiated Rb1 sample. The cytotoxic effects tested in cancer cell lines were increased in the gamma-irradiated group. Therefore, these results suggest that gamma irradiation can be an effective method for the conversion of the ginsenoside Rb1 to Rg3.     

Studies on Intestinal Transport of Ginsenoside Compatibility with Veratrum nigrum via Caco-2 Cell Monolayer Model Coupled with UPLC-ESI-MS Method

The Caco-2 cells have been recognized as effective tools to be applied to imitating the drug absorption in human intestine for the transport of drug. Herein, Caco-2 cell monolayer model was used to study the transport of the ginsenoside compatibility with Veratrum nigrum in different proportions. A specific high performance liquid chromatography-electrospray ionization-mass spectrometry(HPLC-ESI-MS) method was developed for the semiquantitative determination of ginsenoside in intestinal transport with Dioscin as an internal standard. For the Caco-2 model constructed, two influencing factors were investigated, including time and concentration. The results suggest that the absorption of ginsenoside Re, Rg1, Rb1, Rc, Rb2 and Rd are time- and concentration-dependent and the excretions of Rb1, Rc, Rb2 and Rd have a relatronship with some transport proteins. The bioavailability of the ginsenosides has reduced compared to the single Panax ginseng extract when compatibility with a certain amount of Veratrum nigrum.     

Chemical characteristics of three medicinal plants of the Panax genus determined by HPLC-ELSD

The morphological appearance and main ingredients of three Chinese medicines (CMs), P. ginseng, P. quinquefolius, and P. notoginseng of the Panax genus, are similar. However, their pharmacological activities are obviously different. To ensure their safety and efficacy, chemical characteristics of the three CMs were determined using pressurized liquid extraction and HPLC-evaporative light scattering detection. Twelve major saponins, namely notoginsenoside R1, pseudo-ginsenoside F11, ginsenosides Rg1, Re, Rf, Rb1, Rg2, Rc, Rb2, Rb3, Rd, and Rg3 were also quantitatively compared among the three CMs. The contents of total investigated saponins varied considerably, by up to 4-14-fold, between the highest (P. notoginseng, 82.8-136.5 mg/g) and the lowest values (P. ginseng, 10.0-21.1 mg/g). Hierarchical clustering analysis based on the characteristics of 11 investigated saponins (except ginsenoside Rb3) and notoginsenoside R1, pseudo-ginsenoside F11, and the ratio of ginsenoside Rg1/Rb1 and Rg1/Re showed that 56 tested samples were divided into three main clusters in accordance with the three Panax species. Similarity evaluation of chromatograms was also performed using "Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine (Version 2004A)". The results showed that a high degree of similarity existed within individual clusters, but a low degree between the clusters, which could be used for quality control of the three CMs.     

Analysis of Low-polar Ginsenosides in Steamed Panax Ginseng at High-temperature by HPLC-ESI-MS/MS

A high performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry( HPLC-ESI-MS/MS) method was developed for the analysis and identification of ginsenosides in the extracts of raw Panax ginseng(RPG) and steamed Panax ginseng at high temperatures(SPGHT). A total of 25 ginsenosides were extracted include of which 10 low-polar ginsenosides, such as ginsenosides F4, Rk3, Rh4, 20S-Rg3, 20R-Rg3 and so on, were identified according to their HPLC retention time and MS/MS data. The results indicated that the low polar ginsenosides were seldom found in RPG. For the exploration of the transformation pattern of the ginsenosides in steam processing, the standards of ginsenosides Re, Rg1, Rb1, Rc, Rb2, Rb3 and Rd were selected and hydrolyzed at a temperature of 120 ℃. The results show that these polar ginsenosides can be converted to low-polar ginsenosides such as Rg2, Rg6, F4, Rk3 and Rg5 by hydrolyzing the sugar chains.     

Improved high performance liquid chromatographic determination of ginsenosides in Panax ginseng-based pharmaceuticals using a diol column

A reversed-phase high-performance liquid chromatographic assay for the simultaneous quantitative determination of seven ginsenosides, Rb(1), Rb(2), Rc, Rd, Rg(1), Re and Rf in pharmaceutical preparations is described. Chromatographic separation was achieved in less than 20 min using a 250 x 4 mm Lichrospher, 5 microm, 100 A diol column with detection at 203 nm. The method was validated over the range of 2.5-20 ng/microL using a 20 microL sample volume. The average accuracy at five concentrations was 90-100%, and the within-day and between-day precision ranged from 1 to 7% expressed as coefficient of variation. The detection limit and the quantitation limit of the method were 20 and 50 ng injected for each ginsenoside, respectively.