密闭式微波降解法促进常见人参皂苷向稀有人参皂苷转化的规律

采用密闭微波技术对7种常见人参皂苷单体(Rb1,Rb2,Rb3,Rc,Rd,Re和Rg1)进行降解,通过高效液相色谱(HPLC)分析并与相同条件下非微波降解物对比,研究了密闭微波降解人参皂苷的产物在化学结构及组成上的变化规律,以期快速、高效地制备生物活性高的稀有人参皂苷.结果表明,密闭式微波降解法能够使常见人参皂苷基本降解完全,而相同条件下非微波降解法则基本不发生降解.原人参二醇型人参皂苷易水解掉C20位糖,并发生C20位构型变化,生成20(R)-Rg3和20(S)-Rg3,其中20-(R)为优势构型,C20位羟基进一步脱水产生稀有人参皂苷Rk1和Rg5.同时,20(S/R)-Rg3失去C3位的1分子葡萄糖转化为20(S/R)-Rh2,C20位羟基再进一步脱水生成了Rk2和Rh3.此外,人参皂苷C20位所连的糖种类与构型影响了降解产物中各稀有皂苷的组成与比例,但7种原人参二醇型人参皂苷密闭式微波降解产物中Rg5含量均为最高.密闭式微波降解对原三醇型人参皂苷的转化作用与原二醇型人参皂苷具有相似的规律,人参皂苷Re和Rg1的密闭式微波降解产物中Rh4含量均为最高.本文结果进一步说明在相同的降解条件下,密闭式微波降解法的降解效率远高于高温高压非微波降解法,密闭式微波降解可明显促进常见人参皂苷向稀有人参皂苷转化,因此采用密闭微波技术对常见人参皂苷进行降解可以大量获得稀有人参皂苷.     

20(S/R)-人参皂苷Rg_3的制备及调节Th1/Th2免疫失衡活性

采用醋酸溶液作为提取溶剂,使西洋参叶中的二醇组人参皂苷在提取过程中发生降解,从而直接获得20(S)-人参皂苷Rg_3和20(R)-人参皂苷Rg_3,并对其调节Th1/Th2免疫失衡活性进行了研究.正交实验结果表明,当醋酸浓度为50%(体积分数),提取温度为80℃,提取时间为1 h时,20(S)-人参皂苷Rg_3和20(R)-人参皂苷Rg_3的转化率最高,分别为12. 30%和14. 80%.将20(S)-人参皂苷Rg_3和20(R)-人参皂苷Rg_3处理后的朗格汉斯状树突细胞(LDCs)分别作用于小鼠抗原诱导的Th1/Th2免疫失衡模型,发现细胞上层清液中IL-4的水平均显著降低,说明20(S)-人参皂苷Rg_3和20(R)-人参皂苷Rg_3对小鼠Th1/Th2免疫失衡具有调节作用.本文不仅建立了一种制备20(S)-人参皂苷Rg_3和20(R)-人参皂苷Rg_3的新方法,也为人参皂苷Rg_3在免疫系统疾病中的应用提供了新的科学依据.     

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.     

绞股蓝皂苷酸水解次生苷元的分离与鉴定

绞股蓝皂苷用5%硫酸水解,生成的次生皂苷元除已报道的人参二醇和2α-羟基人参二醇之外,尚分离到(20R.25S)-12β,25-环氧20,26-环达玛烷-2α,3β-二醇一新化合物.其结构经波谱分析和X射线衍射鉴定,确证20-C和25-C手性中心的绝对构型分别为R和S型.     

拟人参皂苷HQ的简明高效合成

拟人参皂苷HQ(PHQ),化学名称3β-O-β-D-吡喃葡萄糖基-(20S,24S)-环氧达玛-12β,25-二醇,是一种生物活性较高的稀有人参皂苷Rh2在体内的主要代谢产物,具有潜在的药用价值.目前报道的合成线路复杂且总收率较低,是因为关键的苷元C-3位糖苷化需要合理的保护策略才能实现.通过奥克梯隆型皂苷元C-3位的糖苷化条件探索,首次发现以Ag_2CO_3为促进剂,免保护策略,即可实现苷元C-3位选择性糖苷化制备PHQ.从商品20(S)-原人参二醇出发,经氧化环化、选择性糖苷化和对糖基脱苯甲酰基保护三步完成PHQ的合成.本方法为PHQ及其衍生物的制备提供了一条简明高效途径.     

人参中达玛烷型皂苷的化学转化产物结构和转化途径研究

利用高效液相色谱-电喷雾-多级串联质谱(HPLC-ESI-MSn)技术分析人参中3种达玛烷型皂苷(三七皂苷R1,人参皂苷Rd、20(S)-Rg3)在12-磷钨酸环境中转化的产物结构和转化途径。由原人参三醇型皂苷R1转化获得9种产物:20(S)-25-OH-R2、20(R)-25-OH-R2、25-OH-T5、20(S)-R2、20(R)-R2、20(S)-25-epoxy-R2、20(R)-25-epoxy-R2、T5、3β,12β-二羟基-6α-(2-O-β-D-吡喃木糖基-β-D-吡喃葡糖氧基)达玛烷-20(22),24-二烯。由原人参二醇型皂苷Rd和20(S)-Rg3转化得到10种产物:20(S)-25-OH-Rg3、20(R)-25-OH-Rg3、25-OH-Rk1、25-OH-Rg5、20(S)-Rg3、20(R)-Rg3、(20S,25)-epoxy-Rg3、(20R,25)-epoxy-Rg3、Rk1、Rg5。通过分析转化产物结构,并考察主要产物含量随转化时间的变化趋势,总结了人参中达玛烷型皂苷在酸性水溶液环境中的转化途径,即通过C20位去糖基化和差向异构化反应,以及烯烃链的水合、脱水、环合反应转化为稀有皂苷。     

RRLC-Q-TOF-MS研究人参二醇型皂苷Rb_1,Rb_2和Rc的化学转化

将高分离快速液相色谱-四极杆-飞行时间质谱(RRLC-Q-TOF-MS)联用技术用于人参二醇型(PPD)皂苷Rb_1,Rb_2和Rc在酸性条件下的化学转化研究,并对人参炮制过程中人参二醇型皂苷Rb_1,Rb_2和Rc及其转化产物的相对含量进行了分析.利用RRLC-Q-TOF-MS联用和串联质谱(MS/MS)技术对化合物的保留时间、精确分子量及串联质谱碎片信息进行分析,以鉴定化合物的结构.研究结果表明,人参二醇型皂苷在酸性条件下的化学转化包括:取代糖基的水解反应、Δ20(21)或Δ20(22)位的脱水反应和C24,C25位的水合加成反应.在MS/MS分析中,质谱峰m/z 459,477和441分别为人参二醇苷元、C24,C25位水合人参二醇苷元和Δ20(21)或Δ20(22)位脱水人参二醇型苷元的特征离子,这为人参二醇型皂苷及其转化产物的结构鉴定提供了依据,并以此总结了人参二醇型皂苷的化学转化途径.还利用所建立的方法研究了生晒参和红参(100和120℃)中PPD人参皂苷在炮制过程中的变化.     

微生物酶催化制备人参皂苷20(S)-Rg2,20(S)-Rh1和20(S)-PPT

摘要 人参次级皂苷具有较强的抗癌、抗癌转移等药理活性,但由于在人参中含量少或不存在,因此以人参中含量较高的主要人参皂苷制备药效更高的人参次级皂苷不仅有必要,而且很有意义．本文以微生物Microbacterium esteraromaticum GS514的培养液中分离的粗酶为催化剂水解人参皂苷Re和Rg1,并通过1H NMR和13C NMR谱进行了水解产物的结构表征．实验结果表明,反应体系中无机盐NaCl的存在与否直接影响人参皂苷Re,Rg1与粗酶液的反应结果.人参皂苷与粗酶液直接反应,人参皂苷Re不发生反应,人参皂苷Rg1通过C6所连β-D-吡喃葡萄糖的选择性水解转化成人参皂苷F1.如果该反应是在无机盐NaCl存在下进行,人参皂苷Re通过对C20 所连β-D-吡喃葡萄糖的选择性水解定向转化为20(S)-人参皂苷Rg2;人参皂苷Rg1定向转化成20(S)-人参皂苷Rh1以及20(S)-原人参三醇（PPT）.这说明NaCl的加入激活了C20β-D-吡喃葡萄糖苷酶的活性,这对定向合成不同次级人参皂苷具有重要意义.     

珠子参化学成分分析

从珠子参根茎中分离得到7个化合物. 利用核磁共振、 质谱和红外等手段, 并结合其理化性质, 鉴定了其结构, 它们分别是24(R)-珠子参苷R1, 6-O-[β-D-吡喃葡萄糖基(1→2)-β-D-吡喃葡萄糖基]-20-O-[β-D-吡喃葡萄糖基(1→4)-β-D-吡喃葡萄糖基]-20(S)-原人参三醇、 6″-乙酰基-人参皂苷Rd、 人参皂苷Rf、 竹节参皂苷Ⅳa、 人参皂苷Rd和竹节参皂苷Ⅴ. 其中, 24(R)-珠子参苷R1和6-O-[β-D-吡喃葡萄糖基(1→2)-β-D-吡喃葡萄糖基]-20-O-[β-D-吡喃葡萄糖基(1→4)-β-D-吡喃葡萄糖基]-20(S)-原人参三醇为2个新化合物, 6″-乙酰基-人参皂苷Rd 和人参皂苷Rf为首次从珠子参根茎中得到.     

鲜人参中2种丙二酰基人参皂苷的分离鉴定

采用硅胶柱层析方法,流动相分别为氯仿-甲醇-水(65∶35∶10,V/V)、氯仿-甲醇-水(6∶4∶1)和正丁醇-乙酸乙脂-甲醇-水(4∶2∶1∶1)和高效液相(Nuc leosil C18(250 mm×10 mm,5μm)色谱柱;流动相为己腈-水(75∶25);流速为3.0 mL/m in;柱温30℃;检测波长203 nm。从中国鲜人参中分离得到丙二酰基人参皂苷R c和丙二酰基人参皂苷Rb2,并通过其理化性质、红外光谱、质谱和核磁共振谱对化合物的结构进行了鉴定,证明其结构分别为3-O-[6-O-丙二单酰-β-D-葡萄吡喃糖(1→2)-β-D-葡萄吡喃糖]-20-O-[α-L-阿拉伯呋喃糖(1→6)-β-D-葡萄吡喃糖]-20(S)-原人参二醇和3-O-[6-O-丙二单酰-β-D-葡萄吡喃糖(1→2)-β-D-葡萄吡喃糖]-20-O-[α-L-阿拉伯吡喃糖(1→6)-β-D-葡萄吡喃糖]-20(S)-原人参二醇;丙二酰基人参皂苷R c为首次从中国鲜人参中分得。     

三七叶甙制备抗癌活性成分20(R)-人参皂甙-Rh2和人参皂甙Rg3

人参皂甙-Rh2(ginsenoside Rh2)和Rg3是从人参中分离得到的具有抗癌活性的四环三萜类原人参二醇型低糖链皂甙单体。其中,以人参皂甙为主要成分的抗癌新药Rg3参—胶囊已获国家药品监督管理局颁发的中药一类新药证书。皂甙类成分要从植物中分离困难。为了得到某些活性     

Comprehensive HILIC × RPLC with mass spectrometry detection for the analysis of saponins in Panax notoginseng

A comprehensive off-line two-dimensional liquid chromatography (2D-LC) method coupling hydrophilic interaction liquid chromatography (HILIC) and reversed phase liquid chromatography (RPLC) was developed in this study to detect as many saponins as possible in extracts of Panax notoginseng. The orthogonality of the 2D HILIC × RPLC was up to 81%, and the peak capacity was 10200. In total, 224 saponins were found, and some of them were trace amounts. Besides, a screening table designed by adding molecular weights of possible aglycones and sugars was constructed to help rapidly characterize the saponins using MS information. Unfortunately, the structure of saponins could not be identified by using only MS information.     

HPLC determination of four active saponins from Panax notoginseng in rat serum and its application to pharmacokinetic studies

Four main active saponins (ginsenosides Rg1, Rb1, Rd and notoginsenoside R1) in Panax notoginseng in rat serum after oral and intravenous administration of total saponins of P. notoginseng (PNS) to rats were determined using a simple and sensitive high-performance chromatographic method. The serum samples were pretreated with solid-phase extraction before analysis. The calibration curves for the four saponins were linear in the given concentration ranges. The intra-day and inter-day assay coefficients in serum were less than 10.0% and the recoveries of the method were higher than 80.0% in the high, middle and low concentrations. This method was applied to study the pharmacokinetics following oral and intravenous administration of PNS.     

Efficient method for large-scale preparation of two components H and I of Sg-6 saponins from whole seeds of wild soybean (Glycine soja Sieb. and Zucc.)

New saponin components, Sg-6 saponins, have been recently reported from the seeds of wild soybean (Glycine soja) which may have specific health benefits. To evaluate the possible health benefits, a large amount of Sg-6 saponins are needed, but general group A acetyl saponins and new Sg-6 saponins are eluted in overlapping peaks by ordinal preparative high-performance liquid chromatography and/or open column methods. A new method is proposed in this report. This method includes (1) deacetylation of group A acetyl saponins in alkali condition with KOH, (2) precipitation of Sg-6 saponins in acid condition with HCl, (3) recovery of Sg-6 saponins with aqueous methanol from the precipitate, and (4) elution of Sg-6 saponins by preparative reverse-phase open column. With this method, from 450?g of wild soybean whole seed powder, about 1?g of Sg-6 saponins (mixture of six components) was clearly separated from other saponins with 61% recovery.     

三七总皂甙对牛血清白蛋白溶液构象的影响

应用衰减全反射傅立叶变换红外光谱结合荧光光谱和紫外光谱研究了中药三七 的有效成分三七总皂甙与牛血清白蛋白（BSA）的相互作用，采用对蛋白质红外光 谱酰氨Ⅰ带和酰氨Ⅲ带进行曲线拟合的方法，定量分析了不同浓度三七总皂甙对 BSA二级结构的影响，发现随着三七总皂甙浓度的增加，蛋白分子结构逐渐发生了 由螺旋向折叠的转化。a-螺旋结构减少了3%，β-折叠结构增加了约5%，其它二级 结构没有明显的变化，红外差谱和荧光光谱的结果为药物与蛋白质的作用引起牛血 清白蛋白溶液构象的变化提供了佐证，紫外光谱反映了单体皂甙与蛋白质的结合常 数的差异。     

Analysis of bioactive components and multi‐component pharmacokinetics of saponins from the leaves of Panax notoginseng in rat plasma after oral administration by LC–MS/MS

In this study, simple ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight mass tandem mass spectrometry is used to characterize the absorbed components in rat plasma after the oral administration of saponins from the leaves of Panax notoginseng. Seventeen prototype compounds are structurally characterized. Furthermore, a simple and sensitive liquid chromatography with tandem mass spectrometry method is also used for the simultaneous determination of notoginsenoside Fc, ginsenoside Rb1, ginsenoside Rc, ginsenoside Rb3, ginsenoside Rd, and notoginsenoside Fe in rat plasma within 5 min. After n‐butanol mediated liquid–liquid extraction, all analytes were separated on a C₁₈ column and monitored in negative ion mode. Linearity, sensitivity, intra‐ and inter‐assay precision, accuracy, recovery, matrix effect, and stability were all within acceptable ranges. The validated liquid chromatography with tandem mass spectrometry method is successfully applied to the pharmacokinetic study of saponins from the leaves of Panax notoginseng in rats after oral administration. The results suggest that notoginsenoside Fc and ginsenoside Rb3 showed relatively higher exposure compared with other saponins. All saponins showed a long duration in plasma with a t_1/2 longer than 15 h, except notoginsenoside Fe (t_1/2 = 2.78 h). This study provides important information about the metabolism of saponins from the leaves of Panax notoginseng, which is useful for completely understanding its mechanism of action.     

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.     

蛋白质组学技术鉴定与分析三七粉诱导海兔神经连索表达的差异蛋白质

RP-HPLC分离三七粉提取液,并鉴定含有Rb1、Rg1、Re、R1等皂甙成分。以蓝斑背肛海兔(Notarcusleachii cirrosus Stimpson,NLCS)为分析模型,三七粉提取液为诱导剂,选用蛋白质组技术研究NLCS神经连索诱导前后所表达的差异蛋白质。通过优化双向凝胶电泳分离NLCS神经连索全蛋白质组技术,获得496个蛋白质斑点。采用肽指纹图谱技术和数据库检索比对法,初步鉴定了NLCS受三七粉提取液诱导前后,其神经连索表达13个差异蛋白质,其中较高的匹配率蛋白质为肌动蛋白、3-羟酯酰辅酶A脱氢酶、ATP结合转运子和甲基转移酶12。选用LOC tree软件对13个差异蛋白质进行亚细胞定位,认为它们在保护神经系统中发挥重要的调节作用。     

Studies of Molecular Motions of Ocotillol-Type Saponins in Solution by ~(13)C Nuclear Magnetic Relaxation

In this paper, the fully anisotropicoverall tumbling motions and side groups internal rotation of ocotillol-type saponins separated from the leaves of Panax Quidquefolium L. are investigated by ~(13)C nuclear magnetic relaxation. The fully anisotropic overall tumbling motion model with methyl conformation jumps internal rotation among three equivalent sites is presented, and the spectral density function of this model is derived. The rotation rates for overall tumbling motions to ocotillol-type saponins (OTS) are computed by Woessner's fully anisotropic overall tumbling motion model, and the internal rotation rate and barrier for side groups in OTS are calculated using free diffusion internal rotation model, restriction diffusion internal rotation model and conformation jumps internal rotation model, respectively.     

A novel strategy for rapid quantification of 20(S)-protopanaxatriol and 20(S)-protopanaxadiol saponins in Panax notoginsengP. ginseng and P. quinquefolium

A novel strategy for the qualitative and quantitative determination of 20(S)-protopanaxatriol saponins (PTS) and 20(S)-protopanaxadiol saponins (PDS) in Panax notoginseng, Panax ginseng and Panax quinquefolium, based on the overlapping peaks of main components of PTS (calibrated by ginsenoside Rg1) and PDS (calibrated by ginsenoside Rb1), was proposed. The analysis was performed by using high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD). Under specific chromatographic conditions, all samples showed two overlapping peaks containing several main ginsenosides belonging to PTS and PDS, respectively. The overlapping peaks were also identified by using HPLC–MS. Based on the sum and ratio of PTS and PDS, 60 tested Panax samples were divided into three main clusters according to their species. The findings suggested that this strategy provides a simple and rapid approach to quantify PTS and PDS in Panax herbs.