西洋参不同部位皂苷类成分的指纹图谱研究

以西洋参（Panax quinquefolium L.）为材料,分别取主根、须根、芦头、参皮、参芯、茎、叶、花序、果实和芽孢等不同部位为材料,以高效液相法检测其皂苷类成分。利用系统聚类分析法和中药色谱指纹图谱相似度评价系统对各部位的皂苷种类和含量进行分析,将西洋参的不同部位按照成分组成进行了分类。     

Protection of Staphylococcus aureus-infected septic mice by suppression of early acute inflammation and enhanced antimicrobial activity by ginsan

Ginsan, an acidic polysaccharide prepared from Panax ginseng, demonstrated multiple immunomodulatory effects in previous studies. This study was conducted to elucidate the antiseptic mechanism induced by ginsan in mice infected with Staphylococcus aureus. When mice were treated with ginsan before the bacterial challenge with S. aureus, they were highly protected from sepsis-induced death. The numbers of S. aureus recovered from ginsan-treated mice were considerably lower than those recovered from nontreated mice. The in vivo depletion of monocytes/macrophages caused more S. aureus to be recovered from the bacteria-infected mice. Nevertheless, mice treated with both etoposide and ginsan were able to maintain an antibacterial activity. In addition, the phagocytic activity of ginsan-treated macrophage against S. aureus was considerably enhanced. The synthesis of inflammatory cytokines, such as tumor necrosis factor-alpha interleukin (IL)-1beta, IL-6, IFN-gamma, IL-12, IL-18 and interferon gamma, was significantly downregulated at the early phase of sepsis in mice that were treated with ginsan before the bacterial challenge. Expression of Toll-like receptors (TLRs), including TLR2, TLR4, and TLR9, as well as the adaptor molecule MyD88, was considerably reduced in peritoneal macrophages that were treated with ginsan before a subsequent contact with S. aureus. These data indicated that ginsan protected mice from S. aureus-induced sepsis through the suppression of acute inflammatory responses at an early phase and the enhancement of antimicrobial activities at subsequent phases of infection.     

The Effect of Growth Regulators on Quality Parameters and Ginsenosides Accumulation in Panax quinquefolium L. Roots

American ginseng (Panax quinquefolium L.) is a perennial medicinal herb originally grown in Canada and USA, and recently also in China, Australia, Holland and Poland. Several commercial preparations are produced from ginseng roots, that are known for their antifatigue, antitumor, antistress and immune system stimulating functions. The medicinal properties are due mainly to the active components – ginsenosides. In this work, the results of field cultivation experiments are presented that examine the effects of foliar application of several growth regulators on quality parameters and ginsenoside content of P. quinuefolium roots. The growth regulators tested, i.e., kinetin, daminozide, mixture of gibberellic acid (GA₃) with potassium salt of α-naphthalene acetic acid (kNAA) and new preparation – IPO-1 – benzimidazole derivative (obtained from the Institute of Organic Industry in Warsaw – at present during the process of patent), were applied at a concentration of 100 or 200 mg l⁻¹ in the middle of June in the 2nd year of vegetation. After 4 years of cultivation, the roots were dug up and dried, and subsequently the quantitative analysis of individual saponins (R_b1, R_b2, R_c, R_d, R_e, R_g1) by HPLC was performed. Growth regulators significantly affected quality parameters, morphological features and accumulation of individual and total ginsenosides in ginseng roots. Regardless of doses, the plant roots treated with growth regulators had a higher content of total ginsenosides in comparison to the control. The growth regulators also affected individual ginsenosides level and narrowed the ratio of R_b:R_g group. The application of kinetin, daminozide and benzimidazole derivative for foliar spray during 2nd year of American ginseng vegetation caused a significant increase in air dry weight of roots and aboveground parts whereas the mixture of GA₃ and kNAA showed a decreasing effect. An increase of roots size was observed using higher doses (200 mg l⁻¹) of kinetin and daminozide while a decreasing tendency appeared with the application of the other preparations.     

Defense response mechanisms of ginseng callus cultures induced by Yersinia pseudotuberculosis, a human pathogen

The effect of Yersinia pseudotuberculosis, the bacterial pathogen affecting humans and animals, on growth of ginseng (Panax ginseng C.A. Mey) cell cultures was studied. The bacteria strongly induced the expression of phenylalanine ammonia-lyase and β-1,3-glucanase, the proteins encoded by the defense-related genes of ginseng and inhibited the normal ginseng callus growth but did not affect the resistant cell cultures. The thermostable and thermolabile protein toxins of these bacteria are lethal to mice when induced parentherally, and they also induced the expression of the defense-related genes in ginseng callus cultures. At the same time, the ginseng cells completely suppressed the bacterial cell growth. These data suggest that the ginseng cells recognized the yersinia and developed the immune response to this pathogen. The interaction between the ginseng cells and Y. pseudotuberculosis is similar to the hypersensitive response of plants to plant pathogens.     

Protopanaxadiol 6-hydroxylase and its role in regulating the ginsenoside heterogeneity in Panax notoginseng cells

Various structure-similar plant secondary metabolites like ginseng saponins (ginsenosides) possess different or even totally opposite biological activities. Intentional manipulation of the ginsenoside heterogeneity in cellular biosynthesis is of great interest and significance [Zhong and Yue (2005); Adv Biochem Eng Biotechnol 100:53-88]. In this work, CO-binding spectra of microsomes prepared from the suspended cells of Panax notoginseng showed increases in absorption at 450 nm compared with the control without CO sparging, and protopanaxadiol 6-hydroxylase (P6H), a new enzyme catalyzing the conversion of ginsenoside aglycone protopanaxadiol into protopanaxatriol, was found. P6H was dependent on NADPH and molecular oxygen. The enzymatic reaction was inhibited by carbon monoxide and partially reversible upon illumination with blue light, and sensitive to cytochrome P450 inhibitors. The results supported the contention that P6H was a cytochrome P450-dependent hydroxylase, whose catalytic product was confirmed to be protopanaxatriol by HPLC-MS. Induction of P6H activity by phenobarbital, a cytochrome P450 inducer, was observed. A maximal activity of P6H was obtained with addition of 0.5 mM phenobarbital on day 4 of shake-flask cultivation. The maximum content of protopanaxatriol-type ginsenosides (Rg(1) and Re, Rg group) and the maximum ratio of the content of protopanaxatriol: protopanaxadiol reached 6.88 +/- 0.21 mg g(-1) dry weight and 7.0, respectively, which was about 1.4 and 2.0-fold that of respective controls (without addition of phenobarbital). Oxidative burst was also observed in the cell cultures with addition of phenobarbital. P6H was concluded as a key enzyme in regulating Rg-group ginsenoside biosynthesis in P. notoginseng cells.     

复合酶解法提取三七皂苷的实验研究

以三七提取液中总皂苷的含量和提取物得率为指标,考察了乙醇回流法、渗漉法、纤维素酶解法、果胶酶解法、复合酶解法的优劣,并采用单因素法和四因素（纤维素酶用量、果胶酶用量、酶解温度、乙醇浓度）三水平正交设计法对复合酶解法提取工艺条件进行优选,得到如下较理想的提取工艺条件：纤维素酶用量为15U／g（生药）、果胶酶用量为140U／g（生药）,酶解pH值为4．5,酶解温度为50℃,乙醇浓度为80％,提取时间为2．5h。所得三七提取液中总皂苷的含量为12．01％,提取物得率为35．82％。     

参棚透光率对西洋参叶片光合作用的影响

研究了参棚透光率与西洋参叶片净光合速率之间的关系.结果表明,西洋参叶片光饱和点、净光合速率及其日变型均随参棚透光率的不同,存在一定的差异.4年生西洋参叶片在12%、30%、42%3种透光率下(气温29.0℃左右),光饱和点分别为171.0、323.0和429.0μmol·m^-2·s^-1,净光合速率最大值为6.54mg·dm^-2·h^-1(CO₂),出现在透光率为30%的参棚下;3年生西洋参在透光率不超过25.8%的参棚下,叶片净光合速率日变化呈单峰型,透光率大于25.8%时,呈双峰型,参叶“光合午休”现象明显.单相关分析表明,光量子通量密度是影响西洋参净光合速率的主要因子;回归分析结果表明,各影响因子对参叶净光合速率的综合影响显著.     

Myrothins A–F from Endophytic Fungus Myrothecium sp. BS-31 Harbored in Panax notoginseng

Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe–microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A–F ( 1 – 6 ) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B ( 2 ) and E ( 5 ) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F ( 6 ) showed weak activity against F. oxysporum.     

钮子七提取物的抗氧化作用及对胃癌细胞的抑制作用

以钮子七提取物为材料,通过邻苯三酚自氧化法测定钮子七提取物对超氧阴离子生成的影响,通过邻二氮菲溶液测定钮子七提取物对羟自由基的清除作用;采用噻唑蓝(MTT)法测定钮子七提取物对胃癌细胞生长的影响。结果显示,钮子七水提取物和70%乙醇提取物对超氧阴离子的产生有较强的抑制作用,在浓度大于5.0 mg/m L时,抑制作用显著增强。钮子七70%乙醇提取物和水提取物均有清除羟自由基的作用,在浓度大于2.5 mg/m L时清除作用显著增强。钮子七水提物和乙酸乙酯提取物在24 h、48 h及72 h后对胃癌细胞均有抑制作用,且都以作用72 h后抑制作用最强。结果表明,钮子七提取物具有较强的抗氧化作用以及较强的抑制胃癌细胞的作用。