三七总皂苷酶水解产物成分研究

为了研究葡萄糖苷酶催化三七提取物的水解产物中主要皂苷成分。采用色谱法从三七提取物水解产物中分离纯化得到11个皂苷成分。利用波谱解析确定了它们的结构,分别鉴定为20(S)-原人参二醇-20-O-β-D-吡喃木糖基-(1→6)-β-D-吡喃葡萄糖基-(1→6)-β-D-吡喃葡萄糖苷(1),以及10个已知的皂苷成分分别为:人参皂苷compound K(2)、3β,12β,20(S),25-四羟基达玛-23-烯-20-O-β-D-吡喃葡萄糖苷(3)、3β,20(S)-二羟基达玛-24-烯-12β,23β-环氧-20-O-β-D-吡喃葡萄糖苷(4)、3β,12β,20(S)-三羟基-25-过氧羟基达玛-23-烯-20-O-β-D-吡喃葡萄糖苷(5)、人参皂苷F1(6)、人参皂苷Rg1(7)、人参皂苷Rg2(8)、人参皂苷Mc(9)、20(S)-原人参二醇-3-O-β-D-吡喃木糖基-(1→2)-β-D-吡喃葡萄糖基-20-O-β-D-吡喃葡萄糖苷(10)和人参皂苷Re(11)。其中化合物1为新化合物,化合物3~5和10为首次从三七中被分离得到。     

马比木根的化学成分研究

通过硅胶、MCI和Sephadex LH-20反复柱层析、纯化,从马比木根的甲醇提取物中分离得到14个化合物,运用现代波谱技术鉴定为β-谷甾醇(1),β-胡萝卜苷(2),7-酮基-β-谷甾醇(3),β-sitosteryl-3-O-β-D-glucopyranoside-2'-O-palmitate(4),5α,6β-二羟基胡萝卜苷(5),羽扇豆醇(6),3-乙酰氧基-12-齐墩果烯-28醇(7),喜树碱(8),9-甲氧基喜树碱(9),10-羟基喜树碱(10),9-methoxy-mappicine-20-O-β-D-glucopyranoside(11),mappicine-20-O-β-D-glucopyranoside(12),(3S)-pumiloside(13),(-)-(3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid(14)。化合物1~7、9~14为首次从该植物中分离得到。     

毛茛属刺果毛茛化学成分研究

从刺果毛茛Ranunculus muricatus Linn.全草乙醇提取物分离得到17个化合物,通过MS、NMR等方法鉴定为:小毛茛内酯(1)、阿魏酸(2)、对羟基香豆酸(3)、原儿茶酸(4)、咖啡酰基(5)、丹参素(6)、丹参素甲酯(7)、山萘酚-3-O-β-D-槐糖-7-O-β-D-葡萄糖苷(8)、槲皮素-3-O-(2’’’-E-咖啡酰基)-α-L-阿拉伯糖-(1→2)-β-D-葡萄糖-7-O-β-D-葡萄糖苷(9)、山萘酚-3-O-β-D-葡萄糖-7-O-β-D-葡萄糖苷(10)、槲皮素-7-O-β-D-葡萄糖苷(11)、槲皮素-3-O-(2’’’-E-咖啡酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(12)、山萘酚-3-O-(2’’’-E-咖啡酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(13)、槲皮素-3-O-(2’’’-E-阿魏酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(14)、山萘酚-3-O-(2’’’-E-对羟基香豆酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(15)、芹菜素-8-C-α-L-阿拉伯糖-6-C-β-D-葡萄糖苷(16)、芹菜素-6-C-β-D-葡萄糖-8-C-β-D-葡萄糖苷(17)。除化合物4外,其他化合物均为首次从刺果毛茛中分离得到。     

蒲黄化学成分研究

采用硅胶柱层析、聚酰胺柱层析、凝胶柱层析以及HPLC等色谱技术对蒲黄化学成分进行分离和纯化,从其乙酸乙酯和正丁醇部位分离并鉴定了26个化合物,分别为:柚皮素(1)、异鼠李素-3-O-芸香糖苷(2)、槲皮素-3-O-新橙皮糖苷(3)、槲皮素-3-O-(2G-α-L-鼠李糖基)-芸香糖苷(4)、异鼠李素-3-O-新橙皮糖苷(5)、香蒲新苷(6)、山柰酚-3-O-新橙皮糖苷(7)、山柰酚-3-O-(2G-α-L-鼠李糖基)-芸香糖苷(8)、5α,8α-epidioxyergosta-6,22-dien-3β-ol(9)、stigmastan-3,6-dione(10)、胡萝卜苷-6'-棕榈酸酯(11)、胡萝卜苷-6'-二十烷酸酯(12)、尿囊素(13)、6-氨基嘌呤(14)、次黄嘌呤(15)、尿嘧啶(16)、硬脂酸(17)、十二烷酸(18)、香草酸(19)、二十九烷二醇-6,8(20)、二十九烷二醇-6,10(21)、二十九烷二醇-6,21(22)、二十六烷醇-1(23)、十六烷醇-1(24)、二十五烷(25)、单棕榈酸甘油酯(26)。其中,化合物11、12、13、18、23、24为首次从该属植物中分离得到。     

泽漆的化学成分研究

采用多种分离材料包括硅胶、Sephadex LH-20和反相RP-18从泽漆的95%乙醇提取物的正丁醇部位分离得到12个化合物,经过波谱学方法分别鉴定为Helioscopin D(1),Isofraxidin(2),Swertiamarin(3),13-Car-boxyblumenol C(4),4,4′-dimethoxy-3′-hydroxy-7,9′,7′9-diepoxyligan-3-O-β-D-glucopyranoside(5),(+)-Syringa-resinol-4′-O-β-D-glucoside(6),2S,3R-2,3-Dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-benzofuran-5-(trans)propen-1-ol-3-O-β-glucoside(7),Quinquenin L1(8),(6R,9S)-megastigman-3-one-4,7-ene-9-ol-9-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside(9),2R,3R-2,3-Dihydro-2-(4′-hydroxy-3′-methoxyphenyl)-3-(glucosyloxymethyl)-7-methoxy-benzofuran-5-propanol(dihydrodehydrodiconiferyl-alcohol-β-D-glucoside)(10),Thy-midine(11),和Deoxyuridine(12)。其中化合物1为一个降倍半萜类新化合物,其余化合物从该种中首次分离。     

大型海藻龙须菜的化学成分研究

从大型海藻龙须菜(Gracilaria lemaneiformis(Bory)Daws)中分离获得了9个化合物.通过波谱分析,分别鉴定为(2S)-1-O-棕榈酸-3-O-β-d-吡喃半乳糖甘油酯(1)、(2S)-1-O-棕榈酸-2-O-棕榈油酸-3-O-β-d-吡喃半乳糖甘油酯(2)、(2S)-1-O-棕榈酸-2-O-...     

小金梅草化学成分研究(英文)

从小金梅草乙醇提取物中分离得到了12个化合物,分别为3-O-β-D-槲皮素葡萄糖苷(1)、3-O-β-D-山柰酚葡萄糖苷(2)、5-O-β-D-芹菜素葡萄糖苷(3)、α-菠甾醇(4)、2,6-二甲氧基苯甲酸(5)、3-吲哚甲酸(6)、(2S,3R,4E,8E)-1-(β-D-吡喃葡萄糖苷)-N-[(R)-2’-羟基-二十碳酰基]-9-甲基-4,8-二烯-1,3-二醇-2-氨基-十八烷(7)、正三十二烷醇(8)、14,15-二十碳烯酸(9)、木腊酸(10)、β-谷甾醇(11)、胡萝卜苷(12)。以上化合物均为首次从该植物中得到。     

碎米花杜鹃根的化学成分研究

采用硅胶柱色谱、Sephadex LH-20柱色谱等手段从碎米花杜鹃Rhododendron spiciferum根中分离得到15个化合物,根据化合物的理化性质和光谱数据分别鉴定为(-)-南烛木树脂酚(1)、(+)-环合橄榄树脂素(2)、(-)-南烛木树脂酚-9-O-β-D-葡萄吡喃糖苷(3)、(-)-南烛木树脂酚-9-O-β-D-木吡喃糖苷(4)、3,5,7-三羟基色原酮-3-O-α-L-鼠李吡喃糖苷(5)、3,5,7-三羟基色原酮-3-O-α-L-阿拉伯吡喃糖苷(6)、柚皮素(7)、圣草酚(8)、紫杉叶素(9)、儿茶素(10)、紫杉叶素-3-O-α-L-阿拉伯吡喃糖苷(11)、黄杞苷(12)、紫杉叶素-3-O-α-L-阿拉伯呋喃糖苷(13)、蒲公英赛醇(14)、蒲公英赛醇乙酸酯(15)。其中化合物1~6、8、9、13~15为首次从该植物中分得。     

星状凤毛菊的化学成分研究

采用各种填料的色谱柱层析方法从药用植物星状凤毛菊(Saussurea stella Maxim)的全草中分离纯化出15个化合物,经波谱分析将它们的化学结构分别鉴定为2-甲氧基-4-羟基苯甲醛(1)、3-(3-甲氧基苯基)丙烯醛(2)、松脂素-4′-O-β-葡萄糖苷(3)、胡萝卜苷(4)、木犀草素(5)、金合欢素(6)、洋芹素(7)、日本椴苷(8)、3′-甲氧基木犀草素-7-O-β-葡萄糖苷(9)、洋芹素-7-O-β-葡萄糖苷(10)、槲皮素-3-O-α-L-鼠李糖苷(11)、山奈素3-O-α-L-鼠李糖苷(12)、槲皮素-5-O-β-葡萄糖苷(13)、4′-甲氧基槲皮素-5-O-β葡萄糖苷(14)和3-甲氧基山奈素-6-O-β葡萄糖苷(15)。其中化合物1～5、9～10和13～15是首次从该种植物中分离得到。     

槐角化学成分及其抗骨质疏松作用研究

研究槐角的化学成分及其抗骨质疏松作用。利用硅胶柱、ODS反相硅胶柱、Sephadex LH-20凝胶柱和半制备型高效液相等色谱技术对槐角进行分离纯化,并结合化合物的理化性质和波谱数据确定化合物的结构。从槐角中分离得到15个化合物,分别为染料木素(1)、山萘酚(2)、鸢尾苷(3)、芒柄花苷(4)、α-鼠李异洋槐素(5)、鹰嘴豆芽素A-7-O-β-D-葡萄糖苷(6)、南酸枣苷(7)、thevetiaflavon(8)、香豌豆酚-7-O-β-D-葡萄糖苷(9)、山萘酚-7-O-β-D-葡萄糖苷(10)、槲皮苷(11)、山萘酚-3-O-β-D-槐糖苷(12)、染料木素-7,4'-双葡萄糖苷(13)、槲皮素-3-O-β-D-槐糖苷(14)、山萘酚-3-O-β-D-槐糖-7-O-α-L-鼠李糖苷(15)。其中化合物6~12、14为首次从该种植物中分离得到,化合物7、8、10、14为首次从该属植物中分离得到。对所分离的化合物进行了抗骨质疏松体外药理活性筛选,结果表明除化合物7和15以外,其他化合物均具有促进成骨细胞增殖作用。     

Adenosine A2A receptor is involved in cell surface expression of A2B receptor

The A2A and A2B adenosine receptors (A2AR and A2BR) are implicated in many physiological processes. However, the mechanisms of their intracellular maturation and trafficking are poorly understood. In comparative studies of A2AR versus A2BR expression in transfected cells, we noticed that the levels of cell surface expression of A2BR were significantly lower than those of A2AR. A large portion of the A2BR was degraded by the proteasome. Studies of cell surface expression of A2BR chimeric molecules in transfectants suggested that A2BR does not have the dominant forward transport signal for export from the endoplasmic reticulum to the cell surface. A2BR surface expression was increased in A2BR chimeras where the A2BR carboxyl terminus (CT) was replaced or fused with the A2AR CT. Co-transfection of A2AR with A2BR enhanced surface expression of A2BR though the F(X)(6)LL motif in the A2AR CT. The requirements of A2AR expression for better A2BR cell surface expression was not only established in transfectants but also confirmed by observations of much lower levels of A2BR-induced intracellular cAMP accumulation in response to A2BR-activating ligand in splenocytes from A2AR(-/-) mice than in wild type mice. The results of mechanistic studies suggested that poor A2BR expression at the cell surface might be accounted for mainly by the lack of a dominant forward transport signal from the endoplasmic reticulum to the plasma membrane; it is likely that A2BR forms a hetero-oligomer complex for better function.     

New HLA-A2 variants defined by monoclonal antibodies and cytotoxic T lymphocytes

Three HLA-A2 variants, A2-DW, A2-KC, and A2-Lee, were identified in three Chinese donors using a panel of monoclonal antibodies. A2-DW was negative with two of the ten HLA-A2 monoclonal antibodies tested, whereas A2-KC was negative with five of the ten and A-2 Lee was negative with one.Epstein-Barr virus-specific cytotoxic T cells generated from the A2-DW donor recognized and killed target cells prepared from the A2-KC donor, but did not recognize target cells from HLA-A2.1, –A2.2, or –A2.4 donors. In isoelectric focusing studies, A2-DW and A2-KC focus in identical positions more acidic than the other HLA-A2 antigens tested.     

Adenosine A2A receptor-mediated facilitation of noradrenaline release involves protein kinase C activation and attenuation of presynaptic inhibitory receptor-mediated effects in the rat vas deferens

In the epididymal portion of rat vas deferens, facilitation of noradrenaline release mediated by adenosine A2A receptors, but not that mediated by beta2-adrenoceptors or by direct activation of adenylyl cyclase, was attenuated by blockade of alpha2-adrenoceptors and abolished by simultaneous blockade of alpha2-adrenoceptors, adenosine A1 and P2Y receptors. The adenosine A2A receptor-mediated facilitation was not changed by inhibitors of protein kinase A, protein kinase G or calmodulin kinase II but was prevented by inhibition of protein kinase C with chelerythrine or bisindolylmaleimide XI. Activation of protein kinase C with phorbol 12-myristate 13-acetate caused a facilitation of noradrenaline release that was abolished by bisindolylmaleimide XI and reduced by antagonists of alpha2-adrenoceptors, adenosine A1 and P2Y receptors. Activation of adenosine A2A receptors attenuated the inhibition of noradrenaline release mediated by the presynaptic inhibitory receptors. This effect was mimicked by phorbol 12-myristate 13-acetate and prevented by bisindolylmaleimide XI. It is concluded that adenosine A2A receptors facilitate noradrenaline release by a mechanism that involves a protein kinase C-mediated attenuation of effects mediated by presynaptic inhibitory receptors, namely alpha2-adrenoceptors, adenosine A1 and P2Y receptors.     

Inhibition and inactivation of cytochrome P450 2A6 and cytochrome P450 2A13 by menthofuran, β-nicotyrine and menthol

Nicotine is the primary addictive agent in tobacco products and is metabolized in humans by CYP2A6. Decreased CYP2A6 activity has been associated with decreased smoking. The extrahepatic enzyme, CYP2A13 (94% identical to CYP2A6) also catalyzes the metabolism of nicotine, but is most noted for its role in the metabolic activation of the tobacco specific lung carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In this study, the inhibition and potential inactivation of CYP2A6 and CYP2A13 by two tobacco constituents, 1-methyl-4-(3-pyridinyl) pyrrole (β-nicotyrine) and (-)-menthol were characterized and compared to the potent mechanism based inactivator of CYP2A6, menthofuran. The effect of these compounds on CYP2A6 and CYP2A13 activity was significantly different. (-)-Menthol was a more efficient inhibitor of CYP2A13 than of CYP2A6 (KI, 8.2 μM and 110 μM, respectively). β-Nicotyrine was a potent inhibitor of CYP2A13 (KI, 0.17 μM). Neither menthol nor β-nicotyrine was an inactivator of CYP2A13. Whereas, β-nicotyrine was a mechanism based inactivator of CYP2A6 (KI(inact), 106 μM, kinact was 0.61 min(-1)). Similarly, menthofuran, a potent mechanism based inactivator of CYP2A6 did not inactivate CYP2A13. Menthofuran was an inhibitor of CYPA13 (KI, 1.24 μM). The inactivation of CYP2A6 by either β-nicotyrine or menthofuran was not due to modification of the heme and was likely due to modification of the apo-protein. These studies suggest that β-nicotyrine, but not menthol may influence nicotine and NNK metabolism in smokers.     

LMP2A does not require palmitoylation to localize to buoyant complexes or for function

Epstein-Barr virus (EBV) latent membrane protein 2A (LMP2A) is expressed constitutively in lipid rafts in latently infected B lymphocytes. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids selective for specific protein association. Lipid rafts have been shown to be necessary for B-cell receptor (BCR) signal transduction. LMP2A prevents BCR recruitment to lipid rafts, thereby abrogating BCR function. As LMP2A is palmitoylated, whether this fatty acid modification is necessary for LMP2A to localize to lipid rafts and for protein function was investigated. LMP2A palmitoylation was confirmed in latently infected B cells. LMP2A was found to be palmitoylated on multiple cysteines only by S acylation. An LMP2A mutant that was not palmitoylated was identified and functioned similar to wild-type LMP2A; unmodified LMP2A localized to lipid rafts, was tyrosine phosphorylated, was associated with LMP2A-associated proteins, was ubiquitinated, and was able to block calcium mobilization following BCR cross-linking. Therefore, palmitoylation of LMP2A is not required for LMP2A targeting to buoyant complexes or for function.     

The protein phosphatases involved in cellular regulation. Influence of polyamines on the activities of protein phosphatase-1 and protein phosphatase-2A

The effects of polyamines on the oligomeric forms of protein phosphatase-1 (1G), protein phosphatase-2A (2A0, 2A1 and 2A2) and their free catalytic subunits (1C and 2AC) has been studied using homogeneous enzymes isolated from rabbit skeletal muscle. Spermine increased the activity of protein phosphatase-2A towards eight of nine substrates tested. Half-maximal activation was observed at 0.2 mM with optimal effects at 1-2 mM. Above 2 mM, spermine became inhibitory. The most impressive activation of protein phosphatase-2A was obtained with glycogen synthase, especially when phosphorylated at sites-3 (8-15-fold with protein phosphatase-2A1) and phenylalanine hydroxylase (6-7-fold with protein phosphatase-2A1) as substrates. Activation of protein phosphatases 2A0, 2A1 and 2A2 was greater than that observed with 2AC. Spermine was a more potent activator than spermidine, while putrescine had only a small effect. Qualitatively similar results were obtained with five other substrates, although maximal activation was much less (1.3-3-fold with protein phosphatase-2A1). The rate of dephosphorylation of glycogen phosphorylase was decreased by spermine, inhibition being more pronounced with protein phosphatase-2AC than with 2A0, 2A1 and 2A2. Spermine (I50 = 0.1 mM with protein phosphatase-2AC) was a more potent inhibitor than spermidine (I50 = 0.9 mM) or putrescine (I50 = 8 mM). Partially purified preparations of protein phosphatases-2A0, 2A1 and 2A2 from from rat liver were affected by spermine in a similar manner to the homogeneous enzymes from rabbit skeletal muscle. Spermine did not activate protein phosphatase-1 to the same extent as protein phosphatase-2A. Greatest stimulation (2.5-fold) was again observed with glycogen synthase labelled in sites-3, with half-maximal activation at 0.2 mM and optimal effects at 1-2 mM spermine. Spermine was a much more effective stimulator than spermidine, while putrescine was ineffective. Very similar results were obtained with protein phosphatases 1G and 1C. With four other substrates maximal activation by spermine was less than 1.5-fold, while the dephosphorylation of glycogen synthase (labelled in site-2), phosphorylase kinase, pyruvate kinase and glycogen phosphorylase were inhibited. Spermine (I50 = 0.04 mM) was a more potent inhibitor of the dephosphorylation of glycogen phosphorylase than spermidine (I50 = 0.9 mM) or putrescine (I50 = 9 mM).(ABSTRACT TRUNCATED AT 400 WORDS)     

Relative contribution of arms and legs in humans to propulsion in 25-m sprint front-crawl swimming

Eight male subjects were asked to swim 25 m at maximal velocity while the use of the arm(s) and legs was alternately restricted. Four situations were examined using one arm (1A), two arms (2A), one arm and two legs (1A2L) and both arms and legs (2A2L, normal swim) for propulsion. A significant mean increase of 10% on maximal velocity was obtained in 1A2L and 2A2L compared to 1A and 2A. A non-significant 4% effect was obtained in 1A. This study focused on the actual contribution of leg kick in the 10% gain in maximal velocity. It was clear that the underwater trajectory of the wrist was modified by the action of the legs (most comparisons P < 0.001). Therefore it was thought that the legs enhanced the generated propulsive force by improving the propulsive action of the arm. The arm action was quantified by selecting typical phases from the filmed trajectory of the wrist, namely forward (F), downwards (D) and backwards (B). Although there was a tendency for individual changes in kinematic parameters (F, D and B) to occur with individual changes in velocity when 2A was compared to 2A2L, no relationship was found between the relative changes in F, D and B and relative changes in velocity. This was illustrated by describing the responses of three individuals who could represent three patterns of contribution by legs and arms to propulsion in high speed swimming.     

Histone deacetylase HDAC2 silencing prevents endometriosis by activating the HNF4A/ARID1A axis

Endometriosis is the most major cause of chronic pelvic pain in women of reproductive age. Moreover, the involvement of histone deacetylase 2 (HDAC2) has been identified in endometriosis. However, the specific mechanism of HDAC2 remains to be further elusive. Therefore, this study was designed to explore the mechanism of HDAC2 orchestrating hepatocyte nuclear factor 4α/AT-rich interactive domain 1A (HNF4A/ARID1A) axis in endometriosis. Endometriosis cell line hEM15A and clinical endometriosis tissues were obtained, followed by gain- and loss-of-function assays in hEM15A cells. HDAC2, HNF4A and ARID1A expression was detected by immunohistochemistry and Western blot analysis. Cell viability was determined by Cell Counting Kit-8 Assay, invasion by Transwell assay and apoptosis by flow cytometry. HDAC2 enrichment in HNF4A promoter region and HNF4A enrichment in ARID1A promoter region was detected through chromatin immunoprecipitation. Mouse models of endometriosis were established, followed by immunohistochemistry of Ki-67 expression and TUNEL staining of apoptosis in ectopic tissues. HDAC2 was upregulated but HNF4A and ARID1A were downregulated in endometriosis tissues. HDAC2 inhibited HNF4A expression by deacetylation, and HNF4A was enriched in ARID1A promoter region to activate ARID1A. Silencing HDAC2 or overexpressing HNF4A or ARID1A diminished the viability and invasion and augmented the apoptosis of hEM15A cells. HDAC2 silencing reduced the area and weight of endometriosis tissues, suppressed endometriosis cell proliferation and accelerated endometriosis cell apoptosis. The inhibitory action of silencing HDAC2 via HNF4A/ARID1A axis was reproduced in mouse models. Collectively, HDAC2 silencing might upregulate HNF4A via repression of deacetylation to activate ARID1A, thus preventing the occurrence of endometriosis.     

Immunochemical relatedness between secretory phospholipase A2 and intracellular phospholipase A2

The immunochemical relationship between rat pancreatic phospholipase A2 and rat splenic phospholipase A2 was examined with the use of anti-rat pancreatic phospholipase A2 antibody as a probe. The immunoelectrophoretic patterns showed that the antibody cross-reacted with the splenic enzyme. The immuno-crossreactivity was also shown by counter immunoelectrophoresis. The splenic phospholipase A2, whether it was purified from the cytosolic fraction or the microsomal fraction, formed an immunoprecipitin band with the anti-pancreatic phospholipase A2 antibody. The antibody was shown to inhibit the activity of the pancreatic phospholipase A2 as well as that of the splenic phospholipase A2.