显齿蛇葡萄化学成分的研究

从显齿蛇葡萄地上部分首次分得5个化合物。经理化常数测定,光谱(UV,IR,MS,1HNMR)分析,鉴定为福建茶素、龙涎香醇、β-谷甾醇、杨梅黄素和杨梅甙。     

泌尿宁颗粒定性定量研究

目的 建立泌尿宁颗粒定性定量研究方法.方法 采用TLC法,对泌尿宁颗粒中五味子、黄柏进行定性鉴别;采用HPLC法,测定萹蓄中杨梅苷的含量.结果 TLC特征明显,阴性样品无干扰,专属性强;杨梅苷在0.075 94～0.569 6 mg与峰面积呈良好的线性关系,r=0.9999,平均回收率98.0％,RSD=0.78％(n=6).结论 本方法操作简便、重复性好、结果准确可靠,能够控制该药的质量.     

UPLC测定狭山野豌豆中6种化学成分的含量

目的:建立超高效液相色谱法(UPLC)同时测定狭山野豌豆中6种成分(绿原酸、杨梅苷、金丝桃苷、异槲皮苷、山柰苷、槲皮苷)的含量测定方法。方法:采用Eclipse Plus C18RRHD色谱柱(2.1 mm×50 mm,1.8μm),以乙腈(B)-0.1%甲酸溶液(A)为流动相进行梯度洗脱(0~7 min,5%~10%B;7~11 min,10%~12%B;11~20 min,12%B;20~25 min,12%~19%B;25~30 min,19%~24%B),流速0.2 m L·min-1,检测波长340 nm,柱温30℃。结果:狭山野豌豆中6个成分在线性范围内呈现良好的线性关系,r0.999 9,回收率均在99.15%~101.98%,RSD 0.7%~1.7%。结论:该方法操作简便、精确,稳定性重复性好,可用于同时测定狭山野豌豆中6种化学成分的含量,为狭山野豌豆的质量控制提供依据。     

杨梅素和杨梅苷对一些肿瘤细胞的体外抑制及诱导凋亡作用研究

<正>黄酮类化合物(flavonoids)是植物性食品中广泛存在的一类膳食健康因子,有抗癌、防癌等多重生物学功效,其作用机理可能与黄酮类化合物的促氧化作用有关[1-2]。其中,杨梅素和杨梅苷多存在于水果、茶叶、药用植物和红酒中[3],尤其是存在于杨梅植株及其果实中。杨梅素(3,57,3',4',5'-hexahydroxy-flavonols)是含多羟基的黄酮醇苷元,黄酮母核上连有6个羟基,且B环为邻三羟基,分子量为318.24;杨梅苷(myricetin-3-o-rhamnoside)为杨梅素的糖苷3位上的羟基被鼠李糖取代,分子量为464.37;二者的化学结构式见图1。本研究探讨杨梅素、     

显齿蛇葡萄化学成分研究

目的研究显齿蛇葡萄的化学成分。方法应用硅胶、聚酰胺、反相硅胶、Sephadex LH-20柱色谱和硅胶制备薄层色谱进行分离纯化,根据理化常数和光谱分析鉴定结构。结果从显齿蛇葡萄中分离并鉴定了4个黄酮类化合物:二氢杨梅素(1),杨梅素(2),杨梅苷(3),杨梅素-3-O-β-D-半乳糖苷(4)。结论其中化合物4为首次从该属植物中分离得到,根据2D NMR正确归属了化合物1的1Hand13C NMR数据。     

透骨草药材UPLC指纹图谱研究

目的建立透骨草药材来源中狭山野豌豆Vicia amoena超高效液相色谱(UPLC)指纹图谱,并与其余5种来源品种进行比较,为透骨草药材质量控制提供参考依据。方法用Eclipse Plus C_(18) RRHD(50 mm×2.1 mm,1.8μm)色谱柱,以乙腈-0.1%甲酸溶液为流动相梯度洗脱,体积流量0.2 m L/min;柱温30℃;检测波长340 nm。测定10个不同产地狭山野豌豆指纹图谱,采用中药色谱指纹图谱相似度评价系统(2004A版)计算相似度,并用对照品和液质联用技术指认色谱峰;同条件下比较鉴别透骨草药材其他5种来源品种。结果建立了狭山野豌豆指纹图谱,采用超高效液相色谱-电喷雾-四级杆-飞行时间串联质谱仪(UPLC-ESI-Q-TOF-MS)对14个共有峰中的6个峰进行初步归属,确定为绿原酸、杨梅苷、金丝桃苷、异槲皮苷、山柰苷、槲皮苷;透骨草药材其他5种来源品种与狭山野豌豆指纹图谱的共有模式明显不同。结论该方法重现性好、特征性强,可用于透骨草药材全面质量评价。     

Mitochondrial-dependent, reactive oxygen species-independent apoptosis by myricetin: roles of protein kinase C, cytochrome c, and caspase cascade

Abrogation of mitochondrial permeability and induction of reactive oxygen species (ROS) production have been observed in chemical-induced apoptosis; however, the relationship between the mitochondria and intracellular ROS levels in apoptosis is still unclear. In the present study, myricetin (ME) but not its respective glycoside, myricitrin (MI; myricetin-3-O-rhamnose) reduced the viability of human leukemia HL-60 cells via apoptosis, characterized by the occurrence of DNA ladders and hypodiploid cells. Results of Western blotting and caspase activity assays showed that activation of caspases 3 and 9 but not caspases 1, 6 or 8 with cleavage of PARP and D4-GDI proteins is involved in ME-induced apoptosis. A reduction in mitochondrial functions characterized by a decrease in the Bcl-2/Bax protein ratio and translocation of cytochrome c (cyt c) from the mitochondria to the cytosol in accordance with a decrease in mitochondrial membrane potential were observed in ME-treated HL-60 cells. No significant induction of intracellular ROS levels by ME was observed by the DCHF-DA assay, DPPH assay or plasmid digestion assay, and antioxidants including N-acetyl-cysteine (NAC), catalase (CAT), superoxide dismutase (SOD), and tiron (TIR) showed no protective effects on ME-induced apoptosis. A PKC activator, 12-O-tetradecaoylphorbol-13-acetate (TPA) significantly attenuated ME-induced apoptosis via preventing cytochrome c release to the cytosol and maintaining the mitochondrial membrane potential by inhibiting the decrease in the Bcl-2/Bax protein ratio; these effects were blocked by protein kinase C (PKC) inhibitors including GF-109203X, H7, and staurosporin. Removing mitochondria by ethidium bromide (EtBr) treatment reduced the apoptotic effect of ME. Results of SAR studies showed that the presence of OH at C3′, C4′, and C5′ is important for the apoptosis-inducing activities of ME, and that ME induces apoptosis in another leukemia cell line, Jurkat cells, but not in primary human polymorphonuclear (PMN) cells or in murine peritoneal macrophages (PMs). The results of the present study suggest that apoptosis induced by ME occurs through a novel mitochondrion-dependent, ROS-independent pathway; TPA protects cells from ME-induced apoptosis via PKC activation which prevents the occurrence of mitochondrial destruction during apoptosis.     

矮杨梅茎的化学成分

目的:对杨梅科杨梅属植物矮杨梅的茎进行化学成分研究。方法:采用甲醇回流提取、色谱法分离、波谱法鉴定结构。结果:从该植物茎中共分离鉴定出8个化合物,分别是β-谷甾醇(1)、taraxerol(2)、myricanol(3)、山柰素(4)、槲皮素(5)、杨梅素(6)、杨梅苷(7)、芦丁(8)。结论:文章首次报道了矮杨梅茎的化学成分,化合物2,4为首次从该植物中分离得到。     

Gastrointestinal stability of dihydromyricetin,myricetin, and myricitrin: an in vitro investigation

The gastrointestinal (GI) stability of three flavonoids, dihydromyricetin (DMY), myricetin (MYR), and myricitrin (MYT), was examined in simulated physiological fluids. Several factors that may influence the degradation rate of theses flavonoids were evaluated, including pH and the presence of pepsin and pancreatin enzymes. We found that GI stability followed the order of MYT?>?DMY?>?MYR. These flavonoids were stable in simulated gastric fluids and buffer solutions (pH 1.2), but encountered a pseudo-first-order kinetic degradation in simulated intestinal fluids and buffer solutions (pH 6.8). We conclude that it is the pH, rather than the presence of pepsin or pancreatin, which most strongly influences the stability of these three flavonoids. Further study of the stability of the compounds using a pH range (1.0–8.0) indicated potential instability in the duodenum, small intestine, and colon. Therefore, we conclude that the low bioavailability of these flavonoids may be due to their poor stability in the GI tract.     

A New Diarylheptanoid from Barks of Mangifera indica

Objective To study the chemical constituents from the barks of Mangifera indica.Methods The constituents were separated and purified by different methods of chromatography,and their structures were elucidated by IR,MS,1D and 2D NMR techniques.Results Six compounds were isolated from the barks of M.indica.Their structures were identified as mangiferone(1),mangiferin(2),myricetin(3),myricitrin(4),rutin(5),and quercetin(6).Conclusion Mangiferone(1)is a new diarylheptanoid compound isolated from the barks of M.indica.