RP-HPLC测定杭白芷不同部位5种香豆素的含量

目的:通过高效液相色谱测定栽培杭白芷不同部位中5种香豆素的含量,为合理利用栽培杭白芷资源提供依据.方法:采用Phenomenex Gemini C18(250 mm×4.60 mm,5μm)色谱柱;流动相为甲醇-水(70:30),流速0.8 mL·min-1,柱温30℃;UV检测波长310 nm.结果:栽培杭白芷不同部位的5种香豆素的含量差异显著.结论:栽培杭白芷的根中5种香豆素的总含量最高.     

RP-HPLC测定红丝线中香豆素的含量

采用反相高效液相色谱法,测定红丝线中香豆素的含量。色谱柱为ZORBAXXDB-C18(4.6mm×150mm,5μm);流动相:V(甲醇)∶V(0.01mol/L磷酸二氢钠溶液(pH5.4))=45∶55;流速:1mL/min;检测波长278nm。香豆素的线性范围为2.5~30mg/L(r=0.9998),回收率97.5%~101%。该法简便、准确,重复性好,适用于测定红丝线中香豆素的含量。     

HPLC法测定明党参组织培养物和栽培品中香豆素成分的含量

采用高效液相色谱法同时测定明党参组培和栽培品中7-羟基香豆素、花椒毒酚、欧前胡素和珊瑚菜内酯4种香豆素成分的含量。Agilent-C18色谱柱(250 mm×4.6 mm,5μm);流动相为乙腈—水溶液梯度洗脱,流速1.0 mL/min,柱温30℃;检测波长为314 nm,进样量为10μL。实验结果表明,栽培明党参的根皮4种香豆素成分7-羟基香豆素、花椒毒酚、欧前胡素、珊瑚菜内酯的含量普遍偏高,分别为5.8970、1.2710、0.0301、0.9236mg/g,明党参愈伤组织诱导根中7-羟基香豆素、花椒毒酚含量较高分别为3.7939、0.8384 mg/g;该方法简便、快速、具有良好的重现性,可用于明党参组培和栽培品中香豆素成分的含量测定。     

不同产地川佛手中8种化学成分的分析与评价

建立HPLC法同时测定不同产地川佛手中木犀草素、6,7-二甲氧基香豆素、莨菪亭、5,7-二甲氧基香豆素、7-羟基香豆素、橙皮苷、槲皮素、阿魏酸8种成分含量的方法。采用Thermo BDS HYPERSIL C18(250 mm×4. 6 mm,5μm)色谱柱,甲醇-0. 2%冰醋酸水溶液进行梯度洗脱,流速1 m L/min,柱温30℃,检测波长322 nm。在该色谱条件下,川佛手中8种成分分离良好,平均加样回收率为91. 22%～96. 52%,RSD <5. 0%。不同产地的川佛手中8种成分含量存在差异,部分成分之间存在相关性,样品聚为3类。产于四川省宜宾市长宁县老翁镇的川佛手质量最优。该方法可为川佛手的资源开发利用、质量控制以及安全评价提供参考依据。     

HPLC法测定蛇床子中蛇床子素的含量

目的:建立蛇床子中蛇床子素的含量测定方法.方法:采用高效液相色谱法,色谱柱选择Agilent ZORBAX SB-C18色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇-体积分数0.05％磷酸溶液(体积比70:30),流速为1.0 mL/min,检测波长为322 nm,柱温30℃.结果:蛇床子素的线性关系方程...     

白芷药材水提液指纹图谱的研究

采用高效液相色谱法建立了白芷水提液指纹图谱,色谱柱为Lichrospher 5-C18 (250 mm×4.6 mm,5μm),以甲醇-水为流动相进行二元梯度洗脱,柱温30℃,流速为1 mL/min,检测波长为254 nm.对12批不同产地的白芷药材进行了检测,共发现13个共有色谱峰,各色谱峰分离情况良好.精密度、重复性和稳定性试验中各共有峰相对保留时间和相对峰面积的RSD均小于3％,符合指纹图谱要求.该方法简便、可靠,精密度、稳定性和重复性良好,可用于白芷药材的质量评价.     

HPLC法测定九节菖蒲中琥珀酸含量

目的:建立九节菖蒲中琥珀酸含量的HPLC测定法.方法:采用Kromasil C18色谱柱(150 mm×4.6mm,5μm);甲醇-0.02mol/L KH2PO4缓冲液(7∶93)(pH 2.5)为流动相;流速0.5 mL/min;柱温为30℃;检测波长为214nm.结果:琥珀酸在4～48μg范围内具有良好的线性关系,平均加样回收率为99.15％.九节菖蒲样品中的琥珀酸含量,以干燥品计为0.200％～0.318％.结论:该方法可行,重复性好,可用于九节菖蒲中琥珀酸含量的测定.     

不同采收期东北铁线莲药材中灵仙新苷的含量变化研究

目的:考察不同采收期东北铁线莲药材中灵仙新苷(Clematichinenoside AR)含量,研究其动态含量变化和最佳采收期.方法:采用色谱柱Diamonsil C18(250 mm×4.6 mm,5μm)柱,流动相:乙腈-水溶液梯度洗脱程序,流速1.0 mL/min,检测波长203 nm,柱温:30℃.结果:灵仙新苷以8月下旬到9月中旬的含量最高.结论:东北铁线莲药材的最佳采收期为8月下旬到9月中旬.     

HPLC法测定不同产地僵蚕中草酸铵含量

目的:比较不同产地僵蚕和炒僵蚕中草酸铵的含量.方法:采用反相高效液相色谱法,色谱务件为色谱柱:Diamonsil 5μC18250× 4.6mm Dikma;流动相:磷酸氢二铵水溶液(5 g·L-1,pH 5.30);流速:0.5mL·min-1;柱温:30℃;检测波长:214nm.结果:草酸铵在15.0～150.0μg·ml-1 范围内,峰面积与浓度呈良好的线性关系,r=0.998(n=6),平均加样回收率为97.07%,RSD=2.67%(n=9).结论:炮制僵蚕中草酸铵的含量普遍低于僵蚕生品;僵蚕生品中草酸铵的含量2.21%～5.82%,炮制品2.31%～5.78%.     

反相高效液相色谱法检测脂必妥片中洛伐他汀的含量

对脂必妥片样品进行预处理,得到的混合物用薄层色谱、反相高效液相色谱法进行定性、定量分析,建立检测其含量的方法。当色谱条件为色谱柱:Kromasil(C18250 mm×4.6 mm,5μm);流动相体积比:乙腈∶水为85∶15,;流速:1.0 ml.min-1;检测波长:420 nm;柱温:30℃;测定结果表明被测峰和其它峰可完全分离,在每毫升10.21~200.03μg内具有良好的线性关系,r=0.9997,测得其中洛伐他汀含量为0.25%,回收率:97.73%,RSD:0.56%。这种方法准确、可靠,可用于含洛伐他汀药品的质量控制。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.