Ergot Alkaloids Produced by Endophytic Fungi of the Genus Epichlo?

The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot alkaloids, when present in endophyte-infected tall fescue, are responsible for “fescue toxicosis” in livestock, whereas indole-diterpene alkaloids, when present in endophyte-infected ryegrass, are responsible for “ryegrass staggers”. In contrast, peramine and loline alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the “sleepy grass” and “drunken horse grass” diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.     

Physicochemical quality evaluation of natural compounds isolated from crude drugs

Aconite root has high toxicity caused by diester alkaloids, thus it was necessary to define the limiting value of diester alkaloids used in medicine formulation. To give the quality of “Processed Aconite Root” and “Powdered Processed Aconite Root” in the Japanese Pharmacopoeia (14th edn, supplement II), we established the official specification and evaluation methods of standard substances. High qualitative grade diester alkaloids, aconitine, hypaconitine, jesaconitine and mesaconitine, which were useful to evaluate the purity of processed aconite root and powdered processed aconite root, were prepared and evaluated for their stability. We studied the physicochemical specification and evaluation methods of these alkaloids. In addition, an “Aconitum diester alkaloids standard solution for purity”, which was used for the purity test, was prepared, and we also studied its physicochemical specification and evaluation methods. In addition, to evaluate the quality of processed aconite root and powdered processed aconite root, a TLC identification test was established. A monoester alkaloid of benzoylmesaconine hydrochloride was used as the reference standard in the latter test, and we also investigated its physicochemical specification and evaluation methods.     

不同骨架型乌头总生物碱贴片的经皮渗透性比较研究

目的:对比研究4种不同骨架型乌头总碱贴片的透皮吸收行为,筛选最佳贴片并对其进行体外释放度实验。方法:采用改良的Franz扩散池,以生理氯化钠溶液为接收介质,以大鼠离体背部皮肤为透皮屏障,计算4种骨架型贴片中乌头总碱及新乌头碱的稳态流量及滞后时间。结果:4种经皮给药制剂(TDS)中,黏胶剂骨架型贴片(P-3)稳态流量最高,其中乌头总碱的稳态流量9.2μg.cm-2.h-1,滞后时间1.413 h;新乌头碱的稳态流量0.243 6μg.cm-2.h-1,滞后时间1.172 h。该贴片体外释放符合回归方程,Higuchi方程为S(t)=13.32t1/2 18.428,r=0.980 1,体外释药机制为药物扩散和骨架溶蚀的综合效应。结论:黏胶剂骨架型是乌头总碱经皮给药制剂的理想设计模型。     

HPLC法测定苦参总碱中苦参碱与氧化苦参碱的含量

目的:采用高效液相色谱法测定苦参总碱中苦参碱和氧化苦参碱的含量。方法:采用 Elite Hypersil NH_2柱(5μm,250mm×4.6 mm),乙腈-无水乙醇-3%磷酸溶液(81:10:9)为流动相,流速:1.0 mL·min~(-1),检测波长220 nm,柱温:25℃,进样量:10 μL。结果:苦参碱、氧化苦参碱的线性范围分别为5.32～53.2μg·mL~(-1)(r=0.9997),65.7～525.6μg·mL~(-1)(r=0.9995)。苦参碱平均加样回收率为99.5%,RSD=1.0%(n=6);氧化苦参碱的平均加样回收率为99.7%,RSD=0.6%(n=6)。结论:本方法操作简便、快速、可靠,可用于控制苦参总碱质量。     

阳离子交换树脂酸水洗脱法纯化苦参总碱的工艺优选

目的优选阳离子交换树脂不同浓度盐酸溶液洗脱纯化苦参总碱的最佳工艺条件。方法以苦参碱、氧化苦参碱和总生物碱的洗脱率为考察指标,以盐酸溶液作为洗脱剂,优选阳离子交换树脂纯化苦参总碱的最佳工艺和参数条件。结果苦参总碱阳离子交换树脂纯化洗脱条件为:以5%盐酸溶液作为洗脱剂,以6 BV.h-1的流速洗脱,苦参碱和氧化苦参碱、苦参总碱洗脱率均可达85%。结论采用阳离子交换树脂酸水洗脱法纯化苦参总碱效率高,工艺简便,可用于苦参总碱的提取纯化。     

蒙药紫花高乌头根中二萜生物碱的分离与结构鉴定

目的进一步对蒙药紫花高乌头Aconitum excelsum Reichb．根的化学成分进行分离鉴定。方法通过硅胶柱层析分离，以IR，MS,^1H—NMR，^13C—NMR等光谱鉴定结构。结果从紫花高乌头根中分离得到6个化合物，经光谱分析和理化性质鉴定，确定其结构式分别是ranaconitine（Ⅰ），N—deacetyl lappaconitine（Ⅱ），1α，6，16，-三甲氧基-4，7，8，9，14α-五羟基-N-乙基乌头烷（Ⅲ），N—deacetylranaconitine（Ⅳ），β-谷甾醇（Ⅴ），豆甾醇（Ⅵ）。结论化合物Ⅱ，Ⅲ，Ⅳ，Ⅴ，Ⅵ为首次从该植物中得到，其中化合物Ⅲ为新二萜生物碱。     

元胡产地醋制法的化学评价

对产地醋制法和传统醋制法的元胡炮制品进行了定性定量分析,其结果证明,两种方法的元胡炮制品主要化学成分相同,而元胡总生物碱及延胡索乙素含量则产地醋制法高于传统醋制法。     

党参总碱对东莨菪碱引起小鼠记忆障碍和脑内乙酰胆碱及胆碱乙酰化酶的作用

用跳台法观察到党参总碱(DSA)能改善东莨菪碱(Scop)引起的记忆障碍,并能对抗Scop所致小鼠脑内乙酰胆碱(ACh)浓度下降及胆碱乙酰化酶(ChAT)活性的降低。体外实验发现当在反应液中加入DSA后,ChAT生成ACh的量增加。     

近年来我国中草药生物碱成分合成研究

综述了近年来我国中草药化学成分生物碱及其衍生物和类似物的合成研究。     

金鸡纳生物碱在手性分离中的应用

综述了金鸡纳生物碱作为手性选择剂在高效液相色谱和毛细管电泳中分离光学异构体的应用。