麦角菌发酵物中生物碱的化学研究

利用麦角菌生物合成制取麦角新碱的方法已推广应用于生产。该菌种在小麦种子培养基上培养以后,除麦角新碱外,根据薄层层离鉴定结果证明还产生三种麦角生物碱。为了利用麦角新碱生产过程中母液里的其他麦角生物碱,并为进一步研究生物合成机制提供资料,必须先对母液中所含麦角生物碱进行分离和鉴定。曾采用无粘合剂的氧化鋁薄层层离法,从母液中分离出了四种生物碱。除麦角新碱外,其余三种生物碱通过薄层层离鉴定;熔点、比旋度测定;紫外吸收光谱、红外吸收光谱和元素分析等分别鉴定,证明为麦角异新碱、麦角生碱和麦角异生碱。     

薄层层离法在研究天然化合物中的应用 Ⅰ.麦角新碱、麦角胺、麦角毒碱的鉴定

本文研究了影响麦角新碱、麦角胺和麦角毒碱的氧化铝薄层层离的各种因素.实验结果表明,酸性、中性和弱碱性氧化铝均能使三种麦角生物碱分离.氧化铝细度以小于200号筛的层离效果最好,莹光点圆而集中.苯-无水乙醇(10:0.5)是较为理想的推进剂,不仅分离效果好,而且其组成简单,容易处理和回收.层离板的斜度对层离效果影响不大,但以8—16°角较合适.层离槽放入溶剂后,必须先密闭放置10分钟,才能进行层离,否则容易产生边缘效应.根据以上研究桔果,制订了鉴定麦角中三种主要生物碱的方法.     

薄层层离法在研究天然化合物中的应用 Ⅱ.麦角新碱、麦角胺、麦角毒碱的定量

本文研究了应用无粘合剂氧化鋁薄层层离和光电比色相結合的方法,測定麦角中三种主要生物碱的含量。回收率試驗表明,本方法具有較高的准确性,如麦角新碱的平均回收率为97.3%,标准誤差±1.7%;麦角胺的平均回收率为96.2%,标准誤差±2.2%;麦角毒碱的平均回收率为99.3%,标准誤差±0.9%。加量試驗的結果表明,本方法可以应用于麦角中三种主要生物碱的含量測定。作者用此方法測定了披碱草、老芒麦、高滨麦三种野生麦角和二种麦角菌发酵物中各种麦角生物碱的含量。操作簡便,有机溶剂用量很少。     

鱼粉代替谷氨酸生产麦角新碱的研究

在以前工作的基础上,我们进一步采用鲫鱼粉代替谷氨酸生产麦角新碱取得了比较好的效果。 通过试验证明,鲫鱼粉不仅可代替谷氨酸作为氮源,并能促进麦角新碱的形成,其麦角新碱含量比对照高近一倍,且其来源容易,价格低廉。 麦角菌在200l发酵罐内培养,从第四天开始产生麦角碱,发酵至11天麦角碱含量已达最高峰。在发酵过滤液中麦角总生物碱及麦角新碱含量分别为0.0203％及0.0178％,而在菌丝体中分别达到0.1609％及0.0495％。     

鱼粉代替谷氨酸生产麦角新碱的研究

在以前工作的基础上,我们进一步采用鲫鱼粉代替谷氨酸生产麦角新碱取得了比较好的效果。通过试验证明,鲫鱼粉不仅可代替谷氨酸作为氮源,并能促进麦角新碱的形成,其麦角新碱含量比对照高近一倍,且其来源容易,价格低廉。麦角菌在200l发酵罐内培养,从第四天开始产生麦角碱,发酵至11天麦角碱含量已达最高峰。在发酵过滤液中麦角总生物碱及麦角新碱含量分别为0.0203%及0.0178%,而在菌丝体中分别达到0.1609%及0.0495%。     

麦角单菌核中麦角生物碱的薄层分离及荧光光密度法测定

本文介绍了麦角单菌核中麦角新碱、麦角酰胺、麦角胺及麦角克碱的薄层分离及荧光光密度法定量的分析方法。本法快速、灵敏,检出限度为1×10^-8g,四种生物碱的平均变异系数为6.10%,层离后的薄层斑点避光保存可稳定24小时。本法为探索麦角单个菌核问含麦角生物碱的质和量的变化以及为定向选育菌种提供了可能性。     

分离麦角新碱的新方法

研究了利用离子交换树脂从麦角中分离麦角新碱的方法.用0.05N盐酸溶液从麦角粉末中提取出总生物碱,然后通过离子交换树脂.在6种国产不同交联度的苯乙烯磺酸氢型树脂中,以强酸1—2树脂对酸水提取液中麦角生物碱的交换量最高.酸水提取液的pH以3.5—5.9较为合适.试验证明,采用先碱化树脂,使麦角生物碱游离,再在Soxhlet提取器中用丙酮-乙醚(3:7)或丙酮-氯仿(7∶3)混合溶剂洗脱生物碱的方法,不但可以得到较高的洗脱率,同时节省了有机溶剂.以后利用麦角新碱能与氯仿形成复合结晶,却又难溶于氯仿的特性,可以使麦角新碱与其他麦角生物碱分离.小量试制结果,麦角新碱的收率为60—70%.     

四川轮环藤根中两种新双苄基异喹啉生物碱的分离鉴定

从中国特有植物四川轮环藤(Cyclea sutchuenensis Gagnep.)根中除分得已知的轮环藤碱(Ⅰ)和异粒枝碱(Ⅱ)外,还分离得到两种新双苄基异喹啉生物碱,分别命名为异轮环藤碱(Ⅲ)和四川轮环藤辛碱(Ⅳ)。经物理常数和波谱数据分析鉴定,证明Ⅲ为轮环藤碱的差向异构体,Ⅳ系一种新型的8-12′,12-7′首尾双氧桥双苄基异喹啉生物碱。     

麦角生物碱生物合成研究进展

医用麦角生物碱 (ｅｒｇｏｔａｌｋａｌｏｉｄｓ)大多是由天然麦角生物碱经过结构改造而成 ,多具有重要的临床用途 ,少数天然麦角生物碱可直接作为药物。由于麦角生物碱类药物在临床应用上占有重要位置 ,加之麦角肽碱 (ｅｒｇｏｔｐｅｐｔｉｄｅａｌｋａｌｏｉｄｓ ,ｅｒｇｏｐｅｐｔｉｎｅｓ)有特殊的环肽结构 ,因此麦角生物碱生物合成的研究历来受到重视。近年来 ,现代生物技术和分子生物学方法进一步促进了麦角生物碱生物合成的研究。已基本弄清其生物合成途径 ,尤其是对一些关键酶的研究已有较大进展。1　麦角生物碱的生物合成途径麦角…     

药物分析

197.薄层层析和纸层析时某些试剂对阿片生物碱的灵敏度本文介绍,在进行薄层层析和纸层析测定时,三种试剂对11种阿片生物碱的灵敏度以及利用这些试剂鉴定个别生物碱的可能性。三种试剂为:(1)改良的Dragendorff试     

麦角生物硷的层离研究 Ⅰ.我国野生麦角的成分鉴定及麦角新硷的定量

近年来国内发现几种野生麦角,本院药用植物系进行了调查研究,从分怖地区及麦角外部形态方面作了初步报导,为进一步了解和探讨其中生物硷成分及麦角新硷含量,我们用纸屑离法进行研究。一般化学测定法只能测定麦角总硷含量及水溶性生物硷含量,对于个别生物硷无法测定,自1949年Foster应用纸屑离法后,就大大方便了从事研究麦角复杂成分的方法。 Foster用正丁醇、醋酸、及水的混合液作扩展溶剂,把水溶性及水不溶性生物硷在     

A Targeted UHPLC-MS/MS Method Validated for the Quantification of Ergot Alkaloids in Cereal-Based Baby Food from the Belgian Market

Following pending new legislation in the European Union setting a maximum of 20 ng g⁻¹ for the total sum of ergot alkaloids in dry cereal-based baby food, a new UHPLC-MS/MS method was developed. It is suitable for the quantification of six ergot alkaloids: Ergocornine, ergocristine, ergometrine, ergosine, ergotamine, α-ergocryptine, and their corresponding epimers. The method is able to reliably detect individual ergot alkaloids at a level as low as 0.5 ng g⁻¹. The method uses a modified QuEChERS extraction approach before UHPLC-MS/MS analysis. The method showed good sensitivity, accuracy, and precision. It has been applied to 49 samples from the Belgian market. In 26 samples, not a single ergot alkaloid was detected while in 23 out of 49 samples at least one ergot alkaloid was detected with 2 samples containing 12 ergot alkaloids. Ergometrine was the alkaloid most frequently detected i.e., 16 out of 49 samples. Only one sample, testing positive for all 12 ergot alkaloids, would be non-conforming to the newly proposed Maximum Residue Level (MRL).     

Occurrence of Ergot Alkaloids in Barley and Wheat from Algeria

The natural occurrence of six major ergot alkaloids, ergometrine, ergosine, ergotamine, ergocornine, ergokryptine and ergocristine, as well as their corresponding epimers, were investigated in 60 cereal samples (barley and wheat) from Algeria. Ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and a QuEChERS extraction method were used for sample analysis. The results revealed that 12 out of 60 samples (20%) were contaminated with ergot alkaloids. Wheat was the most contaminated matrix, with an incidence of 26.7% (8 out of 30 samples). The concentration of total ergot alkaloids ranged from 17.8 to 53.9 µg/kg for barley and from 3.66 to 76.0 μg/kg for wheat samples. Ergosine, ergokryptine and ergocristine showed the highest incidences in wheat, while ergometrine was the most common ergot in barley.     

Cleaving Ergot Alkaloids by Hydrazinolysis—A Promising Approach for a Sum Parameter Screening Method

Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40‒60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed.