Effect of salinity and different nitrogen sources on the activity of antioxidant enzymes and indole alkaloid content in Catharanthus roseus seedlings

The activities of antioxidant enzymes viz. glutathione reductase, GR; superoxide dismutase, SOD; peroxidase, POD; catalase, CAT and glutathione-S-transferase, GST and alkaloid accumulation were investigated in leaf pairs (apical, middle, basal) and in roots of Catharanthus roseus seedlings under the conditions of different nitrogen sources (20 mM KNO(3) and 2 mM NH(4)Cl) and salinity, in the absence (non-saline control) and in the presence of 100 mM NaCl in the nutrient solution. Salinity caused a reduction in plant biomass. The biomass production of ammonium-fed plants was lower than that of nitrate-fed plants. The antioxidant enzymes exhibited higher activity in saline-treated plants. Changes in antioxidant enzyme activity caused by different nitrogen sources differed in all leaf pairs, as well as in roots of C. roseus. Ammonium-fed plants showed higher CAT, GR and GST activity in leaf pairs as well as in roots, while POD and SOD activity were higher in nitrate-fed plants. Higher peroxidase activity concomitant with the increased accumulation of alkaloid was found in all leaf pairs, as well as in roots of C. roseus of NO(3)(-) fed plants as compared to NH(4)(+) fed plants.     

钩藤属植物中吲哚生物碱的研究进展

本文对钩藤属植物中吲哚生物碱类成分的植物来源、骨架结构、波谱学特征及生物活性研究进展进行了综述,希望为药理学、天然药物化学、中药化学等领域的研究者提供参考。     

Metabolite Profiling of Anti‐Addictive Alkaloids from Four Mexican Tabernaemontana Species and the Entheogenic African Shrub Tabernanthe iboga (Apocynaceae)

Ibogaine and other ibogan type alkaloids present anti‐addictive effects against several drugs of abuse and occur in different species of the Apocynaceae family. In this work, we used gas chromatography‐mass spectrometry (GC/MS) and principal component analysis (PCA) in order to compare the alkaloid profiles of the root and stem barks of four Mexican Tabernaemontana species with the root bark of the entheogenic African shrub Tabernanthe iboga. PCA demonstrated that separation between species could be attributed to quantitative differences of the major alkaloids, coronaridine, ibogamine, voacangine, and ibogaine. While T. iboga mainly presented high concentrations of ibogaine, Tabernaemontana samples either showed a predominance of voacangine and ibogaine, or coronaridine and ibogamine, respectively. The results illustrate the phytochemical proximity between both genera and confirm previous suggestions that Mexican Tabernaemontana species are viable sources of anti‐addictive compounds.     

高三尖杉酯碱对兔红细胞膜钙调蛋白的抑制作用

本实验显示高三尖杉酯碱能在>5μg/ml浓度以上抑制兔红细胞膜上钙调蛋白活性(P<0.05).推测高三尖杉酯碱能通过影响癌细胞钙调蛋白活性干扰细胞钙代谢和减少阿霉素和长春新碱的抗药性.     

Cyclic Peptides Containing Biaryl and Biaryl Ether Linkages

This review describes the isolation, activities and synthetic approaches of the naturally occurring cyclic peptides containing biaryl and/or biaryl ether linkages. These compounds range from monocyclic, to bicyclic, to the polycyclic glycopeptide antibiotics, and most of them exhibit significant biological properties such as cytotoxic or antimicrobial activities. Interestingly, vancomycin is used clinically as the antibiotic of last resort for the treatment of methicillin-resistant Staphylococcus aureus. The medicinal significance and the structural complexity of these macrocycles have challenged chemists towards the total synthesis of these compounds and in designing synthetic analogues. Non-natural macrocycles reported from 1999 to 2004 are also covered.     

延胡索分类的化学证据

东阳产延胡索与大连产齿瓣延胡索经成分分离和TLC、HPLC对比,发现延胡索以啊扑啡类生物碱如glaucine为主,而齿瓣延胡索则含corynoline类生物碱。根据生物碱的类型及含量比较,二者有明显差异,结合延胡索的植物形态和植化分类特征判断,将延胡索作为与齿瓣延胡索近缘的独立种处理较为合理,即为Corydalis yanhusuo W. T. Wang ex Z.Y. Su et C. Y. Wu     

Secondary metabolism in tobacco

Tobacco has been quite well studied phytochemically, more than 2500 compounds have been identified. Here, the secondary metabolism in tobacco will be reviewed in a biosynthetic perspective. Major groups of compounds which have extensively been studied are the isoprenoids, alkaloids, cinnamoylputrescines, flavonoids, and anthocyanins. Their biosynthetic pathways and its regulation, and their occurrence in cell cultures and in intact plants will be discussed.     

Direct resolution of ergot alkaloid enantiomers on a novel chiral silica-based stationary phase

A new covalently-bonded, silica-based stationary phase, using as the chiral selector the 1-(3-aminopropyl) derivative of (+)-(5R,8S,10R)-terguride, has been developed to resolve optically active isomers by HPLC. Good resolution of structurally related racemic ergot alkaloids were obtained using water-methanol mixtures as the eluent. Analysis of the influence of the type and concentration of the organic modifier, and the pH of the buffer in the mobile phase allowed the enantioseparation of these compounds to be optimized. Determination of the optical purity of a lisuride-containig drug is reported. © 1994 Wiley-Liss, Inc.     

8-Oxoerythrinine: An alkaloid from Erythrina brucei

The flowers of Erythrina brucei afforded, in addition to known compounds, a new erythrina alkaloid, 8-oxoerythrinine. Its structure was elucidated by spectroscopic investigations as well as by chemical transformations.