Alkaloids from Aspidosperma species from Bolivia

Two Bolivian Aspidosperma species were investigated. The seed and stem bark of Aspidosperma macrocarpon Mart. contain six known alkaloids: (-)-vincadifformine, ervinceine, kopsanone, kopsinine, kopsanol in the seed, and kopsanone, kopsinine, kopsanol, 18-epikopsanol in the stem bark. The stem bark of Aspidosperma pyrifolium Mart. contains eleven known alkaloids: (-)-vincadifformine, O-demethylpalosine, haplocine, N-formylaspidospermidine, vallesine, demethoxyaspidospermine, palosine, (-)-aspidospermine, aspidospermidine, akuammicine, tubotaiwine, beside the two new bases dehydroxyhaplocidine and 10-methoxyaspidospermidine.     

Emerging biopharmaceuticals from bioactive peptides derived from marine organisms

Biologically active natural products are spontaneous medicinal entrants, which encourage synthetic access for enhancing and supporting drug discovery and development. Marine bioactive peptides are considered as a rich source of natural products that may provide long‐term health, in addition to many prophylactic and curative medicinal drug treatments. The large literature concerning marine peptides has been collected, which shows high potential of nutraceutical and therapeutic efficacy encompassing wide spectra of bioactivities against a number of infection‐causing agents. Their antimicrobial, antimalarial, antitumor, antiviral, and cardioprotective actions have achieved the attention of the pharmaceutical industry toward new design of drug formulations, for treatment and prevention of several infections. However, the mechanism of action of many peptide molecules has been still untapped. So in this regard, this paper reviews several peptide compounds by which they interfere with human pathogenesis. This knowledge is one of the key tools to be understood especially for the biotransformation of biomolecules into targeted medicines. The fact that different diseases have the capability to fight at different sites inside the body can lead to a new wave of increasing the chances to produce targeted medicines.     

Composition of the essential oil from Thymus moesiacus from Macedonia

Composition of the essential oil of Thymus moesiacus Velen. from Macedonia was examined by GC and GC-MS methods. The main constituents of the oil were geraniol, linalool, geranyl acetate, and terpenyl acetate.     

Decreased sensitivity of isolated hepatocytes from baby rats,from regenerating and from poisoned livers to phalloidin

Summary Isolated hepatocytes, prepared from 5 day old rats, from regenerating livers or from livers after poisoning with carbon tetrachloride, are less sensitive to phalloidin in vitro than hepatocytes from untreated adult controls. The time course of the reduced susceptibility to phalloidin was compared with the ability of hepatocytes to take up bile acids under various conditions. SDS-electrophoresis of cell lysates gave no evidence for decreased levels of actin in cells with reduced sensitivity to phalloidin. In contrast, there was a good relationship between the active uptake of bile acids and the sensitivity of hepatocytes to phalloidin. The decreased response of hepatocytes from baby rats, from regenerating livers or from poisoned livers to phalloidin is more probably related to differences in phalloidin uptake than to a reduced endowment with microfilamentous structures.This work is supported by the Deutsche Forschungsgemeinschaft     

张家界杜仲叶的化学成分研究

目的研究张家界产杜仲叶中的化学成分。方法采用聚酰胺吸附树脂、LSA-5B大孔吸附树脂、葡聚糖凝胶柱,高效液相色谱等分离方法进行分离纯化,并结合理化性质和波谱数据对分离得到的化合物进行结构鉴定。结果从张家界产的杜仲叶中分离得到了9个化合物,分别鉴定为：京尼平苷酸、绿原酸甲酯、绿原酸、咖啡酸、槲皮素木糖基葡萄糖苷、芦丁、槲皮素-3-O-β-D-葡萄糖苷、山奈酚-3-O-β-D-葡萄糖苷、槲皮素。结论其中绿原酸甲酯是首次从杜仲叶中分离得到。     

Drug release from laminated polymeric films prepared from aqueous latexes

Laminated films comprised of a drug-containing reservoir layer and a drug-free, rate-controlling membrane were prepared from aqueous latexes and investigated as an alternative drug delivery system to polymeric films cast from organic solvents. The reservoir layer was prepared by casting and drying the latex [copolymer of poly(ethylacrylate-methylmethacrylate) esters - Eudragit NE 30D (NE 30D)] containing the dissolved drugs (chlorpheniramine maleate, propranolol HCl, or salicylic acid). Monolithic solutions (salicylic acid-NE 30D) or dispersions (chlorpheniramine maleate or propranolol HCl-NE 30D) were formed, depending on the solubility of the drug in the polymer matrix. Zero-order drug release was achieved by laminating a second, drug-free latex film onto the reservoir layer. The rate-controlling membrane was either attached to, or cast directly onto the reservoir. The release rate was independent of loading for the monolithic dispersions, but dependent on loading for the monolithic solution. Release rates were enhanced by the addition of a hydrophilic polymer, hydroxypropyl methylcellulose, to the rate-controlling membrane. An inverse relationship was observed between the release rate and membrane thickness. The rate-controlling membrane, cast from organic polymer solutions, had a denser structure, resulting in slower drug release when compared with latex-cast laminates.