New organic bases from amazonian Banisteriopsis caapi

Three new bases were isolated from Banisteriopsis caapi; they are harmine N-oxide, harmic acid methyl ester (methyl 7-methoxy-β-carboline 1-carboxylate) and harmalinic acid (7-methoxy-3,4-dihydro-β-carboline 1-carboxylic acid).     

Alcaloïdes d'Alstonia vitiensis var. Novo ebudica monachino

Five alkaloids have been isolated from Alstonia vitiensis: pleïocarpamine, vincorine, cabucraline, alstovine (11-methoxycompactinervine) and quaternoxine; the latter two are new alkaloids.     

Orientalidine and isothebaine from cell cultures of Papaver bracteatum

Orientalidine, isothebaine and sanguinarine were isolated from callus cultures of Papaver bracteatum when grown on M & S medium with various horm     

New peptide alkaloids from Hovenia dulcis and H. tomentella

From the root bark of Hovenia dulcis Thunb. and H. tommentella (Makino) Nakai (Rhamnaceae), three peptide alkaloids, frangulanine, hovenins-A and -B have been isolated. Hovenin-A has been shown to be des-N-methylfrangulanine (II).     

Bisbenzylisoquinoline alkaloids and P-glycoprotein function: A structure activity relationship study

Conflicts with the notion that specific substrate interactions were required in the control of reaction path in active transport systems, P-glycoprotein showed extraordinarily low specificity. Therefore, overexpression P-glycoprotein excluded a large number of anticancer agents from cancer cells, and multidrug resistance happened. Several kinds of bisbenzylisoqunoline alkaloids were reported to modulate P-glycoprotein function and reverse drug resistance. In order to provide more information for their structure activity relationship on P-glycoprotein function, the effects of tetrandrine, isotetrandrine, fangchinoline, berbamine, dauricine, cepharanthine and armepavine on the P-glycoprotein function were compared by using daunorubicin-resistant leukemia MOLT-4 cells in the present study. Among them, tetrandrine exhibited the strongest P-glycoprotein inhibitory effect, followed with fangchinoline and cepharanthine, and subsequently with berbamine or isotetrandrine. However, dauricine and armepavine showed little influence on the P-glycoprotein function. These data revealed that the 18-membered ring of the bisbenzylisoquinoline alkaloids maintained the P-glycoprotein inhibitory activity, suggesting that double isoquinoline units connected by two oxygen bridges were indispensable. Moreover, stereo-configuration of bisbenzylisoquinoline 3D structures determined their inhibitory activities, which provided a new viewpoint to recognize the specificity of binding pocket in P-glycoprotein. Our data also indicated that 3D chemical structure was more sensitive than 2D to predict the P-glycoprotein inhibitory-potencies of bisbenzylisoqunoline alkaloids.     

Aporphine Alkaloids from Ocotea puberula with Anti-Trypanosoma Cruzi Potential – Activity of Dicentrine-β-N-Oxide in the Plasma Membrane Electric Potentials

One new aporphine, dicentrine-β-N-oxide ( 1 ), together with five related known alkaloids dehydrodicentrine ( 2 ), predicentrine ( 3 ), N-methyllaurotetanine ( 4 ), cassythicine ( 5 ), and dicentrine ( 6 ) were isolated from the leaves of Ocotea puberula (Lauraceae). Antiprotozoal activity of the isolated compounds was evaluated in vitro against trypomastigote forms of Trypanosoma cruzi. Among the tested compounds, alkaloid 1 exhibited higher potential with EC₅₀ value of 18.2 μM and reduced toxicity against NCTC cells (CC₅₀>200 μM – SI>11.0), similar to positive control benznidazole (EC₅₀ of 17.7 μM and SI=10.7). Considering the promising results of dicentrine-β-N-oxide ( 1 ) against trypomastigotes, the mechanism of parasite death caused by this alkaloid was investigated. As observed, this compound reached the plasma membrane electric potential directly after 2 h of incubation and triggered mitochondrial depolarization, which probably leads to trypomastigote death. Therefore, dicentrine-β-N-oxide ( 1 ), reported for the first time in this work, can contribute to future works for the development of new trypanocidal agents.     

响应面法优化飞龙掌血中总生物碱的提取工艺

以飞龙掌血（Toddalia asiatica（L.）Lam.）的根为实验材料,以总生物碱的含量为检测指标,应用响应面法对飞龙掌血中总生物碱的提取工艺进行了优化。结果显示,当提取条件为乙醇体积分数74.76%、料液比20∶1和提取时间32.87 min时,飞龙掌血提取物中总生物碱的理论含量值可达11.09 mg/g,总生物碱含量达到最高值。按照最佳提取工艺条件进行验证,3次平行实验的均值为（10.74 ±0.18）mg/g,与理论值差异较小,表明利用响应面法来优化飞龙掌血中总生物碱的最佳提取工艺模型拟合良好,具有一定实用价值。     

A potential role of alkaloid extracts from Salsola species (Chenopodiaceae) in the treatment of Alzheimer's disease

From the aerial parts of Salsola oppositofolia, S. soda and S. tragus an alkaloid extract was obtained and tested to evaluate antioxidant and anti-cholinesterase activities. The in vitro study of the antioxidant activity by the DPPH method revealed a significant activity of Salsola alkaloid extracts with IC₅₀ values ranging from 16.30 μg/mL for S. oppositifolia to 26.17 μg/mL for S. tragus. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. S. tragus alkaloid extract exerted the highest inhibitory activity against AChE (IC₅₀ of 30.2 μg/mL) and BChE (IC₅₀ of 26.5 μg/mL). Interestingly, S. soda and S. oppositifolia exhibited a selective inhibitory activity against BChE with IC₅₀ values of 34.3 μg/mL and 32.7 μg/mL, respectively. Tetrahydroisoquinoline alkaloids were identified and quantified by GC/MS analysis.     

Analgesic and anti-inflammatory studies of cyclopeptide alkaloid fraction of leaves of Ziziyphus nummularia

Ziziyphus nummularia (family: Rhamnaceae) is a thorny small bush, grows in abundance in the grazing lands of the arid areas of Rajasthan, India. It is an important ethnomedicinal plant of the Thar Desert; local inhabitants use every part of the plant as medicine. Kernels are prescribed in pregnancy as soporific, antiemetic and for relieving abdominal pain. The insect gall is powered and given orally with water to cure bone fracture. Crushed root is applied on the paining shoulder of the bullock. The decoction of leaves is used for the treatment of cough and cold; leaves are also regarded as diaphoretic and prescribed in typhoid. Paste of leaves is used for healing of cuts, boils and cutaneous disease. It is widely used in pain and inflammatory conditions.Z. nummularia contains a unique group of alkaloids known as cyclopeptide alkaloids, in continuation of our work carried out on the leaves of Z. nummularia, present study was initiated to explore antiinflammatory and analgesic potential of cyclopeptide alkaloids isolated from the leaves of Z. nummularia (IFZN). Anti-inflammatory activity was tested against rat paw oedema, mouse peritonitis and cotton pellet granuloma. For screening of analgesic activity, acetic acid induced writhing, tail flick and hot plate test were performed.IFZN 30 mg/kg shows the anti-oedematogenic effect against paw oedema induced by carrageenan, dextran, serotonin and histamine; IFZN 20 and 30 mg/kg were found to have highly significant anti-nociceptive effects.Result of pharmacological studies indicated that IFZN is a potent and efficacious analgesic agent. The analgesic activity of IFZN is mediated by the peripheral as well as central pathways.