Honeydew analysis for detecting phloem transport of plant natural products

Analysis of honeydew excreted by various sap-sucking insects indicated the presence of certain plant secondary constituents in the phloem of their host plants. Honeydew excreted by mealybugs (Pseudococcus longispinus), living onCastanospermum australe, contained the indolizidine alkaloid castanospermine, a potent -glucosidase inhibitor. Similarly, honeydew from green peach aphids (Myzus persicae), feeding onSenecio vulgaris flower buds, contained the pyrrolizidine alkaloid senecionine, itsN-oxide, and hydrolytic products including retronecine. Cardenolides were detected in the honeydew of oleander aphids (Aphis nerii) feeding on oleander (Nerium oleander), indicating that these compounds are translocated in the phloem. On the other hand, honeydew from greenbugs (Schizaphis graminum), feeding on barley, lacked gramine or related indole metabolites. Similarly MBOA, the breakdown product of DIMBOA, was not detected in the honeydew of greenbugs living on DIMBOA-containing wheat.     

Distribution of amathamide alkaloids within single colonies of the bryozoanAmathia wilsoni

The content and distribution of amathamide alkaloids within single colonies of the bryozoanAmathia wilsoni (Ctenostomata) varied depending on the location in the colony. Three colonies in all, collected from the same site at the same time, were analyzed and gave very similar results. The outermost, more exposed, tips of the colony had an alkaloid content of nearly 9% of dry weight, while basal parts were apparently devoid of alkaloids. Samples taken midway between tips and base yielded intermediate concentrations of about 1%. Very little variation in the proportions of individual amathamides A, B, C, E occurred between exposed tips of the colonies. However, some differences in ratios were found between tips from exposed and more protected regions.     

Determination of contents of eight alkaloids in fruits of Macleaya cordata （Willd） R. Br. from different habitats and antioxidant activities of extracts

A reliable ultrasound-assisted extraction (UAE) method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata (Willd) R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients (R2>0.999 6) and recoveries (from 97.3% to 104.9%) were acceptable. l,l-diphenyl-2-picrylhydrazyl (DPPH) method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant activity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.     

Enzymatic Kinetic Resolution of 2-Piperidineethanol for the Enantioselective Targeted and Diversity Oriented Synthesis

2-Piperidineethanol (1) and its corresponding N-protected aldehyde (2) were used for the synthesis of several natural and synthetic compounds. The existence of a stereocenter at position 2 of the piperidine skeleton and the presence of an easily-functionalized group, such as the alcohol, set 1 as a valuable starting material for enantioselective synthesis. Herein, are presented both synthetic and enzymatic methods for the resolution of the racemic 1, as well as an overview of synthesized natural products starting from the enantiopure 1.     

Sanguinaria canadensis: Traditional Medicine,Phytochemical Composition,Biological Activities and Current Uses

Sanguinaria canadensis, also known as bloodroot, is a traditional medicine used by Native Americans to treat a diverse range of clinical conditions. The plants rhizome contains several alkaloids that individually target multiple molecular processes. These bioactive compounds, mechanistically correlate with the plant’s history of ethnobotanical use. Despite their identification over 50 years ago, the alkaloids of S. canadensis have not been developed into successful therapeutic agents. Instead, they have been associated with clinical toxicities ranging from mouthwash induced leukoplakia to cancer salve necrosis and treatment failure. This review explores the historical use of S. canadensis, the molecular actions of the benzophenanthridine and protopin alkaloids it contains, and explores natural alkaloid variation as a possible rationale for the inconsistent efficacy and toxicities encountered by S. canadensis therapies. Current veterinary and medicinal uses of the plant are studied with an assessment of obstacles to the pharmaceutical development of S. canadensis alkaloid based therapeutics.     

钩吻素甲的气相色谱-质谱分析

取 5 g生物组织绞成均浆状 ,用甲醇、水和盐酸混合液进行溶解和液 -液提取生物碱中的钩吻素甲。用急速升温法减少了样品中杂质对色谱 -质谱测量的影响。在最优化的 GC/ MS条件下获得了钩吻素甲的主要特征峰为 m/ z1 0 8(基峰 )、m/ z2 5 1、m/ z2 79和 m/ z3 2 2 (分子离子 M+ 峰 )。由此确定了钩吻素甲的分子式C2 0 H2 2 N2 O2 、分子量 3 2 2 Da和分子结构。提供了适合司法检验该类毒物的提取和分析方法     

New Mono‐Quarternized Bis‐Cinchona Alkaloid Ligands for Asymmetric Dihydroxylation of Olefins in Aqueous Medium: Unprecedented High Enantioselectivity and Recyclability

New mono‐quaternized allyl bromide salts of bis‐Cinchona alkaloid ligands, [(QD)₂PHAL‐Allyl]Br and [(QN)₂PHAL‐Allyl]Br, have been synthesized which can be converted into their highly water‐soluble multihydroxylated derivatives under asymmetric dihydroxylation (AD) conditions and, thus, easily recovered by a simple extraction method after reaction and reused. These mono‐quaternized ligands exhibited superior catalytic efficiency to their neutral counterparts such as (DHQD)₂PHAL and (DHQ)₂PHAL for the AD reactions of mono‐ and disubstituted styrenes under Upjohn conditions. Merely 0.1 mol % of osmium was enough to complete the reactions of mono‐ and disubstituted styrenes and, moreover, these ligands showed the highest enantioselectivities (e.g., for styrene, 97 % ee with [(QD)₂PHAL‐Allyl]Br) among those ever achieved under Upjohn conditions.     

野罂粟总生物碱对急性气管-支气管炎止咳效应的探索性临床研究

目的: 评价野罂粟总生物碱制剂对急性气管-支气管炎肺气上逆证的止咳效应。方法: 随机、双盲、安慰剂平行对照、叠加试验(add-on design) 设计。观察急性气管-支气管炎肺气上逆证共89 例, 其中野罂粟总生物碱组45 例, 安慰剂对照组44 例。结果: 试验组和安慰剂组服药后咳嗽明显减轻者分别占75.56 %和77.27 %(P=0.8487), 咳嗽明显减轻者的减轻时间分别为19.55±18.57 和25.27±19.60 h (P=0.1993);d 3 咳嗽消失率分别为33.33 %和36.36 %(P=0.7642);咳嗽记分值平均等级分别下降3.53 和4.16(P=0.2786) 。结论: 急性气管-支气管炎中度及重度咳嗽少痰肺气上逆证患者在使用头孢克洛缓释胶囊治疗的基础上, 野罂粟总生物碱制剂没有明显的止咳、平喘作用。     

单萜吲哚生物碱士的宁的合成研究进展

士的宁属于单萜吲哚生物碱,是中药马钱子的主要有效成分,具有复杂的化学结构,包含7个环系和6个手性中心。Woodward经典合成代表了有机合成领域的里程碑。经过半个多世纪的努力已有十几个科研小组以不同策略对士的宁分子进行全合成,丰富和发展了有机合成工艺。士的宁是试验新反应和新合成策略的重要目标。按照成环方式对单萜吲哚生物碱士的宁的多种合成途径进行了总结,以促进相关研究。     

Amaryllidaceae Alkaloids of Norbelladine-Type as Inspiration for Development of Highly Selective Butyrylcholinesterase Inhibitors: Synthesis,Biological Activity Evaluation,and Docking Studies

Alzheimer’s disease (AD) is a multifactorial neurodegenerative condition of the central nervous system (CNS) that is currently treated by cholinesterase inhibitors and the N-methyl-d-aspartate receptor antagonist, memantine. Emerging evidence strongly supports the relevance of targeting butyrylcholinesterase (BuChE) in the more advanced stages of AD. Within this study, we have generated a pilot series of compounds (1–20) structurally inspired from belladine-type Amaryllidaceae alkaloids, namely carltonine A and B, and evaluated their acetylcholinesterase (AChE) and BuChE inhibition properties. Some of the compounds exhibited intriguing inhibition activity for human BuChE (hBuChE), with a preference for BuChE over AChE. Seven compounds were found to possess a hBuChE inhibition profile, with IC₅₀ values below 1 µM. The most potent one, compound 6, showed nanomolar range activity with an IC₅₀ value of 72 nM and an excellent selectivity pattern over AChE, reaching a selectivity index of almost 1400. Compound 6 was further studied by enzyme kinetics, along with in-silico techniques, to reveal the mode of inhibition. The prediction of CNS availability estimates that all the compounds in this survey can pass through the blood-brain barrier (BBB), as disclosed by the BBB score.