野生石蒜中石蒜碱和加兰他敏的分离研究

采用大孔树脂法纯化从野生石蒜中提取的石蒜总碱,用高速逆流色谱法进行分离,用高效液相色谱法进行检测。结果表明,高速逆流色谱法分离石蒜碱和加兰他敏的最佳溶剂体系为:正己烷∶乙酸乙酯∶甲醇∶水=3∶7∶3.5∶6.5(体积比),分离后石蒜碱的纯度为95.36%,加兰他敏的纯度为91.67%。高速逆流色谱法可以同时将石蒜总碱中石蒜碱和加兰他敏分离,分离效果良好。     

Anti‐Dengue‐Virus Activity and Structure–Activity Relationship Studies of Lycorine Derivatives

Dengue is a systemic viral infection that is transmitted to humans by Aedes mosquitoes. No vaccines or specific therapeutics are currently available for dengue. Lycorine, which is a natural plant alkaloid, has been shown to possess antiviral activities against flaviviruses. In this study, a series of novel lycorine derivatives were synthesized and assayed for their inhibition of dengue virus (DENV) in cell cultures. Among the lycorine analogues, 1‐acetyllycorine exhibited the most potent anti‐DENV activity (EC₅₀=0.4 μM ) with a reduced cytotoxicity (CC₅₀>300 μM ), which resulted in a selectivity index (CC₅₀/EC₅₀) of more than 750. The ketones 1‐acetyl‐2‐oxolycorine (EC₅₀=1.8 μM ) and 2‐oxolycorine (EC₅₀=0.5 μM ) also exhibited excellent antiviral activities with low cytotoxicity. Structure–activity relationships for the lycorine derivatives against DENV are discussed. A three‐dimensional quantitative structure–activity relationship model was established by using a comparative molecular‐field analysis protocol in order to rationalize the experimental results. Further modifications of the hydroxy group at the C1 position with retention of a ketone at the C2 position could potentially lead to inhibitors with improved overall properties.     

An ATP-Binding Cassette Transporter,LaABCB11, Contributes to Alkaloid Transport in Lycoris aurea

As a kind of Amaryllidaceae alkaloid which is accumulated in the species of Lycoris plants, lycorine has a range of physiological effects. The biosynthesis pathway of lycorine has been partly revealed, but the transport and accumulation mechanisms of lycorine have rarely been studied. In this study, an ATP-binding cassette (ABC) transporter from Lycoris aurea (L’Hér) Herb., namely LaABCB11, was cloned and functionally characterized. Heterologous expression showed that LaABCB11 transported lycorine in an outward direction, increased the tolerance of yeast cells to lycorine, and caused a lower lycorine accumulation in transformants than control or mutant in yeast. LaABCB11 is associated with the plasma membrane, and in situ hybridization indicated that LaABCB11 was mainly expressed in the phloem of leaves and bulbs, as well as in the cortical cells of roots. These findings suggest that LaABCB11 functions as a lycorine transport and it might be related to the translocation and accumulation of lycorine from the leaves and bulbs to the roots.     

石蒜属植物中石蒜碱的研究进展

石蒜碱(Lycorine)是传统药用植物石蒜中含量较高的生物碱成分,具有抗炎、抗病毒、抗疟疾、抑制乙酰胆碱酯酶、保护心血管以及诱导肿瘤细胞凋亡等多种作用。本文对国内外在石蒜属植物中石蒜碱的结构、提取与纯化方法等方面的研究进行了综述,为石蒜属资源的进一步开发利用提供参考。     

石蒜中石蒜碱的超声波提取研究

以野生石蒜为原料,以乙醇为提取剂,研究了石蒜中石蒜碱的超声波法提取工艺条件.通过单因素实验和正交实验确定超声波法提取石蒜中石蒜碱的最佳工艺条件为:超声波功率300 W、提取温度55℃、提取时间2.0h、料液比1∶ 5(g:mL)、提取2次,在此条件下,产率为0.464％、提取率为94.7％.与传统的溶剂法相比,超声波法...     

Towards a Molecular Understanding of the Biosynthesis of Amaryllidaceae Alkaloids in Support of Their Expanding Medical Use

The alkaloids characteristically produced by the subfamily Amaryllidoideae of the Amaryllidaceae, bulbous plant species that include well know genera such as Narcissus (daffodils) and Galanthus (snowdrops), are a source of new pharmaceutical compounds. Presently, only the Amaryllidaceae alkaloid galanthamine, an acetylcholinesterase inhibitor used to treat symptoms of Alzheimer’s disease, is produced commercially as a drug from cultivated plants. However, several Amaryllidaceae alkaloids have shown great promise as anti-cancer drugs, but their further clinical development is restricted by their limited commercial availability. Amaryllidaceae species have a long history of cultivation and breeding as ornamental bulbs, and phytochemical research has focussed on the diversity in alkaloid content and composition. In contrast to the available pharmacological and phytochemical data, ecological, physiological and molecular aspects of the Amaryllidaceae and their alkaloids are much less explored and the identity of the alkaloid biosynthetic genes is presently unknown. An improved molecular understanding of Amaryllidaceae alkaloid biosynthesis would greatly benefit the rational design of breeding programs to produce cultivars optimised for the production of pharmaceutical compounds and enable biotechnology based approaches.     

一步法提取石蒜中加兰他敏和石蒜碱

采用正交实验法对石蒜中加兰他敏和石蒜碱的一步法提取工艺进行研究,考察乙醇质量分数、提取温度、固液比及提取时间对石蒜中加兰他敏和石蒜碱得率的影响。结果表明,在浸提3次条件下,最佳工艺条件为:75%乙醇、提取温度65℃、提取时间4 h、固液比1∶6(g/mL),加兰他敏和石蒜碱的得率分别为0.04793%和0.03643%。