三尖杉酯碱和高三尖杉酯碱的生物活性及临床应用

概述了从粗榧料植物中分离的抗肿瘤生物碱三尖杉酯碱和高三尖杉酯碱和高三尖杉酯碱等的生物活性,包括其实验及临床药理、临床毒性、分子药理机制,化学研究和未来市场的研究展望。     

高三尖杉酯碱对HL60细胞诱导分化与对细胞膜通道影响相互关…

本实验显示,高三尖杉酯碱能使人白血病ＨＬ６０细胞诱导分化,随着药物浓度的增加,细胞诱导分化率亦明显增加,高三尖杉酯碱能抑制细胞膜Ｎａ＾＋,Ｋ＾＋ＡＴＰ酶活性,并能增加胸腺嘧啶核苷进入细胞,这些均可有是高三尖杉酯碱产生诱导分化的途径。     

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.     

锂和三尖杉酯碱对HL—60细胞增殖,分化和c—myc表达的影响

本研究利用细胞培养技术观察了氯化锂和三尖杉酯碱（ＨＴ）对ＨＬ－６０细胞增殖的影响,不同浓度的氯化锂对ＨＬ－６０细胞的集落形成和３Ｈ－ＴｄＲ参入均呈剂量依赖式抑制;三尖杉酯碱亦有类似的作用。在培养体系中加氯化锂和三尖杉酯碱时,对ＨＬ－６０细胞数及集落形成抑制作用与单用二者相比较有明显增加。用ＮＢＴ还原试验,氯化锂和三尖杉酯碱均促进ＨＬ－６０细胞的分化,小剂量氯化锂还能加强三尖杉酯碱对ＨＬ－６０细胞诱导分化作用。从氯化锂和三尖杉酯碱处理的ＨＬ－６０细胞中提取总ＲＮＡ,应用ＲＴ／ＰＣＲ检测ｃ－ｍｙｃ的表达,结果表明经氯化锂和三尖杉酯碱处理的ＨＬ－６０细胞ｃ－ｍｙｃ表达均降低,与未处理的ＨＬ－６０细胞ｃ－ｍｙｃ比较,说明氯化锂和三尖杉酯碱均能抑制ｃ－ｍｙｃ的表达,提示ｃ－ｍｙｃ很可能在白血病细胞增殖、分化中起调控作用。     

高三尖杉酯碱等四种药物的体外抑制乙肝病毒的实验研究

探讨高三尖杉酯碱、干扰素α1b、羟基喜树碱和诺氟沙星这四种药物对乙肝病毒的体外抑制作用.利用HBV全基因组转染的人肝癌细胞系(HepG2.2.15),采用CPE方法观察四种药物对HepG2.2.15的毒性大小,在最大无毒浓度下,将药物加入HepG2.2.15培养8天收集培养液,用ELISA法和荧光定量PCR法分别测定药物对细胞培养上清中HBsAg和HBeAg及HBV-DNA的抑制作用.结果显示在体外高三尖杉酯碱和干扰素α1b对乙肝病毒均有明显的抑制作用,羟基喜树碱对乙肝病毒仅有一定的抑制作用,诺氟沙星则在各浓度均未见对乙肝病毒有抑制作用.本实验证实了高三尖杉酯碱在体外对乙肝病毒有明显的抑制作用,为临床抗乙肝药物的研究提供了一定的理论依据.     

抗肿瘤药物三尖杉酯碱对HeLa细胞增殖的影响及其与CenpB基因的关系

以人子宫颈癌细胞株HeLa为对象,采用免疫印迹、流式细胞光度术和间接免疫荧光．流式细胞光度术等方法,分析三尖杉酯碱对细胞增殖周期、凋亡等的影响,并检测着丝粒蛋白CenpB基因表达的水平,进一步分析它与细胞增殖的关系及三尖杉酯碱的作用效应。结果表明：0．2μg/mL三尖杉酯碱作用时间的延长带来HeLa细胞G1期缩短、S期延长的时相变化趋势,与之相关的是G2期向G1期过渡的缓慢延迟;凋亡率呈现增加的趋势;相对于未处理的对照细胞,0．2μg/mL三尖杉酯碱的作用使CenpB蛋白表达水平降低,但不呈简单的时间函数关系,这可能是细胞周期检验点应对药物诱导作用的反馈调节的体现,而重要着丝粒结构蛋白CenpB的基因表达调节与之可能有明显的相关性。     

高三尖杉酯碱等四种药物的体外抑制乙肝病毒的实验研究

探讨高三尖杉酯碱、干扰素α1b、羟基喜树碱和诺氟沙星这四种药物对乙肝病毒的体外抑制作用。利用HBV全基因组转染的人肝癌细胞系(HepG2.2.15),采用CPE方法观察四种药物对HepG2.2.15的毒性大小,在最大无毒浓度下,将药物加入HepG2.2.15培养8天收集培养液,用ELISA法和荧光定量PCR法分别测定药物对细胞培养上清中HBsAg和HBeAg及HBV-DNA的抑制作用。结果显示在体外高三尖杉酯碱和干扰素α1b对乙肝病毒均有明显的抑制作用,羟基喜树碱对乙肝病毒仅有一定的抑制作用,诺氟沙星则在各浓度均未见对乙肝病毒有抑制作用。本实验证实了高三尖杉酯碱在体外对乙肝病毒有明显的抑制作用,为临床抗乙肝药物的研究提供了一定的理论依据。     

柔红霉素在人敏感和抗三尖杉酯碱的HL－60细胞中分布和积聚变化

应用激光扫描共焦显微镜和流式细胞术,研究柔红霉素在人敏感和抗三尖杉酯碱的ＨＬ－６０细胞中分布和积聚变化。柔红霉素１０μｇ／ｍｌ处理细胞１小时,激光扫描共焦显微镜观察到：在敏感ＨＬ－６０细胞中,柔红霉素主要分布于细胞核中;而在抗性细胞中,主要分布于细胞一侧。逆转抗药性的药物维拉帕米不改变柔红霉素在抗性细胞中的核质分布。流式细胞术显示：三尖杉酯碱和蛋白激酶Ｃ激活剂佛波脂处理细胞,使柔红霉素在抗性细胞内积聚降低;而粉防己碱和维拉帕米处理细胞１小时,柔红霉素在抗性细胞内积聚明显增加,但维拉帕米处理２４小时,反而使积聚降低。结果表明：抗三尖杉酯碱的ＨＬ－６０细胞改变桑红霉素的胞内分布,降低细胞内的积聚是抗药性的机制之一。     

高三尖杉酯碱对HL_(60)细胞诱导分化与对细胞膜通道影响相互关系的研究

本实验显示,高三尖杉酯碱能使人白血病HL_(50)细胞诱导分化。随着药物浓度的增加。细胞诱导分化率亦明显增加。高三尖杉酯破能抑制细胞膜Na~ ,K~ ATP酶活性(IG_(50)值为156±27μm),并能增加胸腺嘧啶核苷([~3H]TdR)进入细胞。这些均可能是高三尖杉酯碱产生诱导分化的途径。     

台湾三尖杉碱绝对构型研究

从高山三尖杉(Cephalotaxus fortunei Hook.f.var.alpina Li)的枝叶中分离得到了台湾三尖杉碱(wilsonine)。通过X-衍射方法,确定了其绝对构型。     

Selective adsorption of plant products

The results from this study demonstrate that neutral resins can selectively concentrate specific indole alkaloids from dilute aqueous mixtures. Adsorption was observed to provide a one to two order of magnitude improvement in concentrating these alkaloids, as compared to an equivalent single-staged extraction. Since the sorption correlates with the concentration of the neutral form of the dissolved alkaloid, the adsorption is dependent on both the pH of the medium and the pKa of the alkaloids. Also, adsorption is dependent on specific sorbent-sorbate characteristics. In this study, by exploiting differences in the acid-base properties and the sorption characteristics of specific indole alkaloids, separation factors of 20-30 were observed. Although this behavior is valuable for analytical separations, the present study considers the application to the primary recovery of alkaloids from plant cell processes. Throughout this study it was also observed that the polycarboxylic ester resin (XAD-7) behaved quite differently from the styrene divinylbenzene resin (XAD-4). Despite a lower capacity, the XAD-7 resin was considerably more selective in adsorbing indole alkaloids than the XAD-4 resin. These alkaloids could also be desorbed from the XAD-7 resin by acidifying the liquid, while organic solvents were required to desorb these compounds from the XAD-4 resin.     

GC-MS of Crinum latifolium L. alkaloids

A GC-MS analysis of underivatized alkaloids from leaves of Crinum latifolium was performed. From the identified 15 alkaloids, 9 were found for the first time in this plant. Almost all alkaloids belonged to the crinane type. Substantial changes in the methylation and oxidation pattern of the alkaloids at and after flowering were observed.     

Manzamines

Manzamines are a unique class of β-carboline marine alkaloids with an unusual tetra- or pentacyclic system. These alkaloids have shown a variety of bioactivities against infectious diseases, cancer and inflammatory diseases. The greatest potential for the manzamine alkaloids appears to be against malaria, with improved potency relative to chloroquine and artemisinin. Over 80 manzamine-related alkaloids have been isolated from more than 16 species of marine sponges belonging to five families distributed from the Red Sea to Indonesia, which suggests a possible microbial origin for manzamine alkaloids. The current review summarizes marine literature, focusing on the biological activities of manzamines, the possible microbial origin of this class of compounds and the Red Sea as a possible source of manzamines from biosynthetic gene clusters of Red Sea microbes.     

Cellular distribution of alkaloids and their translocation via phloem and xylem: the importance of compartment pH

The physico‐chemical background of alkaloid allocation within plants is outlined and discussed exemplarily for pyrrolizidine alkaloids (PAs) and nicotine. The trigger for this discourse is the finding that, for example, PAs, which are taken up from the soil, are translocated in the xylem, whereas – when genuinely present in plants – they are allocated as N‐oxides via phloem. Special emphasis is put on the impact of different pH values in certain compartments, as this entails significant changes in the relative lipophilic character of alkaloids: tertiary alkaloids diffuse readily through biomembranes, while the corresponding protonated alkaloids are retained in acidic compartments, i.e. vacuoles or xylem. Therefore, this phenomenon, well known as the ‘ion trap mechanism’, is also relevant for long‐distance transport of alkaloids. Any efficient allocation of typical tertiary alkaloids within the phloem can thus be excluded. In contrast, due to their strongly increased hydrophilic properties, alkaloid‐N‐oxides or quarternary alkaloids cannot diffuse through biomembranes and, consequently, would be retained in the acidic xylem during translocation. The major aim of this paper is to sharpen the mind for the chemical peculiarities of alkaloids and to consider them adequately in forthcoming investigations on allocation of alkaloids.     

苦豆子生物碱对萝卜蚜的毒力及其对几种酯酶的影响

苦豆子Sophora alopecuroids(L.)的次生代谢物质为喹诺里西定生物碱类。本研究明确了该生物碱中的野靛碱对萝卜蚜(Lipaphis erysimi)有很高的毒杀作用,对其无翅成蚜的致死中浓度(LC₅₀浸渍法)为(432.59±2.12)mg/L,优于著名的杀蚜生物碱毒黎碱和烟碱,两者对该试虫的LC₅₀分别为(684.70±2.28)mg/L和(1090.65±2.01)mg/L。用小菜蛾(Plutella xylostella)幼虫作试虫,得知苦豆子7种主要生物碱对昆虫的乙酰胆碱酯酶(AChE)有抑制作用,其抑制程度排序为：总碱>野靛碱>槐胺碱>槐定碱>槐果碱>氧化苦参碱>苦参碱>苦豆碱。野靛碱和苦豆碱对a-乙酸萘酯酶、a-乙酸萘酯羧酸酯酶及酯酶同功酶的活性亦表现不同程度的抑制作用。     

New skeletons and new concepts in Amaryllidaceae alkaloids

The Amaryllidaceae alkaloids, represent a group of isoquinoline alkaloids, which are produced almost solely by members of the Amaryllidaceae family. The alkaloids of this family have attracted considerable amount of interest due to some important pharmacological activities they were shown to possess. In the last decade, our phytochemical studies on four Galanthus (Amaryllidaceae) species of Turkish origin have yielded quite a number of new alkaloids with diverse structures. Among these alkaloids, gracilines and plicamines constitute two new subgroups for the Amaryllidaceae alkaloids. The gracilines contain an incorporated 10b,4a-ethanoiminodibenzo[b,d]pyrane skeleton. The plicamines are dinitrogenous compounds, where the oxygen atom in position 7 of a tazettine skeleton is replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety. One of the new alkaloids, galanthindole, which possesses a nonfused indole ring, unlike the already known subgroups of Amaryllidaceae alkaloids, may be considered as the prototype of a third new subgroup of the Amaryllidaceae alkaloids. Additionally, two known isoquinoline alkaloids which do not possess one of the established skeletons of the Amaryllidaceae alkaloids, namely ( − )-capnoidine and (+)-bulbocapnine, have been isolated from a Turkish Galanthus species. Totally, 21 new, 20 known alkaloids and 2 known lignans have been characterized. In this review, the isolation and structure elucidation of these compounds with interesting chemical structures are described.     

The effect of varying alkaloid concentrations on the feeding behavior of gypsy moth larvae, Lymantria dispar (L.) (Lepidoptera: Lymantriidae)

Nine alkaloids (acridine, aristolochic acid, atropine, berberine, caffeine, nicotine, scopolamine, sparteine, and strychnine) were evaluated as feeding deterrents for gypsy moth larvae (Lymantria dispar (L.); Lepidoptera: Lymantriidae). Our aim was to determine and compare the taste threshold concentrations, as well as the ED₅₀ values, of the nine alkaloids to determine their potency as feeding deterrents. The alkaloids were applied to disks cut from red oak leaves (Quercus rubra) (L.), a plant species highly favored by larvae of this polyphagous insect species. We used two-choice feeding bioassays to test a broad range of biologically relevant alkaloid concentrations spanning five logarithmic steps. We observed increasing feeding deterrent responses for all the alkaloids tested and found that the alkaloids tested exhibited different deterrency threshold concentrations ranging from 0.1 to 10 mM. In conclusion, it appears that this generalist insect species bears a relatively high sensitivity to these alkaloids, which confirms behavioral observations that it avoids foliage containing alkaloids. Berberine and aristolochic acid were found to have the lowest ED₅₀ values and were the most potent antifeedants. Handling Editor: Joseph Dickens.     

The production of alkaloids in Annona cacans seedlings is affected by the application of GA4+7 + 6-Benzyladenine

The Annonaceae family presents alkaloids with ecological functions and pharmacological interest. This is the first study to evaluate if the application of plant growth regulators to seeds of this family alters the production of alkaloids over time from germination. This study was carried out in four sequential stages of Annona cacans Warm. development from the resumption of embryo during seed imbibition with the application of plant regulator GA₄₊₇ + 6-Benzyladenine. The concentration of total alkaloids was quantified using the oxoaporphine alkaloid liriodenine as reference standard. In addition, the liriodenine concentration was measured and the profile evaluated by ultra-high-performance liquid chromatography (UHPLC). Results have shown that alkaloids are present in all phases and in all tissues, at higher concentrations in roots (up to 100 times). The proportion of total alkaloids and liriodenine was modified in response to the application of plant regulators. Roots doubled the content of alkaloids and liriodenine. In cotyledonary leaves, the amount of total alkaloids decreased; however, liriodenine remained unchanged. Our results have shown that the use of plant growth regulators based on gibberellins and cytokinins modified the production of alkaloids in tissues in a specific way.     

Alkaloids in Bulgarian Pancratium maritimum L

A GC/MS analysis of alkaloids from leaves, bulbs and roots of Pancratium maritimum was performed. From the identified 16 alkaloids, 5 alkaloids were reported for the first time for this plant. Several compounds with pharmacological activity were found. Haemanthamine was main alkaloid in the leaves and bulbs whereas galanthane was found to be main alkaloid in roots.     

Independent recruitment of a flavin-dependent monooxygenase for safe accumulation of sequestered pyrrolizidine alkaloids in grasshoppers and moths

Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine alkaloids to their respective N-oxide, enabling the insects to avoid high concentrations of toxic pyrrolizidine alkaloids in the hemolymph. We have identified a pyrrolizidine alkaloid N-oxygenase, which is a flavin-dependent monooxygenase, of the grasshopper Zonocerus variegatus. After heterologous expression in E. coli, this enzyme shows high specificity for pyrrolizidine alkaloids of various structural types and for the tropane alkaloid atropine as substrates, a property that has been described previously for a pyrrolizidine alkaloid N-oxygenase of the arctiid moth Grammia geneura. Phylogenetic analyses of insect flavin-dependent monooxygenase sequences suggest that independent gene duplication events preceded the establishment of this specific enzyme in the lineages of the grasshoppers and of arctiid moths. Two further flavin-dependent monooxygenase sequences have been identified from Z. variegatus sharing amino acid identities of approximately 78% to the pyrrolizidine alkaloid N-oxygenase. After heterologous expression, both enzymes are also able to catalyze the N-oxygenation of pyrrolizidine alkaloids, albeit with a 400-fold lower specific activity. With respect to the high sequence identity between the three Z. variegatus sequences this ability to N-oxygenize pyrrolizidine alkaloids is interpreted as a relict of a former bifunctional ancestor gene of which one of the gene copies optimized this activity for the specific adaptation to pyrrolizidine alkaloid containing food plants.