多指标综合评分法优化痛风巴布剂的醇提工艺

目的 优选痛风巴布剂的最佳提取工艺。方法 以青藤碱、总生物碱的含量和干浸膏得率为评价指标,采用正交设计试验,考察乙醇浓度、乙醇用量、提取时间和提取次数对提取结果的影响,确定痛风巴布剂处方药材的最佳提取工艺。结果 痛风巴布剂的最佳提取工艺为65%乙醇,提取3次,每次6倍量溶剂,提取总时间为1.5 h,在该工艺条件下得到的青藤碱含量、总生物碱含量和干浸膏得率分别为2.79 mg·g^-1、1.22%和13.06%。结论 优选的醇提工艺稳定、可行。     

Molecular aspects on the interaction of protoberberine, benzophenanthridine, and aristolochia group of alkaloids with nucleic acid structures and biological perspectives

Alkaloids occupy an important position in chemistry and pharmacology. Among the various alkaloids, berberine and coralyne of the protoberberine group, sanguinarine of the benzophenanthridine group, and aristololactam-beta-d-glucoside of the aristolochia group have potential to form molecular complexes with nucleic acid structures and have attracted recent attention for their prospective clinical and pharmacological utility. This review highlights (i) the physicochemical properties of these alkaloids under various environmental conditions, (ii) the structure and functional aspects of various forms of deoxyribonucleic acid (DNA) (B-form, Z-form, H(L)-form, protonated form, and triple helical form) and ribonucleic acid (RNA) (A-form, protonated form, and triple helical form), and (iii) the interaction of these alkaloids with various polymorphic DNA and RNA structures reported by several research groups employing various analytical techniques like absorbance, fluorescence, circular dichroism, and NMR spectroscopy; electrospray ionization mass spectrometry, thermal melting, viscosity, and DNase footprinting as well as molecular modeling and thermodynamic studies to provide detailed binding mechanism at the molecular level for structure-activity relationship. Nucleic acids binding properties of these alkaloids are interpreted in relation to their biological activity.     

Neolamellarin A 及其相关吡咯类海洋生物碱合成和结构改造研究进展

Lamellarins 是一类从海洋无脊椎动物中分离的具有生物活性的吡咯生物碱, Neolamellarins,Lukianols, Storniamides, Ningalins 等结构新颖的生物碱都属于该家族。Lamellarins 吡咯类生物碱合成的关键是1,3,4-三取代吡咯环的构建,主要策略有分步构建与一锅法构建吡咯环两类,从中涌现了多种极富创新性与可行性的合成方法,既从结构多样性合成的角度丰富了化合物库,同时又以生物活性为导向提高了该类化合物的生物活性。本文对其结构特点、合成、生物活性进行了综述。     

黄柏炮制前后生物碱和柠檬苦素类成分的变化研究

目的分析黄柏在不同温度下进行模拟炮制后,不同炮制品中主要化学成分的变化情况,为解析黄柏不同炮制品的科学内涵提供参考依据。方法采用高效液相色谱法检测黄柏不同炮制品中生物碱类成分小檗碱、小檗红碱、黄柏碱、药根碱、巴马汀和柠檬苦素类成分黄柏内酯、黄柏酮。生物碱类成分检测的色谱条件为Ecosil C18色谱柱(250 mm×4.6 mm,5μm);流动相:乙腈–0.1%磷酸水(50∶50)(每100 m L 0.1%磷酸水加十二烷基硫酸钠0.4 g);检测波长:284 nm;体积流量:1m L/min;柱温:35℃;进样量:3μL。柠檬苦素类成分检测的色谱条件为Ecosil C18色谱柱(250 mm×4.6 mm,5μm);流动相:乙腈–水–磷酸(45∶55∶0.2);检测波长:210 nm;体积流量:1 m L/min;柱温:35℃;进样量:10μL。结果直接烘制品、水润烘制品、酒润烘制品、盐水润烘制品在最佳炮制温度160℃下,总生物碱的质量分数分别为3.009 6%、2.993 1%、3.989 6%、4.537 9%,其中酒润烘制品和盐水润烘制品均较生品3.528 2%高,提示黄柏经辅料炮制后有利于生物碱类成分的溶出,且增加溶出率的是辅料盐和酒,而非水。当炮制温度达到160℃以上时,在相应炮制温度下的直接烘制品和水润烘制品中柠檬苦素类成分质量分数未见明显差异,酒润烘制品和盐水润烘制品随着温度的升高其质量分数相差较大,提示水对黄柏炮制过程中的柠檬苦素类成分基本没有影响,酒、盐炮制具有影响。结论黄柏经炮制后生物碱类和柠檬苦素类成分会发生量变和质变,辅料和温度对其成分的变化有直接的影响,本研究可为黄柏炮制后药性发生改变与其化学成分的变化具有相关性提供参考和依据。     

Alkaloids from Melodinus henryi with anti-inflammatory activity

One new quinolinic scandine-type monoterpeniod alkaloid, 3-oxo-scandine (1), as well as seven known ones (2–8), was isolated from the roots of Melodinus henryi. Their structures were elucidated by extensive spectroscopic analysis. All of the compounds were prepared and evaluated for their anti-inflammatory activities by measuring the inhibitory activity of nitric oxide (NO) in vitro in RAW 264.7 mouse peritoneal macrophages. Compounds 6 and 7 showed significant activities with IC₅₀ values of 8.54 and 5.19 μM, respectively.     

INAUGURAL ARTICLE by a Recently Elected Academy Member:Natural history-driven,plant-mediated RNAi-based study reveals CYP6B46’s role in a nicotine-mediated antipredator herbivore defense

Manduca sexta (Ms) larvae are known to efficiently excrete ingested nicotine when feeding on their nicotine-producing native hostplant, Nicotiana attenuata. Here we describe how ingested nicotine is co-opted for larval defense by a unique mechanism. Plant-mediated RNAi was used to silence a midgut-expressed, nicotine-induced cytochrome P450 6B46 (CYP6B46) in larvae consuming transgenic N. attenuata plants producing MsCYP6B46 dsRNA. These and transgenic nicotine-deficient plants were planted into native habitats to study the phenotypes of larvae feeding on these plants and the behavior of their predators. The attack-behavior of a native wolf spider (Camptocosa parallela), a major nocturnal predator, provided the key to understanding MsCYP6B46’s function: spiders clearly preferred CYP6B46-silenced larvae, just as they had preferred larvae fed nicotine-deficient plants. MsCYP6B46 redirects a small amount (0.65%) of ingested nicotine from the midgut into hemolymph, from which nicotine is exhaled through the spiracles as an antispider signal. CYP6B46-silenced larvae were more susceptible to spider-attack because they exhaled less nicotine because of lower hemolymph nicotine concentrations. CYP6B46-silenced larvae were impaired in distributing ingested nicotine from midgut to hemolymph, but not in the clearing of hemolymph nicotine or in the exhalation of nicotine from hemolymph. MsCYP6B46 could be a component of a previously hypothesized pump that converts nicotine to a short-lived, transportable, metabolite. Other predators, big-eyed bugs, and antlion larvae were insensitive to this defense. Thus, chemical defenses, too toxic to sequester, can be repurposed for defensive functions through respiration as a form of defensive halitosis, and predators can assist the functional elucidation of herbivore genes.Plants produce a pharmacopeia of potent chemical defenses that prevent the attack of unadapted herbivores and thwart the growth of adapted ones. Frequently, lepidopteran herbivores co-opt these diet-acquired toxins for their own defensive purposes. The eastern tent caterpillar (Malacosoma americanum) regurgitates hydrogen cyanide and benzaldehyde ingested from their cyanogenic hostplants when attacked by ants (1). The Atala butterfly (Eumaeus atala) acquires a toxic azoxyglycoside from its cycad hosts and becomes unpalatable to bird and ant predators (2). Similarly, rattlebox moths (Utetheisa ornatrix) co-opt pyrrolizidine alkaloids that their larvae sequester while feeding on rattlebox legume hostplants (Crotalaria spp.) to deter predatory spiders (3). Prey frequently advertise their toxic status with warning colorations, odors, and behaviors, and predators readily learn these aposematic signals to avoid consuming toxic prey (4). The molecular mechanisms of how herbivores co-opt plant defenses for their own defense remain largely unexplored.The pyridine alkaloid nicotine is a defense metabolite of several Nicotiana spp. Nicotine is extremely effective against herbivores because of its ability to poison the essential neuromuscular junction common to all animals that use muscles to move: the acetylcholine receptor (5, 6). Nicotiana spp. hostplants respond to the herbivore attack with large increases in nicotine accumulation (7). However, the tobacco hornworm (Manduca sexta, Ms), a specialist lepidopteran herbivore that feeds on nicotine-producing Nicotiana plants, tolerates doses of nicotine that are lethal for unadapted herbivores (8). More endoparasitoid wasps (Cotesia congregata) emerged as adults from parasitized M. sexta larvae fed on low nicotine varieties of cultivated tobacco than from larvae fed on nicotine-rich varieties (9). The generalist predatory argentine ant (Iridomyrmex humilis) also preferred M. sexta larvae reared on artificial diets (AD) without nicotine over those reared on high nicotine diets, and were deterred by topical nicotine treatments (10). These results suggest that M. sexta larvae might be able to use this diet-derived toxin for their own protection. How this happens remains a mystery, as the larvae’s resistance of ingested nicotine does not appear to include sequestration and storage of this toxin.The exact mechanisms responsible for M. sexta’s nicotine resistance remain unclear, but both efficient excretion and metabolism appear to be involved. Some researchers have focused on the polar metabolites of nicotine, such as cotinine and the N-oxides of both nicotine and cotinine, which are commonly found in the urine and blood of human smokers (8, 11, 12); cytochrome P450s (CYPs) are thought to mediate nicotine’s oxidation to these metabolites (8, 11, 13–15), but other researchers have been unable to find the oxides in M. sexta’s excretions and propose that nicotine is rapidly excreted without modification (16–18). Although this theory is widely accepted, most studies have not been able to recover all of the ingested nicotine in the frass and nicotine can be found in the hemolymph of larvae feeding on nicotine-containing diets. Hence, within these physiological limits of M. sexta’s excretory-based tolerance lie opportunities for the defensive use of nicotine. Whether nicotine-resistance and co-option are regulated by a common mechanism remains unknown.Here we examine how M. sexta larvae co-opt diet-ingested nicotine for their own defense. In a previous unbiased microarray study, we found that a midgut-expressed cytochrome P450 (CYP6B46) was strongly down-regulated in larvae that were fed genetically modified hostplants with suppressed nicotine production (19, 20). To evaluate if this CYP6B46 is involved in nicotine resistance and co-option, we used a reverse genetics approach, plant-mediated RNA interference (PMRi) (20, 21), to silence this gene in larvae feeding on nicotine-containing, native coyote tobacco (Nicotiana attenuata) hostplants transformed to harbor the silencing construct. Lepidopteran herbivores appear to lack the RNA-dependent RNA polymerase required to sustain gene silencing by RNAi; however, a continuous supply of double-stranded (ds)RNA administered via the hostplant (or diet) effectively silences genes in these herbivores (21, 22).N. attenuata plants were transformed with an expression vector containing a 300-bp fragment of CYP6B46 in an inverted repeat (ir) orientation. Continuous dsRNA ingestion efficiently silenced CYP6B46 in the midguts of larvae feeding on these plants in a highly target-sequence–specific manner, as the most similar CYP expressed in larval midguts, CYP6B45, was not cosilenced (20). These PMRi plants were planted into the native habitat of both hostplant and larvae, the Great Basin Desert, Utah, which teems with larval predators—such as bugs, mantids, ants, antlions, spiders, and lizards—but lacks the Argentine ants and C. congregata endoparasitoids previously reported to be nicotine-sensitive. One of these predators, a wolf spider [Camptocosa parallela (Lycosidae)], selectively attacked CYP6B46-silenced larvae just as it did larvae feeding on nicotine-free hostplants. The particular predatory behavior of these spiders revealed the function of MsCYP6B46 in externalizing ingested nicotine for defensive use. The combination of natural history studies and the plant- and herbivore-reverse genetic procedures can fruitfully dissect the molecular mechanisms governing the tritrophic interactions.     

中药活性成分抑制哺乳动物雷帕霉素靶蛋白（mTOR）通路抗肿瘤作用的研究进展

哺乳动物雷帕霉素靶蛋白（mTOR）与癌症有密切关系,抑制mTOR通路可以发挥抗肿瘤作用。目前许多mTOR抑制剂被开发用于癌症的治疗。一些中药活性成分如蒽醌类、生物碱类、萜类、多糖类、黄酮类、多酚类成分可以通过抑制mTOR通路诱导肿瘤细胞凋亡、促进自噬、阻断细胞周期发挥抗肿瘤作用。总结了中药活性成分抑制mTOR通路抗肿瘤作用的研究进展,明确其作用机制,为临床应用提供参考。     

大环双内酯雷公藤生物碱高分辨质谱数据库的建立与应用

目的:建立大环双内酯雷公藤生物碱高分辨质谱数据库(HR-MS-database),并应用于不同种属雷公藤生物碱的快速鉴定分析.方法:采用超高效液相色谱-四极杆-飞行时间质谱联用(UPLC/Q-TOF-MS)技术手段,借助SCIEX公司LibraryView数据库平台,建立大环双内酯雷公藤生物碱高分辨质谱-数据库(HR-...     

川乌中总生物碱提取工艺优化研究

目的:优选川乌药材中总生物碱的最佳提取工艺。方法:采用L9(34)正交法,以提取物得率和乌头碱、次乌头碱和新乌头碱的含量为考察指标,并用RP-HPLC法测定三种生物碱的含量,流动相为甲醇-水-氯仿-二乙胺(70∶30∶2∶0.1)。结果:筛选出的最佳提取工艺为药材用氨试液浸润,加入15倍乙醚溶剂,冷浸24h。结论:该实验提取工艺合理、科学。     

β-咔啉类生物碱对人胃癌SGC-7901细胞增殖、凋亡的影响及机制探讨

目的观察β-咔啉类生物碱对体外培养的人胃癌SGC-7901细胞增殖及凋亡的影响,并探讨其作用机制。方法不同浓度β-咔啉类生物碱处理人胃癌SGC-7901细胞48 h后,检测细胞增殖、凋亡情况,并以荧光定量聚合酶链反应(RTPCR)和蛋白印迹法(Western blot)分别测定细胞中抑癌基因PTEN、蛋白激酶B(AKT)基因mRNA及其蛋白表达。结果不同浓度的β-咔啉类生物碱均能抑制人胃癌SGC-7901细胞的增殖,其中40μg/m L浓度的抑制效果较其他浓度及5-Fu干预组更显著(P0.01),并可诱导细胞凋亡。不同浓度β-咔啉类生物均可引起PTEN mRNA和蛋白表达增加,AKT mRNA和蛋白表达减少,其中40μg/m L浓度的调节效果较其他浓度及5-Fu干预组更显著(P0.01)。结论β-咔啉类生物碱可抑制人胃癌SGC-7901细胞增殖,诱导凋亡,其作用机制可能是通过上调PTEN及下调AKT蛋白的表达实现。