建立2D-HPLC同时检测钩藤碱、异钩藤碱、去氢钩藤碱、异去氢钩藤碱的方法

目的 建立二维高效液相色谱法（2D-HPLC）同时检测钩藤碱、异钩藤碱、去氢钩藤碱、异去氢钩藤碱四种钩藤生物碱含量的方法。方法 采用Aston SC2（3.5 mm×25 mm，5 μm）一维色谱柱，Aston SH C₁₈（3.5 mm×10 mm，5 μm）中间色谱柱，Aston SCB（4.6 mm×125 mm，5 μm）分析色谱柱，一维流动相为CAA-1，分析流动相为BPI-1∶MPI-1∶OPI=45∶14∶41，流速1.0 mL/min，柱温40℃，检测波长254 nm，进样量500 μL，分析时间9.5 min。结果 钩藤碱、异钩藤碱、去氢钩藤碱、异去氢钩藤碱线性范围分别为9.77~10 000.00 ng/mL（r=0.999 6）、10.74~11 000.00 ng/mL（r=0.999 7）、10.74~11 000.00 ng/mL（r=0.999 7）、10.74~11 000.00 ng/mL（r=0.999 6），精密度、稳定性和重复性相对标准偏差（RSD）<5.00%，准确度为95.20%~104.01%，方法回收率为93.63%~101.38%。结论 建立的2D-HPLC同时检测钩藤中四种生物碱含量的方法简单准确，可作为钩藤药材质量控制的新方法。     

钩藤总碱缓释滴丸的制备、含量测定和释放度考察

目的:研制钩藤总碱缓释滴丸。方法:以滴丸释放度、外观质量的综合评分为指标,以钩藤总碱与丙二醇混合后在处方中的用量、硬脂酸与聚乙二醇(PEG)6000的比例、滴制温度和滴速为考察因素,用正交试验优选处方,制备钩藤总碱缓释滴丸;用高效液相色谱法测定制剂中钩藤碱含量;用转篮法测定制剂的释放度。结果:优选的处方为钩藤总碱与丙二醇混合后占45%,硬脂酸与PEG6000的比例为1∶4,滴制温度为70℃,滴速为45滴·min-1;制备的滴丸中钩藤总碱的含量为(85.8±4.2)%;释放过程符合Higuchi方程。结论:钩藤总碱缓释滴丸制备方法可行,制剂质量可控。     

HPLC测定广西产钩藤药材中的钩藤碱

目的评价广西不同产地钩藤Uncaria rhynchophylla的药材质量,确定药材的最佳采收期。方法采用HPLC测定28批不同产地和1个产地不同时期钩藤药材钩藤碱的含量,采用Gemini C18色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇-水(含0.002 mol.L-1三乙胺,用冰乙酸调pH7.5)(64∶36),流速1.0 mL.min-1,检测波长254 nm。结果 28批不同产地钩藤药材中有11批药材能检出钩藤碱,但含量差异较大;有17批药材未能检出钩藤碱成分;不同时期钩藤中钩藤碱的动态积累差异较大。结论广西不同产地钩藤药材的质量有一定差异;钩藤药材于秋、冬二季采收似乎较合理。     

神乐片中钩藤碱的双波长薄层扫描定量法

采用双波长薄层扫描法测定了神乐片中钩藤碱的含量。钩藤碱的最大吸收波长是２５３ｎｍ，参比波长是３７０ｎｍ。本法操作简便，结果较好，为控制产品质量提供了科学依据。     

高效毛细管电泳法测定钩藤中的钩藤碱

目的分离钩藤碱与异钩藤碱,测定钩藤中的钩藤碱。方法采用高效毛细管电泳法,运行缓冲液为0.05 mol.L-1硼砂溶液(pH6.9)-0.02 mol.L-1羟丙基-β-环糊精和0.05 mo.lL-1胆酸钠的甲醇溶液(85:15),操作电压为12 kV,温度为40℃,检测波长为250 nm。结果钩藤碱0.025~0.496 mg.ml-1与峰面积呈良好的线性关系(r=0.9998),加样回收率为99.8%,RSD=1.91%。结论所用方法可快速有效地分离钩藤碱及异钩藤碱,并测定植物中的钩藤碱。     

钩藤中钩藤碱的成分分析

目的:探讨钩藤中所提取的钩藤总碱的有效成分之一钩藤碱进行鉴定和含量测定。方法:采用TLC通过显色剂的显色比较有相同的Rf(比移值)进行鉴定;采用紫外分光光度法对钩藤总碱中的钩藤碱进行含量测定。结果:本品定性鉴定薄层色谱特征明显,与标准品有相同的Rf;紫外分光光度法在246.0nm波长处测得钩藤总碱中钩藤碱的含量为0.71%。结论:此方法快速、简便、经济、准确、重现性好。     

In vitro vasodilator mechanisms of the indole alkaloids rhynchophylline and isorhynchophylline,isolated from the hook of<Emphasis Type="Italic"> Uncaria rhynchophylla</Emphasis> (Miquel)

Rhynchophylline (Rhy) and isorhynchophylline (Isorhy), indole alkaloids from Uncaria hooks, reportedly exert hypotensive and vasodilatory effects, but the mechanism of action is unclear. We therefore investigated the relaxant effects of these two isomeric alkaloids in rat arteries in vitro, in particular in respect of the various functional Ca²⁺ pathways. Both Rhy and Isorhy relaxed aortic rings precontracted with phenylephrine (PE, 1 µM) in a dose-dependent manner (3–300 µM). Removal of endothelium and preincubation with L-NAME (300 µM) slightly inhibited but did not prevent the relaxant response. These results indicate that Rhy and Isorhy act largely in an endothelium-independent manner. Unlike nicardipine, both alkaloids not only inhibited the contraction induced by 60 mM KCl (IC₅₀ 20–30 µM), but also that induced by PE and U46619, albeit to a lesser extent (IC₅₀ 100 and 200 µM, respectively). These results suggest that Rhy and Isorhy may act via multiple Ca²⁺ pathways. In contrast to their inhibitory effects on KCl-induced and receptor-mediated contractions, where both isomers were comparably potent, Rhy was more potent than Isorhy at higher concentrations (>100 µM) in inhibiting both caffeine (25 mM)- and cyclopiazonic acid (CPA, 30 µM)-induced contractions. Similar results observed with caffeine in Ca²⁺-containing medium were also observed in Ca²⁺-free medium. However, 0.1–0.3 µM nicardipine (which completely inhibited KCl-induced contraction) had no significant inhibitory effect on CPA-induced contractions. Taken together, these results indicate discrimination between these two isomers with respect to Ca²⁺-induced Ca²⁺ release and non-L-type Ca²⁺ channel, but not for IP₃-induced Ca²⁺ release and L-type Ca²⁺ channels. Similar relaxant responses to KCl- and caffeine-induced contractions were seen when these two alkaloids were tested on the smaller mesenteric and renal arteries. In conclusion, the vasodilatory effects of Rhy and Isorhy are largely endothelium independent and are mediated by L-type Ca²⁺ channels. At higher concentrations, they also affect other Ca²⁺-handling pathways, although to a lesser extent. While there is no discrimination between the two isomers with respect to the contraction induced by KCl or agonists (PE and U46619), differential effects between Rhy and Isorhy were seen on caffeine- and CPA-induced contractions.     

钩藤碱对血小板聚集和血栓形成的影响

钩藤碱(Rhy)明显抑制AA,胶原及ADP诱导的大鼠血小板聚集。Rhy不影响血小利用外源性AA合成TXA₂,但抑制胶原诱导的TXA₂生成;在抗血小板聚集有效剂量时,对PGI₂的生成无影响。Rhy有显著降低血栓形成诱导剂ADP及胶原加肾上腺素静脉注射所致小鼠死亡率。     

钩藤中钩藤碱、异钩藤碱的提取与含量测定在预后中的应用分析

目的:探讨钩藤中钩藤碱、异钩藤碱的提取与含量测定在预后中的应用。方法:采取水煎液以及甲醇提取液的方式对钩藤中的钩藤碱及异钩藤碱进行提取,并使用高效液相色谱系统分别对其提取的含量进行测定。结果:在2.5~80μg/m L的范围内钩藤碱的线性关系良好,此时的回归方程为Y=76.717 0X-0.072 7(r=0.999 8),RSD8.7%;在2.0~80μg/m L的范围内异钩藤碱的线性关系良好,此时的回归方程为Y=87.472 9X-0.366 6(r=0.999 7),RSD7.3%。甲醇提取液的方式所提取钩藤碱和异钩藤碱的含量高于水煎液的方式,并且使用二十倍质量的甲醇量,24 h的冷侵时间以及60 min的超声时间最合适。结论:使用甲醇进行提取在用于钩藤中钩藤碱及异钩藤碱中作用优异,对其质量的控制性好,重复性高,操作方法简单,可提高预后,值得在临床上应用推广。