RP-HPLC法测定辣椒中辣椒素、二氢辣椒素和降二氢辣椒素含量

目的:建立反相高效液相色谱法同时测定辣椒中辣椒素、二氢辣椒素和降二氢辣椒素含量。方法:采用Nucleosil C18(4.6 mm×250 mm,5μm)色谱柱,流动相为乙腈-水,梯度洗脱,流速1.0 mL.min-1,检测波长280 nm,柱温45℃,外标法定量。结果:3个辣椒碱的线性关系良好,线性范围均为1.0～160.0μg.mL-1,相关系数在0.9991～0.9995之间;精密度、稳定性试验的RSD均低于3%;辣椒素、二氢辣椒素和降二氢辣椒素平均回收率(n=6)分别为96.4%,98.1%,99.3%,RSD分别为2.6%,2.1%,1.2%;检出限分别为0.2,0.1,0.1μg.mL-1。结论:该方法简便快捷,应用本方法测定了10个品种辣椒中3个辣椒碱的含量,结果稳定。     

微波辅助萃取-高效液相色谱-串联质谱法测定辣椒中3种辣椒素

目的:建立微波辅助萃取-高效液相色谱-串联质谱法测定辣椒中3种辣椒素类化合物(辣椒素、二氢辣椒素、降二氢辣椒素)含量。方法:辣椒样品经微波辅助萃取甲醇稀释后分析。色谱分离采用C18反相色谱柱(150 mm×2.1 mm,3.5μm),流动相为0.1%甲酸水溶液和乙腈,梯度洗脱。串联质谱在多反应监测模式下检测目标分析物,以保留时间和特征离子对(母离子和2个碎片离子)信息比较进行定性和定量分析。结果:3种辣椒素的检出限为0.01～0.11 ng.mL-1,定量限为0.03～0.36 ng.mL-1,辣椒素、二氢辣椒素、降二氢辣椒素平均回收率分别为95.4%,94.3%,93.1%;RSD分别为2.1%,2.5%,2.7%。结论:该方法简便、准确、灵敏,可用于辣椒中3种辣椒素的分析。     

HPLC法同时测定关节解痛膏中的辣椒素、二氢辣椒素、欧前胡素和异欧前胡素

目的：建立HPLC测定关节解痛膏中辣椒素、二氢辣椒素、欧前胡素和异欧前胡素含量的方法。方法：CAPCELL PAK C18色谱柱（250 mm×4.6 mm,5μm）;流速：0.8 ml·min^-1;流动相A：甲醇-乙腈（1∶1）,流动相B：1%磷酸溶液,梯度洗脱;检测波长分别为280 nm（辣椒素和二氢辣椒素）和254 nm（欧前胡素和异欧前胡素）。结果：辣椒素、二氢辣椒素、欧前胡素和异欧前胡素分别在0.298-5.956μg（r=0.999 8）、0.152-3.044μg（r=0.999 6）、0.018-0.352μg（r=0.999 5）、0.010-0.204μg（r=0.999 3）范围内进样量与峰面积呈良好的线性关系,平均加样回收率分别为97.8%、97.0%、96.6%、98.1%,RSD分别为1.02%、0.76%、0.65%、1.35%（n=6）。结论：方法简便、准确、灵敏、重复性好,可作为关节解痛膏中辣椒素、二氢辣椒素、欧前胡素和异欧前胡素的含量控制方法。     

壳聚糖树脂吸附提取辣椒素及其含量的测定

目的以干辣椒为原料,用壳聚糖树脂吸附提取辣椒碱并测定其含量。方法采用1%NaOH粗提取,提取液脱脂后用壳聚糖树脂柱吸附,乙醇洗脱、重结晶得淡黄色针状辣椒素的晶体。采用香兰素-亚硝酸钠比色法测定辣椒素含量,用HPLC分析晶体中辣椒碱和二氢辣椒碱的含量。结果辣椒素收率为0.38%,辣椒素晶体纯度为91.20%,其中辣椒碱为63.17%,二氢辣椒碱为26.75%。结论采用壳聚糖树脂吸附提取辣椒碱,方法简便,成本低廉,产率和纯度较高。     

一测多评法测定藏药小米辣中3种辣椒碱的含量

目的：建立藏药小米辣中3种辣椒碱类化学成分含量测定的一测多评法,探讨一测多评法在民族药质量控制中的应用。方法：采用超高压液相色谱法,使用Waters ACQUITY BEH C18（2.1 mm×100mm,1.7 μm）色谱柱,流动相为乙腈-水（50︰50）,流速：0.2 mL·min^-1,柱温30℃,检测波长280 nm,进样量1 μL。以辣椒素为内参物,分别建立二氢辣椒素、降二氢辣椒素相对于辣椒素的相对校正因子,分别采用外标法和一测多评法测定3种辣椒碱的含量,并通过相对标准偏差（RSD）和Pearson系数比较二者结果的相对误差。结果：降二氢辣椒素、辣椒素、二氢辣椒素进样量分别在2.21~22.1 ng、8.96~89.6 ng、3.75~37.5 ng范围内线性关系良好;降二氢辣椒素和二氢辣椒素相对于辣椒素的相对校正因子分别为0.970和1.159;且在不同实验条件下重现性良好（RSD < 3.0%）;一测多评法的计算结果与外标法测得结果无显著差异。10批不同产地小米辣样品中降二氢辣椒素、辣椒素和二氢辣椒素的含量范围分别为0.0281%~0.0534%、0.258%~0.389%和0.115%~0.209%。结论：建立的一测多评法可作为小米辣中3种辣椒碱类化学成分的含量测定方法,一测多评法为民族药质量控制提供了一个新的模式与方法。     

HPLC法测定辣椒中辣椒素的含量

目的：测定辣椒中辣椒素含量。方法：采用HPLC法测定辣椒中辣椒素含量。结果：辣椒素线性范围为0．12～0．28μg；平均回收率为99.32％（RSD=0．62％）；结论：该方法准确、重现性好、简便、易行。     

HPLC法测定辣椒浸出物中辣椒素的含量

目的:采用HPLC法测定辣椒浸出物中辣椒素的含量.方法:C18色谱柱,以乙腈-水(50:50)为流动相,检测波长为 229 nm.结果:本方法重现性及精密度良好,回收率为99.4%,RSD为1.22%.结论:方法简便,专属性强;可用于辣椒浸出物的质量控制.     

反相高效液相色谱法制备纯辣椒素的研究

目的 从辣椒中制备纯辣椒素。方法从辣椒中提取、分离和纯化出辣椒辣素，然后利用RP-HPLC制备纯辣椒素，并进行HPLC和MS分析。结果从辣椒中分离到一种白色片状结晶，其MS谱显示有2个分子离子峰（m/e305和m/e307）；HPLC分析出现2个色谱峰，进一步用HPLC分离该结晶制得的组分其HPLC和MS均显示为单一化合物。结论根据最终化合物的MS谱与标准辣椒素质谱对比，用此方法制得的辣椒素是单体。     

高效液相色谱法测定温辣贴中辣椒素的含量

目的:采用高效液相色谱法测定中成药温辣贴中辣椒素的含量。方法:高效液相色谱法,Alltima C_(18)(150 mm×4.6 mm,5μm),0.08%磷酸-乙腈(55:45)为流动相,流速:1 mL·min~(-1),检测波长为280 nm,柱温:40℃。同时完成3个样品的测定。结果:辣椒素在0.004～0.2μg范围内色谱响应线性关系良好,r=0.9995,回归方程为 Y=5.76×10~6X-1.40×10~3;仪器精密度的 RSD(n=6)为0.9%;方法重复性的 RSD(n=6)为1.3%。平均回收率(n=6)为98.1%,RSD=2.1%。结论:本法快速简便,重复性好,测定准确灵敏。     

高效液相色谱法测定生发凝胶中辣椒素含量

目的：建立生发凝胶中辣椒素含量测定的高效液相色谱方法。方法：采用Diamonsil C18色谱柱，以甲醇-0．1％磷酸（65：35）为流动相，流速为1．0mL·min^-1，检测波长为280nm，柱温为40℃。结果：辣椒素在5．0～100．0mg·L^-1，范围内与峰面积呈良好的线性关系（r=0．9999），平均回收率为101．32%，RSD为1．72%（n=6）。结论：该方法简便、准确、重复性好，可作为生发凝胶中辣椒素的含量测定方法。     

HPLC法测定辣椒总碱中辣椒碱及二氢辣椒碱的含量

在 C6H5键合硅胶为填充剂的色谱柱上 ,以乙腈 - 0 .1% H3 PO4(33∶ 6 7)为流动相 ,检测波长为 2 80 nm,同时测定了辣椒总碱中辣椒碱及二氢辣椒碱的含量。结果表明 ,辣椒总碱中辣椒碱及二氢辣椒碱的含量约为5 8%和 30 % ,方法的平均加样回收率分别为 98.2 %和 97.6 %。     

一测多评法测定天然辣椒碱中2种主要成分

目的建立以1种对照品同时测定天然辣椒碱中2种成分的质量评价方法。方法以辣椒辣素为对照,采用一测多评法,同时测定辣椒辣素和二氢辣椒辣素的含量。结果测得辣椒辣素与二氢辣椒辣素的相对校正因子为1.12,同时采用外标法和一测多评法测定样品中二氢辣椒辣素含量,采用t检验对二者测定值进行比较,二者之间无显著差异(P>0.05);以辣椒辣素的保留时间为1.00,计算得二氢辣椒辣素的相对保留时间为1.355,相对保留时间及保留时间差的RSD均小于5%。结论采用一测多评法,以辣椒辣素为对照,利用相对校正因子可实现同时测定辣椒辣素和二氢辣椒辣素的含量。     

Effects of vehicle on the uptake and elimination kinetics of capsaicinoids in human skin in vivo

While the physiologic and molecular effects of capsaicinoids have been extensively studied in various model systems by a variety of administration routes, little is known about the uptake and elimination kinetic profiles in human skin following topical exposure. The present study evaluated the uptake and elimination kinetics of capsaicinoids in human stratum corneum following a single topical exposure to 3% solutions containing 55% capsaicin, 35% dihydrocapsaicin, and 10% other analogues prepared in three vehicles: mineral oil (MO), propylene glycol (PG), and isopropyl alcohol (IPA). Capsaicinoid solutions were evaluated simultaneously in a random application pattern on the volar forearms of 12 subjects using a small, single 150-microg dose. Capsaicin and dihydrocapsaicin were recovered from human skin using commercial adhesive discs to harvest stratum corneum from treated sites. Capsaicinoids were extracted from the stratum corneum-adhesive discs and quantified by liquid chromatography/mass spectroscopy (LC/MS). Both capsaicinoids were detected in stratum corneum 1 min after application with all vehicles and achieved a pseudo-steady state shortly thereafter. IPA delivered three times greater capsaicin and dihydrocapsaicin into the human stratum corneum than PG or MO at all time points investigated. The Cmax of capsaicin in IPA, PG, and MO was 16.1, 6.2, and 6.5 microg, respectively. The dihydrocapsaicin content was 60% of capsaicin with all vehicles. The estimated T(half) of capsaicin and dihydrocapsaicin in the three vehicles was similar (24 h). Thus, maximal cutaneous capsaicinoid concentrations were achieved quickly in the human stratum corneum and were concentration and vehicle dependent. In contrast, capsaicinoid half-life was long and vehicle independent.     

Dihydrocapsaicin-induced hypothermia and substance P depletion

Administration of dihydrocapsaicin to rats resulted in a dose-dependent (0.5-10 mg/kg s.c.) hypothermia. Dihydrocapsaicin was approximately 65% more effective in producing hypothermia than capsaicin. Desensitization and cross-tolerance occurred to the hypothermic effects of both capsaicin and dihydrocapsaicin. Repeated administration of either dihydrocapsaicin or capsaicin resulted in chemogenic antinociception but not marked thermal antinociception. In addition, repeated administration of dihydrocapsaicin, like capsaicin, resulted in depletion of substance P from dorsal root ganglia and dorsal spinal cord but not from the hypothalamus, corpus striatum or ventral spinal cord. These data indicate that dihydrocapsaicin, or radiolabelled dihydrocapsaicin, may be a useful tool for investigating the mechanisms by which capsaicin alters thermoregulation and primary afferent neuron function.     

Gastrointestinal absorption and metabolism of capsaicin and dihydrocapsaicin in rats

Gastrointestinal absorption of capsaicin and dihydrocapsaicin was studied in rats in vivo and in situ. Rapid absorption of capsaicin or dihydrocapsaicin from stomach and small intestine occurred in vivo. About 85% of the dose was absorbed in the gastrointestinal tract within 3 hr. In situ, within 60 min after the administration of capsaicin and dihydrocapsaicin into stomach, jejunum, and ileum, about 50, 80, and 70% of the respective dose had disappeared from the lumen. When 2,4-dinitrophenol or NaCN was added, no significant reduction in uptake of [3H]dihydrocapsaicin was observed in the jejunum. These results suggested that capsaicin and its analogs were absorbed by a nonactive process in jejunum. [3H]Dihydrocapsaicin was mainly absorbed via the portal system but not a mesenteric lymphangial one. The radioactivity in the portal blood was composed of 85% of [3H]dihydrocapsaicin and 15% of its metabolite (8-methyl nonanoic acid) bound to the albumin fraction. Dihydrocapsaicin-hydrolyzing enzyme activity was found in jejunal tissue. These results suggest that capsaicin and its analogs partly received a first-pass effect, i.e., metabolism of a compound following first absorption in the gastrointestinal tract. It is concluded that capsaicin and its analogs are readily transported to the portal vein through the gastrointestinal tract by a nonactive process and partly metabolized during absorption.     

Determination of capsaicin,nonivamide, and dihydrocapsaicin in blood and tissue by liquid chromatography-tandem mass spectrometry

A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the analysis of capsaicin, nonivamide, and dihydrocapsaicin in blood and tissue has been developed. The method utilized a one-step liquid-liquid extraction that yielded an approximate 90% recovery of capsaicinoids from blood. Chomatographic separation of the capsaicinoids was achieved using a reversed-phase high-performance liquid chromatography column and a stepwise gradient of methanol and distilled water containing 0.1% (v/v) formic acid. Identification and quantitation of the capsaicinoids was achieved using electrospray ionization-tandem mass spectrometry monitoring the precursor-to-product-ion transitions for the internal standard octanoyl vanillamide (m/z 280 --> 137), capsaicin (m/z 306 --> 137), dihydrocapsaicin (m/z 308 -->137), and nonivamide (m/z 294 --> 137). Calibration curves, 1.0 to 250 ng/mL, were constructed by plotting concentration versus peak-area ratio (analyte/internal standard) and fitting the data with a weighted quadratic equation. The accuracy of the assay ranged from 90% to 107% for all analytes. The intra-assay precision (%RSD) for capsaicin was 4% at 2.5 ng/mL, 3% at 10 ng/mL, and 7% at 100 ng/mL. The interassay precision (% RSD) for capsaicin was 6% at 2.5 ng/mL, 6% at 10 ng/mL, and 7% at 100 ng/mL. Similar values for inter- and intra-assay precision were obtained for nonivamide and dihydrocapsaicin. This method was used to assay for capsaicinoids in blood and tissue samples collected from rats exposed to capsaicinoids via nose-only inhalation. The concentration of capsaicin in these samples ranged from < 1.0 to 90.4 ng/mL in the blood, < 5.0 to 167 pg/mg in the lung, and < 2.0 to 3.4 pg/mg in the liver.     

Effects of capsaicin and dihydrocapsaicin on human and rat liver microsomal CYP450 enzyme activities in vitro and in vivo

Capsaicin and dihydrocapsaicin, the two most abundant members of capsaicinoids in chili peppers, are widely used as food additives and for other purposes. In this study, we examined the inhibitory potentials of capsaicin and dihydrocapsaicin against CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4/5 activities in human liver microsomes. The effects of these two capsaicinoids on CYP450 enzymes were also evaluated in vivo in rats. The results demonstrated that capsaicin and dihydrocapsaicin moderately inhibited five isozymes (IC₅₀ values ranging from 4.4 to 61.8 μM), with the exception of CYP2E1 (IC₅₀>200 μM). Both capsaicinoids exhibited competitive, mixed, and noncompetitive inhibition on these isozymes (K _i = 3.1 ± 0.5 ? 78.6 ± 8.4 μM). Time-dependent inhibition of CYP3A4/5 by capsaicin was found. After multiple administrations of capsaicin and dihydrocapsaicin (1, 4, and 10 mg/kg) to rats, chlorzoxazone 6-hydroxylase activity and the expression of CYP2E1 were increased in liver microsomes. Our findings indicated that the possibility of food–drug interactions mediated by capsaicin and dihydrocapsaicin could not be excluded, and provided the useful information for evaluating the anticarcinogenic potentials of these two capsaicinoids.     

胡桃楸枝和根中5个成分含量测定方法的建立及其含量差异分析

目的:建立同时测定胡桃楸枝和根中没食子酸、逆没食子酸、1,6-二-O-没食子酰基-β-D-葡萄糖、1,2,6-三-O-没食子酰基-β-D-葡萄糖、1,2,3,6-四-O-没食子酰基-β-D-葡萄糖等5个成分含量的方法,并分析枝和根中上述5个成分的含量差异。方法:采用高效液相色谱法,以Agilent Poroshell 120 SB-C18为色谱柱,以水(含0.2%甲酸)-乙腈(含0.2%甲酸)为流动相进行梯度洗脱,流速为0.3 mL/min,柱温为30℃,检测波长为270 nm,进样量为5μL。利用独立样本t检验和偏最小二乘法判别分析对5个成分含量进行比较分析。结果:没食子酸、逆没食子酸、1,6-二-O-没食子酰基-β-D-葡萄糖、1,2,6-三-O-没食子酰基-β-D-葡萄糖、1,2,3,6-四-O-没食子酰基-β-D-葡萄糖检测质量浓度的线性范围分别为0.989~63.3、1.58~101、1.01~64.7、3.31~212、3.34~214μg/mL(r≥0.9973);精密度、重复性、稳定性(12 h)试验的RSD均小于3.2%,平均加样回收率分别为103.2%、99.1%、101.5%、102.9%、104.7%(RSD分别为4.85%、2.80%、1.31%、2.73%、1.28%)。在胡桃楸枝中,上述成分的平均含量分别为0.2965、0.6211、0.5625、3.1117、3.4513 mg/g;在根中,上述成分的平均含量分别为0.6734、2.7555、0.9640、2.9466、4.8364 mg/g;在枝、根中上述成分的平均总量分别为8.0432、12.1759 mg/g。根中没食子酸、逆没食子酸和1,6-二-O-没食子酰基-β-D-葡萄糖含量均显著高于枝中的含量(P<0.05或P<0.01),而枝和根中其余2个成分的含量及5个成分的总量比较差异均无统计学意义(P>0.05)。偏最小二乘法判别分析所建模型的累积解释度(R²X、R²Y)、累积预测度(Q²)分别为0.943、0.745、0.710;模型载荷图显示,逆没食子酸与原点距离最远,仅逆没食子酸含量的变量投影重要性值大于1。结论:成功建立了可同时测定胡桃楸枝和根中5个成分含量的方法。除1,2,6-三-O-没食子酰基-β-D-葡萄糖外,胡桃楸根中其余4个成分的含量及总含量均高于胡桃楸枝,逆没食子酸是区分两类样品的主要差异成分。     

Effects of capsaicin and dihydrocapsaicin on human and rat liver microsomal CYP450 enzyme activities in vitro and in vivo

Capsaicin and dihydrocapsaicin, the two most abundant members of capsaicinoids in chili peppers, are widely used as food additives and for other purposes. In this study, we examined the inhibitory potentials of capsaicin and dihydrocapsaicin against CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4/5 activities in human liver microsomes. The effects of these two capsaicinoids on CYP450 enzymes were also evaluated in vivo in rats. The results demonstrated that capsaicin and dihydrocapsaicin moderately inhibited five isozymes (IC??) values ranging from 4.4 to 61.8 μM), with the exception of CYP2E1 (IC?? > 200 μM). Both capsaicinoids exhibited competitive, mixed, and noncompetitive inhibition on these isozymes (K (i) = 3.1 ± 0.5 - 78.6 ± 8.4 μM). Time-dependent inhibition of CYP3A4/5 by capsaicin was found. After multiple administrations of capsaicin and dihydrocapsaicin (1, 4, and 10 mg/kg) to rats, chlorzoxazone 6-hydroxylase activity and the expression of CYP2E1 were increased in liver microsomes. Our findings indicated that the possibility of food-drug interactions mediated by capsaicin and dihydrocapsaicin could not be excluded, and provided the useful information for evaluating the anticarcinogenic potentials of these two capsaicinoids.