西地那非哌啶衍生物的负离子电喷雾多级质谱研究

采用负离子检测方式对 4种西地那非哌啶衍生物进行了电喷雾离子阱质谱研究。这 4种化合物在结构上的差异仅在于烷基取代基不同 ,通过比较它们之间碎片离子的异同 ,对其质谱裂解图解进行分析 ,获得了它们的结构碎片信息。在阐明化合物结构信息方面 ,这一方法与通常所用的同位素标记的方法类似。实验结果表明 ,这 4种西地那非哌啶衍生物的 ( -) ESI-MS2 质谱均产生磺酰基 S-N键断裂的碎片 ;其 ( -) ESI-MS3质谱均产生 S-C键断裂的碎片 ;其 ( -) ESI-MS4质谱均产生脱去苯环上烷氧基的烷基自由基碎片。这些特征可用于阐明西地那非衍生物及其结构类似物的结构     

新型磷酸二酯酶抑制剂Sildenafil的合成

以1－甲基－3－丙基吡唑－5－甲酸为起始原料，经硝化，一次酰胺，氢化还原，二次酰胺化，环合，氯磺酰化，N-甲基呱嗪化七步反应合成了磷酸二酯酶抑制剂Sildenafil。     

中成药保健食品中西地那非的液质联用确证方法研究

通过提高去簇电压(declustering potential)的方式促使西地那非准分子离子在进入Q₁前发生碰撞诱导解离,产生一级碎片离子,然后采用三重四极杆质谱仪的MS²模式对其中丰度较大的碎片离子进行质谱分析,从而获得ESI-MS³碎片离子信息,并以此探讨西地那非主要裂解途径,确定裂解产生的4个主要碎片离子。在此基础上建立液相色谱-质谱多反应监测模式,测定这4个碎片离子的色谱峰,建立的确证方法有较高的检测灵敏度,测定结果清晰、明确、易于判定,具有超过规定要求的4个鉴别点,完全能满足成分复杂的中成药和保健食品样品添加西地那非的确证检验。     

Isolation and structural characterisation of a propoxyphenyl-linked thiohomosildenafil analogue found in a herbal product

A propoxyphenyl-linked thiohomosildenafil analogue, one of the sildenafil analogues, was found in an herbal product. It was isolated by semi-preparative high-performance liquid chromatography (HPLC). The structure was established based on a comparison of chromatographic and spectroscopic behaviour with other sildenafil analogues using HPLC with diode array detection, quadrupole time-of-flight mass spectrometry (Q-TOF/MS), and nuclear magnetic resonance (NMR) spectroscopy. The HPLC analysis showed separation from known sildenafil analogues with a similar chromatographic retention time. An [M + H]⁺ ion at m/z 519.22 was detected by mass spectrometry corresponding to an empirical formula of C₂₄H₃₄N₆O₃S₂. The structure was similar to that of thiohomosildenafil, except that the ethoxy group attached to the phenyl ring was substituted for a propoxy group. It was assigned as 5-[2-propoxy-5-(4-ethylpiperazin-4-ylsulfonyl)phenyl]-3-methyl-1-n-propyl-4,5,dihydro-1H-pyrazole[7,1,d]pyrimidin-4-thione and named as propoxyphenyl-thiohomosildenafil because the structure was considerably similar to thiohomosildenafil.     

Biotransformation of Sildenafil in the Male Rat: Evaluation of Drug Interactions with Testosterone and Carbamazepine

The biotransformation of sildenafil to its major circulating metabolite, UK-103,320, was studied in male rat liver microsomes. The conversion of sildenafil to UK-103,320 by rat microsomes followed Michaelis–Menten kinetics, for which the parameters were V_max?=?1.96 μM/minand K_m?=?27.31 μM. Using substrates of CYP3A4 of testosterone and carbamazepine, the active sites on CYP3A4 responsible for metabolizing sildenafil were also evaluated. Sildenafil biotransformation was inhibited in the individual presence of testosterone and carbamazepine. The results showed drug interaction was observed in the sildenafil-testosterone and sildenafil-carbamazepine. Although testosterone and carbamazepine can inhibit sildenafil demethylation in concentration- and incubation time-dependent manners, sildenafil did not inhibit testosterone hydroxylation or carbamazepine epoxidation. These results may be explained by a model in which multiple substrates or ligands can concurrently bind to the active site of a single CYP3A4 molecule. However, the contribution of separate allosteric sites and conformational heterogeneity to the atypical kinetics of CYP3A4 cannot be ruled out in this study.     

4-氨基-1-甲基-3-正丙基吡唑-5-甲酰胺合成工艺研究

以 3 正丙基吡唑 5 羧酸乙酯为起始原料 ,经多步反应合成了 4 氨基 1 甲基 3 正丙基吡唑 5 甲酰胺 ,并对工艺进行了如下改进 :(1)将甲基化、水解两步反应合并为“一勺烩”工艺 ,中间产物不需硅胶柱分离、提纯 ,直接进行水解 ;(2 )硝化后处理增加了溶媒提取工序 ;(3)还原反应采用催化还原法 ,以价廉的甲酸铵代替氯化亚硒作还原剂。总收率达到 39 3% ,较原工艺提高了8 5 % ,具有操作简单 ,反应条件温和 ,宜于工业化生产 ,为合成 4 氨基 1 甲基 3 正丙基吡唑 5 甲酰胺提供了一个较好的方法。     

邻乙氧基苯甲酸的合成

对以水杨酸甲酯为原料制取西地那非重要中间体邻乙氧基苯甲酸的合成工艺进行了改进,先制得水杨酸甲酯钠盐,经干燥后与溴乙烷乙基化得到邻乙氧基苯甲酸甲酯,然后将邻乙氧基苯甲酸甲酯水解制得邻乙氧基苯甲酸。产品纯度为99.88%(HPLC法),总收率为89.5%。该工艺已在重庆康尔威药业股份有限公司中试。     

Sildenafil vaginal suppositories: preparation,characterization, in vitro and in vivo evaluation

Aim: The main objective was to investigate the in vitro release profile/kinetics, and in vivo plasma pharmacokinetics (PK) and organ biodistribution (BD) of the prepared sildenafil vaginal suppositories (SVS).

Methods: Suppositories containing 25?mg of sildenafil were prepared by the cream melting technique using Witepsol H-15 as a suppository base. The suppositories were characterized for weight variation, content uniformity, hardness, disintegration time and crystallinity change. The in vitro dissolution in pH 4.5, and in vivo plasma PK and organ BD of sildenafil from SVS in female Sprague Dawley rats, were also investigated.

Results: The mean weight variation, content uniformity, hardness and disintegration time of the prepared SVS were 1.127?±?0.020?g, 98.25?±?2.50%, 2.5?±?0.08?kg and 9?±?1.0?min, respectively. The release of sildenafil from the SVS was more than 90% at 30?min, with a release kinetic of Hixson--Crowell model and non-Fickian diffusion (n?=?0.464). The plasma PK study demonstrated a significantly lower C_max (～10 times) and AUC_0–24?h (～13 times) of sildenafil in plasma following intravaginal (IVG) administration of suppositories compared to oral (PO) administration of sildenafil solution. Nevertheless, the organ BD study showed a phenomenally higher C_max (～40 times) and AUC_0–24?h (～20 times) of sildenafil in uterus following IVG administration of suppositories than PO administration of sildenafil solution.

Conclusion: This study demonstrated enhanced sildenafil exposure in the uterus following IVG administration of SVS, which could be used to target the uterus for therapeutic benefits.     

降血糖类保健食品中非法添加的8 种药物检测及实例分析

目的：建立检测降血糖类保健食品中非法添加8 种药物的方法并用于实际检测。方法：采用高效液相色谱-串联质谱法,以ZORBAX Eclipse Plus C18（2.1 mm×50 mm,1.8 μm）色谱柱,以0.1%甲酸溶液为流动相A,甲醇为流动相B,梯度洗脱。通过分子离子峰、二级碎片、色谱保留时间等信息,对宣称辅助降血糖类保健食品非法添加8 种化学药物进行鉴别和定量测定。结果：8 种药物实现了同时分离与专属鉴定,检出限为5.5～76 ng/g,精密度为0.22%～1.19%,回收率为74.0%～111.9%;本法适用于硬胶囊样品;利用本法,从15 批样品中检测出9 批含非法添加化学药物。结论：本方法专属性强、灵敏度高,结果准确可靠,可作为宣称辅助降血糖类保健食品中检测非法添加化学药物的方法参考。     

超高效液相色谱串联质谱法测定酒和功能饮料中3种西地那非衍生物的含量

目的建立超高效液相色谱串联质谱法(ultra performance liquid chromatography tandemmass spectrometry,UPLC-MS/MS)测定酒和功能饮料中3种西地那非衍生物(N-去甲基西地那非、吡唑N-去甲基西地那非、异丁基西地那非)含量的分析方法。方法采用Agilent Eclipse Plus C18 (3.0 mm×150 mm, 1.8μm)反相色谱柱,0.1%甲酸水和0.1%甲酸乙腈为流动相,梯度洗脱,采用多反应监测(multiplereaction monitoring,MRM)检测。结果在50～500 ng/mL的浓度范围内, N-去甲基西地那非、吡唑N-去甲基西地那非、异丁基西地那非均表现出良好的线性关系,本方法中3种化合物的检出限(limit of detection, LOD)均为15 ng/mL,定量限(limit of quantitation, LOQ)均为50 ng/mL。结论该方法操作简便,结果可靠,灵敏度高,可用于酒和功能饮料中N-去甲基西地那非、吡唑N-去甲基西地那非、异丁基西地那非含量的快速测定。