雷公藤内酯醇-溶菌酶偶联物的性能研究及体外评价

目的 研究肾靶向前体药物雷公藤内酯醇-溶菌酶偶联物的理化性质.方法 采用HPLC法考察偶联物在37℃不同pH缓冲液、大鼠血浆及大鼠肾脏溶酶体溶液中的稳定性及细胞毒性.结果 体外稳定性试验表明,偶联物在37℃的不同pH缓冲液及大鼠血浆中稳定,在大鼠肾脏溶酶体溶液中可降解.偶联物能降低肾近端小管的细胞毒性,减少脂多糖引导的NO产生.结论 雷公藤内酯醇-溶菌酶偶联物可提高雷公藤内酯醇的肾靶向性,并可降低不良反应.     

2-亚氨基-2-甲氧基乙基-1-硫代-β-D-半乳吡喃糖苷的合成及其肝靶向应用研究

目的:合成具有肝靶向意义的2-亚氨基-2-甲氧基乙基-1-硫代-β-D-半乳吡喃糖苷,并考察其肝脏靶向性能.方法:以半乳糖为起始物,经乙酰化、溴代、缩合、置换,加醇后得目的化合物.小鼠尾静脉注射给药后,HPLC测定药物在小鼠肝脏及血液中的浓度.结果:目标化合物经IR和MS进行了结构确证.白蛋白微球表面偶联2-亚氨基-2-甲氧基乙基-1-硫代-β-D-半乳吡喃糖苷,肝靶向效率增大约1.5倍.结论:所制半乳糖白蛋白微球趋肝性能增强.     

含有α-氨基醇片段的2H-1,4-苯并噁嗪类化合物的合成研究

目的合成含有α-氨基醇片段的2H-1,4-苯并噁嗪类化合物。方法以邻硝基苯酚类化合物为原料,经与2-溴代羧酸酯的Williamson醚合成、还原硝基成氨基、分子内酯胺解关环酰基化、LiBEt_3H还原得到目标化合物。结果与结论合成了9个α-氨基醇型2H-1,4-苯并噁嗪类化合物,其结构经~1H-NMR和MS谱表征。该合成方法适合2位无取代或小结构取代的该类型化合物的合成。     

雷公藤中二萜内酯类成分的研究(Ⅱ)

为对雷公藤(Tripterygium willfordii Hook.f)进行植物化学和药理的研究,应用现代色谱技术对雷公藤植物的化学成分进行了提取分离,应用UV、IR、MS、HR-MS、1H NMR、13C NMR、1H-1H COSY、1H-13C COSY和NOESY技术对分离得到的4个化合物进行结构确证。4个化合物分别归属为:化合物1为雷公藤内酯酮(triptonide)、化合物2为新雷公藤内酯四醇(neo-triptetraolide)、化合物3命名为2α-羟基雷公藤内酯酮(2α-hydroxytriptonide)和化合物4命名为15-羟基雷公藤内酯酮(15-hydroxytriptonide)。其中化合物3、4为新的二萜内酯并对K562细胞(慢性粒细胞白血病细胞)及HL60细胞(急性髓性白血病细胞)具有显著抑制作用。     

雷公藤内酯醇结构修饰和构效关系研究进展

雷公藤中的雷公藤内酯醇具有抗肿瘤、免疫抑制等多种生物活性,但是副作用大等特点限制了临床的使用。为了获得高效低毒的雷公藤内酯醇衍生物,对其结构进行了改造。近5年来对雷公藤内酯醇的结构改造又有了新进展,包括对其14位羟基、不饱和五元内酯环、B环、13位异丙基和10位甲基的结构改造,得到一系列衍生物。其中对14位羟基进行前药设计,从而降低了雷公藤内酯醇的毒性,14位羟基改造为α-羟基衍生物后发现了与雷公藤内酯醇活性相当的衍生物。综述了近5年来对雷公藤内酯醇的结构改造及构效关系研究进展。     

雷公藤叶中二萜化合物的研究

从雷公藤(Tripterygium wilfordii)叶中分离出九个二萜化合物,经物理常数测定、化学反应、以及波谱数据分析,分别鉴定为雷公藤内酯酮(triptonide,1)、雷公藤内酯醇(triptolide,2)、雷公藤内酯二醇(tripdiolide,3);雷醇内酯(triptolidenol,4)、16-羟基雷公藤内酯醇(16-hydroxytriptolide,5)、雷公藤氯内酯醇(tripehlorolide,6)、雷藤内酯三醇(triptriolide,7),以及新化合物雷公藤内酯二醇酮(tripdiotolnide,8)和13,14-环氧9,11,12-三羟雷公藤内酯(13,14-epoxide 9,11,12-trihydroxytriptolide,9)。新化合物的生物活性正在研究。     

雷公藤中的二萜内酯类成分

目的研究雷公藤(Tripterygium wilfordii Hook.F.)的化学成分。方法应用各种色谱技术进行分离纯化，用UV，IR，¹H NMR，MS，HRMS，¹H-¹H COSY，¹H-¹³C COSY和NOESY等光谱鉴定化合物的结构。结果共分离得到4个化合物：I为16-羟基雷公藤内酯醇(16-hydroxytriptolide)，II为15-羟基雷公藤内酯醇(雷醇内酯，triptolidenol)，III为雷公藤乙素(tripdiolide)，IV为雷公藤乙素的差向异构体，命名为2-表雷公藤乙素(2-epitripdiolide)。结论化合物IV为新二萜内酯化合物。     

雷公藤内酯醇的结构修饰

为降低雷公藤内酯醇的毒性,寻找高效低毒的抗炎免疫化合物,对雷公藤内酯醇(trip-tolide,1)的结构进行了修饰,合成了九个雷公藤内酯醇衍生物。初步活性测定显示雷公藤氯内酯(tri-pchlorolide,2)和雷公藤溴内酯醇(tripbromolide,3)的免疫抑制活性与雷公藤内酯醇近似,但毒性有所降低。其他化合物的活性大大低于雷公藤内酯醇。     

雷公藤内酯醇在大鼠体内的组织分布

目的：建立雷公藤内酯醇的反相高效液相色谱分析方法,并对其在大鼠的组织分布进行测定。方法：用HPLC紫外检测方法测定大鼠i.v.雷公藤内酯醇后各组织中药物的含量。结果：大鼠i.v.200μg/kg的雷公藤内酯醇后药物在体内分布广泛,以肺、肝、肾中分布较高,各组织的药物含量于给药后5min最高,60min后显著下降。结论：雷公藤内酯醇在大鼠体内分布快且广泛,消除也快,且可穿越血脑屏障和血睾屏障分布到脑和睾丸中。     

氨基葡萄糖改性阿魏酸的溶解性和美白功效研究

目的：改造阿魏酸分子结构,使其具有良好的水溶性,适宜配方化妆品,同时提高其美白功效。方法：利用绿色化学合成法,将氨基葡萄糖与阿魏酸反应生成阿魏酸-g-氨基葡萄糖,并确定最佳合成工艺,同时通过溶解度测定实验、人体美白实验和酪氨酸酶抑制实验分别测定其溶解度和美白功效。结果：最佳合成反应条件为阿魏酸：氨基葡萄糖：1：1,pH=8,于60℃反应2h,阿魏酸接枝率为96．49％。阿魏酸-g-氨基葡萄糖的溶解性明显改善,美白功效更显著。结论：本方法符合原子经济学原理和环境友好策略,对于酰胺类阿魏酸衍生物的制备具有指导意义。解决了阿魏酸在用于化妆品时析出晶体的问题,所得改性产品阿魏酸-g-氨基葡萄糖可作为一种新型美白化妆品原料。     

Antineoplastic agents 460. Synthesis of combretastatin A-2 prodrugs

The original synthesis of combretastatin A-2 (1a) was modified to provide an efficient scale-up procedure for obtaining this antineoplastic stilbene. Subsequent conversion to a useful prodrug was accomplished by phosphorylation employing in situ formation of dibenzylchlorophosphite followed by cleavage of the benzyl ester protective groups with bromotrimethylsilane to afford the phosphoric acid intermediate 11. The latter was immediately treated with sodium methoxide to complete a practical route to the disodium phosphate prodrug (2a). The phosphoric acid precursor (11) of phosphate 2a was employed in a parallel series of reactions to produce a selection of metal and ammonium cation prodrug candidates. Each of the phosphate salts (2a-q) was evaluated with respect to relative solubility behavior, cancer cell growth inhibition and antimicrobial activity.     

Antineoplastic agents 429. Syntheses of the combretastatin A-1 and combretastatin B-1 prodrugs

The original synthesis of combretastatin A-1 (1) was modified to allow an efficient scale-up procedure for obtaining this anti-neoplastic stilbene. Subsequent conversion to a useful prodrug was accomplished by diphosphorylation (to 10), with in situ formation of dibenzylchlorophosphite, followed by cleavage of the benzyl ester protecting groups with trimethyliodosilane. The phosphoric acid intermediate was treated with sodium methoxide to complete a practical route to the sodium phosphate prodrug (4). Selective hydrogenation of phosphate 10 and treatment of the product with sodium methoxide led to combretastatin B-1 prodrug (5). The phosphoric acid precursor of prodrug 4 was employed in a parallel series of reactions to produce a selection of metal and ammonium cation prodrug candidates. Each of the phosphate salts was evaluated from the perspective of relative solubility behavior and cancer cell growth inhibition. The sodium phosphate prodrug of combretastatin A-1 (4) was selected for detailed antineoplastic studies.     

熊果酸前药的设计合成及抗多发性硬化症活性评价

目的 设计、合成熊果酸前药,以改善熊果酸的水溶性,并对其抗多发性硬化症(multiple sclerosis,MS)活性进行评价。方法 根据前药策略,选取了琥珀酸、二肽氨基酸和艾莎康唑侧链片段,通过缩合、酯化反应等与熊果酸的3位羟基进行结合,采用紫外-可见分光光度法测定前药的水溶性,并建立小鼠实验性自身免疫性脑脊髓炎模型来进行抗MS活性评价。结果 共合成了3个前药,目标化合物的结构经¹H-NMR、¹³C-NMR和LCMS(ESI)进行确证;前药1和2水溶性较熊果酸提升110倍以上,前药3水溶性提升200倍以上;体内抗MS活性结果显示,所得前药化合物的抗MS活性均有一定提高,其中前药1的抗MS活性显著高于熊果酸组,其机制可能是通过抑制外周炎症细胞浸润中枢以及抗脱髓鞘从而发挥抗MS活性;前药1体内代谢结果显示,前药1以原型形式在体内的暴露量为熊果酸的6倍,表明前药1可能主要是以钠盐原型发挥抗MS活性。结论 前药1具有较大的抗MS潜力,值得深入研究。该研究为开发具有抗MS活性的熊果酸前药提供一定依据及有益指导。     

Testosterone 17beta-N,N-dimethylglycinate hydrochloride: A prodrug with a potential for nasal delivery of testosterone

The purpose of this study was to examine the potential of the nasal route for the systemic delivery of the poorly water-soluble drug testosterone (TS) using a water-soluble prodrug, TS 17beta-N,N-dimethylglycinate hydrochloride. The physicochemical properties of the prodrug, in vitro hydrolysis in human liver homogenate, and in vivo nasal and intravenous experiments were performed in rats. The aqueous solubility of the prodrug was more than 100 mg/mL, compared with 0.01 mg/mL for TS, and its log partition coefficient between 0.05 M, phosphate buffer (pH 6) and octanol was 2.4. The prodrug was found to generate TS in 33% human liver homogenate and was absorbed from the nasal cavity rapidly and quantitatively. The bioavailabilities of both the prodrug and TS after nasal administration of the prodrug were similar to that after equivalent intravenous doses. These studies in rats suggest that this water-soluble prodrug of TS may have therapeutic utility for the management of TS deficiency.     

Synthesis of congeners and prodrugs. 3. Water-soluble prodrugs of taxol with potent antitumor activity

Taxol has shown good in vivo antitumor activity in a number of test systems. The formulation of taxol for antitumor testing has been difficult. Esterification at either C-2' or C-7 resulted in loss of in vitro tubulin assembly activity but not cytotoxicity. These observations suggested that esters at C-2' and/or C-7, which would tend to promote water solubility, might serve as useful prodrugs of taxol. The reaction of taxol with either succinic anhydride or glutaric anhydride in pyridine solution at room temperature gave the crystalline mono 2'-adducts 1b and 1f, respectively. Salts of these acids (1b, 1f, 1i) were formed by the addition of 1 equiv of the corresponding base, followed by evaporation and/or freeze-drying of the solvent(s). The salts had improved antitumor activity as compared to the free acids. The triethanolamine and N-methylglucamine salts showed greatly improved aqueous solubility and were more active than the sodium salts. The glutarate series was preferred because of the higher activity and the higher yields obtained. 2'-Glutaryltaxol (1f) was coupled with 3-(dimethylamino)-1-propylamine, using CDI, to form in excellent yield the amino amide 1o. The hydrochloride salt (1p) showed good solubility and was extremely potent and active. At 10 mg/kg, in the B16 screen, 1p gave a T/C of 352 with 5 out of 10 cures. In the MX-1 breast xenograft assay, this prodrug gave values of -100 at doses of 40 and 20 mg/kg, with all live animals being tumor free.     

Preparation,characterization and pharmacokinetic studies of total paeony glycoside nanocrystals

Total paeony glycoside (TPG) is obtained from Radix Paeoniae Rubra with a variety of bioactivities. However, the low solubility and bioavailability limit its application. The present study aimed to develop TPG nanocrystals to increase the dissolution and then improve the oral bioavailability. TPG nanocrystals were prepared via precipitation and high-pressure homogenization method. The physical-chemical properties of the optimal TPG nanocrystals in terms of particle size, zeta potential, morphology and crystallinity were evaluated. The results showed that TPG nanocrystals had a mean particle size of (210.2±2.5) nm, a polydispersity index of 0.191±0.033 and a zeta potential of (–22.4±1.2) mV. The result of differential scanning calorimetry showed that the nanocrystals were still in crystalline state after the preparation procedure. Transmission electron microscopy (TEM) results showed that the nanosuspension was in spherical shape. The pharmacokinetics of TPG nanocrystals for rats was investigated by liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Compared with the TPG coarse suspension, TPG nanocrystals exhibited significant increase in AUC_0–∞ (approximately 1.85-fold). Taken together, TPG nanocrystals could be used as a promising drug delivery system due to the enhanced oral bioavailability of TPG.     

HPLC法测定盐酸吲哚美辛2-[2-(6-甲氧基-2-萘基)吗啉基]乙酯的平衡溶解度和脂水分配系数

目的:测定盐酸吲哚美辛2-[2-(6-甲氧基-2-萘基)吗啉基]乙酯在乙醇、乙腈、丙酮、乙酸乙酯等溶剂中的平衡溶解度以及在正辛醇-水和正辛醇-缓冲液体系中的表观油水分配系数。方法:采用HPLC法测定盐酸吲哚美辛2-[2-(6-甲氧基-2-萘基)吗啉基]乙酯的浓度,采用摇瓶法测定其表观油水分配系数。结果:25℃时盐酸吲哚美辛2-[2-(6-甲氧基-2-萘基)吗啉基]乙酯在乙醇、乙腈、丙酮、乙酸乙酯中的平衡溶解度分别为31.36,141.50,575.77,598.68 g.L-1。pH=4时此目的化合物的平衡溶解度最小,而表观油水分配系数最大。结论:盐酸吲哚美辛2-[2-(6-甲氧基-2-萘基)吗啉基]乙酯的平衡溶解度及油水分配系数与介质的pH有关。其水溶性较差,脂溶性好。     

Design of ester prodrugs to enhance oral absorption of poorly permeable compounds: challenges to the discovery scientist

Many drugs are administered at sites that are remote from their site of action. The most common route of drug delivery is the oral route. The optimal physicochemical properties to allow high transcellular absorption following oral administration are well established and include a limit on molecular size, hydrogen bonding potential and adequate lipophilicity. For many drug targets, synthetic strategies can be devised to balance the physicochemical properties required for high transcellular absorption and the SAR for the drug target. However, there are drug targets where the SAR requires properties at odds with good membrane permeability. These include a requirement for significant polarity and groups that exhibit high hydrogen bonding potential such as carboxylic acids and alcohols. In such cases, prodrug strategies have been employed. The rationale behind the prodrug strategy is to introduce lipophilicity and mask hydrogen bonding groups of an active compound by the addition of another moiety, most commonly an ester. An ideal ester prodrug should exhibit the following properties: 1). Weak (or no) activity against any pharmacological target, 2). Chemical stability across a pH range, 3). High aqueous solubility, 4). Good transcellular absorption, 5). Resistance to hydrolysis during the absorption phase, 6). Rapid and quantitative breakdown to yield high circulating concentrations of the active component post absorption. This paper will review the literature around marketed prodrugs and determine the most appropriate prodrug characteristics. In addition, it will examine potential Discovery approaches to optimising prodrug delivery and recommend a strategy for prosecuting an oral prodrug approach.     

赤芍总苷提取液体外清除自由基和抗凝血活性的研究

目的:研究赤芍总苷(TPG)提取液体外清除自由基和抗凝血的活性。方法:通过相同溶剂不同方法提取TPG,采用二苯基三硝基苯肼(DPPH)自由基体系、超氧阴离子自由基体系、羟基自由基体系检测TPG清除自由基的活性,同时测定TPG提取液对凝血酶原时间(PT)、部分凝血酶时间(APTT)、凝血酶时间(TT)的影响。结果:沸水浴0.5h提取2次,TPG含量为4.682%;采用不同方法得到的TPG提取液对DPPH清除率为92.36%～96.65%,抗超氧阴离子活力和活性氧活力分别为415.15～496.97U.L-1和774.32～1911.60U.L-1;当TPG浓度≥0.012g.L-1时可显著延长PT(P<0.05),当TPG浓度≥0.0012g.L-1时可显著延长APTT(P<0.05)和TT(P<0.01)。结论:采用不同方法得到的TPG提取液均有较强的清除自由基和抗凝血活性。     

Acetylacroninium salts as soluble prodrugs of the antineoplastic agent acronine.

The low aqueous solubility of acronine (approximately 2 mg/liter) has been overcome by identification of quaternary prodrug salts exhibiting apparent molar solubilities two to five orders of magnitude greater than acronine. The synthesis and kinetics of hydrolysis of the various prodrug acetylacroninium salts were studied, and the half-life for hydrolysis under conditions approximating the in vivo situation was estimated to be about 5 min. Such rapid reversion, together with the greatly increased solubility, appears to qualify the prodrug for intravenous use.