灯盏乙素苷元4’-N-取代氨甲基苯甲酸酯-7-取代烟酸酯衍生物的合成与体外抗氧化活性研究

本研究以灯盏乙素苷元,N-取代氨甲基苯甲酸以及6-取代烟酸为原料,在偶联剂DCC/DMAP的作用下经4步反应制备了灯盏乙素苷元4’-N-取代氨甲基苯甲酸酯-7-取代烟酸酯衍生物1a~1f,并经1H NMR,ESI-MS以及HRMS确证结构。对化合物1a~1f进行了神经细胞氧化损伤保护活性与理化性质研究,结果显示,烟酸酯结构的引入能够提高化合物抗氧化活性以及水溶性,其中化合物1d具有较高的水溶性、体外稳定性及抗氧化活性,值得进一步研究。     

灯盏乙素苷元4'-L-氨基酸衍生物的设计、合成与抗氧化活性

为了设计合成具有较强神经细胞氧化损伤保护作用及较好理化性质的灯盏乙素苷元4'-L-氨基酸衍生物,以灯盏乙素苷元为先导化合物,根据主动转运原理在改善口服药物生物利用度应用上取得的成功经验,采用拼合设计原理在先导化合物的4'-羟基上引入L-氨基酸酯、醚结构,设计、合成灯盏乙素苷元4'-L-氨基酸衍生物。采用H2O2诱导PC12细胞氧化损伤模型对设计化合物进行了体外抗氧化活性评价,同时进行了目标化合物理化性质研究。结果发现设计的化合物均具有抗氧化活性,5个化合物抗氧化活性优于VE,灯盏乙素苷元L-氨基酸醚类化合物在缓冲液中稳定性(t1/2 9～92 h)优于酯类衍生物(t1/2 0.5 h),灯盏乙素苷元L-氨基酸酯类衍生物18、19与醚类衍生物22、24～27的水溶解度分别为1 796～4 100μg·mL-1和27.7～81.1μg·mL-1,两者水溶性分别达到灯盏乙素的120～280倍和2～6倍。以上研究提示L-氨基酸前药设计策略可适用于灯盏乙素苷元的结构修饰,以获得具有较好抗氧化活性及理化性质的灯盏乙素苷元前药。     

川芎嗪灯盏乙素苷元抗缺血性脑卒中孪药的合成及活性研究

目的:设计合成川芎嗪灯盏乙素苷元孪药,研究其对于缺血性脑卒中的治疗作用.方法:以川芎嗪和灯盏乙素苷元为原药,通过共价键将其拼合,并对所合成目标化合物进行体外抗氧化损伤、抗凝血活性研究,筛选得到目标化合物4进行体内缺血再灌注损伤保护作用研究.结果:设计合成得到6个川芎嗪灯盏乙素苷元孪药,受试化合物均表现出良好的抗氧化损伤...     

灯盏乙素衍生物的合成及其体外抗凝血活性研究

目的 对灯盏乙素葡萄糖醛酸羧基进行结构修饰,合成葡萄糖醛酸羧基酯类衍生物,并测定这些衍生物的体外抗凝血活性。方法 通过将灯盏乙素葡萄糖醛酸羧基先成盐后酯化的方法合成6个灯盏乙素酯类衍生物,其中灯盏乙素乙酯及苄酯为已知化合物,其余4个为新化合物,目标化合物的抗凝血活性采用家兔的贫血小板血浆（PPP）进行凝血酶原时间（PT）、凝血酶时间(TT)、活化部分凝血活酶时间（APTT）及纤维蛋白原（FIB）的测定,以80% EtOH作溶剂,以生理盐水作为阳性对照。结果与结论 合成了6个灯盏乙素酯类衍生物Ⅱa~Ⅱf。药理实验表明,该类衍生物的抗凝血活性没有灯盏乙素强,灯盏乙素羧酸基改造后对凝血活性影响不大。     

“一锅法”制备乙酰灯盏乙素苷元

目的探索制备乙酰灯盏乙素苷元的方法。方法以灯盏乙素为起始原料,与乙酸酐和吡啶共回流,经一步反应获得四乙酰灯盏乙素苷元和部分乙酰化产物6,7,4'-O-三乙酰基灯盏乙素苷元。结果与结论采用"一锅法"合成了乙酰灯盏乙素苷元,总收率在80%以上。乙酰灯盏乙素苷元和其乙酰化产物6,7,4'-O-三乙酰基灯盏乙素苷元均是灯盏乙素结构改造和修饰的重要中间体。与现有的两步合成法相比,本方法具有合成路线短、收率高、反应条件简单等特点,该法为同时获得2个重要中间体提供了有价值的参考。     

青蒿素类似物的研究 Ⅳ.含卤素、氮、硫等杂原子的青蒿素衍生物的合成

为增强双氢青蒿素酯和醚类衍生物的抗疟作用,我们合成了42个侧链上带有卤素、氮或硫取代的双氢青蒿素酯和醚类化合物。抗疟筛选表明,多数化合物的活性高于青蒿素,但并未超过相应的无杂原子取代的衍生物,唯双氢青蒿素的问-三氟甲基苯甲酸酯(17)的抗疟活性为间-甲基苯甲酸酯的4倍,化合物(17)和(6)为青蒿素的10倍。     

灯盏乙素衍生物代谢性质的快速体外评价

目的应用肝微粒体模型研究以灯盏乙素及其苷元为先导的系列化合物代谢特征,筛选代谢性质优于灯盏乙素的化合物。方法采用UPLC-MS/MS法测定大鼠肝微粒体温孵体系中不同时间点各候选化合物的含量,筛选T1/2和CLint较优的候选化合物,比较候选化合物与灯盏乙素的酶促动力学特征及其转化情况。结果与灯盏乙素及其苷元相比,候选化合物W11的半衰期较长、清除率较低;W11酶促动力学参数Vmax为(10.25±0.93)μmol·min-1·g-1,Km为(4.48±0.10)μmol·L-1,CLint为(2.29±0.23)L·min-1·g-1;灯盏乙素酶促动力学参数Vmax为(45.95±9.50)μmol·min-1·g-1,Km为(10.19±1.66)μmol·L-1,CLint为(4.48±0.20)L·min-1·g-1;W11可能代谢为M1(W11脱掉甲基后分子质量为577的化合物),并释放出灯盏乙素。结论候选化合物W11可能具有优于灯盏乙素的代谢性质并能释放活性代谢产物灯盏乙素。     

灯盏乙素衍生物的合成及其生物活性

目的为提高灯盏乙素的生物利用度,设计合成了一系列灯盏乙素衍生物,评价其抗脂质过氧化和抗肿瘤的生物活性。方法通过羟乙基化、羟丙基化、酯化反应合成了一系列灯盏乙素衍生物,采用生化法测试部分衍生物对小鼠脑脂质过氧化产物丙二醛(malondialdehyde,MDA)的抑制作用,采用台盼蓝法测试体外抑制白血病细胞HL-60生长活性。结果合成了13个灯盏乙素衍生物,其中7个为未见文献报道的新化合物,其结构经1H-NMR和MS确证;化合物1、13对MDA的抑制作用显著,6-9具有中等强度的抗肿瘤活性。结论灯盏乙素结构中的酚羟基是其抑制脂质过氧化产物MDA的活性基团,葡萄糖醛酸的6-位游离羧基能够增强抗肿瘤活性。     

N-芳甲酰基-N’-取代嘧啶基硫脲类 化合物的合成与初步活性研究

目的 合成N-芳甲酰基-N’-取代嘧啶基硫脲类化合物,并初步测试其对血管平滑肌细胞增殖的抑制活性。方法　以2-氨基-5-溴-4-取代嘧啶与芳甲酰基异硫氰酸酯反应,得到一系列N-芳甲酰基-N’-取代嘧啶基硫脲类化合物;采用MTT法测定目标化合物对血清诱导的血管平滑肌细胞增殖的抑制活性。结果与结论　合成的10个目标化合物,均未见文献报道,所有目标化合物结构经1H-NMR及MS确证;活性测试结果表明,化合物6b、6c、6g、6j 具有一定的血管平滑肌细胞增殖抑制活性。     

4-氯苯甲酸取代马蹄金素衍生物的合成及其抗HBV活性研究

目的设计和合成含4-氯苯甲酸取代马蹄金素(Matijin-Su,MTS)衍生物,以期寻找到抗乙肝病毒(HBV)活性更强的MTS衍生物。方法以马蹄金素为先导化合物,通过引入4-氯苯甲酸取代,设计合成一系列MTS衍生物并对其进行抗HBV活性测试。结果设计合成了4-氯苯甲酸取代的MTS衍生物11个(3、4a、4b、4c、4d、4e、4f、4g、4h、4i、5),其中化合物4b、4d、4e、4h表现出良好的抗HBV活性,IC50分别为9.19、15.30、13.48、14.90μmol·L~(-1)。结论 4-氯苯甲酸取代的MTS衍生物具有更强的抗HBV活性,具有进一步研究的价值。     

Permeability of novel 4′-<Emphasis Type="Italic">N</Emphasis>-substituted (aminomethyl) benzoate-7-substituted nicotinic acid ester derivatives of scutellarein in Caco-2 cells and in an in vitro model of the blood-brain barrier

A series of 4′-N-substituted (aminomethyl) benzoate-7-substituted nicotinic acid ester derivatives of scutellarein was designed and synthesized. Evaluation of physiochemical properties showed that the newly designed compounds had greater chemical stability and aqueous solubility than scutellarin or scutellarein. The permeabilities (P _{app AP to BL}) of compounds 7b and 7e in Caco-2 cells were 5.9-fold and 3.7-fold higher than that of scutellarin, and 3.7-fold and 2.4-fold higher than that of scutellarein. The permeabilities (P _{app AP to BL}) of compounds 7b and 7e in an in vitro model of the blood–brain barrier were 9.7-fold and 5.9-fold higher than that of scutellarin, and 9.2-fold and 5.6-fold higher than that of scutellarein.     

Pharmacokinetics of scutellarin and its aglycone conjugated metabolites in rats.

Scutellarin, a flavonoid glycoside, is the primary active ingredient in breviscapine that is a mixture of flavonoid glycosides extracted from a Chinese herb Erigeron breviscapus (Vant.) Hand.-Mazz. The pharmacokinetics of scutellarin and its aglycone conjugated metabolites after intraperitoneal injection and oral administration of breviscapine was investigated in rats. The plasma concentration of scutellarin and scutellarein conjugates in serial samples was measured by validated high-performance liquid chromatography methods. The pharmacokinetic results indicated that scutellarin underwent rapid and extensive biotransformation in vivo. After intraperitoneal injection, scutellarin was absorbed rapidly. The profiles of scutellarin and scutellarein conjugates were fitted to a two-compartment open model. Scutellarin and scutellarein conjugates showed a similar time course. No significant difference in tmax, t0.5(alpha) and t0.5(beta) was observed between scutellarin and scutellarein conjugates (p>0.05). After oral administration, fluctuations were observed in the concentration-time profiles of both scutellarin and scutellarein conjugates and the pharmacokinetics could not be explained by classical compartment model. The relative bioavailability of oral administration was very low, 10.67 % +/- 4.78% for scutellarin and 7.92% +/- 1.90% for scutellarein conjugates.     

Pharmacokinetics and metabolism of the flavonoid scutellarin in humans after a single oral administration.

Scutellarin is widely used in treating various cardiovascular diseases. Few data are available regarding its metabolism and pharmacokinetics in humans. The objectives of this study were to develop methods to identify major metabolites of scutellarin in human urine and plasma and to determine simultaneously the parent drug and its major metabolites in human plasma for pharmacokinetic studies. Four metabolites were detected in urine samples by liquid chromatography coupled with electrospray multi-stage mass spectrometry (MS), but only one of them was found in plasma. Its structure was confirmed as scutellarein 6-O-beta-D-glucuronide by MS, NMR, and UV absorbance spectra. The plasma concentrations of scutellarin and the major metabolite were simultaneously determined using liquid chromatography-tandem MS. After a single p.o. administration of 60 mg of scutellarin to 20 healthy subjects, the plasma concentrations of scutellarin were very low, and its plasma concentration-time curve was also anomalous. Plasma concentration of the major metabolite was comparatively high, and the peak plasma concentration was 87.0 +/- 29.1 ng/ml. The Tmax was late (7.85 +/- 1.62 h), and part of individual pharmacokinetic profiles showed double peaks, which indicated scutellarin could be absorbed into the intestine after hydrolysis to its aglycone by bacterial enzymes. This was followed by reconjugation in the intestinal cell and/or liver with glucuronic acid catalyzed by the phase II enzyme, which showed regioselectivity and species difference. The regioselectivity of glucuronoconjugation for scutellarin may be of importance for pharmacological activity. Plasma concentration of isoscutellarin can be used as a biomarker of scutellarin intake.     

Metabolic and pharmacokinetic studies of scutellarin in rat plasma, urine, and feces

Aim:

To study the metabolic and pharmacokinetic profile of scutellarin, an active component from the medical plant Erigeron breviscapus (Vant) Hand-Mazz, and to investigate the mechanisms underlying the low bioavailability of scutellarin though oral or intravenous administration in rats.

Methods:

HPLC method was developed for simultaneous detection of scutellarin and scutellarein (the aglycone of scutellarin) in rat plasma, urine and feces. The in vitro metabolic stability study was carried out in rat liver microsomes from different genders.

Results:

After a single oral dose of scutellarin (400 mg/kg), the plasma concentrations of scutellarin and scutellarein in female rats were significantly higher than in male ones. Between the female and male rats, significant differences in AUC, t_max2 and C_max2 for scutellarin were found. The pharmacokinetic parameters of scutellarin in the urine also showed significant gender differences. After a single oral dose of scutellarin (400 mg/kg), the total percentage excretion of scutellarein in male and female rats was 16.5% and 8.61%, respectively. The total percentage excretion of scutellarin and scutellarein in the feces was higher with oral administration than with intravenous administration. The in vitro t_1/2 and CL_int value for scutellarin in male rats was significantly higher than that in female rats.

Conclusion:

The results suggest that a large amount of ingested scutellarin was metabolized into scutellarein in the gastrointestinal tract and then excreted with the feces, leading to the extremely low oral bioavailability of scutellarin. The gender differences of pharmacokinetic parameters of scutellarin and scutellarein are due to the higher CL_int and lower absorption in male rats.     

RP-HPLC法测定小飞蓬总黄酮中野黄芩苷、槲皮素和木犀草素的含量

目的:建立测定小飞蓬总黄酮(总黄酮含量为76.52%)中野黄芩苷、槲皮素和木犀草素含量的方法。方法:采用反相高效液相色谱法。色谱柱为AgilentZORBAXSB-C18(250mm×4.6mm,5μm),流动相为甲醇-0.5%冰醋酸水溶液(梯度洗脱),检测波长为360nm,流速为1mL·min-1,柱温为30℃。结果:野黄芩苷、槲皮素和木犀草素进样量均在0.52～1.17μg范围内与各自峰面积积分值呈良好线性关系(r均为0.9999);三者平均加样回收率分别为97.23%、96.57%和97.33%,RSD分别为1.44%、0.80%和1.72%(n均为6)。结论:本方法简便、快速、准确,可为有效控制小飞蓬总黄酮的质量提供依据。     

高效液相色谱法测定复方斑蝥胶囊中野黄芩苷含量

目的建立测定复方斑蝥胶囊中野黄芩苷含量的高效液相色谱法。方法采用C18色谱柱(250 mm×4.6 mm,5μm),以甲醇-0.3%磷酸溶液(40∶60)为流动相,检测波长为335 nm。结果野黄芩苷进样量在0.122 76～1.227 6μg范围内与峰面积线性关系良好,加样回收率为98.61%,RSD为0.49%(n=6)。结论高效液相色谱法快速、准确,可用于复方斑蝥胶囊的质量控制。     

Design,Synthesis, and Biological Evaluation of Scutellarein Derivatives Based on Scutellarin Metabolic Mechanism In Vivo

Three series of scutellarein derivatives have been designed and synthesized based on metabolic mechanism of scutellarin ( 1 ) in vivo. Their thrombin inhibition activities were tested through the analyzation of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FIB). The antioxidant activities of these target products were assessed by 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) assay and the ability to protect PC12 cells against H₂O₂‐induced cytotoxicity, and their solubilities were evaluated by ultraviolet (UV) spectrophotometer. The results showed that the two isopropyl groups substituted derivative ( 18c ) demonstrated stronger anticoagulant activity, better water solubility, and good antioxidant activity compared with scutellarein ( 2 ), which warrants further development of 18c as a promising agent for ischemic cerebrovascular disease treatment.