甲壳素/壳聚糖及其衍生物抗菌、抗肿瘤活性研究进展

主要从甲壳素 /壳聚糖及其衍生物在抗菌、抗肿瘤活性两方面的研究进展进行了综述。     

氨基酸5-氟尿嘧啶酯类衍生物的合成及其抗肿瘤活性研究

以N-保护的氨基酸钾盐与1-(ω-溴丙基)-5-氟尿嘧啶和1-(ω-溴丁基)-5-氟尿嘧啶反应,制备了18种氨基酸的ω-(N¹-5-氟尿嘧啶基)-丙醇酯和丁醇酯的盐酸盐,并确定了它们的结构。动物试验的初步结果表明,酪氨酸、苯丙氨酸的3-(N¹-5-氟尿嘧啶基)-丙醇酯盐酸盐对小鼠艾氏腹水癌的抑制率分别为88.1%和86.7%。     

稀土-全反式维甲酸-精氨酸三元配合物的合成、表征及抗肿瘤活性研究

合成了4种新型稀土三元固体配合物:REL2L′Cl·nH2O(RE:Nd3+、Eu3+、La3+、Sc3+;L=全反式维甲酸;L′=L-精氨酸阳离子),并对其进行红外光谱、紫外光谱、荧光光谱、元素分析和TG-DTA等测试。利用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)测试方法,初步探讨了配合物对体外培养的人肝癌细胞HepG2、人肺癌细胞A549和人宫颈癌细胞Hela生长的影响。结果表明:4种稀土配合物和稀土硝酸盐、配体全反式维甲酸和L-精氨酸盐酸盐对3种癌细胞株的生长都有一定的抑制作用,但在一定的浓度范围内,三元固体配合物的抑制效果明显优于稀土硝酸盐和2种配体;稀土配合物对3种癌细胞株生长的抑制作用基本上随配合物浓度的增大而增强;在浓度为1 mmol·L-1时,4种配合物对3种肿瘤细胞的抑制率超过60%,ScL2L′Cl配合物表现出最强的作用,抑制率在80%以上。通过荧光,粘度和紫外光谱方法研究了配合物与药物靶分子DNA的相互作用,结果表明配合物与DNA以嵌入的方式相互作用,推测配合物抗肿瘤活性的起效与这种嵌入DNA双螺旋结构的作用方式有关     

稀土-全反式维甲酸-精氨酸三元配合物的合成、表征及抗肿瘤活性研究

为进一步研究稀土配合物作为药物使用方面的应用,本文报道了4种新型稀土三元固体配合物：REL₂L’Cl·nH₂O（RE：Nd³⁺、Eu³⁺、La³⁺、Sc³⁺;L=全反式维甲酸;L’=L-精氨酸阳离子）的合成和红外光谱、紫外光谱、荧光光谱、元素分析和TG-DTA的测试结果。并利用3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐（MTT）测试方法,初步探讨了配合物对体外培养的人肝癌细胞HepG₂、人肺癌细胞A₅₄₉和人宫颈癌细胞Hela生长的影响。结果表明：4种稀土配合物和稀土硝酸盐、配体全反式维甲酸和L-精氨酸盐酸盐对3种癌细胞株的生长都有一定的抑制作用,但在一定的浓度范围内,三元固体配合物的抑制效果明显优于稀土硝酸盐和2种配体;稀土配合物对3种癌细胞株生长的抑制作用基本上随配合物浓度的增大而增强;在浓度为1mmol·L^-1时,4种配合物对3种肿瘤细胞的抑制率超过60%,ScL₂L’Cl配合物表现出最强的作用,抑制率在80%以上。通过荧光,粘度和紫外光谱方法研究了配合物与药物靶分子DNA的相互作用,结果表明配合物与DNA以嵌入的方式相互作用,推测配合物抗肿瘤活性的起效与这种嵌入DNA双螺旋结构的作用方式有关。本文的研究工作为设计合成高效低毒的稀土抗肿瘤药物提供了一定的思路和实验依据。     

Synthesis and Tuberculostatic Activity of Methyl 3-Isonicotinoyldithiocarbazate and S,S'-Dimethyl Dithiocarbonate Isonicotinoylhydrazone, and Their Reactions with Amines and Hydrazines

Methyl 3-isonicotinoyldithiocarbazates and S,S'-dimethyl dithiocarbonate isonicotinoylhydrazone were prepared. Their reactions with primary and secondary amines, diamines, and hydrazines were studied. The newly obtained derivatives did not show tuberculostatic activity in vitro.     

电解煤浆制氢阳极的制备及电催化活性研究

将钛片进行预处理, 用处理后的钛片作为电极基体, 然后用循环伏安法在钛基体上沉积制备了Pt/Ti, Pt-Ru/Ti, Pt-Ir/Ti, Pt-Ru-Ir/Ti催化电极, 通过扫描电镜(SEM)、X射线衍射(XRD)、电子能谱(EDS)以及等离子发射光谱(ICP)等方法对所制备电极进行了表征, 包括电极表面形貌、组分的沉积状态、催化层成分组成以及电极寿命等; 在煤浆电解过程中, 采用两电极体系, 对所制备电极的电催化活性进行了测试. 结果表明: 所制备的电极催化活性都高于同面积的铂片电极, 含有Ru, Ir的二元催化电极的活性好于镀铂催化电极. 在一定范围内, 随着Ru元素比例增大, 电极活性增强, 而Ir元素含量过大, 电极活性反而稍微降低, 所以Pt-Ir(1∶0.5)/Ti, Pt-Ru(1∶5)/Ti两电极的催化活性相对较好. 本文所制备的三元催化电极的催化活性低于二元催化电极. Pt-Ru/Ti电极催化活性最好, 相同条件下具有最大的电解电流, H₂的电解效率可达95%以上.     

镧、钆、镱三种稀土离子诱导背根神经元凋亡及膜上钾电流的比较研究

运用流式细胞仪和膜片钳技术研究La3+,Gd3+,Yb3+三种稀土离子诱导大鼠背根神经元DRG凋亡以及膜上钾离子通道的影响。结果表明:10,100,1000μmol.L-1LaCl3和GdCl3处理DRG神经元96 h,细胞不出现凋亡;YbCl3处理96 h,细胞的凋亡率明显递增。胞外La3+,Gd3+,Yb3+抑制瞬间外向钾电流IA,使IA的激活和失活过程都显著右移,抑制和右移的程度La3+最弱,Gd3+次之,Yb3+最强;胞内的La3+,Gd3+,Yb3+抑制延迟整流钾电流IK,抑制的程度也呈增长趋势。稀土离子在胞内外的结合位点不同;Yb3+较La3+和Gd3+的神经毒性强。     

Synthesis of Novel Methyl 7-[(Hetero)arylamino]thieno[2,3-b]pyrazine-6-carboxylates and Antitumor Activity Evaluation: Effects in Human Tumor Cells Growth,Cell Cycle Analysis,Apoptosis and Toxicity in Non-Tumor Cells

Several novel methyl 7-[(hetero)arylamino]thieno[2,3-b]pyrazine-6-carboxylates were synthesized by Pd-catalyzed C–N Buchwald–Hartwig cross-coupling of either methyl 7-aminothieno[3,2-b]pyrazine-6-carboxylate with (hetero)arylhalides or 7-bromothieno[2,3-b]pyrazine-6-carboxylate with (hetero)arylamines in good-to-excellent yields (50% quantitative yield), using different reaction conditions, namely ligands and solvents, due to the different electronic character of the substrates. The antitumoral potential of these compounds was evaluated in four human tumor cell lines: gastric adenocarcinoma (AGS), colorectal adenocarcinoma (CaCo-2), breast carcinoma (MCF7), and non-small-cell lung carcinoma (NCI-H460) using the SRB assay, and it was possible to establish some structure–activity relationships. Furthermore, they did not show relevant toxicity against a non-tumor cell line culture from the African green monkey kidney (Vero). The most promising compounds (GI₅₀ ≤ 11 µM), showed some selectivity either against AGS or CaCo-2 cell lines without toxicity at their GI₅₀ values. The effects of the methoxylated compounds 2b (2-OMeC₆H₄), 2f and 2g (3,4- or 3,5-diOMeC₆H₃, respectively) on the cell cycle profile and induction of apoptosis were further studied in the AGS cell line. Nevertheless, even for the most active (GI₅₀ = 7.8 µM) and selective compound (2g) against this cell line, it was observed that a huge number of dead cells gave rise to an atypical distribution on the cell cycle profile and that these cells were not apoptotic, which points to a different mechanism of action for the AGS cell growth inhibition.     

A Study on the Chemistry and Biological Activity of 26-Sulfur Analogs of Diosgenin: Synthesis of 26-Thiodiosgenin S-Mono- and Dioxides,and Their Alkyl Derivatives

A chemoselective procedure for MCPBA oxidation of 26-thiodiosgenin to corresponding sulfoxides and sulfone was elaborated. An unusual equilibration of sulfoxides in solution was observed. Moreover, α-alkylation of sulfoxide and sulfone was investigated. Finally, the biological activity of obtained compounds was examined.     

(E)-N-芳基-3-[2-(8-羟基喹啉基)-乙烯基]咔唑的合成、抗氧化活性及促进鼠骨髓间质干细胞增殖的研究

设计合成了3-[2-(8-羟基喹啉基)-乙烯基]-N-对甲苯基咔唑(8)和3-[2-(8-羟基喹啉基)-乙烯基]-N-对甲氧苯基咔唑(9)两个新的化合物, 用IR, MS, 1H NMR和元素分析确认其结构. 并利用DPPH•方法, 超氧阴离子自由基( )法, 羟基自由基HO•法和噻唑蓝比色法(MTT法)分别测定了目标产物的抗氧化活性和调控鼠骨髓间质干细胞(MSCs)的作用. 结果表明, 这两种化合物对DPPH•自由基、超氧阴离子自由基和羟基自由基具有较强的抗氧化活性, 化合物9在低浓度时对鼠骨髓间质干细胞增殖有很好的促进作用.