尼日利亚螫毛果(Cnestis ferruginca)中一种具有清除自由基的活性化合物的分离鉴定

用二苯基苦基苯肼自由基薄层实验法（DPPH-TLC-ASSAY）,从尼日利亚螫毛果（Cnestis ferruginca)植物的甲醇提取物中发现了一种具有很强的清除自由基活性的物质;用柱色谱及反相制备柱色谱（RP-LPPLC）,制备出了该活性物质的纯品;用质谱（HR ESI-MS）,核磁共振氢谱（^1H0,碳谱（^13C,DEPT)。紫外光谱及化学方法对该物质进行了结构鉴定,鉴定结果为对苯酚基-6-O-反式咖啡酸基-β-D-吡喃葡萄糖甙。     

黑柄炭角菌产生的DPPH自由基捕捉成分

对黑柄炭角菌深层发酵制品中的DPPH自由基捕捉成分进行研究。经硅胶柱层析、中压液相色谱顺相和反相分离、制备型高压液相色谱分离等一系列步骤 ,共获得相对纯度在85%以上 ,收量在 2mg以上的自由基捕捉物质 2 0个 ,对其中的B4 1 6进行了质谱、1H NMR、13C NMR、1H 13CHMBC、红外光谱等的测定 ,测得分子式为C10 H10 O4 ,推断它为 5,8二羟基 3 甲基 3,4二氢异香豆素。在 2 0 μmol L时 ,它的DPPH自由基捕捉活性为维生素C的 1 67倍 ,维生素E的 2 1倍。     

一种白僵菌代谢产物中生物活性物质的研究 Ⅰ.具有清除自由基的活性物质的分离和制备

通过对白僵菌Beauveriasp.的液体培养及生物活性测定,发现该菌代谢产物具有较强的清除自由基的活性,我们用甲醇成功地提取出该活性成分,同时用色谱等方法对该活性成分进行了分离和制备,并用高压液相色谱法和DPPH薄层试验对其纯度及活性进行了检验,得到了具消除自由基活性的纯化合物P-24-3。     

一种被毛孢菌丝体中抗肿瘤活性组分的分离纯化和液质联用分析

在一次多菌株的生物活性测定中,发现一株被毛孢菌株RCEF0851菌丝体提取物具有较强的抗肿瘤CHO细胞的活性。本研究用不同溶剂对活性组分进行了提取试验,发现乙酸乙酯能最大程度地提取出该活性成分。分离试验表明该提取物较适于用反相柱Synergi Hydro进行分离。活性指导下的分离得到一活性组分的纯品Hh-1。该组分在40μg/mL时对CHO细胞的抑制率达到83.61%。高分辨质谱分析表明该活性化合物的可能分子式是C30H22O10。该分子为首次从虫生真菌中发现。     

尼日利亚螫毛果(Cnestis ferruginca)中一种具有清除自由基的活性化合物的分离鉴定

用二苯基苦基苯肼自由基薄层实验法(DPPH-TLC-ASSAY),从尼日利亚螫毛果(Cnestisferruginca)植物的甲醇提取物中发现了一种具有很强的清除自由基活性的物质;用柱色谱及反相制备柱色谱(RP-LPPLC),制备出了该活性物质的纯品;用质谱(HRESI-MS)、核磁共振氢谱(¹H)、碳谱(¹³C、DEPT)、紫外光谱及化学方法对该物质进行了结构鉴定,鉴定结果为对苯酚基-6-O-反式咖啡酸基-β-D-吡喃葡萄糖甙.     

一种白僵菌代谢产物中生物活性物质的研究 Ⅰ.具有清除自由基的活性物质的分离和制备

通过对白僵菌 Beauveria sp. 的液体培养及生物活性测定,发现该菌代谢产物具有较强的清除自由基的活性,我们用甲醇成功地提取出该活性成分,同时用色谱等方法对该活性成分进行了分离和制备,并用高压液相色谱法和DPPH薄层试验对其纯度及活性进行了检验,得到了具消除自由基活性的纯化合物：P-24-3。     

一种白僵菌代谢产物中生物活性物质的研究——Ⅰ.具有清除自由基？…

通过对白僵菌Ｂｅａｒｖｅｒｉａ ｓｐ．的液体培养及生物活性测定,发现该菌代谢产物个有较强的清除自由基的活性,我们用甲醇成功地提取出该活性成分,同时用色谱等方法对该活性成分进行了分离和制备,并用高压液相色谱法和ＤＰＰＨ薄层试验对其纯讴及活性进行了检验,得到了具消除自由基活性的纯化合物：Ｐ－２４－３。     

高效抗氧化大型真菌的筛选

为获得高效抗氧化菌株,采用直接提取方式从20个大型真菌菌株菌丝体培养液中提取抗氧化活性物质,采用邻苯三酚自氧化法、水杨酸法、DPPH法测定各菌株菌丝体培养粗提液对超氧阴离子自由基(O2)、羟基自由基.(OH)及1,1-二苯代苦味酰基自由基(DPPH-)的清除作用。结果表明:各菌株菌丝体培养粗提液对(O2)、.OH及DPPH-均有一定的清除作用,其中菌株NG菌丝体培养粗提液对OH-的清除效果最好,清除率为75.56%;菌株02菌丝体培养粗提液对(O2-)的清除效果最好,清除率为37.51%;菌株EG菌丝体培养粗提液对DPPH-清除效果最好,清除率为66.91%。     

桦褐孔菌活性物质的提取工艺及体外抗糖尿病活性

对桦褐孔菌活性物质的提取工艺及其体外抗糖尿病活性进行研究。桦褐孔菌子实体用乙醇浸提后,乙醇粗提物用不同有机溶剂萃取,醇提残渣再以热水浸提,用标准曲线法测定活性组分中活性成分的含量,并检测活性物质对羟基自由基(·OH)、超氧阴离子自由基(O2-·)的清除效果以及对关键糖代谢酶α-淀粉酶、α-葡萄糖苷酶的抑制作用。结果表明:4种活性组分(乙酸乙酯相、正丁醇相、水相和粗多糖)对羟基自由基(·OH)和超氧阴离子自由基(O2-·)都有较强的清除作用,其中乙酸乙酯组分的活性最高,乙醇粗提物萃取组分对α-淀粉酶有抑制活性,而粗多糖对α-葡萄糖苷酶有抑制作用;桦褐孔菌具有抗氧化和抗糖尿病活性,其活性与活性物质种类及其含量具有相关性。     

尾叶远志抗氧化活性研究

采自贵州兴义的尾叶远志(Polygala caudata Rehd.et Wils.)根,经乙醇提取,再用不同溶剂萃取和柱层析分离,得到了12个不同的组分.用比色法研究了各组分还原三价铁离子及清除脂性自由基DPPH能力,采用化学发光法观察各组分清除羟自由基和超氧阴离子的活性.研究发现,尾叶远志各组分均有一定的清除自由基作用,并且其活性成分可能主要集中在PC-BuOH组分.     

拟细羽束梗孢发酵菌丝体中自由基清除活性成分分析

用二苯基苦基苯肼(DPPH)自由基法,首次对拟细羽束梗孢(Isaria gracilioides RCEF3 279)菌丝体的不同溶剂提取物进行了自由基清除活性的定性定量分析,发现其甲醇提取物具有较强的清除自由基活性,当菌丝浓度为10 g/L时,其甲醇提取物的自由基清除率达到了92.4％±0.3％.DPPH自显影-薄层...     

Dual-acting agents that possess free radical scavenging and antithrombotic activities: design, synthesis, and evaluation of phenolic tetrahydro-beta-carboline RGD peptide conjugates

A new approach to construct a single dual-acting agent is described. Compounds 6a-c are potent free radical scavengers as demonstrated by the EC(50) values in PC12 cell survival assay in term of NO, H(2)O(2), and ()OH scavenging activity. The Ach-induced vaso-relaxation assay further confirms the potent NO scavenging activity of compounds 6a-c. In addition, 6a-c are efficacious in a rat arterial thrombosis, and are active in ADP- or PAF-induced in vitro platelet aggregation assay, suggesting that compounds 6a-c also possess anti-thrombotic activities. Since both free radical and thrombogenesis are important risk factors in myocardial ischemic/reperfusion injuries, these dual-acting agents having both free radical scavenging and antithrombolic activities may potentially be beneficial toward their treatment.     

Pyridine nucleotide-dependent generation of hydrogen peroxide by a particulate fraction from human neutrophils

The catalytic oxidation of [14C]-formate to 14CO2 was adapted to measure H2O2 formation in cellfree system. Standard curves employing glucose-glucose oxidase and xanthine-xanthine oxidase demonstrated linearity between 14CO2 evolution and enzyme concentration. A particulate fraction from human neutrophils was capable of oxidizing [14C]-formate; this reaction was dependent upon the presence of catalase, reduced pyridine nucleotide, and cellular material. Reaction increased with time of incubation and protein concentration, although not in a strictly linear fashion. The pH optimum was approximately 5.5 NADPH was a significantly better substrate than NADH, although both were capable of generating H2O2. The particulate fraction derived from phagocytizing cells was more active than a corresponding fraction from resting cells with either substrate. H2O2 production was abnormal in particulate fractions derived from 2 patients with chronic granulomatous disease. H2O2 production was markedly inhibited by superoxide dismutase or cytochrome c (scavengers of superoxide anion) but not by scavengers of singlet oxygen or hydroxyl radical. Reaction was greatly stimulated by the addition of manganous ion. These results are consistent with the hypothesis that the respiratory burst in human neutrophils is initiated by an oxidase that can utilize either NADPH or NADH but exhibits a marked preference for the former. Further, the inhibitor studies strongly support a mechanism involving an initial enzymatic reaction followed by a self-sustaining free radical reaction involving superoxide anion.     

An Alternative Standard for Trolox‐Equivalent Antioxidant‐Capacity Estimation Based on Thiol Antioxidants. Comparative 2,2′‐Azinobis[3‐ethylbenzothiazoline‐6‐sulfonic Acid] Decolorization and Rotational Viscometry Study Regarding Hyaluronan Degradation

Comparison of the effectiveness of antioxidant activity of three thiol compounds, D ‐penicillamine, reduced L ‐glutathione, and 1,4‐dithioerythritol, expressed as a radical‐scavenging capacity based on the two independent methods, namely a decolorization 2,2′‐azinobis[3‐ethylbenzothiazoline‐6‐sulfonic acid] assay and a rotational viscometry, is reported. Particular concern was focused on the testing of potential free‐radical scavenging effects of thiols against hyaluronan degradation, induced by hydroxyl radicals. A promising, solvent‐independent, antioxidative function of 1,4‐dithioerythritol, comparable to that of a standard compound, Trolox^®, was confirmed by the 2,2′‐azinobis[3‐ethylbenzothiazoline‐6‐sulfonic acid] assay. The new potential antioxidant 1,4‐dithioerythritol exhibited very good solubility in a variety of solvents (e.g., H₂O, EtOH, and DMSO) and could be widely accepted and used as an effective antioxidant standard instead of a routinely used Trolox^® on 2,2′‐azinobis[3‐ethylbenzothiazoline‐6‐sulfonic acid] assay.     

Antioxidant activity in vitro of two aromatic compounds from Caesalpinia sappan L

Two antioxidant compounds were isolated from C. sappan L by multiple steps of column chromatography and thin layer chromatography in succession with superoxide scavenging assay as activity monitor. Structures of the two compounds were determined by spectroscopic methods as 1',4'-dihydro-spiro[benzofuran-3(2H),3'-[3H-2]benzopyran]-1',6',6',7'-tetrol (compound 1) and 3-[[4,5-dihydroxy-2(hydroxymethyl) phenyl]-methyl]-2,3-dihydro-3,6-benzofurandiol (compound 2). Characterization of antioxidant properties of these two compounds was done by determining the inhibitory effect on xanthine oxidase activity as well as scavenging effect on superoxide anion and hydroxyl radicals. Our results indicated that compounds 1 and 2 inhibited xanthine oxidase activity and scavenged superoxide anion and hydroxyl radicals. Compounds 1 and 2 possessed similar radical scavenging activities as ascorbic acid, and they were more effective than other well-known antioxidants such as alpha-tocopherol, beta-carotene, and BHT. As inhibitors of free radical formation, compounds 1 and 2 were more effective than all the other antioxidants tested. In conclusion, compounds 1 and 2 can be regarded as primary antioxidants with radical-scavenging and chain-breaking activities as well as secondary antioxidants with inhibitory effect on radical generation.     

四株虫生真菌的鉴定及其醇提取物对Hela细胞的抑制作用

【背景】虫生真菌是非常重要的自然资源,但被发现和利用的种类相对较少。【目的】鉴定从野外采集的4株虫生真菌,并探讨4株菌的醇提物对宫颈癌Hela细胞的抑制活性。【方法】结合形态学特征与rDNA ITS和β-Tubulin序列分析对4株虫生真菌进行种类鉴定,采用四甲基偶氮唑盐[3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl-2-H-Tetrazolium Bromide,MTT]比色法分析它们的菌丝醇提物(M-1、M-2、M-3、M-4)和发酵液醇提物(F-1、F-2、F-3、F-4)对Hela细胞增殖的抑制活性,并进一步利用细胞形态学观察和流式细胞术检测所筛选抑制作用最强的醇提取物的抑制活性。【结果】经鉴定,菌株IS和LS均为环链棒束孢(Isaria cateniannulata),菌株HLS和HLS2均为粉棒束孢(Isaria farinosa);MTT实验结果显示8种醇提物对Hela细胞增殖均有一定的抑制作用,而且菌丝醇提物和发酵液醇提物的抑制作用大小排序均为:粉棒束孢HLS>环链棒束孢LS>粉棒束孢HLS2>环链棒束孢IS,其中,粉棒束孢HLS的发酵液醇提物F-3的抑制活性最强(P<0.001),处理24h后其IC₅₀值为0.6678 mg/mL,而其他7种醇提物的IC₅₀值均大于1 mg/mL;细胞形态学观察显示F-3在处理时间24h时,对Hela细胞生长的抑制作用随着浓度的增加而加大,而对正常细胞BHK-21仅有轻微的毒性作用;流式细胞仪检测发现F-3可诱导Hela细胞凋亡,当处理浓度为1.0 mg/mL时,细胞总凋亡率可达到32.45%。【结论】4株菌对Hela细胞增殖的抑制作用存在着显著差异,这可能与4株菌的地理来源、寄主等因素有关;来源于粉棒束孢HLS株系的发酵液醇提物F-3对正常细胞BHK-21的增殖和生长无显著抑制作用,但对Hela癌细胞的增殖和生长抑制活性最强,而且具有诱导肿瘤细胞凋亡的作用,暗示其具有研究利用价值。     

Design and synthesis of benzo[c,d]indolone-pyrrolobenzodiazepine conjugates as potential anticancer agents

A series of benzo[c,d]indol-2(1H)one-PBD conjugates (11a-l) have been designed and synthesized as potential anticancer agents. These compounds were prepared by linking the C8-position of DC-81 with a benzo[c,d]indol-2(1H)one moiety through different alkane spacers in good yields and confirmed by (1)H NMR, mass and HRMS data. The DNA binding ability of these conjugates was evaluated by thermal denaturation studies and interestingly, compound 11l showed enhanced DNA binding ability. These compounds were also evaluated for their anticancer activity in selected human cancer cell lines of lung, skin, colon and prostate by using MTT assay method. These new conjugates showed promising anticancer activity with IC(50) values ranging from 1.05 to 36.49 μM. Moreover, cell cycle arrest in SubG1 phase was observed upon treatment of A549 cells with 1 and 2 μM (IC(50)) concentrations of compound 11l and it induced apoptosis. This is confirmed by Annexin V-FITC, Hoechst staining, caspase-3 activity as well as DNA fragmentation analysis.