大血藤抗氧化及抗菌活性研究

本文评价了大血藤乙醇提取物和石油醚、二氯甲烷、乙酸乙酯和水部位的体外抗氧化和抑菌活性以及与总酚含量的相关性。采用清除DPPH自由基法、Fe3+还原力法评价了各部位的抗氧化活性,采用纸片扩散法评价各部位的抑菌活性。采用Folin-Ciocalteu法测定各部位总酚含量,并采用HPLC-UV解析活性部位物质基础。结果表明,水部位清除DPPH能力最强(IC505.53μg/m L),优于对照组Vc,其它部位顺序为乙酸乙酯部位乙醇提取物二氯甲烷部位石油醚部位,还原Fe3+的能力顺序与此相同。总酚含量与抗氧化活性正相关。石油醚部位、二氯甲烷部位、乙酸乙酯部位有中等强度的抑制革兰氏阴性菌作用。表明大血藤可能会成为有价值的天然抗氧化和抗菌资源。     

虎刺抗氧化和抗菌活性研究

考察虎刺80%乙醇提取物和石油醚、二氯甲烷、乙酸乙酯、水溶性部位的抗氧化和抗菌活性以及与总黄酮含量的关系。乙酸乙酯部位在清除DPPH自由基和还原力模型中抗氧化活性最强,水溶性部位在总抗氧化力模型中抗氧化活性最强,而石油醚部位抗氧化活性最弱。二氯甲烷部位、乙酸乙酯部位和石油醚部位具有一定的抑菌活性。虎刺黄酮类成分可能是其抗氧化的物质基础。     

香露兜叶的抗氧化活性(英文)

本文评价了香露兜叶的乙醇提取物以及石油醚、乙酸乙酯、正丁醇和水相组分的抗氧化活性。在体外测定了提取物和组分的总抗氧化活性,二苯代苦味肼基(DPPH)自由基清除活性,超氧阴离子自由基清除活性和铁离子还原能力,并利用分光光度法测定了其总酚和总黄酮的含量。结果表明,所有的提取物和组分均表现出抗氧化和自由基清除活性。抗氧化活性的大小如下:正丁醇部分>乙酸乙酯部分>乙醇提取物>水部分>石油醚部分。总酚含量的顺序和其相似,说明提取物和组分中的酚类化合物使其具有抗氧化活性。香露兜叶提取物可能会成为有价值的天然抗氧化资源,并将在保健品和食品中得到应用。     

排风藤内生真菌PFT-2发酵产物抗氧化活性研究北大核心CSCD

采用DPPH·法及Fe3+还原力法对排风藤内生真菌PFT-2提取物的抗氧化活性进行研究,首先测定发酵液乙酸乙酯萃取物和菌丝体甲醇总提物的活性,然后测定菌丝体总提物各极性部位,即石油醚、氯仿、乙酸乙酯、正丁醇,丙酮、甲醇和水层剩余物部位的活性,同时以VC作为阳性对照。结果表明:内生真菌PFT-2菌丝体甲醇总提取物各样品抗氧化活性较强,尤其是甲醇提取物部位、丙酮提取物部位和正丁醇部位;它们对DPPH·的清除作用与Vc相当,其中甲醇提取物部位IC50值为0.023 mg/m L,活性略高于VC,同时以上提取物对Fe3+也具有很强的还原能力。     

排风藤内生真菌PFT-2发酵产物抗氧化活性研究

采用DPPH·法及Fe3+还原力法对排风藤内生真菌PFT-2提取物的抗氧化活性进行研究,首先测定发酵液乙酸乙酯萃取物和菌丝体甲醇总提物的活性,然后测定菌丝体总提物各极性部位,即石油醚、氯仿、乙酸乙酯、正丁醇,丙酮、甲醇和水层剩余物部位的活性,同时以VC作为阳性对照。结果表明:内生真菌PFT-2菌丝体甲醇总提取物各样品抗氧化活性较强,尤其是甲醇提取物部位、丙酮提取物部位和正丁醇部位;它们对DPPH·的清除作用与Vc相当,其中甲醇提取物部位IC50值为0.023 mg/m L,活性略高于VC,同时以上提取物对Fe3+也具有很强的还原能力。     

红背叶提取物的体外抗氧化活性

采用DPPH法、FRAP法、ABTS法和清除羟基自由基法四种抗氧化活性方法,测定了红背叶不同溶剂萃取60%EtOH提取物得到的部位清除自由基的能力.结果表明,乙酸乙酯提取物的抗氧化能力最强,强于阳性对照VC和Trolox;其次是60%乙醇提取物,其抗氧化能力基本与阳性对照BHA相当.     

益智的抗氧化作用

本文探讨了益智(Alpinia oxyphylla Miquel)超临界CO2提取物及其渣的水提物、正丙醇提取物和乙酸乙酯提取物的抗氧化作用,测定了总酚含量、黄酮含量、抗氧化力、还原能力、DPPH清除率.结果表明,益智超临界CO2提取物和正丙醇提取物的总酚含量最高,均为5.53%,乙酸乙酯提取物的总酚含量为4.04%,水提物总酚含量最低,为O.89%.抗氧化力与酚含量相关(R2=0.703).四种提取物中黄酮含量顺序为:乙酸乙酯提取物(6.29%)＞丙醇提取物(5.81%)＞水提取物(4.85%)＞超临界CO2提取物(4.70%).在还原能力、清除DPPH自由基和羟自由基方面,乙酸乙酯提取物表现出了很强的抗氧化能力,呈现剂量依赖关系.     

黄连抗氧化活性研究

利用DPPH、FRAP和ABTS三种抗氧化活性分析方法对黄连植物不同部位的有机溶剂提取部分进行抗氧化评价,将所测定结果与Trolox进行比较,发现黄连植物不同部位抗氧化活性不同。其中,黄连须根的抗氧化活性最高;同一部位中,乙酸乙酯和甲醇提取物抗氧化活性一般要高于石油醚提取物。在三种方法中,黄连不同部位的提取物清除自由基的能力均随浓度增大而增大;三种方法之间有很好的相关性,以FRAP法与DPPH法相关性最好(r=0.9261,P<0.01)。     

桐花树叶醇提取物乙酸乙酯部位对大鼠皮肤抗氧化与抗衰老能力的影响

萃取法获得桐花树叶75%乙醇提取物的石油醚、二氯甲烷、乙酸乙酯、正丁醇和水部位(醇沉),从中筛选出多酚与总黄酮含量均较高、DPPH自由基清除能力较强的乙酸乙酯部位作为辅料试配成膏状体,并通过对SD大鼠背部皮肤进行连续外涂实验,测定其皮肤组织匀浆的总超氧化物歧化酶(T-SOD)活性、羟基自由基清除能力、丙二醛(MDA)含量、羟脯氨酸(HYP)和胶原蛋白含量。结果表明:2.0%桐花树叶乙酸乙酯部位膏状体处理组的皮肤组织T-SOD活性、羟基自由基清除能力、HYP和胶原蛋白含量均极显著高于,但MDA含量极显著低于阴性对照组(仅含化妆品基质的膏状体)、阳性对照组(2.0%熊果苷膏状体)与1.0%、0.5%乙酸乙酯部位膏状体处理组(P0.01)。说明桐花树叶乙酸乙酯部位是一种潜在的抗氧化或抗衰老化妆品辅料,2.0%乙酸乙酯部位含量是试配该化妆品的有效添加剂量。增强T-SOD活性、提高自由基清除能力、降低MDA含量、促进胶原蛋白合成可能是桐花树叶乙酸乙酯部位预防或延缓皮肤衰老的作用机制。     

天山雪莲不同器官中黄酮、总酚含量和抗氧化活性分析

研究了天山雪莲不同部位的总黄酮、总酚含量及抗氧化活性。以天山雪莲根、茎、叶、花、花苞片为材料,测定其80%乙醇提取物的总黄酮含量、总酚含量、Fe3+还原力和对DPPH自由基的清除率。结果表明,天山雪莲中总黄酮和总酚的含量高低依次为叶花苞片≈花根茎;对Fe3+还原能力大小次序是叶花苞片花根茎;对DPPH的清除能力依次为叶≈花苞片花根茎。实验结果表明叶片可以作为天山雪莲采摘和药用的主要部位;天山雪莲花苞片中可能含有黄酮和酚类之外的抗氧化物质。     

印度块菌提取物抗氧化活性的研究

对印度块菌Tuber indicum子实体的提取物,包括55%乙醇粗提物(ECE)、石油醚提取物(PEF)和乙酸乙酯提取物(EAF)的清除DPPH自由基和羟基自由基能力、铁离子鳌合能力以及各提取物的总酚含量等进行了研究和测定,结果显示,3种提取物的清除自由基能力和铁离子鳌合能力具有显著差异(P0.05);ECE对DPPH自由基的清除活性最高,其EC50值为1.61g/L;EAF对羟基自由基及铁离子表现出较强的清除或螯合的能力,其EC50值分别为3.31g/L和0.70g/L;EAF的总酚含量(2.964mg GAE/g提取物)最高,其次是ECE,总酚含量为(2.618mg GAE/g提取物);PEF的清除自由基和铁离子鳌合能力较差,其总酚含量也最低(1.124mg GAE/g提取物);总酚含量与印度块菌提取物清除自由基以及鳌合铁离子的能力密切相关。     

Antioxidant properties of methanol extract and its solvent fractions obtained from selected Indian red seaweeds

In vitro antioxidant activities of three selected Indian red seaweeds - viz., Euchema kappaphycus, Gracilaria edulis and Acanthophora spicifera were evaluated. Total phenolic content and reducing power of crude methanol extract were determined. The antioxidant activities of total methanol extract and five different solvent fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were also evaluated. EA fraction of A. spicifera exhibited higher total antioxidant activity (32.01 mg ascorbic acid equivalent/g extract) among all the fractions. Higher phenolic content (16.26 mg gallic acid equivalent/g extract) was noticed in PE fraction of G. edulis. Reducing power of crude methanol extract increased with increasing concentration of the extract. Reducing power and hydroxyl radical scavenging activity of E. kappaphycus were higher compared to standard antioxidant (alpha-tocopherol). The total phenol content of all the seaweeds was significantly different (P<0.05). In vitro antioxidant activities of methanol extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.     

朱红栓菌提取物抗氧化、抗肿瘤活性评价及相关化学成分分析

采用石油醚、乙酸乙酯、乙醇浸提朱红栓菌 Trametes cinnabarina 子实体干粉,得到不同极性提取物;采用清除DPPH 自由基、羟自由基、超氧阴离子自由基能力,测定提取物的体外抗氧化活性;MTT法检测提取物对人肝癌细胞株HepG2细胞增殖的抑制作用。结果表明,朱红栓菌石油醚、乙酸乙酯、乙醇提取物均具有一定的抗氧化、抗肿瘤活性;各提取物在浓度为4-5mg/mL时,对DPPH自由基、羟自由基和超氧阴离子自由基清除能力大小依次为乙酸乙酯提取物>乙醇提取物>石油醚提取物;乙酸乙酯提取物对3种自由基的最高清除率分别为60.23%、74.49%、63.84%。各提取物对人肝癌细胞株HepG2细胞增殖抑制作用大小依次为乙酸乙酯提取物>乙醇提取物>石油醚提取物;乙酸乙酯提取物的抑制率最高达55.93%。采用硅胶和凝胶等柱色谱方法结合核磁、波谱和质谱等技术对乙酸乙酯提取物的化学组分进行分析,共分离纯化出11种化合物,分别鉴定为：麦角甾醇（1）,邻苯二甲酸二丁酯（2）,对羟基苯甲酸甲酯（3）,麦角甾-7,22,二烯-3-酮（4）,1-[(12E,16E)-12,16-二十碳二烯酰基]-2-[(E,E)-7,11-十八碳二烯酰基]-3-硬脂酰基甘油（5）,cinnabarin（6）,过氧麦角甾醇（7）,尿嘧啶（8）,甘露醇（9）,腺嘌呤核苷（10）,豆甾-7,22-二烯-3β,5α,6β-三醇（11）。除化合物6外均为首次从朱红栓菌子实体中分离得到。研究结果为开发利用朱红栓菌子实体提供了科学依据。     

Antioxidant activity of the phenol rich fractions of leaves of Chukrasia tabularis A. Juss

The present study was designed to explore the antioxidant potential of chloroform, ethyl acetate, n-butanol and water fractions of 80% methanol extract of leaves Chukrasia tabularis by 2,2'-diphenyl-1-picrylhydrazyl (DPPH), deoxyribose degradation (non-site specific and site specific), reducing power and DNA nicking assays. The different fractions showed significant activities in all the free radical scavenging tests and these findings have also shown direct relationship between antioxidant activity and phenolic content. Among the fractions, ethyl acetate fraction exhibited highest inhibition of 93.14%, 89.99%, 87.04% in DPPH, non-site specific and site specific deoxyribose degradation assays, respectively and 91.20% reduction of ferricyanide to give Prussian blue coloured complex in reducing power assay at maximum concentration tested. This preliminary study indicates the antioxidant activity of the leaves of Chukrasia tabularis, and moreover the results showed correlation with the amount of phenolic content present in different fractions.     

Various solvent effects on phytochemical constituent profiles,analysis of antioxidant and antidiabetic activities of Hopea parviflora

The current research has been designed to assess the phytochemical composition, antioxidant and antidiabetic properties of Hopea parviflora, sequentially extracted with petroleum ether, chloroform, ethyl acetate, ethanol and methanol. All the five extracts were tested for qualitative and quantitative phytochemicals. DPPH, Superoxide, FRAP, ABTS and metal chelating antioxidant activities were evaluated. Antidiabetic potentials of all the five extracts were tested using standard in vitro α- amylase and α - glycosidase inhibition assays. Qualitative phytochemical screening showed the presence of alkaloids in all the extracts except petroleum ether and ethyl acetate. Steroids were present in the petroleum ether, ethyl acetate and chloroform extracts whereas glycosides were present in all the extracts, except ethanol. The total phenol, flavonoid, tannin and saponins contents varied from solvent to solvent, with the highest values being 18.9, 18.2, 0.98 and 39.9 mg/mL, respectively. Methanolic extract showed the highest antioxidant activities in DPPH, FRAP and superoxide assays. Moreover, effective results were observed for the ethanol and ethyl acetate extracts in the ABTS and metal chelating assays. The methanolic extract showed potential antidiabetic activities with the IC₅₀ values of 230.2 and 308.2 μg/mL in α- amylase and α -glycosidase inhibition assays, respectively.     

Antioxidant activities of extracts and fractions from Lysimachia foenum-graecum Hance

The antioxidant activities of water extract, methanol extract, ethyl acetate, and n-BuOH fractions of methanol extract from Lysimachia foenum-graecum Hance were investigated in this study. Various methods, such as the total antioxidant capacity measured by phosphomolybdenum method, scavenging activities towards 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, superoxide anion radical, and hydroxyl radical, were established in in vitro systems. The amounts of total phenolics and total flavonoids in the extracts and fractions were also determined by spectrophotometric methods. The results showed that all the extracts and fractions exhibited antioxidant and radical-scavenging activities at different magnitudes of potency. The decreasing order of antioxidant and radical-scavenging activities among the extracts assayed through all the four methods were found to be ethyl acetate fraction>n-BuOH fraction>methanol extract>water extract. This similar order of the amounts of total phenolics and total flavonoids shows that the extent of antioxidant and radical-scavenging activities is in accordance with the amounts of phenolics and flavonoids present in extracts and fractions. The extracts of L. foenum-graecum Hance might be valuable antioxidant natural sources and seemed to be applicable in both healthy medicine and food industry.     

桑黄菌丝体和子实体中次级代谢产物及其活性的比较

研究桑黄发酵菌丝体次级代谢产物及活性与子实体的差异性,探讨其替代子实体的可能性。研究通过高效液相色谱分析和化学法比较菌丝体和子实体石油醚、氯仿、乙酸乙酯和正丁醇4个萃取相中的成分差异,以二苯基三硝基苯肼自由基（DPPH）清除率和Trolox当量抗氧化能力（TEAC）作为抗氧化活性的指标、HepG2和MCF-7癌细胞的抑制率作为抑制肿瘤细胞生长的指标,比较其活性差异。结果表明,菌丝体和子实体4个萃取相在化学成分上存在差异;在活性方面,菌丝体各萃取相的抗氧化活性高于子实体,而子实体抗肿瘤活性优于菌丝体。菌丝体醇提取的总黄酮含量高于子实体醇提物,抗氧化活性和总黄酮含量有显著相关性,发酵菌丝体在抗氧化活性方面具有替代子实体的可行性。