沙棘籽粕原花青素的提取与抗心肌细胞缺氧活性研究

研究沙棘籽粕中原花青素的提取与抗心肌缺氧活性.用乙酸乙酯萃取沙棘籽粕的乙醇提取物得原花青素乙酸乙酯萃取物,再经Sephadex LH-20柱层析50%乙醇洗脱得沙棘籽粕原花青素50%乙醇洗脱物.以乳鼠心肌细胞缺氧/复氧为模型,分别给予不同剂量的原花青素干预,采用MTT法检测心肌细胞的存活率.结果表明,乙酸乙酯萃取物和50%乙醇洗脱物能显著提高缺氧/复氧心肌细胞的存活率,对心肌细胞损伤有很好的保护作用.     

阳荷不同极性部位体外抑菌活性研究

为研究阳荷的体外抑菌活性,采用70%乙醇回流提取阳荷粉末,依次用石油醚、乙酸乙酯、正丁醇萃取乙醇提取物,得到乙醇提取物、石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物;用滤纸片对乙醇提取物及不同极性萃取物进行抑菌活性测定,有抑菌活性的部位进一步测定其最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal concentration,MBC)。试验结果表明阳荷乙醇提取物、石油醚萃取物、乙酸乙酯萃取物和正丁醇萃取物,MIC值在3.125 mg/mL~12.5 mg/mL之间,MBC值为25 mg/mL;阳荷乙醇提取物、石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物对枯草芽孢杆菌有较强的抑菌效果,MIC值在3.125 mg/mL~12.5 mg/mL之间,MBC值为25 mg/mL;阳荷乙醇提取物和石油醚萃取物对大肠杆菌、肺炎克雷伯菌、粪肠球菌、铜绿假单胞菌和鲍曼不动杆菌均有抑菌效果;阳荷乙醇提取物、石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物对苏云金芽孢杆菌没有抑菌作用。阳荷对革兰氏阳性菌和革兰氏阴性菌具有广谱抑菌活性。     

虫草头孢菌粉抗心律失常活性成分的分离纯化及结构鉴定

目的：研究虫草头孢(Cephalosporium sinensis)菌粉的抗心律失常活性成分。方法：在活性检测结果的指导下,采用硅胶柱色谱法、ODS RP C18高效液相色谱法分离纯化虫草头孢菌粉中的抗心律失常活性化学成分,根据化合物的理化性质和波谱数据鉴定其化学结构。结果：从虫草头孢菌粉乙醇提取物的水饱和正丁醇萃取部位中分离得到5个化合物,分别是尿苷(化合物1)、胸苷(化合物2)、腺苷(化合物3)、2’-脱氧尿苷(化合物4)、尿嘧啶(化合物5)。结论：核苷类化合物为虫草头孢菌粉中的主要的抗心律失常成分。     

侧柏球果体外抑菌作用初探

目的：观察侧柏球果乙醇提取物的体外抑菌活性。方法：运用渗漉法提取并制备石油醚、乙酸乙酯、正丁醇和水萃取物,用滤纸片法对粗提物及各萃取物进行粗筛,有抑菌作用的萃取物进一步用微量肉汤稀释法测定其最低抑菌浓度（MIC）。结果：侧柏球果乙醇提取物及石油醚和乙酸乙酯萃取物具有抑制金黄色葡萄球菌等3种孳兰氏阳性菌和大肠埃希菌等3种举兰氏阴性菌生长繁殖的活性,乙醇提取物抑菌作用最强,对金黄色葡萄球菌、大肠埃希菌和肺炎克雷伯菌的MIC均为19．6μg·mL-1,对地衣芽孢杆菌、无乳链球菌和铜绿假单胞菌的MIC均为39．1μg·mL-1;石油醚萃取物对6种测试菌的MIC均为78．2ug·mL-1,乙酸乙酯萃取物对铜绿假单胞菌的MIC为625μg·mL,对无乳链球菌和肺炎克雷伯菌的MIC为312．5ug·mL-1,对其余3种测试菌的MIC为156．3ug·mL-1结论：侧柏球果乙醇提取物及石油醚和乙酸乙酯萃取物能湿著抑制金黄色葡萄球菌、地农芽抱杆菌、无乳链球菌、大肠埃希菌、肺炎克雷伯菌和铜绿假单胞菌的生长繁殖。     

不同溶剂提取乳苣的抗氧化作用研究

以乳苣全草为原料,75%乙醇为溶剂提取乳苣,提取液用不同极性溶剂依次萃取,得石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物,同时测定了各相提取物对羟自由基、超氧阴离子自由基、DPPH自由基的清除能力,并与VC进行比较。结果表明:各萃取物均具有一定的抗氧化活性,且随着浓度的增加而增强;对羟自由基的清除能力大小依次为乙酸乙酯萃取物>正丁醇萃取物>VC>水萃取物>石油醚萃取物;对超氧阴离子自由基清除能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>石油醚萃取物>水萃取物;对DPPH自由基清除能力大小依次为VC>乙酸乙酯萃取物>正丁醇萃取物>水萃取物>石油醚萃取物;各萃取物还原能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>水萃取物>石油醚萃取物。     

牛蒡叶乙醇提取物的抗氧化性能

用95%乙醇浸泡提取传统药食两用植物牛蒡叶,并用石油醚、乙酸乙酯和正丁醇依次对浸提液进行萃取。利用DPPH自由基清除法、O2-.清除法及.OH清除法测定各萃取部位的抗氧化活性,以VC、VE和叔丁基对苯二酚(TBHQ)为对照物。结果表明:牛蒡叶乙醇提取物具有较好的体外抗氧化活性,其中乙酸乙酯萃取物(E2)和正丁醇萃取物(E3)具有较强的清除DPPH自由基的能力,且活性强于TBHQ,利用标准曲线法对乙酸乙酯萃取物和正丁醇萃取物进行绿原酸含量的测定,发现绿原酸含量分别达44.34mg/g和35.48mg/g。     

全叶青兰提取物抗氧化活性的研究

以全叶青兰经超临界CO2萃取后的萃取物为原料,采用乙醇提取后,根据极性差异经乙醚、乙酸乙酯和正丁醇依次萃取,对所得提取物的抗氧化活性进行了研究。结果表明,3种提取物对DPPH自由基和羟基自由基均具有比较强的抗氧化活性。其清除DPPH自由基的能力比较接近,而对羟基自由基的清除能力三者差异较大。其中,乙酸乙酯和乙醚提取物清除羟基自由基的半数清除率要明显小于同等条件下的对照品芦丁和BHT的清除浓度,正丁醇提取物清除DPPH自由基的半数清除率的浓度明显要小于清除羟基自由基的浓度,乙酸乙酯萃取物和乙醚萃取物在两个体系内的差异较小。     

无瓣海桑果实乙醇提取物及其不同极性萃取物抗氧化活性

研究了无瓣海桑果实乙醇提取物及其不同极性萃取物的抗氧化活性。无瓣海桑果实采用95%乙醇浸提后经减压浓缩得到乙醇提取物,然后依次采用乙酸乙酯、正丁醇等有机溶剂进行萃取并收集剩余液体得到乙酸乙酯相萃取物、正丁醇相萃取物、水相残留物。在超氧阴离子自由基、DPPH自由基、ABTS+自由基清除能力和还原能力的抗氧化活性测试体系中,无瓣海桑果实乙醇提物及不同极性萃取物均具有一定的抗氧化活性,并且呈明显的量效关系。乙醇提取物在DPPH自由基清除和还原能力测定中表现出较好的抗氧化活性。乙酸乙酯相萃取物在4种测定体系中均表现出很好的抗氧化活性,且其DPPH自由基清除活性(IC50=1.69μg·m L-1)明显强于阳性对照VE(IC50=6.06μg·m L-1),超氧阴离子自由基清除活力(IC50=0.35 mg·m L-1)与阳性对照VC(IC50=0.30 mg·m L-1)相近。     

菱角壳分级萃取物对肿瘤细胞增殖及凋亡的影响

目的:制备菱角壳乙醇提取物的分级萃取物,并研究其对肿瘤细胞增殖及凋亡的作用。方法:采用有机溶剂萃取法将菱角壳乙醇提取物分为乙酸乙酯萃取物和正丁醇萃取物2个不同极性部分,并测定其黄酮与多酚含量,CCK-8法测定菱角壳分级萃取物对肿瘤细胞增殖的抑制作用,流式细胞术检测菱角壳萃取物诱导肿瘤细胞凋亡的作用。结果:乙酸乙酯萃取物中多酚和黄酮含量高于正丁醇萃取物。在两种萃取物浓度为25、50、100、200、400 μg/mL时均能抑制胃癌细胞(SGC-7901)、肝癌细胞(Hep G2)的增殖,最高抑制率均达60%以上,并存在明显的剂量与效应关系。两种萃取物均能促进肿瘤细胞凋亡,400 μg/mL的乙酸乙酯、正丁醇萃取物作用肝癌细胞24 h,凋亡率分别为45.57%和33.34%;作用胃癌细胞24 h,凋亡率分别为31.01%和21.65%。结论:菱角壳乙酸乙酯萃取物具有抑制肿瘤细胞增殖及促肿瘤细胞凋亡的生物活性。     

金花葵花黄酮提取物不同溶剂萃取物的抗氧化活性

目的:研究金花葵花黄酮不同极性溶剂萃取物的体外抗氧化能力,并考察黄酮含量与抗氧化活性的相关性。方法:采用不同极性溶剂对金花葵花乙醇提取物进行液-液萃取,得到金花葵花黄酮样品为:石油醚相、乙酸乙酯相、正丁醇相、水相萃取物。测定不同极性溶剂萃取物中总黄酮含量,研究各萃取物的清除DPPH自由基能力、清除羟基自由基能力、还原能力、清除超氧阴离子能力和抗油脂氧化能力,分析黄酮含量与抗氧化活性的相关关系。结果:金花葵花黄酮不同极性溶剂萃取物均有抗氧化活性,顺序均为乙酸乙酯相正丁醇相乙醇提取物石油醚相水相。在0.20～1.00 mg/mL的萃取物质量浓度范围内,随着质量浓度的增加,抗氧化活性相应增大。质量浓度在1.00 mg/mL时,乙酸乙酯和正丁醇相萃取物的抗氧化活性接近于V_C。各萃取物中黄酮含量与抗氧化活性呈现较好相关关系(p0.05)。结论:金花葵花黄酮具有较高的体外抗氧化能力,乙酸乙酯相和正丁醇相萃取物可作为分离活性成分的研究重点。     

拐枣抗氧化活性的研究

用体外化学试验和TLC比较法对拐枣用乙醇、石油醚、乙酸乙酯、正丁醇和水提取物的抗氧化作用和抗氧化成分极性强弱进行了比较分析。结果表明拐枣提取物抗氧化作用从强到弱依次为乙酸乙酯提取物>正丁醇提取物>石油醚提取物>乙醇提取物>水提取物。拐枣具有较强的抗氧化活性,抗氧化活性成分主要存在乙酸乙酯提取物中。     

Antioxidant and antimicrobial activity of Cynara cardunculus extracts

The whole, fresh involucral bracts of cardoon, Cynara cardunculus L. (Compositae), were extracted with EtOH and an aqueous suspension of the obtained EtOH extract was partitioned successively with CHCl₃, EtOAc and n-BuOH, leaving a residual water extract. All obtained extracts were evaluated for their antioxidant and antimicrobial properties. The antioxidant potential was evaluated using following in vitro methods: FRAP (ferric reducing antioxidant power) assay, and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Antimicrobial activity was estimated using a microdilution technique against food-borne, mycotoxin producers and human pathogenic bacteria and micromycetes. The following bacteria were tested: Salmonella typhimurium, Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, as well as micromycetes: Aspergillus niger, Aspergillus ochraceus, Aspergillus flavus, Penicillium ochrochloron, Penicillium funiculosum, Trichoderma viride, Fusarium tricinctum and Alternaria alternata. Results showed that all extracts possessed concentration-dependent antioxidant activity. In biological assays, C. cardunculus extracts showed antimicrobial activity comparable with standard antibiotics.     

Antioxidant activities in vitro of ethanol extract from brown seaweed <Emphasis Type="Italic">Sargassum pallidum</Emphasis>

The crude extract (CE) was obtained by extracting the powder of Sargassum pallidum with a solution of 70% ethanol. Then, CE dissolved in distilled water was fractionated with chloroform (Cf), ethyl acetate (EtOAc), and n-butanol (n-BuOH), respectively, affording four fractions of Cf, EtOAc, n-BuOH and aqueous. First, the contents of total polyphenols, vitamin C (V_C) and vitamin E (V_E) in CE and its four fractions were determined. As results, the contents of total polyphenols in CE and its fractions decreased in the following order: aqueous fraction > n-BuOH fraction > EtOAc fraction > CE > Cf fraction. The aqueous fraction had significantly higher V_C content (1.82%) compared with CE and fractions of Cf, EtOAc, and n-BuOH (P < 0.05). The contents of V_E in CE and its fractions were all in low level compared with the total polyphenol content and V_C content. Second, the antioxidant activities in vitro of CE and its four fractions were evaluated. Among all the fractions, EtOAc fraction exhibited the highest total antioxidant activity (0.52 μmol FeSO₄ equivalent/mg extract), while fractions of EtOAc and n-BuOH exhibited the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and capacity of chelating iron ions, respectively. In addition, a higher content of total polyphenols (52.08 mg chlorogenic acid equivalent/g extract) and reducing power (0.505 at A₇₀₀) for aqueous fraction were noticed. Finally, it was found that the extracts of S. pallidum contained large amounts of phlorotannin dimers and trimer based on the analytical results of ultra high performance liquid chromatography–mass spectroscopy. The results suggest that S. pallidum can be a good source of natural antioxidant.     

Evaluation of the antioxidant activity of extracts from buntan (Citrus grandis Osbeck) fruit tissues

The goal of the present work was to evaluate the antioxidant properties of buntan (Citrus grandis Osbeck) using various solvents, such as n-hexane, ethyl acetate (EtOAc), butanol and methanol. The antioxidant activities of crude extracts were evaluated by using the free radical scavenging β-carotene assay and total polyphenol. Ethyl acetate extracts of falvedo exhibited high antioxidative activities, followed by albedo and segment membrane extracts. Chromatography separation of EtOAc extract of flavedo using a silica gel column, yielded six fractions (A, B, C, D, E and F) using gradient elution with benzene and acetone (19:1, 14:1, 9:1, 5:1, 1:1 and 0:l). Among them, two fractions (C and D) showed strong antioxidant activities using the free radical scavenging activity (DPPH) antioxidant assay. These two fractions were further purified using silica gel column chromatography and preparative TLC. Their extracts could well be useful to prevent oxidation in fruit juices and essential oil food products as well as for health supplements. Identification of the responsible components is underway.     

Methyl jasmonate treatment of strawberry fruits enhances antioxidant activity and the inhibition of nitrite production in LPS-stimulated Raw 264.7 cells

The effect of methyl jasmonate postharvest application on the antioxidant and anti-inflammatory activity of strawberry fruits was evaluated. Results showed that the methyl jasmonate treated strawberry extract had higher antioxidant activity and suppresses the nitrite production in LPS-stimulated RAW 264.7 murine macrophages. The HPLC profiles of both treated and untreated strawberry extracts were compared. To evaluate which compounds are responsible of these higher activities it was also investigated the antioxidant and anti-inflammatory capacities of the hexane, chloroform, EtOAc, and n-butanol fractions obtained from the methyl jasmonate treated strawberry. The EtOAc and n-butanol fractions exhibited the most potent antioxidant activity compared to the hexane and chloroform fractions. In addition the n-butanol fraction was able to decrease nitrite production. The EtOAc and n-butanol fractions were analyzed by LC–MS. These results showed that methyl jasmonate promotes antioxidant and anti-inflammatory capacity of strawberry fruits by the stimulation of phenolic compounds and anthocyanins production.     

Antioxidant activity of grape seed (Vitis vinifera) extracts on peroxidation models in vitro

Antioxidant-rich fractions were extracted from grape seeds (Vitis vinifera) using various solvents, such as acetone, ethyl acetate, methanol and mixtures of different solvents, such as ethyl acetate (EtOAc) and water in 9:1, 17:3 and 4:1 ratios. The antioxidant activity of the extracts was evaluated using a β-carotene-linoleate model system and linoleic acid peroxidation method. At 100 ppm concentration, various extracts showed 65–90% antioxidant activity. Mixtures of EtOAc and water at different concentrations exhibited more antioxidant activity than other extracts. These extracts also showed good reducing power, at 500 μg/ml concentration, by the potassium ferricyanide reduction method. Grape seed extracts may be exploitable for the preservation of food products as well as for health supplements and nutraceuticals.     

Analytical Methods for Enzyme and DPPH Radical Scavenging Activities of Natural Pigments from Some Plants

The enzyme activities in different fractions of Dioscorea japonica Thunb. and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity in 15 natural plant pigments from black rice, purple sweet potato, yellow bitter melon, yellow paprika, red cabbage, yellow gardenia, blue gardenia, Chinese foxglove, mulberry leave, onion peel, grape peel, mulberry, red beet, gromwell, and cactus were determined. The antioxidant activity in the cosmetic composition of mulberry leaves, grape peel, mulberry, and red cabbage pigments was relatively high in comparison with all other studied plants. Enzyme activities in investigated plants were evaluated as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). The cosmetic composition of mulberry leaf pigment had the highest SOD enzyme activity of 67.1% while onion peel pigment showed the lowest SOD enzyme activity of 15.3%. The activity of CAT and APX from cosmetic composition of natural plant pigments has also been investigated. Both CAT and APX showed higher values in the cactus, mulberry, and red cabbage cosmetic compositions in comparison with other plant pigments. The cosmetic composition in EtOAc extract of D. japonica Thunb. had the highest SOD enzyme activity while the BuOH and EtOH extracts were comparatively low. CAT and APX activities showed significantly high values in EtOH and EtOAc extracts. The antioxidant enzyme activities of D. japonica Thunb. differ significantly in different plant pigments during their extraction. In conclusion, we showed that the plant pigments and D. japonica Thunb. had the potent biological activities. Therefore, these plant resources having anti-aging components could be good materials for development of source of natural cosmetics.     

细脚拟青霉活性成分分析及清除自由基活性研究

以冬虫夏草生药为对照品,对细脚拟青霉RCEF0441的深层发酵菌丝体和发酵液冻干粉进行活性成分分析。结果表明：RCEF0441 菌丝体和发酵液冻干粉中粗蛋白和氨基酸总量均明显高于冬虫夏草生药;菌丝体中多糖、麦角甾醇、甘露醇及腺苷等多种物质的含量亦高于冬虫夏草生药;RCEF0441 深层发酵菌丝体和发酵液冻干粉中还含有丰富的对人体健康非常重要的Zn、Fe、Ca 等元素。用二苯代苦味肼基自由基(DPPH)-TLC 法和DPPH 酶标仪法对RCEF0441菌丝体和发酵液冻干粉的甲醇- 乙酸乙酯混合液提取物清除DPPH自由基活性进行分析,发现两种提取物均具有较强的清除自由基活性,在浓度为5.0mg/ml,于37℃下保温10min 时,两种提取物对0.4 mg/ml 的DPPH自由基的清除率分别达到61.28% 和81.12%。     

Phlorotannins of the edible brown seaweed Ecklonia cava Kjellman induce sleep via positive allosteric modulation of gamma-aminobutyric acid type A-benzodiazepine receptor: A novel neurological activity of seaweed polyphenols

The primary objective was to investigate whether seaweeds have hypnotic activity. Methanol extracts of 30 seaweeds were screened for their binding activity at the GABA type A-benzodiazepine (GABA_A-BZD) receptor, a well-characterised molecular target for sedative-hypnotics. The most active seaweed was Ecklonia cava Kjellman (ECK). An ethanol extract of ECK (ECK-E) significantly potentiated pentobarbital-induced sleep in mice. In four solvent fractions separated from ECK-E, hypnotic activity was proportional to contents of total phenols and total phlorotannins, known as seaweed polyphenols. Major phlorotannins of the ethyl acetate (EtOAc) fraction with the highest activity were eckol, eckstolonol, dieckol, and triphlorethol-A, and their K_i (binding affinity, μM) values for [³H]-flumazenil binding were 1.070, 1.491, 3.072, and 4.419, respectively. Hypnotic effects of ECK-E and the EtOAc fraction were fully inhibited by flumazenil, a specific GABA_A-BZD receptor antagonist. These results imply that phlorotannins of ECK induce sleep by positive allosteric modulation of the GABA_A-BZD receptor.