玫瑰细胞露的化学成分及活性研究

玫瑰细胞露是玫瑰花在水蒸气提取玫瑰精油后产生的玫瑰花水溶液。本文针对玫瑰细胞露进行了植物化学分析和生物活性分析,通过GC-MS定量分析结合HPLC分析发现玫瑰细胞露主要化学成分包括：芳樟醇,苯乙醇,香茅醇,α-红没药醇,山奈酚-3-O-芦丁苷,同时对细胞露的酪氨酸酶抑制活性,抗氧化活性,抗菌活性进行了系统评价。结果表明：细胞露的酪氨酸酶抑制活性为IC50=2.45 mL,DPPH抗氧化活性为IC50=2.58 mL,ABTS自由基清除活性为3.43 mL;另外,细胞露具有较强的抗菌活性,对具核梭杆菌有较强的抑制率,最低抑菌浓度为MIC=32 μL,最低杀菌浓度MBC=125 μL。为玫瑰细胞露在化妆品和食品行业中的应用提供理论基础。     

超声波辅助酶解对玉米醇溶蛋白酶解产物抗氧化及ACE抑制活性的影响

作为玉米加工的副产物,玉米醇溶蛋白可以在酶的作用下形成具备生物活性的多肽物质,应用于药物的生产加工过程.而常规的酶解工艺存在酶的利用率低下、产物转化率低、耗费时间长等缺陷,本文研究了超声波辅助酶解对玉米醇溶蛋白酶解产物抗氧化及ACE抑制活性的影响.研究结果表明,超声功率为200W,超声时间为40min,料液比为1 ∶1...     

Angiotensin-I converting enzyme inhibitory and antioxidant activities of egg protein hydrolysates produced with gastrointestinal and nongastrointestinal enzymes

Egg is a well-known rich source of bioactive peptides. In this study, egg protein (egg white and egg yolk proteins) hydrolysates were produced with gastrointestinal enzymes (pepsin and pancreatin) or nongastrointestinal enzymes (thermolysin and alcalase), and fractionated by ultrafiltration and cation exchange chromatography. Angiotensin-I converting enzyme (ACE) inhibitory and antioxidant activities, amino acid composition and molecular weight distribution were studied, and the physicochemical properties were related with the bioactivities. Our results showed that egg protein hydrolysates produced with non-GI enzymes (thermolysin and alcalase) showed significantly higher ACE inhibitory activity, whereas similar or even lower antioxidative activities, than those of hydrolysates produced with GI enzymes. ACE-inhibitory activity significantly correlated with the amino acid composition, especially the proportion of positively charged amino acid, whereas antioxidant activities correlated with the proportion of low molecular weight peptides under 500 Da. Understanding the relationship between the bioactivities and physicochemical properties of the hydrolysates/fractions is important to facilitate the development technologies for preparing fractions with improved bioactivities.     

In vitro antihypertensive activity of bioactive peptides derived from porcine blood corpuscle and plasma proteins

New bioactive peptides with antihypertensive property from red blood corpuscle (RBC) and plasma (PL) hydrolysate fractions of porcine blood were identified. Three peptides with the highest Angiotensin-converting enzyme (ACE) inhibitory activity from RBC, including RBC7 (TPYPCV), RBC15 (VVYPWR) and RBC9 (FLCT), showed IC₅₀ values of 2.58 ± 0.87, 5.22 ± 2.56 and 6.53 ± 0.34 µm , respectively. By comparison, PL1 (YTFPFH), PL2 (WGHGNPHV) and PL7 (VPLW) from PL displayed higher IC₅₀ values at 24.12 ± 2.44, 15.33 ± 0.44 and 32.80 ± 38.96 µm , respectively. Molecular docking was employed to simulate the interactions of RBC7 and RBC15 with the catalytic site of the ACE receptor. RBC7 and RBC15 interacted with residues in the ACE receptor that normally coordinated with Zn(II), and RBC7 also interacted extensively with residues within S1, S2 and S’1 active sites. Taken together, these results illustrate that porcine blood is an excellent source of antihypertensive peptides and could be of great benefits to people with high blood pressure.     

花中多糖化学组成与生物活性研究进展

花具有很高的药用价值,除了含有黄酮、挥发油、有机酸、萜和生物碱等次生代谢产物外,多糖作为花的重要活性成分,具有抗氧化、抗炎、降血糖、降血脂、抗肿瘤和提高免疫力等多种生物活性.本文对近5年内报道的花中多糖化学组成与生物活性研究进展进行综述,并对花中多糖的研究方向与应用前景进行展望,以促进花中多糖的深入研究,为相关保健食品...     

油茶籽多酚提取物生物活性的研究

山茶籽油是我国特色食用油,具有多种活性,多酚是其主要功能成分之一。为探究油茶籽多酚的活性特点,研究比较了15个油茶籽多酚样品和5种非油茶植物多酚(肉桂多酚、苹果多酚、葡萄皮多酚、紫锥菊多酚、石榴皮多酚)抑制脂氧合酶(lipoxidase, LOX)、环氧合酶-2(cyclooxygenase 2,COX-2)、 α-葡萄糖苷酶、α-淀粉酶和胰脂肪酶活性,羟自由基清除率、超氧阴离子清除率,抗脂质氧化活性,并通过“蓝精灵”实验评估了多酚对果蝇肠炎的抑制活性。结果表明：油茶籽多酚提取物对几种酶均有抑制作用,油茶籽多酚提取物对果蝇肠炎和LOX活性的抑制作用显著高于非油茶籽多酚提取物;相关性分析结果显示,多酚抗LOX活性和抗果蝇肠炎活性之间呈极显著正相关(r=0.725,P<0.01)。油茶籽多酚是α-葡萄糖苷酶选择性抑制剂,其抗炎效果强于非油茶籽多酚,抗氧化、抑制LOX活性可能是油茶籽多酚抗肠炎机制之一。     

Comparative structural, emulsifying, and biological properties of 2 major canola proteins, cruciferin and napin

ABSTRACT:  Canola is an economically important farm-gate crop in Canada. To further explore the potential of canola protein as value-added food and nutraceutical ingredients, a better understanding of fundamental properties of 2 major canola proteins is necessary. Two major protein components, cruciferin and napin, were isolated from defatted canola meal by Sephacryl S-300 gel filtration chromatography. SDS-PAGE showed that cruciferin consists of more than 10 polypeptides, and noncovalent links are more important than disulphide bonds in stabilizing the structural conformation. Napin consists of 2 polypeptides and is stabilized primarily by disulphide bonds. Purified cruciferin showed 1 major endothermic peak at 91 °C compared with that of 110 °C for napin. Emulsion prepared by cruciferin showed significant higher specific surface area and lower particle size than that of napin. The study indicated that the presence of napin could detrimentally affect the emulsion stability of canola protein isolates. Hydrolysates from cruciferin and napin showed potent angiotensin I-converting enzyme inhibitory activity (IC₅₀: 0.035 and 0.029 mg/mL, respectively), but weaker than that of canola protein isolate hydrolysate (IC₅₀: 0.015 mg/mL).     

Antimicrobial spectrum activity of bacteriocinogenic Staphylococcus strains isolated from goat and sheep milk

Bacteriocins have attracted great attention as potential alternatives to antibiotics and chemical food additives. In the present study, 243 Staphylococcus isolates from milk samples (n = 110) of goat and sheep herds located in Fars province, Iran, were screened for antimicrobial substance production. Twenty-eight isolates showed an antagonistic activity against the indicator strain Micrococcus luteus ATCC 4698. The susceptibility of all antimicrobial substances to proteolytic enzymes allowed us to consider them as bacteriocin-like inhibitory substances (BLIS). The term BLIS is applied to uncharacterized proteinaceous antimicrobials produced by gram-positive bacteria. Based on molecular identi?cation methods, the isolates belonged to the species Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus pseudintermedius, Staphylococcus aureus, and Staphylococcus agnetis. Pulsed-?eld gel electrophoresis revealed a high level of genotype diversity among the Staph. chromogenes isolates. All of the isolates harbored nukA or bsaA2 genes, suggesting that their BLIS were related to nukacin or Bsa. The antimicrobial compounds from test strains were not effective against gram-negative pathogens, including Salmonella enterica serovar Typhimurium, Escherichia coli O157:H7, and Klebsiella pneumonia as well as the indicator mold Aspergillus fumigatus. All the gram-positive targets, including Bacillus cereus, Listeria monocytogenes, Enterococcus faecalis Ef37 (a tyramine-producer strain), Lactobacillus saerimneri 30a (a histamine-producer strain), and methicillin-resistant Staph. epidermidis, were inhibited by the Staph. chromogenes isolates. Staphylococcus haemolyticus 4S12 was able to inhibit the majority of gram-positive bacteria. Listeria monocytogenes strains were the only indicators sensitive to the antimicrobial agents produced by Staph. agnetis 4S97B. The other Staphylococcus strains were ineffective on all the organisms tested. Based on their inhibitory capacities, the BLIS produced by the Staph. chromogenes isolates seem to be interesting candidates for developing novel antimicrobial agents.     

蒌叶挥发油的提取及抗氧化和抑菌活性研究

采用水蒸气提取法对蒌叶挥发油进行提取,在单因素实验的基础上,以正交实验筛选最佳的提取工艺条件;同时考察蒌叶挥发油抗氧化和抑菌活性。结果表明,蒌叶挥发油提取的最佳工艺条件为:料液比m_干蒌叶粉∶V_水=50∶1000（g/m L）,超声时间为30 min,超声温度70℃,超声功率192 W,加热回流提取4 h,蒌叶挥发油的得率为2.96%。蒌叶挥发油清除DPPH·和·OH的IC₅₀分别为33.19、71.11μg/m L;挥发油对金黄色葡萄球菌、枯草杆菌、大肠杆菌、蜡状芽孢杆菌、四联球菌、藤黄八叠球菌、白色葡萄球菌、黑曲霉、毛霉、青霉均有明显的抗菌活性,其MIC分别为0.625、1.25、0.625、0.625、0.625、2.50、1.25、0.313、0.625、0.313 mg/m L,故蒌叶挥发油具有较强的抗氧化和抑菌活性。      

鹿茸血制备ACE抑制肽的分离及结构鉴定

以天山马鹿的鹿茸血为原料,酶解制备血管紧张素转化酶（angiotensin converting enzyme,ACE）抑制肽。用碱性蛋白酶水解,水解产物具有较高的ACE抑制活性,对该水解产物进行分离,鉴定其中活性最强的组分的结构为PPLY（Pro-Pro-Leu-Tyr）。本实验证明从天山马鹿鹿茸血碱性蛋白酶水解物中可分离得到的一种新的ACE抑制肽PPLY。      

Antioxidant, antimicrobial and anticancer activities of three Parmelia species

BACKGROUND: Lichens are symbiotic organisms consisting of algae and fungi. They are used for human and animal nutrition and in the production of colours, perfumes and alcohol. Lichens have also been used in traditional medicine to treat diseases such as jaundice, pulmonary, stomach and cranial diseases. In this study the acetone extracts of three lichens, Parmelia caperata, Parmelia sulcata and Parmelia saxatilis, were tested for their antioxidant, antimicrobial and anticancer potential. RESULTS: Of the lichens tested, P. saxatilis had the highest free radical‐scavenging activity (55.3% inhibition). Moreover, all tested extracts showed effective reducing power and superoxide anion radical scavenging. Strong relationships between total phenolic and flavonoid contents and antioxidant effects of the tested extracts were observed. The extract of P. sulcata was most active in terms of antimicrobial ability, with minimum inhibitory concentration values ranging from 0.78 to 12.5 mg L^?1. All extracts were found to have strong anticancer activity, with IC₅₀ values ranging from 9.55 to 22.95 µg mL^?1. CONCLUSION: The present study showed that the tested lichen extracts exhibited strong antioxidant, antimicrobial and anticancer effects. This suggests that lichens may be used as possible natural antioxidant, antimicrobial and anticancer agents. Copyright © 2012 Society of Chemical Industry     

Comparative study of the essential oils of three Beilschmiedia species and their biological activities

This study was designed to examine the chemical compositions of the essential oils from three Beilschmiedia species and antioxidant, antimicrobial, antityrosinase, acetylcholinesterase and anti‐inflammatory activities. The essential oils of B. kunstleri, B. maingayi, B. penangiana gave β‐caryophyllene (10.6–12.1%), β‐eudesmol (17.5–24.1%) and δ‐cadinene (17.5–28.7%) as the most abundant components respectively. The bark oil of B. maingayi showed the highest activity in β‐carotene/linoleic acid (125.9%) and phenolic content (288.2 mg GA g^?1), while B. penangiana bark oil was found to have strong activity in DPPH (IC₅₀ 84.7 μg mL^?1) and ABTS (IC₅₀ 108.3 μg mL^?1). The essential oils of B. penangiana showed the best activity against Candida glabrata with MIC value 31.3 μg mL^?1. The bark oil of B. penangiana gave 82.5% tyrosinase inhibiton. The leaf oil of B. maingayi gave the highest inhibition in AChE (66.6%) and lipoxygenase (77.0%) assay. Our findings demonstrate that the essential oils have great potential for applications in pharmaceutical and food industries.     

乳源ACE抑制肽的制备及应用

近年来高血压成为威胁人类健康的第一大慢性病,由于常规降压药物对人体的损害,食源性降压肽成为研究的热点。目前研究发现了多种乳源ACE抑制肽,并得到应用。本文综述乳源ACE抑制肽的制备、纯化及应用现状。