Isolation and Comparative Analysis of Glycolipid Fractions in Bifidobacteria

A comparative TLC analysis of lipid extracts from Bifidobacterium longum B 379 M, B. bifidum 791, and B. adolescentis 94 BIM has been performed. It is demonstrated that carbohydrate-containing lipid components were present in the bacteria, which differed in their chromatographic mobility (R _f ) from similar compounds isolated from actinomycetes Stomatococcus mucilaginosus PCM 2415^T, Nocardiopsis dassonvillei PCM 2492, Propionibacterium propionicum PCM 2431, Saccharopolyspora hirsuta PCM 2279 (= ATCC 27875^T), Rhodococcus equi PCM^T 559 (= ATCC 3969), and Gordonia bronchialis PCM 2167. Polar lipids of bifidobacteria exhibited the closest similarity to their counterparts from propionic acid bacteria. Preparative chromatography (silica gel column I; elution with chloroform, acetone, and methanol) of the lipid extract of B. adolescentis 94 BIM made it possible to isolate fractions containing nonpolar lipids, glycolipids, and phospholipids. Further purification of the glycolipid fraction (column II; eluant, methanol gradient in chloroform) produced preparations of glycolipids and phospholipids. The preparations were studied by two-dimensional TLC using solvent systems chloroform-methanol-H₂O MiLi Q (65 : 25 : 4, v/v/v) and n-butanol-acetic acid-H₂O MiLi Q (60 : 20 : 20, v/v/v) for directions I and II, respectively. Two major glycolipids were revealed (G₁ and G₂), in addition to compounds characteristic of the polar lipid group and minor glycolipids (g), the latter being present in considerably lesser amounts.     

Patterns of growth and β-galactosidase production by Bifidobacteria

We investigated the patterns of growth and β-galactosidase production in the strains Bifidobacterium adolescentis GO-13, MS-42, 91-BIM, and 94-BIM and b. bifidum No.1, LVA-3, 791 on media with various carbon sources. The synthesis of β-galactosidase was shown to be associated with exponential growth of the cultures involved. The maximum specific rate of β-galactosidase synthesis of 0.20 U mg^?1 h^?1 was observed in B. bifidum LVA-3 after 3–6 h of cultivation. This value for B. adolescentis 91-BIM and 94-BIM was lower and amounted to 0.03–0.08 U mg^?1h^?1. On the medium with lactose, the highest specific growth rates for B. bifidum LVA-3 and B. bifidum No.1 were 0.38 and 0.60 h^?1, respectively, after 3–6 h of cultivation. For B. adolescentis 91-BIM and 94-BIM, this parameter peaked at 12–15 h of cultivation at 0.13 and 0.22 h^?1, respectively. The hydrolytic activity of β-galactosidase in the growth medium decreased during the stationary growth phase of the tested cultures.     

Lipids of ripening tomato fruit and its mitochondrial fraction

The lipid composition of tomato fruit and its mitochondrial fraction were examined at various stages of fruit ripeness. Phosphatidyl choline, phosphatidyl ethanolamine, monogalactosyl diglyceride, digalactosyl diglyceride and phosphatidyl inositol were found to be the major lipids of tomato pericarp at all stages of ripeness. Mitochondrial lipids resembled those of the parent tissue except for the absence of monogalactosyl diglyceride and a greater percentage of diphosphatidyl glycerol and phosphatidic acid. Changes in the lipid-protein ratio of mitochondria were noted with ripening.     

假马齿苋的生物活性及其临床研究

假马齿苋(Bacopa monniera,BM)具有提高记忆,镇静,抗癫痫和抗炎,镇痛,退烧,强心等生物活性。假马齿苋皂苷(bacosides)是主要的益智活性成分。     

天然产物黄檀内酯的研究进展

本文概述了目前已发表的天然产物黄檀内酯在植物中分布、生物合成、全合成及生物活性的研究进展。     

人降钙素类似物的合成及活性研究

通过对鲑鱼降钙素和人降钙素结构的比较,设计并合成了人降钙素类似物ｍｈＣＴ－２。利用空气氧化获得分子内二硫键,经分离纯化,产物达ＨＰＬＣ及毛细管电泳均一,蛋白质序列分析和质谱分析符合理论值。在大鼠降血钙生物活性测定中,利用量反应平行线法进行ｍｈＣＴ－２的生物效价判定达２０００ＩＵ／ｍｇ,比ｈＣＴ的效价高一个数量级。     

Unique Sugar Metabolic Pathways of Bifidobacteria

Bifidobacteria have many beneficial effects for human health. The gastrointestinal tract, where natural colonization of bifidobacteria occurs, is an environment poor in nutrition and oxygen. Therefore, bifidobacteria have many unique glycosidases, transporters, and metabolic enzymes for sugar fermentation to utilize diverse carbohydrates that are not absorbed by host humans and animals. They have a unique, effective central fermentative pathway called bifid shunt. Recently, a novel metabolic pathway that utilizes both human milk oligosaccharides and host glycoconjugates was found. The galacto-N-biose/lacto-N-biose I metabolic pathway plays a key role in colonization in the infant gastrointestinal tract. These pathways involve many unique enzymes and proteins. This review focuses on their molecular mechanisms, as revealed by biochemical and crystallographic studies.     

Effect of Lipids on the Activity of Calpain in Subcellular Fractions Obtained from the Rat Brain

We studied the effect of lipids on the activity of a neutral cysteine proteinase, calpain, in subcellular fractions obtained from the rat brain. Extraction of nearly 23% of membrane cholesterol from the coarse mitochondrial fraction did not result in modifications of specific activity of calpain in this fraction. Detergents (digitonin or Triton Х-100) used in 0.3% concentration enhanced the activity of calpain in the coarse mitochondrial fraction. Examination of the effects of preparations of different phospholipids on the activity of calpain in the cytoplasm demonstrated that only phosphatidylcholine, but not phosphatidylserine and/or cardiolipin, insignificantly increased the activity of calpain (independently of the size and structure of phospholipid vesicles). We hypothesize that the mechanisms underlying interaction between calpain and lipids are not universal; in native cells and model experiments, they can differ noticeably from each other and are modified depending on the corresponding conditions. Neirofiziologiya/Neurophysiology, Vol. 41, No. 1, pp. 3–9, January–February, 2009.     

Investigation of the Physiological and Biochemical Characteristics of Bifidobacteria at the Late Stages of Their Development

An investigation of the physiological and biochemical characteristics of the Bifidobacterium bifidumno. 1, B. adolescentisMC-42, and B. adolescentis94-BIM strains showed that bifidobacteria with a higher growth rate produced greater amounts of the end fermentation products, acetate and lactate. The growth of the strains in batch cultures was found to be inhibited by acidic fermentation products. The growth of B. bifidumno. 1 in a batch mode lasted 100 h at a population density of 10⁶CFU/ml and the growth of B. adolescentisMC-42 and 94-BIM lasted 96–120 h at population densities from 10⁴to 10⁷CFU/ml. Analysis of the bifidobacterial populations by light and electron microscopy showed that they represent conglomerates of cells with a lysed cytoplasm in the cell center and an intact cytoplasm in the apical parts of the cells. The maximum production of extracellular and cell-bound proteinases was observed in the logarithmic growth phase. By the 120th h of cultivation, the metabolic activity of cells, the production of proteinases, and the protein content of bifidobacterial cultures considerably decreased. In the first, second, and third subcultures of 96-h-old bifidobacterial cells on fresh nutrient media, the population density of bifidobacteria and their normal physiological and biochemical characteristics were restored after 48 to 72 h of cultivation.     

猪脑水解液的制备及其生物学活性研究

研究了猪脑水解液的制备及其生物学作用。结果表明:猪脑水解液含有17种氨基酸,其中包括8种必需氨基酸,总氨基酸含量为10493.9mg/L。实验组小鼠服用本品6天后,避暗试验和跳台试验的错误率明显下降(P<0.01),实验组大鼠服用28天后其脑重和雌性大鼠实验组血红蛋白水平显著高于对照组(P<0.05),雌性实验组大鼠在游泳30min后,血乳酸含量明显低于对照组(P<0.05)。提示猪脑水解液不但对脑营养价值高,而且能促进动物的被动学习能力和增强体质     

大肠杆菌RecQ解旋酶的表达纯化和生物学活性研究

RecQ家族解旋酶是DNA解旋酶中高度保守的一个重要家族,在维持染色体的稳定性中起着重要的作用.人类RecQ家族解旋酶突变会导致几种与癌症有关的疾病.本研究旨在诱导大肠杆菌RecQ解旋酶体外表达,并应用生物化学和生物物理学技术研究大肠杆菌RecQ解旋酶的生物学活性. 体外诱导表达获得纯度达90% 以上并具有高活性的大肠杆菌重组RecQ解旋酶,其可溶性好;经生物学活性分析显示具有DNA结合活性、ATP依赖的DNA解链活性、DNA依赖的ATP酶活性. 较之双链DNA（dsDNA）,大肠杆菌RecQ解旋酶更容易与单链DNA(ssDNA)结合( P<0.01 ),但与长度不同的dsDNA的结合特性有差异(P<0.01)而与ssDNA没有差异(P>0.05);大肠杆菌RecQ解旋酶对3种dsDNA的解链速率不同(P<0.05);大肠杆菌RecQ解旋酶的ATP酶活性与辅助因子ssDNA长度也呈正相关(P<0.01). 这些研究结果将有助于阐明大肠杆菌RecQ解旋酶的分子作用机制,并为研究RecQ解旋酶家族其它成员的结构与功能提供帮助.     

Ethnopharmacology,Biological Activity and Phytochemistry of Scaevola spinescens

Scaevola spinescens is endemic to Australia and has traditionally been used by Aboriginal and Torres Strait Islander communities to treat a variety of conditions including colds, flu, fever, stomach pain, urinary disorders, sores, tinea, leprosy, and cancer. Extracts prepared from S. spinescens are non-toxic and have been linked with various medicinal properties including antiviral, antibacterial, anti-inflammatory, and anticancer activities. These studies support the ethnopharmacological use of S. spinescens by Indigenous peoples of Australia and highlight the need for further investigations on the plant for potential use in pharmaceutical and food applications. This review provides a comprehensive, up-to-date review of the literature on S. spinescens focusing on the traditional use, medicinal properties, phytochemicals, and factors that affect their composition during pre-treatment and extraction, as well as providing a framework for future studies of the plant.     

三七总皂苷的药用生物学活性研究进展

三七总皂苷是中药三七的主要有效成分,对中枢神经系统、心血管系统、血液系统等具有抗炎、抗纤维化、抗衰老、抗肿瘤等方面的生物学活性,是现代中药、药理等领域的研究热点.近年来随着研究的不断深入,三七总皂苷的生物学活性被进一步发现,其用途也越来越广.本文就三七总皂苷在生物学方面的研究情况和用途进行综述,并对其前景予以讨论.     

柠檬苦素类似物的生物活性和 构效关系研究进展

柠檬苦素类似物;生物活性;构效关系;结构修饰     

Novel Nociceptin Analogues: Synthesis and Biological Activity

Syntheses are described of the nociceptin (1–13) amide [NC(1–13)-NH₂] and of several analogues in which either one or both the phenylalanine residues (positions 1 and 4), the arginine residues (positions 8 and 12) and the alanine residues (positions 7 and 11) have been replaced by N-benzyl-glycine, N-(3-guanidino-propyl)-glycine and β-alanine, respectively. The preparation is also described of NC(1–13)-NH₂ analogues in which either galactose or N-acetyl-galactosamine are β-O-glycosidically linked to Thr⁵ and/or to Ser¹⁰. Preliminary pharmacological experiments on mouse vas deferens preparations showed that Phe⁴, Thr⁵, Ala⁷ and Arg⁸ are crucial residues for OP₄ receptor activation. Manipulation of Phe¹ yielded peptides endowed with antagonist activity but [Nphe¹] NC(1–13)-NH₂ acted as an antagonist still possessing weak agonist activity. Introduction of the βAla residue either in position 7 or 11 of the [Nphe¹] NC(1–13)-NH₂ sequence, abolished any residual agonist activity and [Nphe¹, βAla⁷] NC(1–13)-NH₂ and [Nphe¹, βAla¹¹] NC(1–13)-NH₂ acted as competitive antagonists only. Modification of both Ala⁷ and Ala¹¹ abolished the antagonist activity of [Nphe¹]NC(1–13)-NH₂ probably by hindering receptor binding. Changes at positions 10 and 11 gave analogues still possessing agonist activity. [Ser(βGal)¹⁰] NC(1–13)-NH₂ displayed an activity comparable with that of NC(1–13)-NH₂, [Ser(βGalNAc)¹⁰] NC(1–13)-NH₂ and [βAla¹¹] NC(1–13)-NH₂ were five and 10 times less active, respectively.The α-amino acid residues are of the l-configuration. Standard abbreviations for amino acid derivatives and peptides are according to the suggestions of the IUPAC-IUB Commission on Biochemical Nomeclature (1984), Eur. J. Biochem. 138, 9–37. Abbreviations listed in the guide published in (2003), J. Peptide Sci. 9, 1–8 are used without explanation.     

nHAP对大鼠肝线粒体的生物活性作用

为了探讨羟基磷灰石纳米粒子(nHAP)对大鼠肝线粒体生物活性的影响,将nHAP直接作用于线粒体,在不同浓度和时间下测定线粒体标志酶琥珀酸脱氢酶(SDH)比活性,并与对照组进行比较。结果显示,当nHAP中水含量在10%以下时,线粒体生物活性未发现改变;当nHAP浓度递增时,在等时间段内,对线粒体SDH比活性呈逐步抑制作用;在不等时间段内,nHAP对线粒体SDH比活性的抑制作用与对照组相比较差异有显著性(p<0.05)。因此,nHAP对线粒体SDH比活性的抑制有浓度和时间的依赖性。     

Composition,Chemical Variability and Biological Activity of Cymbopogon schoenanthus Essential Oil from Central Algeria

Cymbopogon schoenanthus (L.) Spreng . (Poaceae) is an aromatic plant whose aerial parts and rhizome produced an essential oil with pleasant odor. A chemical variability has been observed depending of the countries where the plant grows wild, including Algeria. The chemical compositions of 24 oil samples isolated from plants harvested in Central Algeria have been investigated, to evidence homogeneity or chemical variability within a given area of harvest. Twenty of these were dominated by cis‐ and trans‐p‐menth‐2‐en‐1‐ols (22.6 %±3.6 and 14.3 %±1.7, resp.) beside four atypical compositions. Otherwise, aerial parts and rhizomes produced similar essential oils. Lastly, a fair antimicrobial activity was measured against Staphylococcus aureus strain, while the antioxidant potential was low.     

Analysis of phospholipids in bifidobacteria

Methods of preparative chromatography on silica gel columns were used for obtaining preparations of polar lipids of bifidobacteria. Studies of the preparations by one-dimensional and two-dimensional TLC demonstrated that diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were the predominant phospholipids; minor phospholipids (phosphorus-containing components present in considerably lower amounts) included phosphatidylinositol (PI) and lyso-phosphatidylcholine (lyso-PC). Parameters of qualitative composition of phospholipids and glycolipids may serve as a set of chemotaxonomic markers in modern procedures for identifying Bifidobacterium species.     

Noni果的活性成分和生理功能的研究进展

主要介绍了Noni果中的主要活性成分及其生理功能的研究进展,并对未来的研究方向进行了展望。     

不同温度段核桃壳木醋液的组分分析及生物活性研究

以核桃壳为材料,根据木材裂解规律、不同温度段木醋液得率和颜色的不同,收集精制得90℃～190℃(K1)、190℃～300℃(K2)、300℃～480℃(K3)及90℃～480℃(K)温度段木醋液。采用种子萌发法对精制后各木醋液进行生物活性测定,GC-MS测定脱水后的K1、K2和K3中有机组分,并利用核磁共振技术对其中的主要成分进行验证。结果显示:不同温度段木醋液含有的有机组分不同,含量差别大。K1、K2和K3分别检出13种、42种和37种物质,11种共有物质的相对总含量分别为76.38%、59.83%和57.08%,其中乙酸的相对含量随收集温度的升高逐渐减少。种子萌发试验表明,K1稀释1 000倍、K2稀释25 000倍时,对小麦根、苗生长和干物质的积累有显著促进作用,K和K3在供试范围对苗长、根长和干重都呈不同程度的抑制作用。