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1.
Hiroyuki Nakamura Jong-Dae Lee Manabu Ueno Yusuke Miyajima Hyun Seung Ban 《NanoBioTechnology》2007,3(2):135-145
High accumulation and selective delivery of boron into tumor tissues are the most important requirements to achieve efficient
neutron capture therapy of cancers. We focused on liposomal boron delivery system to achieve a large amount of boron delivery
to tumor. We succeeded in the synthesis of the double-tailed boron cluster lipids 4a–c and 5a–c, which has a B12H11S-moiety as a hydrophilic function, by S-alkylation of B12H11SH with bromoacetyl and chloroacetocarbamate derivatives of diacylglycerols. Size distribution of liposomes prepared from
the boron cluster lipid 4b, dimyristoylphosphatidylcholine, polyethyleneglycol-conjugated distearoylphosphatidylethanolamine, and cholesterol was determined
as 100 nm in diameter by an electrophoretic light scattering spectrophotometer. Calcein-encapsulation experiments revealed
that these boronated liposomes are stable at 37 °C in fetal bovine serum solution for 24 h. 相似文献
2.
Doaa Awad Luminita Damian Göran Karlsson Detlef Gabel 《Chemistry and physics of lipids》2009,157(2):78-5721
Previous investigations have revealed that the boron cluster compound Na2B12H11SH (BSH) is very potent in causing major structural rearrangements of and leakage from phosphatidylcholine liposomes. This somewhat unexpected finding is interesting from a fundamental point of view and may also constitute the basis of future important pharmaceutical/medical applications of BSH. In order to further explore the BSH-lipid interaction, we have studied the effects caused by BSH on dimyristoyl phosphatidylcholine (DMPC) liposomes.Cryo-transmission electron microscopy showed that BSH induces aggregation, membrane rupture and increasing wall thickness of the liposomes. Differential scanning calorimetry revealed a BSH dependent shift of the gel to liquid crystalline phase transition temperature of DMPC. The zeta potential of the liposomes decreases with increasing BSH concentrations, and an apparent dissociation constant of 0.23 mM was found.BSH caused leakage of liposome-encapsulated carboxyfluorescein; leakage was higher at 23 °C (near the phase transition temperature) than at 15 °C and 37 °C. It induced lipid mixing only at very high concentrations. 相似文献
3.
Mauri PL Basilico F Pietta PG Pasini E Monti D Sauerwein W 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,788(1):9-16
Boron neutron capture therapy is a promising binary treatment for cancer. It is based on the nuclear fission that occurs when non-radioactive 10B absorbs thermal neutrons. One of the two boron compounds currently used in clinical trials for this therapy is BSH. To ensure differentiated retention in the tumour versus normal tissue prior to treatment, routine analytical methods to determine pharmacokinetics must be available. For this purpose we have developed a new, easy and time saving approach, in which the separation of boron derivatives is performed by means of capillary electrophoresis (CE). The CE method allows analyses to be performed in short times (less than 18 min), sensitively (LOD 8 pg loaded on the capillary) quantitatively (LOQ 5 microg/ml) and with a high efficiency of separation. Moreover it is simpler than HPLC and more reproducible (intra- and inter-day values were +/-1% and +/-3%, respectively), and does not require a specific column of derivatization. Mass spectrometry analysis of boron derivatives in different samples was also performed to ensure correct attribution of the CE peaks. 相似文献
4.
Gilberto Vinícius de Melo Pereira Bruna de Oliveira Coelho Antonio Irineudo Magalhães Júnior Vanete Thomaz-Soccol Carlos Ricardo Soccol 《Biotechnology advances》2018,36(8):2060-2076
International competition within the dairy market and increasing public awareness about the importance of functional food consumption are providing new challenges for innovation in the probiotic sector. In this context, countless references are currently dedicated to the selection and characterization of new species and more specific strains of probiotic bacteria. In general, these studies adopt basic selection criteria established by the World Health Organization (WHO), including host-associated stress resistance, epithelium adhesion ability, and antimicrobial activity. These aspects are applied to ensure that the candidate probiotic could withstand the stressful conditions of the human digestive system and exert functional proprieties. However, it cannot be assumed that these novel microbial strains are capable of offering several biological benefits attributed to probiotics. Additionally, safety-associated selection criteria, such as plasmid-associated antibiotic resistance spreading and enterotoxin production, are often neglected. This article reviews the recent developments in the processes, strategies, and methods, such as anticarcinogenic, antidepression, antianxiety, antiobesity, antidiabetic, immunostimulatory, and cholesterol-lowering assessments, to select probiotic strains with the ultimate objective of assisting future probiotic microbe evaluation studies. 相似文献
5.
A gene coding for bile salt hydrolase (BSH) from Bifidobacterium adolescentis was cloned and expressed in Escherichia coli, and the nucleotide sequence was determined. The BSH of E. coli transformants was produced intracellularly in the absence of bile salts. A unique bsh promoter (Pbsh) sequence was identified by using a Neural Network Promoter Prediction (NNPP, version 2.2). In spite of their high-level sequence homology with other bsh genes in the Bifidobacterium species, their genetic organization surrounding the bsh gene and their promoter sequences are different depending on the species. 相似文献
6.
Spencer C. Harris Saravanan Devendran João M.P. Alves Sean M. Mythen Phillip B. Hylemon Jason M. Ridlon 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2018,1863(3):276-283
Background
The multi-step bile acid 7α-dehydroxylating pathway by which a few species of Clostridium convert host primary bile acids to toxic secondary bile acids is of great importance to gut microbiome structure and host physiology and disease. While genes in the oxidative arm of the 7α-dehydroxylating pathway have been identified, genes in the reductive arm of the pathway are still obscure.Methods
We identified a candidate flavoprotein-encoding gene predicted to metabolize steroids. This gene was cloned and overexpressed in E. coli and affinity purified. Reaction substrate and product were separated by thin layer chromatography and identified by liquid chromatograph mass spectrometry-ion trap-time of flight (LCMS-IT-TOF). Phylogenetic analysis of the amino acid sequence was performed.Results
We report the identification of a gene encoding a flavoprotein (EDS08212.1) involved in secondary bile acid metabolism by Clostridium scindens ATCC 35704 and related species. Purified rEDS08212.1 catalyzed formation of a product from 3-dehydro-deoxycholic acid that UPLC-IT-TOF-MS analysis suggests loses 4 amu. Our phylogeny identified this gene in other bile acid 7α-dehydroxylating bacteria.Conclusions
These data suggest formation of a product, 3-dehydro-4,6-deoxycholic acid, a recognized intermediate in the reductive arm of bile acid 7α-dehydroxylation pathway and the first report of a gene in the reductive arm of the bile acid 7α-dehydroxylating pathway. 相似文献7.
本文探讨了罗氏乳杆菌DSM122460无细胞上清培养液(Cell-Free Supernatant,CFS)移除胆固醇的能力。采用邻苯二甲醛法测定DSM122460和对照菌株ST-III发酵过程中及其CFS对胆固醇的移除能力,并研究不同CFS浓度下的移除能力。并采用HPLC法测定CFS对照、热处理组和pH7.0组的胆盐水解酶活力,同时测定其移除胆固醇能力。结果显示,DSM122460不仅在发酵过程中具有较高的移除胆固醇能力,其CFS也表现出较高的移除能力,CFS中含有除胆盐水解酶以外的可移除胆固醇的蛋白类成分。这提示可能存在一种乳酸菌移除胆固醇的新机制。 相似文献
8.
Varahenage R. Perera Gerald L. Newton Jonathan M. Parnell Elizabeth A. Komives Kit Pogliano 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014
Background
Gram-positive bacteria in the phylum Firmicutes synthesize the low molecular weight thiol bacillithiol rather than glutathione or mycothiol. The bacillithiol transferase YfiT from Bacillus subtilis was identified as a new member of the recently discovered DinB/YfiT-like Superfamily. Based on structural similarity using the Superfamily program, we have determined 30 of 31 Staphylococcus aureus strains encode a single bacillithiol transferase from the DinB/YfiT-like Superfamily, while the remaining strain encodes two proteins.Methods
We have cloned, purified, and confirmed the activity of a recombinant bacillithiol transferase (henceforth called BstA) encoded by the S. aureus Newman ORF NWMN_2591. Moreover, we have studied the saturation kinetics and substrate specificity of this enzyme using in vitro biochemical assays.Results
BstA was found to be active with the co-substrate bacillithiol, but not with other low molecular weight thiols tested. BstA catalyzed bacillithiol conjugation to the model substrates monochlorobimane, 1-chloro-2,4-dinitrobenzene, and the antibiotic cerulenin. Several other molecules, including the antibiotic rifamycin S, were found to react directly with bacillithiol, but the addition of BstA did not enhance the rate of reaction. Furthermore, cells growing in nutrient rich medium exhibited low BstA activity.Conclusions
BstA is a bacillithiol transferase from S. aureus that catalyzes the detoxification of cerulenin. Additionally, we have determined that bacillithiol itself might be capable of directly detoxifying electrophilic molecules.General significance
BstA is an active bacillithiol transferase from S. aureus Newman and is the first DinB/YfiT-like Superfamily member identified from this organism. Interestingly, BstA is highly divergent from B. subtilis YfiT. 相似文献9.
Antonella Crivello Carlo Nervi Roberto Gobetto Simonetta Geninatti Crich Iboya Szabo Alessandro Barge Antonio Toppino Annamaria Deagostino Paolo Venturello Silvio Aime 《Journal of biological inorganic chemistry》2009,14(6):883-890
Abstract Sodium borocaptate (BSH) is widely used for boron neutron capture therapy (BNCT) of brain tumors. One drawback is the large
uptake by the liver causing a decrease of its availability at the tumor region as well as bringing about toxicity problems.
A novel carborane-based compound containing a boron payload very similar to that of BSH has been synthesized and tested on
rat glioma (C6) cells, hepatoma tissue culture (HTC) cells, and hepatocytes. The newly synthesized system consists of an o-carborane unit (C2B10H11, o-CB) conjugated to a glutamine residue through a proper spacer, namely, o-CB-Gln. As compared with BSH, it showed the same uptake by C6 cells, but a 50% decrease in uptake by HTC cells and an 80%
decrease in uptake by healthy hepatocytes. On this basis o-CB-Gln appears an interesting candidate for BNCT of brain tumors as it is expected to have a therapeutic index analogous
to that of BSH accompanied by a much lower liver toxicity.
Graphical Abstract A novel carborane based compound, consisting in an o-carborane unit (C2B10H11, o-CB) conjugated to a glutamine residue through a proper spacer (namely o-CB-Gln) has been synthesized, characterized and tested on rat glioma (C6), hepatoma (HTC) and hepatocytes. As compared to
sodium borocaptate (BSH), widely used for boron neutron capture therapy (BNCT) of brain tumors, the newly synthesized system
showed the same uptake by C6 cells, but a 50% decrease by HTC and 80% decrease by healthy hepatocytes. On this basis o-CB-Gln appears an interesting candidate for BNCT of brain tumors as it is expected to have a therapeutic index analogous
to BSH accompanied by a much lower liver toxicity.
相似文献
10.
Zhen-Hui Cao Julia M. Green-Johnson Nicole D. Buckley Qiu-Ye Lin 《Biotechnology advances》2019,37(1):223-238
For centuries, fermented soy foods have been dietary staples in Asia and, now, in response to consumer demand, they are available throughout the world. Fermentation bestows unique flavors, boosts nutritional values and increases or adds new functional properties. In this review, we describe the functional properties and underlying action mechanisms of soy-based fermented foods such as Natto, fermented soy milk, Tempeh and soy sauce. When possible, the contribution of specific bioactive components is highlighted. While numerous studies with in vitro and animal models have hinted at the functionality of fermented soy foods, ascribing health benefits requires well-designed, often complex human studies with analysis of diet, lifestyle, family and medical history combined with long-term follow-ups for each subject. In addition, the contribution of the microbiome to the bioactivities of fermented soy foods, possibly mediated through direct action or bioactive metabolites, needs to be studied. Potential synergy or other interactions among the microorganisms carrying out the fermentation and the host's microbial community may also contribute to food functionality, but the details still require elucidation. Finally, safety evaluation of fermented soy foods has been limited, but is essential in order to provide guidelines for consumption and confirm lack of toxicity. 相似文献