Water-soluble Moieties Research Articles

Distyryl Carboxylic Acid Substituted BODIPY and BODIPY‐C60 Systems for Generation of Singlet Oxygen

AbstractBODIPY based molecules functionalized with water soluble moieties have been developed and recognized as liable triplet photosensitizers for phototherapeutic applications. In this work, we have prepared BODIPY analogues with dicarboxylic acid groups and bearing iodine or fullerene moieties for efficient intersystem crossing which display far‐red absorption band and high singlet oxygen production both in organic and aqueous media. In this perspective by using similar design the effect of the halogenation of the dyes versus spin converter on the skeleton were compared. The structures of the synthesized BODIPYs and BODIPY‐C60 (6–10) were elucidated by mass, 1H and 13C NMR spectroscopic techniques. Photophysical and photochemical properties of the compounds were examined using UV‐Vis. absorption and fluorescence emission spectrophotometers. The absorption intensities of the trap molecules (DPBF and ADBA) reduced because of singlet oxygen generation in the media. This study may provide useful infrastructure to elucidate the relationship between the use of fullerene (9) or iodine (10) where singlet oxygen quantum yield of 9 and 10 are determined as 0.87 and 0.97 respectively.

Synthesis and characterization of water-soluble C60-peptide conjugates.

With the aim of developing biocompatible and water-soluble C60 derivatives, three types of C60-peptide conjugates consisting of hydrophilic oligopeptide anchors (oligo-Lys, oligo-Glu, and oligo-Arg) were synthesized. A previously reported Prato reaction adduct of a biscarboxylic acid-substituted C60 derivative was subjected to a solid phase synthesis for amide formation with N-terminal amines of peptides on resin to successfully provide C60-peptide conjugates with one C60 and two peptide anchors as water-soluble moieties. Among three C60-peptide conjugates prepared, C60-oligo-Lys was soluble in water at neutral pH, and C60-oligo-Glu was soluble in buffer with a higher pH value, but C60-oligo-Arg was insoluble in water and most other solvents. C60-oligo-Lys and C60-oligo-Glu were characterized by 1H and 13C NMR. Photoinduced 1O2 generation was observed in the most soluble C60-oligo-Lys conjugate under visible light irradiation (527 nm) to show the potential of this highly water-soluble molecule in biological systems, for example, as a photosensitizer in photodynamic therapy.

Nanosponges- A Versatile Approach of Drug Delivery System

With the escalating number of diseases, an opportunistic target drug delivery system is needed. Nanosponges (NS) are nanosized drug delivery systems having three-dimensional (3D) configurations, fabricated by crosslinking of polymers to ensnare a wide assortment of drugs. These small particles move inside the body till they arrive at the target site and deliver the medication in a specific and controlled way. They can ensnare (entrap) both hydrophilic and hydrophobic moieties in a smarter manner and improve the solubility and bioavailability of drugs. NS have been utilized to examine the medication conveyance by oral, parenteral, and topical routes. Another significant property of NS is that they can work on the solvency of ineffectively water-soluble moieties and are utilized for the storage of gases, and proteins as well as for the removal of toxins from the systemic circulation. The present review highlights the types of nanosponges, their methods of preparation, characterization, and applications in drug delivery.

Poly(N,N-bis(2-methoxyethyl)acrylamide), a thermoresponsive non-ionic polymer combining the amide and the ethyleneglycolether motifs

Poly(N,N-bis(2-methoxyethyl)acrylamide) (PbMOEAm) featuring two classical chemical motifs from non-ionic water-soluble polymers, namely, the amide and ethyleneglycolether moieties, was synthesized by reversible addition fragmentation transfer (RAFT) polymerization. This tertiary polyacrylamide is thermoresponsive exhibiting a lower critical solution temperature (LCST)–type phase transition. A series of homo- and block copolymers with varying molar masses but low dispersities and different end groups were prepared. Their thermoresponsive behavior in aqueous solution was analyzed via turbidimetry and dynamic light scattering (DLS). The cloud points (CP) increased with increasing molar masses, converging to 46 °C for 1 wt% solutions. This rise is attributed to the polymers’ hydrophobic end groups incorporated via the RAFT agents. When a surfactant-like strongly hydrophobic end group was attached using a functional RAFT agent, CP was lowered to 42 °C, i.e., closer to human body temperature. Also, the effect of added salts, in particular, the role of the Hofmeister series, on the phase transition of PbMOEAm was investigated, exemplified for the kosmotropic fluoride, intermediate chloride, and chaotropic thiocyanate anions. A pronounced shift of the cloud point of about 10 °C to lower or higher temperatures was observed for 0.2 M fluoride and thiocyanate, respectively. When PbMOEAm was attached to a long hydrophilic block of poly(N,N-dimethylacrylamide) (PDMAm), the cloud points of these block copolymers were strongly shifted towards higher temperatures. While no phase transition was observed for PDMAm-b-pbMOEAm with short thermoresponsive blocks, block copolymers with about equally sized PbMOEAm and PDMAm blocks underwent the coil-to-globule transition around 60 °C.

Determination of Hexavalent Chromium Fractions in Plastics Using Laboratory-Based, High-Resolution X-ray Emission Spectroscopy.

Cr(VI) is a well-known human carcinogen with many water-soluble moieties. Its presence in both natural and man-made substances poses a risk to public health, especially when contamination of groundwater is possible. This has led the European Union and other jurisdictions to include Cr(VI) in restriction of hazardous substances regulations. However, for several important industrial and commercial purposes, analytical capability to characterize Cr(VI) is known to be insufficient for regulatory purposes. For example, advanced X-ray spectroscopies, particularly synchrotron-based X-ray absorption fine structure (XAFS) studies, have shown that species interconversion and under-extraction can be difficult to prevent in many existing liquid extraction protocols when applied to plastics, mining ores and tailings, and paint sludges. Here, we report that wavelength dispersive X-ray fluorescence spectroscopy taken at energy resolutions close to the theoretical limit imposed by the core-hole lifetime, generally called X-ray emission spectroscopy (XES) in the synchrotron community, can be used in the laboratory setting for noninvasive, analytical characterization of the Cr(VI)/Cr ratio in plastics. The selected samples have been part of ongoing efforts by standards development organizations to create improved Cr(VI) testing protocols, and the present work provides a direct proof-of-principle for the use of such extremely high-resolution laboratory WDXRF as an alternative to liquid extraction methods for regulatory compliance testing of Cr(VI) content. As a practical application of this work, we report a value for the Cr(VI) mass fraction of the new NIST Standard Reference Material 2859 Restricted Elements in Polyvinyl Chloride.

On the synthesis of functionalized porphyrins and porphyrin conjugates via β-aminoporphyrins

A two-step methodology to prepare a series ofmeso-tetraarylporphyrin conjugates bearing water-soluble moieties, anchoring groups and receptor subunits.

Ultrasound accelerated gelation of novel l-lysine based hydrogelators

We reported a novel hydrogelator with L-lysine as a linker to connect 7-carboxyl methoxycoumarin and hydrazine as lipophilic and water-soluble moieties. Ultrasound accelerated the gelation and induced homogenous self-assembly of fibrils into entangled 3D networks. The hydrogel exhibits great potential for future biomedical applications.

MICROWAVE-ASSISTED RAPID BIOSYNTHESIS OF STABLE SILVER NANOPARTICLES USING CLOVE BUDS (SYZYGIUM AROMATICUM) SOLUTION

This is an extended work on the biosynthesis of noble metal nanoparticles using dried clove buds. Here microwave assistance is taken not only for accelerating the reaction rate but also for denaturing the proteins and other enzymes, which will prevent obtaining desired functionalized nanoparticles. FTIR studies infer that nanoparticles thus obtained are found adsorbed with water soluble organic moieties, mostly flavonoids. The bathochromic shift from 320 nm in ultra-violet range indicates the involvement of water soluble bio-moieties of the clove in the formation of AgNP . X-ray diffraction (XRD) spectrum confirmed that the AgNP are crystalline in nature. The surface morphology is studied using FESEM, TEM and AFM techniques infer that the AgNP are well dispersed, roughly spherical in shape and are in the range of 30–60 nm. The AgNP with the organic moiety will have synergic antimicrobial action.

Aged Garlic Extract Scavenges Superoxide Radicals

There is increasing evidence to suggest that many degenerative or pathological processes, such as aging, cancer, and coronary heart disease, are related to reactive oxygen species and radical-mediated reactions. We examined the effectiveness of aged garlic extract (AGE), a garlic preparation rich in water-soluble cysteinyl moieties, and its component for scavenging of superoxide by using the hypoxanthine-xanthine oxidase and human neutrophils. In the hypoxanthine-xanthine oxidase system, electron spin resonance showed that aged garlic extract scavenged superoxide radicals in a dose-dependent manner up to 54%. The EC(50) value of aged garlic extract for the superoxide radical scavenging effect was 0.80 mg/ml. N-α-(1-deoxy-D-fructos-1-yl)-L-arginine (25.9%) and (1S, 3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-1,3-dicarboxylic acid (20.8%), water-soluble moieties of AGE, also exerted superoxide scavenging effects. Phorbol 12-myristate 13-acetate-activated human neutrophils produced superoxide radical of 56.6 ± 9.27 nmol/min/10(7) cells. Aged garlic extract (3 mg/ml) significantly inhibited superoxide production in comparison to the control. These data suggest that aged garlic extract may be useful for preventing diseases associated with reactive oxygen species.

Glomerular Filtration Barrier and Molecular Segregation

The normal phenotype of the glomerular filtration barrier (GFB) and the mechanisms that underlie it have intrigued physiologists, microvascular biologists, and renal physicians for decades, especially because, in health, the multilayered barrier differentially restricts the passage of molecules of

Modulation of xenobiotic metabolising enzymes by anticarcinogens—focus on glutathione S-transferases and their role as targets of dietary chemoprevention in colorectal carcinogenesis

There is evidence that consumption of certain dietary ingredients may favourably modulate biotransformation of carcinogens. Associated with this is the hypothesis that the risk for developing colorectal cancer could be reduced, since its incidence is related to diet. Two main groups of biotransformation enzymes metabolize carcinogens, namely Phase I enzymes, which convert hydrophobic compounds to more water-soluble moieties, and Phase II enzymes (e.g. glutathione S-transferases [GST]), which primarily catalyze conjugation reactions. The conjugation of electrophilic Phase I intermediates with glutathione, for instance, frequently results in detoxification. Several possible colon carcinogens may serve as substrates for GST isoenzymes that can have marked substrate specificity. The conjugated products could be less toxic/genotoxic if GSTs are induced, thereby reducing exposure. Thus, numerous studies have shown that the induction of GSTs by antioxidants enables experimental animals to tolerate exposure to carcinogens. One important mechanism of GST induction involves an antioxidant-responsive response element (ARE) and the transcription factor nuclear factor E2-related factor 2 (Nrf2), which is bound to the Kelch-like ECH associated protein 1 (Keap1) in the cytoplasm. Antioxidants may disrupt the Keap–Nrf2 complex, allowing Nrf2 to translocate to the nucleus and mediate expression of Phase II genes via interaction with the ARE. GSTs are also induced by butyrate, a product of gut flora-derived fermentation of plant foods, which may act via different mechanisms, e.g. by increasing histone acetylation. GSTs are expressed with high inter-individual variability in human colonocytes, which points to large differences in cellular susceptibility to xenobiotics. Enhancing expression of GSTs in human colon tissue could therefore contribute to reducing cancer risks. However, it has not been demonstrated in humans that this mechanism is associated with cancer prevention. In the future, it will be useful to determine GSTs during dietary intervention studies to enhance our understanding of this protective mechanism.

Protein Translation Inhibition by Stachybotrys Chartarum Conidia with and without the Mycotoxin Containing Polysaccharide Matrix

Recent studies have correlated the presence of Stachybotrys chartarum in structures with SBS. S. chartarum produces mycotoxins that are thought to produce some of the symptoms reported in sick-building syndrome (SBS). The conidia (spores) produced by Stachybotrys species are not commonly found in the air of buildings that have been found to contain significant interior growth of this organism. This could be due in part to the large size of the Stachybotrys spores, or the organism growing in hidden areas such as wall cavities. However, individuals in buildings with significant Stachybotrys growth frequently display symptoms that may be attributed to exposure to the organism's mycotoxins. In addition, Stachybotrys colonies produce a "slime" or polysaccharide (carbohydrate) matrix that coats the hyphae and the spores. The intent of this project was to determine whether the carbohydrate matrix and the mycotoxins embedded in it could be removed from the spores by repeated washings with either aqueous or organic solvents. The results demonstrated that the process of spore washing removed compounds that were toxic in a protein translation assay as compared to spores that were washed with an organic solution, however a correlation between carbohydrate removal during the washing process and the removal of mycotoxins from the spore surface was not observed. These data demonstrated that mycotoxins are not likely to be found exclusively in the carbohydrate matrix of the spores. Therefore, mycotoxin removal from the spore surface can occur without significant loss of polysaccharide. We also showed that toxic substances may be removed from the spore surface with an aqueous solution. These results suggest that satratoxins are soluble in aqueous solutions without being bound to water-soluble moieties, such as the carbohydrate slime matrix.

Targeting Coenzyme Q Derivatives to Mitochondria

This chapter analyzes the approaches to target coenzyme Q derivatives to mitochondria. Coenzyme Q is an essential electron carrier and an important antioxidant in the mitochondrial inner membrane. Manipulating coenzyme Q content within mitochondria may help in understanding its functions and exploring its therapeutic potential. One way to increase the mitochondrial concentration of coenzyme Q is to administer it to isolated mitochondria, cells, or organisms, but the hydrophobicity of native coenzyme Q and its consequent low solubility and bioavailability limit this approach. The hydrophobicity of coenzyme Q is due to the long isoprenoid chain at ring position 6. Less hydrophobic but still active derivatives of coenzyme Q can be made by replacing the carbon chain with more water soluble moieties. The chapter describes the concepts related to synthesis and handling of mitochondria-targeted coenzyme Q derivatives. The chapter also discusses the incorporation of radioactive and stable isotopes into mitochondria-targeted coenzyme Q derivatives. The chapter elaborates the modifying and measuring coenzyme Q redox state. The chapter provides a brief about experiments with mitochondria-targeted coenzyme Q derivatives. The chapter provides an analysis of mitochondrial uptake of mito Q and locationof targeted coenzyme Q derivatives within mitochondria.

An Overview of Uremic Toxicity

About 100 uremic retention solutes have been identified at present, but not all of these compounds are necessarily toxic. They can be defined as uremic toxins if they exert biochemical/biological actions. Based on their physicochemical characteristics, there are three major groups of uremic retention solutes: 1) the small water-soluble compounds (<500 Da), which are easily removed by standard low-pore-size dialyzer membranes; 2) the protein-bound solutes (also mostly <500 Da), whose dialytic removal is hampered by their protein binding, irrespective of the membrane type; and 3) the so-called middle molecules (>500 Da), which can be removed only by membranes with a large pore size and/or adsorptive capacity. In the present review, we will summarize the currently known information about the toxicity of the uremic retention solutes. Although removal of small water-soluble urea has been recognized for many years as a current measure of dialysis adequacy, data on its toxicity are very scanty. Almost 50 other water-soluble compounds are known to be retained in uremia, but only a few exert biological effects. Most of the toxic water-soluble moieties, such as the guanidines, phosphate, xanthine, and hypoxanthine show an intra-dialytic compartmental behavior, which is different from urea. A substantial number of uremic solutes are protein bound, and most of them exert biological action. Among them are the phenols, indoles, homocysteine, and carboxy-methyl-propyl-furanpropionic acid. Recent data suggest that protein binding acts as a buffer against the toxic effects of these compounds, and that hypoalbuminemia increases both their free fraction and their toxicity. In addition, many middle molecules, such as ss(2)-microglobulin, leptin, and advanced glycation end products, have been related to biological/clinical effects. Our current knowledge of the biological impact of the middle molecules is very likely incomplete. It is concluded that many of the water-soluble compounds exert little or no toxicity, and that urea removal pattern per se is not identical to that of many biologically active molecules. Hence, in dialysis, more than urea removal alone should be pursued.

New Polymeric Coagulants Tested in Water and Wastewater

In this work, new polymeric flocculants are presented for use in water-treatment operations. Efficiencies are reported from results obtained by conventional bench-scale tests. These tests are carried out in three systems: a bentonite suspension, biologically treated wastewater effluents and chemically treated effluents. The polymers are water-soluble moieties of the zwitterionic type, which present considerable chain expansion in the presence of high ionic strengths or high salinity, in contrast to the behavior exhibited by common polyelectrolytes. In the case of biologically treated wastewater, 87% of turbidity removal is obtained with the polymer alone. In the case of chemically treated mixed industrial wastewater, the new polymers are compared with cationic and anionic polymers. This work illustrates that high efficiencies may be obtained using anionic or zwitterionic polymers. With 0.2 mg l−1 of zwitterionic polymer and 20 mg l−1 aluminum sulfate, removals of 38% and 96% in chemical oxygen demand (COD) and total suspended solids (TSS), respectively, can be obtained. For Mexico City's wastewater flow, the highest efficiencies are obtained with 250 mg l−1 of Ca(OH)2 and 0.1 mg l−1 of zwitterionic polymer (48% COD and 87% TSS). In this particular case good results are also obtained using anionic flocculants with aluminum sulfate.

Cryo-TEM of CTAB micelles and microemulsions

Single-tailed surfactant molecules in aqueous solutions can associate into several different microstructural forms within a one-phase region of the phase diagram (Fig. 1). The molecules associate into globular aggregates called spherical micelles above a surfactant concentration called the critical micelle concentration, or cmc. At higher surfactant concentrations some surfactants will associate into rod-like micelles called cylindrical micelles. In systems containing ionic surfactants the transition from spherical to cylindrical micelles can be brought about at lower surfactant concentrations by adding an electrolyte. The electrolyte screens the electrostatic repulsion between surfactant head groups and allows formation of the lower mean curvature cylindrical microstructures. Micellar aggregates are equilibrium microstructures in which the nonpolar (often hydrocarbon or fluorocarbon) moieties of the surfactant molecules are shielded from the aqueous medium by the water-soluble moieties of the surfactant molecules. The solubilization of oil into the nonpolar micelle interior produces an aqueous solution of oil swollen micelles, i.e., a microemulsion.

Lipid metabolism of Borrelia hermsi.

The synthesis of complex lipids by Borrelia hermsi while growing in Kelly medium was investigated by labeling cultures with D-[14C]glucose or [14C]palmitic acid. Labeled glucose was incorporated into phosphatidyl choline, phosphatidyl glycerol, monogalactosyl diglyceride, cholesterol glucoside, and acylated cholesteryl glucoside. The fatty acid composition reflected that of the medium suggesting that this spirochete directly incorporates acyl chains unaltered from its external milieu. Furthermore, the distribution of labeled carbon between acyl groups (lipid-soluble) and water-soluble moieties indicates that there is no metabolic exchange between these two pools. The relationship of B. hermsi to other spirochetes is discussed in terms of lipid metabolism as a generic characteristic.

Phospholipids of the pulmonate land snailCepaea nemoralis (L.)

AbstractThe phospholipids of the snailCepaea nemoralis, comprising the major lipid fraction (65%) in this terrestrial pulmonate, were investigated by thin‐layer and column chromatography. Detailed gas chromatographic analyses of liberated fatty acid fractions and amino acid analyses of the water soluble moieties of isolated phospholipid classes were carried out. Phosphatidyl choline (47%) and phosphatidyl ethanolamine (21%) were found to be the predominant phospholipid classes, while phosphatidyl serine (8%), phosphatidyl inositol (6%), diphosphatidyl glycerol (3%), ceramide amino‐ethylphosphonate (7%), lysophosphatidyl choline (1%), and phosphatidic acid (1%) were present in lesser amounts. In the phosphatidyl ethanolamine and phosphatidyl serine fractions, minor quantities of plasmalogen analogues were detected. Fatty acid profiles of the various phospholipid classes appeared to be strikingly diverse, e.g. a characteristic component, such as linoleic (18∶2ω6) acid, ranging from 3–54%. In vivo radioisotope studies using 1‐14C‐acetate demonstrated the high biosynthetic rate of all phospholipid classes and their respective fatty acid fractions. Results are discussed in relation to data on the phospholipids from other invertebrate species.

Radioisotopic studies on the biosynthesis of the glyceryl diether lipids of Halobacterium cutirubrum.

Cells of the obligate halophile Halobacterium cutirubrum were grown to the stationary phase in the presence of 32P-orthophosphate, 35S-sulfate, or 14C-labelled precursors (acetate, malonate, mevalonate, glycerol). 32P was incorporated into the phosphatide components in proportion to their relative concentrations, thus: phosphatidyl glycerophosphate (diether analogue) &gt; unidentified minor phosphatide &gt; phosphatidyl glycerol (diether analogue). 35S-Sulfate was incorporated mostly into the glycolipid sulfate ester component, but small amounts of 35S also appeared in a more polar sulfolipid and in a minor unidentified sulfolipid.14C-Mevalonate was the most efficient precursor for the phytanyl chains, followed in decreasing order by acetate and glycerol. Only traces of 14C from the malonate precursor were incorporated, and these appeared entirely in the phytanyl groups. A considerable proportion of 14C from the glycerol precursor was found in the glycerol and sugar moieties of the lipids. Little or no labelling of the water-soluble moieties of the lipids was observed with the other carbon precursors.Only traces of 14C-labelled fatty acids were detected with any of the 14C precursors; with acetate, in particular, only 0.3% of the 14C in the total lipids was found in fatty acids. It is concluded that the predominant biosynthetic route for the lipid chains is the mevalonate pathway for synthesis of isoprenoid groups, and that the malonyl-CoA pathway for synthesis of fatty acids is operating at a very low level of activity.

N -METHYL GROUPS IN BACTERIAL LIPIDS

Goldfine, Howard (Harvard Medical School, Boston, Mass.), and Martha E. Ellis. N-methyl groups in bacterial lipids. J. Bacteriol. 87:8-15. 1964.-The ability of bacteria to synthesize lecithin was examined by measuring the incorporation of the methyl group of methionine into the water-soluble moieties obtained on acid hydrolysis of bacterial lipids. Of 21 species examined, mostly of the order Eubacteriales, only 2, Agrobacterium radiobacter and A. rhizogenes, incorporated the methyl group of methionine into lipid-bound choline. Evidence was also obtained for the formation of lipid-bound N-methylethanolamine and N,N'-dimethylethanolamine in these two organisms. Two other species, Clostridium butyricum and Proteus vulgaris, incorporated the methyl group of methionine into lipid-bound N-methylethanolamine, but did not appear to be able to further methylate these lipids to form lecithin. The results of this study lend further strength to the generalization that bacteria, with the exception of the genus Agrobacterium, are unable to synthesize lecithin.