Search

Due to their modular design from inorganic building units (IBUs) and organic linker molecules, metal-organic frameworks (MOFs) exhibit great flexibility and variability in terms of their inherent properties. However, the creation of MOF-based electronic and optoelectronic devices, suitable for real-world applications, critically depends on the availability of highly adaptable materials, that can be patterned down to the nanometer scale. MOFs based on the linker benzophenone dicarboxylate (bzpdc) present a promising platform in this regard: They allow for the photochemical integration of almost any functionality into their frameworks through easily accessible postsynthetic modifications (PSMs). While this approach has been limited to powdered bulk materials so far, transitioning to more processable forms such as membranes or thin films is now crucial for their integration into practical applications. Light, the key initiator of the reaction, can be manipulated in various ways to create spatially resolved selective structures within bzpdc-MOFs. The PhD thesis presented here, addresses this issue and can be thematically divided into two main areas. The first section covers the shaping of a zirconium-based bzpdc-MOF for applications extending to 3D micropatterning. The second section of the PhD thesis is dedicated to the development of a novel, multifunctional bzpdc-MOF.

Background Benzophenone-3 (BP-3) and its major metabolite benzophenone-1 (BP-1) are widely used as UV filters in sunscreens and cosmetics to prevent sunburn and skin damage, or as stabilizers to prevent photodegradation in many commercial products. As a result, their presence is ubiquitous in the environment, wildlife and humans. Based on endocrine disruption concerns, international regulatory agencies are performing a closer evaluation. Objective and methods This work aimed to comprehensively review the available human relevant evidence for safety issues in MEDLINE/PubMed in order to create a structured database of studies, as well as to conduct an integrative analysis as part of the Human Biomonitoring for Europe (HBM4EU) Initiative. Results A total of 1,635 titles and abstracts were screened and 254 references were evaluated and tabulated in detail, and classified in different categories: i) exposure sources and predictors; ii) human biomonitoring (HBM) exposure levels to perform a meta-analysis; iii) toxicokinetic data in both experimental animals and humans; iv) in vitro and in vivo rodent toxicity studies; and v) human data on effect biomarkers and health outcomes. Our integrative analysis showed that internal peak BP-3 concentrations achieved after a single whole-body application of a commercially available sunscreen (4% w/w) may overlap with concentrations eliciting endocrine disrupting effects in vitro, and with internal concentrations causing in vivo adverse female reproductive effects in rodents that were supported by still limited human data. The adverse effects in rodents included prolonged estrous cycle, altered uterine estrogen receptor gene expression, endometrium hyperplasia and altered proliferation and histology of the mammary gland, while human data indicated menstrual cycle hormonal alterations and increased risk of uterine fibroids and endometriosis. Among the modes

BACKGROUND: Humans are widely exposed to chemicals with known or suspected endocrine disrupting effects. Among those are several benzophenones, bisphenols and other phenols commonly used in consumer products. OBJECTIVES: To provide human biomonitoring data from young families including infants and their parents as well as longitudinal data of infants exclusively breastfed versus on mixed diet. METHOD: Twenty-two benzophenones, bisphenols and other phenols, were measured in urine sample sets collected from more than 100 infants and their parents (the TRIO study) and in paired samples from 61 infants when exclusively breastfed and after introduction of mixed diet (the FOOD study). RESULTS: Twelve out of 22 substances were detectable in more than half of the urine samples from infants, mothers or fathers. Large variation in excreted levels of almost all the substances were observed. The TRIO study showed that infants had comparable or even significantly higher daily urinary excretion (DUE) of benzophenone, 4-hydroxy-benzophenone, bisphenol A, bisphenol S, triclosan and 2-phenylphenol than their parents. In the FOOD study, exclusively breastfed infants had higher or similar DUE of triclosan and benzophenones compared to when they received mixed diet. Urinary levels of triclosan and the benzophenones, BP-1 and BP-3 were significantly correlated between all trio members, indicating exposure from the same sources at home. For triclosan, BP-1 and BP-3, the within family variation was lower than between families in the TRIO study. Many substances were positively correlated both within infants and parents, indicating that some families were exposed to several of these substances concurrently. CONCLUSION: Participants in this study excreted relatively low chemical levels, however, simultaneous exposure to several chemicals with endocrine disrupting abilities is of concern due to the dose-additive effects of these substances in combination with other chemicals.

BACKGROUND: Humans are widely exposed to chemicals with known or suspected endocrine disrupting effects. Among those are several benzophenones, bisphenols and other phenols commonly used in consumer products. OBJECTIVES: To provide human biomonitoring data from young families including infants and their parents as well as longitudinal data of infants exclusively breastfed versus on mixed diet. METHOD: Twenty-two benzophenones, bisphenols and other phenols, were measured in urine sample sets collected from more than 100 infants and their parents (the TRIO study) and in paired samples from 61 infants when exclusively breastfed and after introduction of mixed diet (the FOOD study). RESULTS: Twelve out of 22 substances were detectable in more than half of the urine samples from infants, mothers or fathers. Large variation in excreted levels of almost all the substances were observed. The TRIO study showed that infants had comparable or even significantly higher daily urinary excretion (DUE) of benzophenone, 4-hydroxy-benzophenone, bisphenol A, bisphenol S, triclosan and 2-phenylphenol than their parents. In the FOOD study, exclusively breastfed infants had higher or similar DUE of triclosan and benzophenones compared to when they received mixed diet. Urinary levels of triclosan and the benzophenones, BP-1 and BP-3 were significantly correlated between all trio members, indicating exposure from the same sources at home. For triclosan, BP-1 and BP-3, the within family variation was lower than between families in the TRIO study. Many substances were positively correlated both within infants and parents, indicating that some families were exposed to several of these substances concurrently. CONCLUSION: Participants in this study excreted relatively low chemical levels, however, simultaneous exposure to several chemicals with endocrine disrupting abilities is of concern due to the dose-additive effects of these substances in combination with other chemicals.

Most aromatic ketones containing first-row elements undergo unexpectedly fast intersystem crossing in a few tens of picoseconds and a quantum yield close to unity. Among them, xanthone (9H-xanthen-9-one) possesses one of the fastest singlet- triplet rates of only similar to 1.5 ps. The exact mechanism of this unusually fast transition is still under debate. Here, we perform wavepacket dynamics of the photochemistry of xanthone in the gas phase and in polar solvents. We show that xanthone follows El-Sayed's rule for intersystem crossing. From the second singlet excited state, the mechanism is sequential: (i) an internal conversion between singlets 1 pi pi* -* 1n pi* (85 fs), (ii) an intersystem crossing 1n pi* -* 3 pi pi* (2.0 ps), and (iii) an internal conversion between triplets 3 pi pi* -* 3n pi* (602 fs). Each transfer finds its origin in a barrierless access to electronic state intersections. These intersections are close to minimum energy structures, allowing for efficient transitions from the initial singlet state to the triplets.

Atomic hydrogen dry etching was used for microstructure fabrication. Photolithography was proposed and achieved by a dry development process using atomic hydrogen irradiation. The reaction system of poly(methyl methacrylate) mixed with molecular benzophenone was examined as a model system for a proof-of-concept study. Optical patterning was experimentally made on a thin layer of poly(methyl methacrylate) with benzophenone by UV light exposure with a photomask. The reaction system acted as a negative tone resist in the proposed process. Thus, a model system for a new atomic hydrogen dry development process was proposed and successfully demonstrated.

Lactisole, which has a 2-phenoxy propionic acid skeleton, is well-known as an inhibitor of sweet taste receptors. We recently revealed some of the structure-activity relationships of the aromatic ring and chiral center of lactisole. Photoaffinity labeling is one of the common chemical biology methods to elucidate the interaction between bioactive compounds and biomolecules. In this paper, the novel asymmetric synthesis of lactisole derivatives with common photophores (benzophenone, azide and trifluoromethyldiazirine) for photoaffinity labeling is described. The synthetic compounds are subjected to cell-based sweet taste receptors, and the substitution with trifluoromethyldiazirinyl photophore shows the highest affinity to the receptor of the synthesized compounds.

Lactisole, which has a 2-phenoxy propionic acid skeleton, is well-known as an inhibitor of sweet taste receptors. We recently revealed some of the structure-activity relationships of the aromatic ring and chiral center of lactisole. Photoaffinity labeling is one of the common chemical biology methods to elucidate the interaction between bioactive compounds and biomolecules. In this paper, the novel asymmetric synthesis of lactisole derivatives with common photophores (benzophenone, azide and trifluoromethyldiazirine) for photoaffinity labeling is described. The synthetic compounds are subjected to cell-based sweet taste receptors, and the substitution with trifluoromethyldiazirinyl photophore shows the highest affinity to the receptor of the synthesized compounds.

The Zr-based metal–organic framework, Zr-bzpdc-MOF, contains the photoreactive linker molecule benzophenone-4,4'-dicarboxylate (bzpdc) which imparts the possibility for photochemical post-synthetic modification. Upon irradiation with UV light, the keto group of the benzophenone moiety will react with nearly every C-H bond-containing molecule. Within this paper, we further explore the photochemical reactivity of the Zr-bzpdc-MOF, especially with regard to which restrictions govern internal versus external reactions. We show that apart from reactions with C-H bond-containing molecules, the MOF reacts also with water. By studying the reactivity versus linear alcohols we find a clear delineation in that shorter alcohol molecules (up to butanol as a borderline case) react with photoexcited keto groups throughout the whole crystals whereas longer ones react only with surface-standing keto groups. In addition, we show that with the alkanes n-butane to n-octane, the reaction is restricted to the outer surface. We hypothesize that the reactivity of the Zr-bzpdc-MOF versus different reagents depends on the accessibility of the pore system which in turn depends mainly on the size of the reagents and on their polarity. The possibility to direct the post-synthetic modification of the Zr-bzpdc-MOF (selective modification of the whole pore system versus surface modification) gives additional degrees of freedom in the design of this metal–organic framework for shaping and for applications. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Ultraviolet filters (UVFs) are emerging organic compounds found in most water systems. They are constituents of personal care products, as well as industrial ones. The concentration of UVFs in the water bodies in space and time is mostly determined by degradation and sorption, both processes being determinant of their bioavailability and toxicity to ecosystems and humans. UVFs are a wide group of compounds, with different sorption behavior expected depending on the individual chemical properties (pKa,Koc,Kow). The goal of this work is framed in the context of improving our understanding of the sorption processes of UVFs occurring in the aquifer; that is, to evaluate the role of biomass growth, solid organic matter (SOM) and redox conditions in the characterization of sorption of a set of UVFs. We constructed a conceptual and a numerical model to evaluate the fate of selected UV filters, focused on both sorption and degradation. The models were validated with published data by Liu et al. (2013), consisting in a suite of batch experiments evaluating the fate of a cocktail of UVs under different redox conditions. The compounds evaluated included ionic UV filters (Benzophenone-3; 2-(3-t-butyl-2-hydroxy-5-methylphenyl)5-chloro-benzotriazole; 2-(2'-hydroxy-5'-octylphenyl)-benzotriazole) and neutral ones (octyl 4-methoxycinnamatte; and octocrylene)., We thank the reviewers for their comments and suggestions, which helped improve the quality of the manuscript. Financial support was provided by Spanish government, MONOPOLIOS PROJECT, RTI2018-101990-B-100 (MINECO/FEDER), MARADENTRO project (PCI2019-103425-WW2017), and Catalan government by the project 2017-SGR-1485 from Agència de Gestió d’Ajuts Universitaris i de Recerca., Peer Reviewed, Postprint (author's final draft)

Lactisole, which has a 2-phenoxy propionic acid skeleton, is well-known as an inhibitor of sweet taste receptors. We recently revealed some of the structure-activity relationships of the aromatic ring and chiral center of lactisole. Photoaffinity labeling is one of the common chemical biology methods to elucidate the interaction between bioactive compounds and biomolecules. In this paper, the novel asymmetric synthesis of lactisole derivatives with common photophores (benzophenone, azide and trifluoromethyldiazirine) for photoaffinity labeling is described. The synthetic compounds are subjected to cell-based sweet taste receptors, and the substitution with trifluoromethyldiazirinyl photophore shows the highest affinity to the receptor of the synthesized compounds.

[EN] Polymethylene-linked bipyrimidine models have been designed with different C5 substitutions and bridge lengths. Selective irradiation of 2'-methoxyacetophenone (2M) with the bipyrimidine models affords cyclobutane pyrimidine dimers, even in the presence of bulky substituents. Substitution at CS affects both the relative triplet energies (E-T(rel)) of the pyrimidines (Pyr) and the steric hindrance toward intermolecular energy transfer and intramolecular triplet Pyr* quenching. Photophysical studies showed that alkyl substitution resulted in a significant decrease in the E-T(rel) value. Quenching of the triplet excited state of 2M by the Pyr derivatives was proven and established their quenching rate constants (k(q)). As a general trend, the thymine-containing compounds showed k(q) values higher than 10(9) M(-1)s(-1), while in the uracil and tert-butyluracil analogues, k(q) was markedly lower. These data are explained considering three different scenarios: (a) triplet energy transfer is the rate controlling step, (b) excited state cyclization is the rate controlling step, and (c) the rate controlling step switches along the reaction. Thus, by introducing variations in the substitution at C5, the length of the linking bridge, or the substrate concentration, it is possible to switch from a process governed by the intrinsic dimerization step to an energy transfer-controlled process.

[EN] Polymethylene-linked bipyrimidine models have been designed with different C5 substitutions and bridge lengths. Selective irradiation of 2'-methoxyacetophenone (2M) with the bipyrimidine models affords cyclobutane pyrimidine dimers, even in the presence of bulky substituents. Substitution at CS affects both the relative triplet energies (E-T(rel)) of the pyrimidines (Pyr) and the steric hindrance toward intermolecular energy transfer and intramolecular triplet Pyr* quenching. Photophysical studies showed that alkyl substitution resulted in a significant decrease in the E-T(rel) value. Quenching of the triplet excited state of 2M by the Pyr derivatives was proven and established their quenching rate constants (k(q)). As a general trend, the thymine-containing compounds showed k(q) values higher than 10(9) M(-1)s(-1), while in the uracil and tert-butyluracil analogues, k(q) was markedly lower. These data are explained considering three different scenarios: (a) triplet energy transfer is the rate controlling step, (b) excited state cyclization is the rate controlling step, and (c) the rate controlling step switches along the reaction. Thus, by introducing variations in the substitution at C5, the length of the linking bridge, or the substrate concentration, it is possible to switch from a process governed by the intrinsic dimerization step to an energy transfer-controlled process.

The focus in many fields of research is the generation of materials with adjustable properties for specific applications. Among porous materials, metal-organic frameworks (MOFs) have developed over the past 20 years to a material class with enormous potential. Due to the modular design of MOFs from metal cations and organic linkers, it is possible to tailor the properties of the resulting extended frameworks by selecting individual components for the needs of specific applications. Careful selection of metal ions and organic molecules with functional groups makes it possible to adjust and influence the pore system, the type of linkage and the physical and chemical properties of the framework. In the present work, the main aspect was the preparation of a novel MOF with high adjustability of its properties, based on light-induced postsynthetic reactions on the organic linker molecules. The framework is composed of Zr4+ ion-based oxo clusters and benzophenone-4,4'-dicarboxylate anions (bzpdc2–) as linker molecules. The benzophenone unit is able to react with any molecule that contains C–H bonds after excitation with photons, resulting in a covalent bond. This reaction opens the possibility of changing the properties of the framework post-synthetically. The novel Zr-bzpdc MOF is chemically and thermally stable and has a two-dimensional structure, which opens up the possibility of obtaining nanometer-thin layers through delamination methods. Further studies have shown that the adaptation of the surface chemistry by the linkage of molecules has a huge impact on the dispersibility in polar and nonpolar solvents. Furthermore, the direct polymerization of a conductive polymer, starting from the surface of the MOF, yields electrically conductive composite materials. Interestingly, in the course of this study it was found that the unmodified MOF is also electrically conductive. Furthermore, a systematic study concerned with the postsynthetic modification of Zr-bzpdc-MOF with a

The electrocatalytic hydrogenation of benzophenone was performed at room temperature and atmospheric pressure using a polymer electrolyte membrane electrochemical reactor (PEMER). Palladium (Pd) nanoparticles were synthesised and supported on a carbonaceous matrix (Pd/C) with a 28 wt % of Pd with respect to carbon material. Pd/C was characterised by transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Cathodes were prepared using Pd electrocatalytic loadings (LPd) of 0.2 and 0.02 mg cm−2. The anode consisted of hydrogen gas diffusion for the electrooxidation of hydrogen gas, and a 117 Nafion exchange membrane acted as a cationic polymer electrolyte membrane. Benzophenone solution was electrochemically hydrogenated in EtOH/water (90/10 v/v) plus 0.1 M H2SO4. Current densities of 10, 15 and 20 mA cm−2 were analysed for the preparative electrochemical hydrogenation of benzophenone and such results led to the highest fractional conversion (XR) of around 30% and a selectivity over 90% for the synthesis of diphenylmethanol upon the lowest current density. With regards to an increase by ten times the Pd electrocatalytic loading the electrocatalytic hydrogenation led neither to an increase in fractional conversion nor to a change in selectivity.

The electrocatalytic hydrogenation of benzophenone was performed at room temperature and atmospheric pressure using a polymer electrolyte membrane electrochemical reactor (PEMER). Palladium (Pd) nanoparticles were synthesised and supported on a carbonaceous matrix (Pd/C) with a 28 wt % of Pd with respect to carbon material. Pd/C was characterised by transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Cathodes were prepared using Pd electrocatalytic loadings (LPd) of 0.2 and 0.02 mg cm−2. The anode consisted of hydrogen gas diffusion for the electrooxidation of hydrogen gas, and a 117 Nafion exchange membrane acted as a cationic polymer electrolyte membrane. Benzophenone solution was electrochemically hydrogenated in EtOH/water (90/10 v/v) plus 0.1 M H2SO4. Current densities of 10, 15 and 20 mA cm−2 were analysed for the preparative electrochemical hydrogenation of benzophenone and such results led to the highest fractional conversion (XR) of around 30% and a selectivity over 90% for the synthesis of diphenylmethanol upon the lowest current density. With regards to an increase by ten times the Pd electrocatalytic loading the electrocatalytic hydrogenation led neither to an increase in fractional conversion nor to a change in selectivity.

The aim of the present PhD thesis was to study UV(-A and -B) induced lipid peroxidation sensitized by synthetic (benzophenone) and endogenous photosensitizers (bilirubin, riboflavin) in the presence of quercetin as antioxidant. Phospholipid mixure was used as a ”protective target” and the whole process was followed in the simplest possible system – methanolic solution. Photodegradation of sensitizers and quercetin with the consequent occurrence of their degradation products both individually and in the mutual mixture, as well as in the mixture with phospholipids (where beside the mentioned processes peroxides production occurs), was followed by RP-HPLC chromatography. Unambiguous identification of degradation products was enabled by UHPLC-ESI-MS technique while free radical species were identified by EPR spectroscopy. Benzophenone was photostabile, photodegradation of bilirubin gave biliverdin and dipiroles while main degradation products of riboflavin were lumichrome and lumiflavin. Insight into the mechanism and control of lipid peroxidation provided ”conjugated diene” assay, by following the signal at 234 nm (the absorption maximum of conjugated diene structures). As typical Type I sensitizer, benzophenone generated superoxide radical anion, while riboflavin generated both superoxide and singlet oxygen by mixed Type I and II mechanisms. Irradiation of bilirubin-riboflavin mixture showed, in the indirect way, that bilirubin is typical Type II sensitizer. Photosensitizing capability of the studied sensitizers decreases in the order: riboflavin > benzophenone > bilirubin. Quercetin exhibited efficient antioxidant activity, mediated by its own degradation, in terms of its preventive (absorbing UV radition), chain-breaking activities (scavenging of generated superoxide radical anion, singlet oxygen and lipid peroxides) and besides all this effectively quenched triplet exited states of sensitizers (first of all benzophenone and riboflavin).

The efficiency of thymine (Thy) and uracil (Ura) to form cyclobutane pyrimidine dimers (CPDs) in solution, upon UV irradiation differs by one order of magnitude. This could to be partially related to the steric hindrance induced by the methyl at C5 in thymine. The aim of the present work is to establish the influence of a bulky moiety at this position on the photoreactivity of pyrimidines. With this purpose, photosensitization with benzophenone and acetone of a 5-tert-butyl uracil derivative (1) and the equivalent Thy (2) has been compared. Introduction of the tert-butyl group completely blocks CPD formation. Moreover, the mechanistic insight obtained by laser flash photolysis is in accordance with the observed photoreactivity.

Irradiation of benzophenone (BP)-doped poly(epsilon-caprolactone) (PCL) films at lambda > 350 nm alters the molecular characteristics, viscoelastic properties and hydrolytic degradation rate. The influence of BP concentration on changes caused by irradiation of BP-doped PCL film was investigated using gel permeation chromatography along with analyses of gel content, DSC and rheology. Changes in the rate of basic hydrolysis of irradiated BP-doped PCL films were also investigated. Irradiation of PCL film doped with at least 0.5% w/w BP led to cross-linking and gel formation, even though simultaneous degradation was also observed. Polar groups formed during the irradiation of BP-doped PCL films enhanced the hydrolysis of cross-linked PCL films compared with untreated films. (C) 2015 Elsevier Ltd. All rights reserved.

Irradiation of benzophenone (BP)-doped poly(epsilon-caprolactone) (PCL) films at lambda > 350 nm alters the molecular characteristics, viscoelastic properties and hydrolytic degradation rate. The influence of BP concentration on changes caused by irradiation of BP-doped PCL film was investigated using gel permeation chromatography along with analyses of gel content, DSC and rheology. Changes in the rate of basic hydrolysis of irradiated BP-doped PCL films were also investigated. Irradiation of PCL film doped with at least 0.5% w/w BP led to cross-linking and gel formation, even though simultaneous degradation was also observed. Polar groups formed during the irradiation of BP-doped PCL films enhanced the hydrolysis of cross-linked PCL films compared with untreated films. (C) 2015 Elsevier Ltd. All rights reserved.

Tato bakalářská práce se zabývá studiem analýzy vybraných toxických látek, a to Bisfenolu A, parabenů a benzofenonu, v tělních tekutinách, především v krvi, moči a potu. Tyto látky se od 20. století používají běžně v domácnostech, ale jejich vliv na lidské zdraví je nezanedbatelný. V práci jsou diskutovány separační techniky, které se pro stanovení těchto látek nejčastěji využívají. Dále je pozornost věnována izolacím sledovaných látek s využitím různých typů extrakčních technik., This bachelor thesis is focused on study of selected toxic compounds, such as Bisphenol A, parabens and benzophenone, in body fluids, especially blood, urine and sweat. These compounds are commonly used in households from the 20th century, but their impact on human health is not negligible. In this work the separation techniques, which are used for the analysis, are discussed. Further, the attention is paid on the isolation of selected toxic compounds using different extraction techniques., Ústav organické chemie a technologie, Studentka úspěaně přednesla a obhájila svou bakalářskou práci.

Cholesterol is one of the most important building blocks of cell membranes. It is also one of the main targets for oxidation via Type I hydrogen abstraction (HA), which leads to a variety of physiological consequences in the human body. To provide a deeper understanding of the oxidation mechanism, steady-state H-1 CIDNP, steady-state and laser-flash photolysis in combination with quantum mechanical calculations were applied to study HA in three model systems. The experiments involved photoinduced reactions in a cholesterol-benzophenone mixture and two derivatives, in which aminocholestene and benzophenone are covalently coupled yielding a dyad. It has been found, that a specific orientation of the benzophenone moiety toward the allylic hydrogens of cholesterol/aminocholestene is crucial for the efficient HA. Such a confined topology may play an important role for the particular oxidation of cholesterol in cell membranes.

2-Phenylethylamine is well known as a substructure of many biologically active compounds, and the synthesis of its photoreactive derivatives to allow the analysis of biological functions is reported. This allowed us to synthesise ligands for adenosine receptors, which have many functional roles in biology and have been extensively studied for their many roles in maintaining homeostasis. Adenosine is one of the most common biochemical compounds, but photoaffinity labeling has not yet been used to study adenosine receptors. Synthetic methods for producing photoreactive adenosine derivatives that can be used with adenosine receptors were established for the photophores phenyl azide and benzophenone. The effect of the introduction of the photoreactive components was determined using an adenosine receptor assay.

Photoaffinity labeling is a reliable analytical method for biological functionalanalysis. Three major photophores—aryl azide, benzophenone and trifluoromethyldiazirineare utilized in analysis. Photophore-bearing L-phenylalanine derivatives, which are used for biological functional analysis, were inoculated into a Klebsiella sp. isolated from the rhizosphere of a wild dipterocarp sapling in Central Kalimantan, Indonesia, under nitrogenlimiting conditions. The proportions of metabolites were quite distinct for each photophore. These results indicated that photophores affected substrate recognition in rhizobacterial metabolic pathways, and differential photoaffinity labeling could be achieved using different photophore-containing L-phenylalanine derivatives.

Simple and stereocontrolled preparation of benzoylated phenylalanine derivatives from optically pure phenylalanine using Friedel-Crafts reaction in trifluoromethanesulfonic acid (TfOH) is reported; these derivatives are useful for photoaffinity labeling. Protected or unprotected phenylalanine derivatives were converted to benzoyl derivatives in TfOH at room temperature in a short time without loss of optical purity. The reaction condition was applied to synthesize novel photoreactive phenylalanine derivative, which has two photophores (benzophenone and diazirine). The detail analysis of photo-irradiation for two different photophores contained phenylalanine derivative was also investigated.

Photoaffinity labeling is a reliable analytical method for biological functionalanalysis. Three major photophores—aryl azide, benzophenone and trifluoromethyldiazirineare utilized in analysis. Photophore-bearing L-phenylalanine derivatives, which are used for biological functional analysis, were inoculated into a Klebsiella sp. isolated from the rhizosphere of a wild dipterocarp sapling in Central Kalimantan, Indonesia, under nitrogenlimiting conditions. The proportions of metabolites were quite distinct for each photophore. These results indicated that photophores affected substrate recognition in rhizobacterial metabolic pathways, and differential photoaffinity labeling could be achieved using different photophore-containing L-phenylalanine derivatives.

Simple and stereocontrolled preparation of benzoylated phenylalanine derivatives from optically pure phenylalanine using Friedel-Crafts reaction in trifluoromethanesulfonic acid (TfOH) is reported; these derivatives are useful for photoaffinity labeling. Protected or unprotected phenylalanine derivatives were converted to benzoyl derivatives in TfOH at room temperature in a short time without loss of optical purity. The reaction condition was applied to synthesize novel photoreactive phenylalanine derivative, which has two photophores (benzophenone and diazirine). The detail analysis of photo-irradiation for two different photophores contained phenylalanine derivative was also investigated.

Simple and stereocontrolled preparation of benzoylated phenylalanine derivatives from optically pure phenylalanine using Friedel-Crafts reaction in trifluoromethanesulfonic acid (TfOH) is reported; these derivatives are useful for photoaffinity labeling. Protected or unprotected phenylalanine derivatives were converted to benzoyl derivatives in TfOH at room temperature in a short time without loss of optical purity. The reaction condition was applied to synthesize novel photoreactive phenylalanine derivative, which has two photophores (benzophenone and diazirine). The detail analysis of photo-irradiation for two different photophores contained phenylalanine derivative was also investigated.

2-Phenylethylamine is well known as a substructure of many biologically active compounds, and the synthesis of its photoreactive derivatives to allow the analysis of biological functions is reported. This allowed us to synthesise ligands for adenosine receptors, which have many functional roles in biology and have been extensively studied for their many roles in maintaining homeostasis. Adenosine is one of the most common biochemical compounds, but photoaffinity labeling has not yet been used to study adenosine receptors. Synthetic methods for producing photoreactive adenosine derivatives that can be used with adenosine receptors were established for the photophores phenyl azide and benzophenone. The effect of the introduction of the photoreactive components was determined using an adenosine receptor assay.

Photoaffinity labeling is a reliable analytical method for biological functionalanalysis. Three major photophores—aryl azide, benzophenone and trifluoromethyldiazirineare utilized in analysis. Photophore-bearing L-phenylalanine derivatives, which are used for biological functional analysis, were inoculated into a Klebsiella sp. isolated from the rhizosphere of a wild dipterocarp sapling in Central Kalimantan, Indonesia, under nitrogenlimiting conditions. The proportions of metabolites were quite distinct for each photophore. These results indicated that photophores affected substrate recognition in rhizobacterial metabolic pathways, and differential photoaffinity labeling could be achieved using different photophore-containing L-phenylalanine derivatives.

The photodegradation of polystyrene films has been investigated in the presence of sensitizers such as benzophenone (BP) and thioxanthone (TX). The phototransformations were studied by infrared and UV-Vis spectroscopy. The results indicate that these photosensitizers accelerate and increase the efficiency of the photodegradation and the photo-oxidation processes in polystyrene and increase the formation of double bonds in the polymer. In all these process, TX showed a larger photosensitization efficiency than BP. Flash photolysis experiments indicate that the triplet reactivity of both sensitizers towards polystyrene are similar, so that the higher efficiency of thioxanthone when compared with benzophenone should be assigned to its larger absorptivity, as well as to the absorptivity of its degradation products in the irradiating region.

The present invention relates to a novel process of preparing branched polymers by cyclotrimerization and branched organic materials containing triaroylbenzene moieties as base structural unit. The polymerization is a simple one-pot reaction, strictly regioselective and highly functionality-tolerant giving oligomeric and polymeric polymers with high degree of branching (up to 100%) in high yields (up to 99%). The polymers are processible, easily film-forming, transformable (curable) into thermosets by heat or irradiation, and readily crosslinkable by UV irradiation to give patterns with nanometer resolution. The polymers of the present invention can be blend with a variety of macromolecules for general use. The polymers can be metallified utilizing organometallic acetylene as building blocks and ceramization of the patterns of the obtained polymers afford ferromagnetic ceramic patterns with high resolution.

The present invention relates to a novel process of preparing branched polymers by cyclotrimerization and branched organic materials containing triaroylbenzene moieties as base structural unit. The polymerization is a simple one-pot reaction, strictly regioselective and highly functionality-tolerant giving oligomeric and polymeric polymers with high degree of branching (up to 100%) in high yields (up to 99%). The polymers are processible, easily film-forming, transformable (curable) into thermosets by heat or irradiation, and readily crosslinkable by UV irradiation to give patterns with nanometer resolution. The polymers of the present invention can be blend with a variety of macromolecules for general use. The polymers can be metallified utilizing organometallic acetylene as building blocks and ceramization of the patterns of the obtained polymers afford ferromagnetic ceramic patterns with high resolution.

Xanthone in mangosteen fruit hull has antioxidant activities. The objective of this experiment was to determine xanthones content, physical and chemical characters, and antioxidant potentials of several groups of mangosteens qualities. The experiment was carried out from January 2008 to August 2008. The research used a randomized complete block design with four replications. The treatments were four physical fruit conditions: large size mangosteens (≥ 100 g), small size mangosteens (min. 50 g), yellow sap dotted fruits, and scabbed fruit. The parameters being observed were physical and chemical characteristics, xanthone content, and radical scavenging activity of mangosteen fruit hull extract. The results demonstrated that the physical condition of fruit significantly affected physical fruit hull characters and chemical fruit characters. Characters of fruit hull, thickness, fresh weight, and dry weight, differed among fruit qualities. The physical condition of fruit hull also significantly influenced total soluble solid and vitamin C content, but did not affect total titrable acid and degree of acidity of the fruits. Fruit hulls of all groups of mangosteen qualities had similar antioxidant properties with the IC50 value of 5.57-6.11 ppm.

Ten ionic liquids were made for a series of experiments meant to help characterize the usefulness of room temperature ionic liquids (RTILs) in various settings. This series of experiments used laser flash photolysis to study the effect of ionic liquids on the rate constants of the recombination of ketyl radicals, created from flash photolysis of benzophenone in the presence of benzhydrol. From the RTILs, the data showed that most ionic liquids had a faster rate constant than the diffusion limit predicted by the Einstein-Stokes-Smoluchowski equation. The main exception was that EMIM-NTf2 where the reaction was slower than its predicted diffusion limit.

AlCl3-mediated chlorocarbonylation of a first arene by oxalyl chloride followed by in situ Friedel-Crafts acylation of a second electron-rich arene expeditiously provides, in a one-pot procedure, either symmetrical or unsymmetrical benzophenones with yields ranging from 17-52%. Best results are obtained when the more activated substrate is used as the second arene. Another advantage is that the resultant benzophenone precipitates from the reaction mixture allowing facile workup.

Voltage sensing is due mainly to the movement of positively charged S4 segments through the membrane electric field during changes of membrane potential. The roles of other transmembrane segments are under study. The S3 segment of domain 4 (D4/S3) in the sodium channel Na(v)1.4 carries two negatively charged residues and has been implicated in voltage-dependent gating. We substituted cysteines into nine putative "high impact" sites along the complete length of D4/S3 and evaluated their accessibilities to extracellular sulfhydryl reagents. Only the four outermost substituted cysteines (L1433C, L1431C, G1430C, and S1427C) are accessible to extracellular sulfhydryl reagents. We measured the voltage-dependent modification rates of the two cysteines situated at the extreme ends of this accessible region, L1433C and S1427C. Independent of the charge on the sulfhydryl reagents, depolarization increases the reactivity of both of these residues. Thus, the direction of the voltage dependence is opposite to that expected for a negatively charged voltage sensor, namely an inward translational movement in response to depolarization. Intrinsic electrostatic potentials were probed by charged sulfhydryl reagents and were either negative or positive, respectively, near L1433C and S1427C. The magnitude of the electrostatic potential near S1427C decreases with depolarization, suggesting that the extracellular crevice next to it widens during depolarization. S1427C experiences 44% of the electric field, as probed by charged cysteine reagents. To further explore movements around D4/S3, we labeled cysteines with the photoactivatable cross-linking reagent benzophenone-4-carboxamidocysteine methanethiosulfonate and examined the effects of UV irradiation on channel gating. After labeling with this reagent, all accessible cysteine mutants show altered gating upon brief UV irradiation. In each case, the apparent insertion efficiency of the photoactivated benzophenone increases with depolariza

Voltage sensing is due mainly to the movement of positively charged S4 segments through the membrane electric field during changes of membrane potential. The roles of other transmembrane segments are under study. The S3 segment of domain 4 (D4/S3) in the sodium channel Na(v)1.4 carries two negatively charged residues and has been implicated in voltage-dependent gating. We substituted cysteines into nine putative "high impact" sites along the complete length of D4/S3 and evaluated their accessibilities to extracellular sulfhydryl reagents. Only the four outermost substituted cysteines (L1433C, L1431C, G1430C, and S1427C) are accessible to extracellular sulfhydryl reagents. We measured the voltage-dependent modification rates of the two cysteines situated at the extreme ends of this accessible region, L1433C and S1427C. Independent of the charge on the sulfhydryl reagents, depolarization increases the reactivity of both of these residues. Thus, the direction of the voltage dependence is opposite to that expected for a negatively charged voltage sensor, namely an inward translational movement in response to depolarization. Intrinsic electrostatic potentials were probed by charged sulfhydryl reagents and were either negative or positive, respectively, near L1433C and S1427C. The magnitude of the electrostatic potential near S1427C decreases with depolarization, suggesting that the extracellular crevice next to it widens during depolarization. S1427C experiences 44% of the electric field, as probed by charged cysteine reagents. To further explore movements around D4/S3, we labeled cysteines with the photoactivatable cross-linking reagent benzophenone-4-carboxamidocysteine methanethiosulfonate and examined the effects of UV irradiation on channel gating. After labeling with this reagent, all accessible cysteine mutants show altered gating upon brief UV irradiation. In each case, the apparent insertion efficiency of the photoactivated benzophenone increases with depolariza

It is well known that the subdomain III A (site II) of human serum albumin (HSA) binds a variety of endogenous and exogenous substances. However, the nature of the microenvironment of the binding site remains unclear. Ketoprofen (KP), an arylpropionic acid NSAID which contains a benzophenone moiety, was used as a photoaffinity labeling agent to label the binding region. Subsequent CNBr cleavage of the photolabeled HSA revealed that the 11.6 kDa and 9.4 kDa fragments contained most of the incorporated radioactivity. Competition experiments showed that the 11.6 kDa fragment contains the common binding region for site II ligands. This fragment was redigested with Achromobacter lyticus protease I (AP-I) and the amino acid sequence of the photolabeled peptide was determined to be XCTESLVNRR, which corresponds to the sequence 476C-485K of HSA. The complete amino acid sequence of the corresponding AP-I digested HSA peptide encompasses residues 476 to 499, which form helices 5 and 6 of subdomain III A. The HSA-Myr X-ray crystallography data showed that helix 5 is involved to the least extent in ligand binding. A docking model provided further support that helix 6 represents the photolabeled region of KP.

Polycondensation of ferrocene with ketones in the presence of the catalyst ZnCl2 + HCl has been studied at atmospheric pressure. At a 1:2 molar ratio of the monomers, soluble and insoluble ferrocene-containing polymers are formed. Their behavior has been studied. The condensation of ketones (acetone, methyl ethyl ketone, cyclohexanone and acetophenone) in the presence of ZnCl2 + HCl and in the absence of ferrocene occurs only with the formation of dimers and trimers. The condensation of benzophenone does not occur in this case. During the polycondensation of ketones in the presence of ZnCl2 + HCl and 5 mole % of ferrocene, the activity of the system increases resulting in the formation of liquid and solid polymers that do not contain iron and ferrocene-containing polymers. (Author), Edited trans. of Vysokomolekulyarnye Soedineniya. Seriya A (USSR) v9 n3 p677-683 1967, by F. Dion.

© 2017 Elsevier B.V. An approach for the determination of solvation enthalpies of substituted aromatic compounds is developed. In this work the solvation enthalpy of a reference unit (benzophenone, fluorene and diphenyl ether) is calculated as the difference between solution enthalpy and sublimation enthalpy at 298 K. An additive approach for the determination of solvation enthalpies of substituted aromatic compounds was used. Solvation enthalpies of sixteen substituted benzophenones, fluorenes and diphenyl ethers were calculated by this approach. Thermochemical data of solution enthalpies of benzophenones, fluorenes and diphenyl ether were measured by a precision solution calorimeter at 298 K. Then sublimation enthalpies of the studied compounds were derived by a solution calorimetry (SC) approach at 298 K. We have also found that in a number of cases instead of the solution enthalpy in benzene at 298 K the fusion enthalpy at the melting temperature can be used. A comparison between literature data and the calculated vaporization and sublimation enthalpies demonstrates a satisfactory performance of the proposed approach.

© 2017 Elsevier B.V. An approach for the determination of solvation enthalpies of substituted aromatic compounds is developed. In this work the solvation enthalpy of a reference unit (benzophenone, fluorene and diphenyl ether) is calculated as the difference between solution enthalpy and sublimation enthalpy at 298 K. An additive approach for the determination of solvation enthalpies of substituted aromatic compounds was used. Solvation enthalpies of sixteen substituted benzophenones, fluorenes and diphenyl ethers were calculated by this approach. Thermochemical data of solution enthalpies of benzophenones, fluorenes and diphenyl ether were measured by a precision solution calorimeter at 298 K. Then sublimation enthalpies of the studied compounds were derived by a solution calorimetry (SC) approach at 298 K. We have also found that in a number of cases instead of the solution enthalpy in benzene at 298 K the fusion enthalpy at the melting temperature can be used. A comparison between literature data and the calculated vaporization and sublimation enthalpies demonstrates a satisfactory performance of the proposed approach.

Joint Research on Environmental Science and Technology for the Earth

Joint Research on Environmental Science and Technology for the Earth