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6 results on '"Octabenzone"'

1. Predicting estrogen receptor activation by a group of substituted phenols: An integrated approach to testing and assessment case study.

Author

Webster, Francina, Gagné, Matthew, Patlewicz, Grace, Pradeep, Prachi, Trefiak, Nicholas, Judson, Richard S., and Barton-Maclaren, Tara S.

Subjects
*BISPHENOL A, *ESTROGEN receptors, *HEALTH risk assessment, *PHENOLS, *ENDOCRINE disruptors, *RISK assessment
Abstract

Traditional approaches for chemical risk assessment cannot keep pace with the number of substances requiring assessment. Thus, in a global effort to expedite and modernize chemical risk assessment, New Approach Methodologies (NAMs) are being explored and developed. Included in this effort is the OECD Integrated Approaches for Testing and Assessment (IATA) program, which provides a forum for OECD member countries to develop and present case studies illustrating the application of NAM in various risk assessment contexts. Here, we present an IATA case study for the prediction of estrogenic potential of three target phenols: 4-tert-butylphenol, 2,4-di-tert-butylphenol and octabenzone. Key features of this IATA include the use of two computational approaches for analogue selection for read-across, data collected from traditional and NAM sources, and a workflow to generate predictions regarding the targets' ability to bind the estrogen receptor (ER). Endocrine disruption can occur when a chemical substance mimics the activity of natural estrogen by binding to the ER and, if potency and exposure are sufficient, alters the function of the endocrine system to cause adverse effects. The data indicated that of the three target substances that were considered herein, 4-tert-butylphenol is a potential endocrine disruptor. Further, this IATA illustrates that the NAM approach explored is health protective when compared to in vivo endpoints traditionally used for human health risk assessment. • The use of New Approach Methodologies (NAMs) in chemical risk assessment is explored. • A workflow for the prediction of estrogen receptor activation by substituted phenols. • The workflow is applied to: 4-tert-butylphenol, 2,4-di-tert-butylphenol, octabenzone. • Two computational approaches for analogue selection were used and evaluated. • When compared to in vivo endpoints, the NAM approach was health protective. [ABSTRACT FROM AUTHOR]

Published
2019
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2. FTIR and rheology analysis of aging on different ultraviolet absorber modified bitumens

Author

Xinjun Li, Zhengang Feng, Bian Huijuan, Wang Shujuan, and Qi-long Guo

Subjects
Condensation polymer, Materials science, 0211 other engineering and technologies, 02 engineering and technology, Building and Construction, 021001 nanoscience & nanotechnology, medicine.disease_cause, chemistry.chemical_compound, Rheology, Octabenzone, chemistry, Asphalt, 021105 building & construction, medicine, General Materials Science, Fourier transform infrared spectroscopy, Composite material, 0210 nano-technology, Spectroscopy, Ultraviolet, BUMETRIZOLE, Civil and Structural Engineering
Abstract

Three different kinds of ultraviolet absorbers (UVAs), including octabenzone, bumetrizole and tinuvin770, were used to modify the road bitumen. The base and UVA modified bitumens were aged by the thin film oven test (TFOT), pressurized aging vessel (PAV) and ultraviolet (UV) aging. The Fourier transform infrared (FTIR) spectroscopy was applied to investigate the chemical structures of the UVA modified bitumens. Several structural indexes based on the FTIR results were defined to evaluate the aging extent of the binders. Finally, the rheological properties of the UVA modified bitumens were tested in order to confirm the validity of the FTIR analysis. Results show that the UVAs have little influence on the branched aliphatic structure of bitumen, but increase the aromatic structure of bitumen. The thermal- and photo-oxidative aging of the bitumen can be restrained by the three UVAs since the reactions of chain scission, polycondensation and oxidation of the bitumen are slowed down by the UVAs during aging. Among the three UVAs, the tinuvin770 exhibits the most significant improvement on the thermal- and photo-oxidative aging resistance of bitumen.

Published
2016

3. The Physical Properties and Photostability of Bitumen with Different Ultraviolet Absorbers

Author

Dongliang Kuang, Jianying Yu, and Zhengang Feng

Subjects
Chemical transformation, Materials science, General Chemical Engineering, digestive, oral, and skin physiology, Energy Engineering and Power Technology, General Chemistry, Geotechnical Engineering and Engineering Geology, medicine.disease_cause, law.invention, chemistry.chemical_compound, Fuel Technology, Chemical engineering, Octabenzone, chemistry, Asphalt, law, medicine, Flame ionization detector, Organic chemistry, Uv absorber, Ductility, BUMETRIZOLE, Ultraviolet
Abstract

Effects of different ultraviolet (UV) absorbers (octabenzone and bumetrizole) on physical properties and photostability of bitumen were investigated. Thin-layer chromatography with flame ionization detection was applied to analyze the likely mechanism of UV absorber on chemical transformation and ageing properties of bitumen. Results indicate that ductility of bitumen is significantly enhanced by addition of small amount of UV absorbers, especially for the addition of octabenzone, which is mainly attributed to the increase of aromatics content of bitumen. The influence of UV absorbers on photostability of bitumen is dependent on the origin of bitumen and type of UV absorber. Bitumen from different origins shows specific selectivity for different UV absorbers.

Published
2013

4. Rheological and aging properties of ultraviolet absorber/styrene-butadiene-styrene-modified bitumens

Author

Zhengang Feng, Yubin Sun, Jianying Yu, and Lihui Xue

Subjects
chemistry.chemical_classification, Styrene-butadiene, Materials science, Polymers and Plastics, General Chemistry, Polymer, medicine.disease_cause, Surfaces, Coatings and Films, Styrene, chemistry.chemical_compound, chemistry, Rheology, Octabenzone, Asphalt, Materials Chemistry, medicine, Composite material, Elasticity (economics), Ultraviolet
Abstract

The prevention of the ultraviolet (UV) aging of styrene–butadiene–styrene (SBS)-modified bitumen is of great significance because UV aging is considered to be a critical factor in the deterioration of the performance of bituminous roads. In this study, we selected two UV absorbers (octabenzone and bumetrizole) as modifiers to evaluate their effects on the rheological and UV-aging properties of different SBS-modified bitumens (linear and radial types) by means of dynamic shear rheological testing. The thermooxidative aging of the binders was also investigated through thin-film oven testing. The results show that for the linear- and radial-SBS-modified bitumens, octabenzone only enhanced their elasticity at high temperatures, but bumetrizole could increase the elastic response at intermediate temperatures on the one hand and the viscous response at high temperatures on the other hand. The UV aging of the radial-SBS-modified bitumens could effectively be alleviated by both octabenzone and bumetrizole, whereas that of the linear ones could only be improved by bumetrizole. The influence of the UV absorbers on the thermooxidative-aging properties of the SBS-modified bitumens was dependent on the types of UV absorbers and SBS polymers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Published
2012

5. Effect of ultraviolet aging on rheology, chemistry and morphology of ultraviolet absorber modified bitumen

Author

Jianying Yu, Zhengang Feng, Henglong Zhang, Lihui Xue, and Dongliang Kuang

Subjects
Materials science, Interface and colloid science, Building and Construction, medicine.disease_cause, chemistry.chemical_compound, Rheology, Octabenzone, chemistry, Mechanics of Materials, Asphalt, Service life, Dynamic shear rheometer, medicine, General Materials Science, Fourier transform infrared spectroscopy, Composite material, Ultraviolet, Civil and Structural Engineering
Abstract

Seeking a new method to solve the ultraviolet (UV) aging of bitumen is of great importance for road applications since the UV aging is considered to be one of the main causes leading to the performance deterioration of bitumen. In this paper, two UV absorbers (octabenzone and bumetrizole) were applied to modify the bitumen by melt blending. Effect of UV aging on rheology, chemistry and morphology of the UV absorber modified bitumens was investigated, by means of dynamic shear rheometer, thin-layer chromatography with flame ionization detection, Fourier transform infrared spectroscopy and atomic force microscopy, to reveal the mechanisms of action for bitumen and UV absorbers. Results show that the two UV absorbers show opposite influences on the UV aging performance of bitumen depending on the type of UV absorbers. The bumetrizole improves the UV aging resistance of bitumen remarkably since the bumetrizole can inhibit reactions of aromatization and oxidation of bitumen molecules to a certain extent during the UV aging, and thus slows down the rate at which the bitumen transforms from sol to gel. The bumetrizole modified bitumen has the potential to be used in pavement for improvement of the UV aging resistance during service life.

Published
2012

6. Oral chemoprevention of skin cancer in mice by benzophenone sunscreens dioxybenzone and octabenzone in drinking water.

Author

Rao GS, Tokuda H, Ichiishi E, Takasaki M, Iida A, Suzuki N, Konoshima T, and Kapadia GJ

Subjects
Animals, Anticarcinogenic Agents therapeutic use, Benzophenones therapeutic use, Cell Transformation, Neoplastic, Drinking Water, Female, Mice, Mice, Hairless, Sunscreening Agents therapeutic use, Anticarcinogenic Agents administration & dosage, Benzophenones administration & dosage, Skin Neoplasms drug therapy, Skin Neoplasms prevention & control, Sunscreening Agents administration & dosage
Abstract

Background: Sunscreen compounds with added benefit of skin cancer prevention have both public and commercial interests. Our earlier study using the Epstein-Barr virus early antigen in vitro assay reported on skin cancer chemoprevention potential of benzophenone sunscreens. We now report the in vivo antitumor activity of two of the benzophenone sunscreens which tested positively in the in vitro assay, octabenzone (UV-1) and dioxybenzone (UV-2), in the two-stage mouse skin carcinogenesis model using (±)-(E)-4-methyl-2-[-(E)-hydroxyamino]-5-nitro-6-methoxy-3-hexanamide (NOR-1) as inducer and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) as promoter., Materials and Methods: Pathogen-free, female hairless mice of HOS:HR-1 strain, 15 animals per control and test groups, were used. Skin tumors were induced by a single dose of NOR-1 (390 nmol in 100 μl of acetone). One week later, TPA (1.7 nmol in 100 μl of acetone) was applied to skin twice weekly for 20 weeks as tumor a promoter. The test compounds UV-I or UV-2 were administered at 0.0025% to mice through drinking water ad libitum, starting one week prior to and stopping one week after tumor initiation. All animals were examined weekly for the development of skin papillomas., Results: In both UV-1- and UV-2-treated mice, a two-week delay in tumor appearance, and significant inhibition (p<0.001) of tumor incidence (50% and 60%, respectively) and tumor burden (papilloma inhibition/mouse, 50% and 70%, respectively) were observed when compared to the positive control group. UV-2 (dihydroxy derivative) was a more potent inhibitor of skin tumor than UV-1 (monohydroxy derivative), which followed their antioxidant activity ranking., Conclusion: The results affirm the skin cancer chemoprevention potential of orally-ingested benzophenone sunscreens in mice and warrant studies in humans to validate synergistic protection achievable by complementation of oral and topical sunscreen usage.

Published
2013

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